Science.gov

Sample records for biceps femoris muscles

  1. Functional analysis of the biceps femoris muscle during locomotor behavior in some primates.

    PubMed

    Kumakura, H

    1989-07-01

    In order to investigate a correlation between morphological variations of the biceps femoris muscle and its homologues in four primate species (Japanese macaque, spider monkey, white-handed gibbon, and chimpanzee) and each type of species-specific locomotor behavior, I carried out both morphological and functional analyses of these muscles. The description of the level of insertion reveals interspecific variation is in the level of crural attachment, especially in species with a bicipital biceps femoris muscle. Electromyograms (EMGs) were induced from both the long and short head of the biceps femoris muscle during four kinds of locomotor behavior (horizontal quadrupedal walking, climbing on an inclined pole, vertical climbing, and bipedal walking). In the case of the monoceptual ischiocruralis lateralis muscle of the Japanese macaque, EMGs were induced from both the one-joint femoral part and the two-joint crural part. Though during horizontal quadrupedal locomotion the crural part of the monocipital-type muscle functioned to maintain the knee joint angle, it functioned to gain propulsive force when the kinematic load became larger, as in vertical climbing and bipedal walking. On the other hand, the long heads of the biceps femoris muscles were active in propulsion regardless of the kinematic load. But in bipedal walking, the long head muscle also acted with the short head muscle to maintain the knee joint angle. These functional features of various biceps femoris muscles of primates correlated with their species-specific locomotor behavior. PMID:2504047

  2. Physical principles demonstrate that the biceps femoris muscle relative to the other hamstring muscles exerts the most force: implications for hamstring muscle strain injuries

    PubMed Central

    Dolman, Bronwyn; Verrall, Geoffrey; Reid, Iain

    2014-01-01

    Summary Of the hamstring muscle group the biceps femoris muscle is the most commonly injured muscle in sports requiring interval sprinting. The reason for this observation is unknown. The objective of this study was to calculate the forces of all three hamstring muscles, relative to each other, during a lengthening contraction to assess for any differences that may help explain the biceps femoris predilection for injury during interval sprinting. To calculate the displacement of each individual hamstring muscle previously performed studies on cadaveric anatomical data and hamstring kinematics during sprinting were used. From these displacement calculations for each individual hamstring muscle physical principles were then used to deduce the proportion of force exerted by each individual hamstring muscle during a lengthening muscle contraction. These deductions demonstrate that the biceps femoris muscle is required to exert proportionally more force in a lengthening muscle contraction relative to the semimembranosus and semitendinosus muscles primarily as a consequence of having to lengthen over a greater distance within the same time frame. It is hypothesized that this property maybe a factor in the known observation of the increased susceptibility of the biceps femoris muscle to injury during repeated sprints where recurrent higher force is required. PMID:25506583

  3. Accuracy assessment of CKC high-density surface EMG decomposition in biceps femoris muscle

    NASA Astrophysics Data System (ADS)

    Marateb, H. R.; McGill, K. C.; Holobar, A.; Lateva, Z. C.; Mansourian, M.; Merletti, R.

    2011-10-01

    The aim of this study was to assess the accuracy of the convolution kernel compensation (CKC) method in decomposing high-density surface EMG (HDsEMG) signals from the pennate biceps femoris long-head muscle. Although the CKC method has already been thoroughly assessed in parallel-fibered muscles, there are several factors that could hinder its performance in pennate muscles. Namely, HDsEMG signals from pennate and parallel-fibered muscles differ considerably in terms of the number of detectable motor units (MUs) and the spatial distribution of the motor-unit action potentials (MUAPs). In this study, monopolar surface EMG signals were recorded from five normal subjects during low-force voluntary isometric contractions using a 92-channel electrode grid with 8 mm inter-electrode distances. Intramuscular EMG (iEMG) signals were recorded concurrently using monopolar needles. The HDsEMG and iEMG signals were independently decomposed into MUAP trains, and the iEMG results were verified using a rigorous a posteriori statistical analysis. HDsEMG decomposition identified from 2 to 30 MUAP trains per contraction. 3 ± 2 of these trains were also reliably detected by iEMG decomposition. The measured CKC decomposition accuracy of these common trains over a selected 10 s interval was 91.5 ± 5.8%. The other trains were not assessed. The significant factors that affected CKC decomposition accuracy were the number of HDsEMG channels that were free of technical artifact and the distinguishability of the MUAPs in the HDsEMG signal (P < 0.05). These results show that the CKC method reliably identifies at least a subset of MUAP trains in HDsEMG signals from low force contractions in pennate muscles.

  4. Short-latency crossed responses in the human biceps femoris muscle

    PubMed Central

    Stevenson, Andrew J T; Kamavuako, Ernest N; Geertsen, Svend S; Farina, Dario; Mrachacz-Kersting, Natalie

    2015-01-01

    Interlimb reflexes contribute to the central neural co-ordination between different limbs in both humans and animals. Although commissural interneurons have only been directly identified in animals, spinally-mediated interlimb reflexes have been discovered in a number of human lower limb muscles, indicating their existence in humans. The present study aimed to investigate whether short-latency crossed-spinal reflexes are present in the contralateral biceps femoris (cBF) muscle following ipsilateral knee (iKnee) joint rotations during a sitting task, where participants maintained a slight pre-contraction in the cBF. Following iKnee extension joint rotations, an inhibitory reflex was observed in the surface electromyographic (EMG) activity of the cBF, whereas a facilitatory reflex was observed in the cBF following iKnee flexion joint rotations. The onset latency of both cBF reflexes was 44 ms, which is too fast for a transcortical pathway to contribute. The cBF inhibitory and facilitatory reflexes followed the automatic gain control principle, with the size of the response increasing as the level of background pre-contraction in the cBF muscle increased. In addition to the surface EMG, both short-latency inhibitory and facilitatory cBF reflexes were recorded directly at the motor unit level by i.m. EMG, and the same population of cBF motor units that were inhibited following iKnee extension joint rotations were facilitated following iKnee flexion joint rotations. Therefore, parallel interneuronal pathways (probably involving commissural interneurons) from ipsilateral afferents to common motoneurons in the contralateral leg can probably explain the perturbation direction-dependent reversal in the sign of the short-latency cBF reflex. PMID:25970767

  5. Quality properties and adsorption behavior of freeze-dried beef meat from the Biceps femoris and Semimembranosus muscles.

    PubMed

    Aykın, Elif; Erbaş, Mustafa

    2016-11-01

    The aim of this research was to determine the quality properties and adsorption behavior of freeze-dried beef meat from the Biceps femoris and Semimembranosus muscles. Most quality properties of both muscles were similar apart from total fat content. Freeze-dried meat pieces were kept in ten different equilibrium levels of relative humidity (2.0-97.3%) at 5, 15, 25 and 30°C. The experimental data were evaluated using BET (Brunauer-Emmett-Teller) and GAB (Guggenheim, Anderson and deBoer) models. The equilibrium moisture contents of freeze-dried Biceps femoris were lower than those of Semimembranosus at all water activities and temperature. The constants m0 and C of BET and GAB equations were determined to be between 6.27 and 8.07g/100g dry matter and 9.32-13.73, respectively. Constant k was about 0.90 at all temperatures, and the GAB equation exhibited a better fit to the experimental data of both muscles as a result of all %E values being approximately equal to 10%. PMID:27379930

  6. [Isolated rupture of the distal tendon of the biceps femoris muscle in a sport climber: an uncommon injury].

    PubMed

    Geronikolakis, S; Best, R

    2012-06-01

    An isolated rupture of the distal tendon of the biceps femoris muscle without a direct trauma is an extremely rare injury. To date only a few case reports have been described in the literature. For sport climbers such an injury has never been described before. We report about a 41-year-old male sport climber complaining of such an injury after indoor rock-climbing. Unlike the previously described reports, the rupture occured during a phase of maximum static tension, without acceleration or movement of the knee joint. History and clinical characteristics, sonography and magnetic resonance imaging confirm the diagnosis and should always be performed to exclude other injuries. Early operative treatment with anatomic refixation of the ruptured tendon is necessary to restore function, although there are differences in the type of postoperative treatment. PMID:22415714

  7. Neuromuscular efficiency of the vastus lateralis and biceps femoris muscles in individuals with anterior cruciate ligament injuries☆

    PubMed Central

    Aragão, Fernando Amâncio; Schäfer, Gabriel Santo; de Albuquerque, Carlos Eduardo; Vituri, Rogério Fonseca; de Azevedo, Fábio Mícolis; Bertolini, Gladson Ricardo Flor

    2015-01-01

    Objective To analyze strength and integrated electromyography (IEMG) data in order to determine the neuromuscular efficiency (NME) of the vastus lateralis (VL) and biceps femoris (BF) muscles in patients with anterior cruciate ligament (ACL) injuries, during the preoperative and postoperative periods; and to compare the injured limb at these two times, using the non-operated limb as a control. Methods EMG data and BF and VL strength data were collected during three maximum isometric contractions in knee flexion and extension movements. The assessment protocol was applied before the operation and two months after the operation, and the NME of the BF and VL muscles was obtained. Results There was no difference in the NME of the VL muscle from before to after the operation. On the other hand, the NME of the BF in the non-operated limb was found to have increased, two months after the surgery. Conclusions The NME provides a good estimate of muscle function because it is directly related to muscle strength and capacity for activation. However, the results indicated that two months after the ACL reconstruction procedure, at the time when loading in the open kinetic chain within rehabilitation protocols is usually started, the neuromuscular efficiency of the VL and BF had still not been reestablished. PMID:26229914

  8. The physical and biochemical changes in springbok (Antidorcas marsupialis) Longissimus thoracis et lumborum and Biceps femoris muscle during ageing.

    PubMed

    North, M K; Frylinck, L; Hoffman, L C

    2015-12-01

    This study aimed to determine the optimum ageing period for vacuum-packed springbok (Antidorcas marsupialis) Longissimus thoracis et lumborum (LTL) and Biceps femoris (BF) muscle stored at 5.4 ± 1.0°C. Portions of muscle from seven male and six female springbok were aged 1, 2, 5, 8, 14 or 21 days. The Warner Bratzler shear force declined most during the first five days post-mortem (PM), while purge and cooking losses increased significantly with ageing. Calpains I and II and calpastatin activity declined significantly up to five days PM, suggesting that they may be responsible for tenderization. Cathepsins B, BL and H activity increased significantly during ageing. The BF muscle had significantly higher pH, lower purge loss, higher cooking loss, higher WBSF and higher calpain and calpastatin activity than the LTL. No significant differences between the genders or muscles were found for the collagen content or collagen solubility. Springbok LTL and BF muscles should not be aged for longer than five days. PMID:26225930

  9. Musculotendon variability influences tissue strains experienced by the biceps femoris long head muscle during high-speed running

    PubMed Central

    Fiorentino, Niccolo M.; Blemker, Silvia S.

    2014-01-01

    The hamstring muscles frequently suffer injury during high-speed running, though the factors that make an individual more susceptible to injury remain poorly understood. The goals of this study were to measure the musculotendon dimensions of the biceps femoris long head (BFlh) muscle, the hamstring muscle injured most often, and to use computational models to assess the influence of variability in the BFlh’s dimensions on internal tissue strains during high-speed running. High-resolution magnetic resonance (MR) images were acquired over the thigh in 12 collegiate athletes, and musculotendon dimensions were measured in the proximal free tendon/aponeurosis, muscle and distal free tendon/aponeurosis. Finite element meshes were generated based on the average, standard deviation and range of BFlh dimensions. Simulation boundary conditions were defined to match muscle activation and musculotendon length change in the BFlh during high-speed running. Muscle and connective tissue dimensions were found to vary between subjects, with a coefficient of variation (CV) of 17 ± 6% across all dimensions. For all simulations peak local strain was highest along the proximal myotendinous junction, which is where injury typically occurs. Model variations showed that peak local tissue strain increased as the proximal aponeurosis width narrowed and the muscle width widened. The aponeurosis width and muscle width variation models showed that the relative dimensions of these structures influence internal muscle tissue strains. The results of this study indicate that a musculotendon unit’s architecture influences its strain injury susceptibility during high-speed running. PMID:25189094

  10. The changes in springbok (Antidorcas marsupialis) Longissimus thoracis et lumborum and Biceps femoris muscles during the rigour period.

    PubMed

    North, M K; Frylinck, L; Hoffman, L C

    2016-02-01

    This study describes the changes taking place during rigour in springbok (Antidorcas marsupialis) Longissimus thoracis et lumborum (LTL) and Biceps femoris (BF) muscles. Samples from six male and six female springbok were snap-frozen at 2, 3, 5, 8, 12, 18, 24 and 30h post-mortem (PM) and the pH, calpains I, II and calpastatin activities and cathepsins B, BL and H activities were determined. The temperature was also recorded. Significant third-order interactions were found for the pH and temperature, with the female LTL cooling more rapidly and acidifying slower than the other samples. Female muscles were at risk of developing cold-shortening and all the samples cooled more rapidly than recommended for cattle or sheep. Cathepsin BL activity increased PM, likely due to the degradation of the lysosomes. Calpains I, II and calpastatin activity declined during rigour, indicating that the calpains were activated early PM. Gender and muscle had a significant effect on calpain and cathepsin activity. PMID:26497102

  11. Distal Insertions of the Biceps Femoris

    PubMed Central

    Branch, Eric A.; Anz, Adam W.

    2015-01-01

    Background: Avulsion of the biceps femoris from the fibula and proximal tibia is encountered in clinical practice. While the anatomy of the primary posterolateral corner structures has been qualitatively and quantitatively described, a quantitative analysis regarding the insertions of the biceps femoris on the fibula and proximal tibia is lacking. Purpose: To quantitatively assess the insertions of the biceps femoris, fibular collateral ligament (FCL), and anterolateral ligament (ALL) on the fibula and proximal tibia as well as establish relationships among these structures and to pertinent surgical anatomy. Study Design: Descriptive laboratory study. Methods: Dissections were performed on 12 nonpaired, fresh-frozen cadaveric specimens identifying the biceps femoris, FCL, and ALL, and their insertions on the proximal tibia and fibula. The footprint areas, orientations, and distances from relevant osseous landmarks were measured using a 3-dimensional coordinate measurement device. Results: Dissection produced 6 easily identifiable and reproducible anatomic footprints. Tibial footprints included the insertion of the ALL and an insertion of the biceps femoris (TBF). Fibular footprints included the insertion of the FCL, a distal insertion of the biceps femoris (DBF), a medial footprint of the biceps femoris (MBF), and a proximal footprint of the biceps femoris (PBF). The mean area of these footprints (95% CI) was as follows: ALL, 53.0 mm2 (38.4-67.6); TBF, 93.9 mm2 (72.0-115.8); FCL, 86.8 mm2 (72.3-101.2); DBF, 119 mm2 (91.1-146.9); MBF, 46.8 mm2 (29.0-64.5); and PBF, 215 mm2 (192.4-237.5). The mean distance (95% CI) from the Gerdy tubercle to the center of the ALL footprint was 24.3 mm (21.6-27.0) and to the center of the TBF was 22.5 mm (21.0-24.0). The center of the DBF was 8.68 mm (7.0-10.3) from the anterior border of the fibula, the center of the FCL was 14.6 mm (12.5-16.7) from the anterior border of the fibula and 20.7 mm (19.0-22.4) from the tip of the fibular

  12. Biceps femoris and semitendinosus—teammates or competitors? New insights into hamstring injury mechanisms in male football players: a muscle functional MRI study

    PubMed Central

    Schuermans, Joke; Van Tiggelen, Damien; Danneels, Lieven; Witvrouw, Erik

    2014-01-01

    Background The hamstring injury mechanism was assessed by investigating the exercise-related metabolic activity characteristics of the hamstring muscles using a muscle functional MRI (mfMRI) protocol. Methods 27 healthy male football players and 27 football players with a history of hamstring injuries (recovered and playing fully) underwent standardised mfMR Imaging. The mfMRI protocol consisted of a resting scan, a strenuous bilateral eccentric hamstring exercise and a postexercise scan. The exercise-related T2 increase or the signal intensity shift between both scans was used to detect differences in metabolic activation characteristics (1) between the different hamstring muscle bellies and (2) between the injury group and the control group. Results A more symmetrical muscle recruitment pattern corresponding to a less economic hamstring muscle activation was demonstrated in the formerly injured group (p<0.05). The injured group also demonstrated a significantly lower strength endurance capacity during the eccentric hamstring exercise. Conclusions These findings suggest that the vulnerability of the hamstring muscles to football-related injury is related to the complexity and close coherence in the synergistic muscle recruitment of the biceps femoris and the semitendinosus. Discrete differences in neuromuscular coordination and activity distribution, with the biceps femoris partly having to compensate for the lack of endurance capacity of the semitendinosus, probably increase the hamstring injury risk. PMID:25388959

  13. Biceps femoris tendon injuries sustained while playing hockey

    PubMed Central

    Watura, Christopher; Harries, William

    2011-01-01

    A 42-year-old female nurse presented in March 2008 with a left proximal hamstring tendon injury sustained while playing hockey. At surgery, the proximal biceps femoris tendon and semitendonosus were found to be ruptured and were repaired. The patient made a good recovery but sustained a further hockey injury in January 2010 involving a complete tear and rupture of the biceps femoris tendon distally. This was managed conservatively and the patient was able to return to playing hockey 10 months later. Biceps femoris tendon injuries have been reported in sport but this is the first documented case of the injury occurring while playing hockey and is also the first reported case of a biceps tendon rupture proximally (hamstring tendon) followed by distal biceps femoris rupture at the knee in the same leg. PMID:22715185

  14. Effects of live weight at slaughter on fatty acid composition of Longissimus dorsi and Biceps femoris muscles of indigenous Lori goat.

    PubMed

    Kiani, Ali; Fallah, Rozbeh

    2016-01-01

    This study aimed to determine fatty acid (FA) composition of Longissimus dorsi (LD) and Biceps femoris (BF) muscles of an Iranian indigenous goat (Lori goat) at two live weights at slaughter (LWS). Twenty male Lori goats (5 to 8 months) raised in nomadic system were slaughtered either at LWS less than 20 kg (light) or LWS more than 30 kg (heavy). Carcass dressing and FA composition of intramuscular fat of LD and BF muscles as well as cholesterol content of LD muscle were determined. Heavy goats had higher dressing percentage than light ones (42.7vs.39.3%, P < 0.01). The predominant n-6 FA were C18:2, and C20:4 while C22:5, C20:5, C18:3, C20:3, and C22:6 were the n-3 FA detected. Polyunsaturated and saturated FA contributed 22% and 36% of the total FA in both muscles, respectively. Palmitic acid (C16:0) of LD was higher in heavy compared to the light goats (P < 0.05). BF muscle had higher α-linolenic acid (18:3 n-3) as percentage than LD muscle (P < 0.05). The ratio of n-6/n-3 FA and polyunsaturated/saturated FA were 3.8 and 0.6, respectively. Cholesterol content of LD muscle of light and heavy goats were 71.2 ± 16 and 59.5 ± 14 mg per 100 g fresh meat respectively. In conclusion, desirable PUFA/SFA (0.6) and n-3/n-6 ratio (3.8) found in indigenous Lori goat propose healthy source of lean meat for the consumers. PMID:26431711

  15. Effects of fibre type and structure of longissimus lumborum (Ll), biceps femoris (Bf) and semimembranosus (Sm) deer muscles salting with different Nacl addition on proteolysis index and texture of dry-cured meats.

    PubMed

    Żochowska-Kujawska, J

    2016-11-01

    The aim of the present study was to describe the effect of fibre type and structure as well as NaCl level on the proteolysis index and texture parameters observed in dry-cured meats produced from individual deer muscles. The biceps femoris, semimembranosus and longissimus lumborum muscles were cut from deer main elements, shaped into blocks by trimming off the edges, cured by adding 4, 6 and 8% of salt (w/w) and dried in a ripening chamber for 29days. The results indicated that deer dry-cured muscles with higher percentage of red fibres (type I) showed higher texture parameters, proteolysis index as well as lower moisture losses than muscles with higher amount of white fibres (type IIB). Dry-cured deer muscles with lower NaCl content showed higher values of proteolysis index and lower hardness, cohesiveness, springiness, and chewiness, as well as lower changes in structure elements. PMID:27442183

  16. Tenderization effect of soy sauce on beef M. biceps femoris.

    PubMed

    Kim, Hyun-Wook; Choi, Yun-Sang; Choi, Ji-Hun; Kim, Hack-Youn; Lee, Mi-Ai; Hwang, Ko-Eun; Song, Dong-Heon; Lim, Yun-Bin; Kim, Cheon-Jei

    2013-08-15

    This study was conducted to evaluate the tenderization effect of soy sauce on beef M. biceps femoris (BF). Five marinades were prepared with 4% (w/v) sodium chloride and 25% (w/v) soy sauce solutions (4% salt concentration) and mixed with the ratios of 100:0 (S0, pH 6.52), 75:25 (S25, 5.40) 50:50 (S50, 5.24), 25:75 (S75, 5.05), and 0:100 (S100, 4.85), respectively. The BF samples which were obtained from Hanwoo cows at 48 h postmortem (n=24) were marinated with five marinades for 72 h at 4°C (1:4 w/w), and the effects of soy sauce on tenderness were evaluated. Soy sauce marination resulted in a decrease in the pH value of the BF sample. However, there were no significant differences in the water holding capacity (P<0.05). The S100 treatment showed the significant (P<0.05) increase in collagen solubility and myofibrillar fragmentation index, contributing to decreased shear force compared to S0 (control). Reduction in intensity of few myofibrillar protein bands were observed for S100 treatment compared to control using SDS-PAGE. Scanning electron microscopy revealed breakdown of connective tissue surrounding muscle fibers of the S100 treatment. The tenderization effect of soy sauce may attribute various mechanisms such as increased collagen solubility or proteolysis which depend on soy sauce level in marinade. PMID:23561150

  17. Relationship of beef longissimus tenderness classes to tenderness of gluteus medius, semimembranosus, and biceps femoris.

    PubMed

    Wheeler, T L; Shackelford, S D; Koohmaraie, M

    2000-11-01

    The objective of this study was to determine the relationship of longissimus tenderness classes to tenderness of three other major muscles. Ninety-eight crossbred steers and heifers (14 to 17 mo of age) were humanely slaughtered over 9 wk and the carcasses were chilled 48 h at 0 degrees C. At 48 h postmortem, carcasses were assigned to one of three tenderness classes (tender < or = 26 kg, intermediate = 26 to 42 kg, tough > or = 42 kg) using slice shear force from the MARC Beef Classification System (n = 20, 67, and 11, respectively). The longissimus thoracis, gluteus medius, semimembranosus, and biceps femoris were removed, aged at 2 degrees C, and frozen at -30 degrees C at 14 d postmortem. Two 2.54-cm-thick steaks were obtained from each muscle, thawed to 5 degrees C, cooked with a belt grill at 163 degrees C for 5.5 min, and served warm to an eight-member trained descriptive attribute panel. Panelists evaluated each sample for tenderness, connective tissue amount, juiciness, and beef flavor intensity on 8-point scales. The mean 2-d longissimus slice shear force values were 20.7, 34.4, and 46.3 kg, respectively, for the "tender," "intermediate," and "tough" classes. Tenderness ratings were lowest (P < 0.05) for the "tough" class and highest (P < 0.05) for the "tender" class for all muscles except the gluteus medius, for which the "tender" and "intermediate" classes were not different (P > 0.05; longissimus, 7.7, 7.1, 6.3, and 7.1; semimembranosus, 6.4, 5.8, 5.1, and 5.8; biceps femoris, 5.9, 5.4, 4.8, and 5.4; gluteus medius, 6.8, 6.5, 5.8, and 6.5 for the "tender," "intermediate," "tough," and "unsorted" classes, respectively). The magnitude of the differences in tenderness ratings between the "tender" and "intermediate" classes and between the "intermediate" and "tough" classes was similar for all muscles. The percentages of tenderness ratings greater than 5.0 (slightly tender) for the "tender" and "unsorted" classes, respectively, were as follows: longissimus

  18. Use of Ultrasound to Monitor Biceps Femoris Mechanical Adaptations after Injury in a Professional Soccer Player.

    PubMed

    Kellis, Eleftherios; Galanis, Nikiforos; Chrysanthou, Chrysanthos; Kofotolis, Nikolaos

    2016-03-01

    This study examined the use of ultrasound to monitor changes in the long head of the biceps femoris (BF) architecture of aprofessional soccer player with acute first-time hamstring strain. The player followed a 14 session physiotherapy treatment until return to sport. The pennation angle and aponeurosis strain of the long head of the biceps femoris (BF) were monitored at 6 occasions (up until 1 year) after injury. The size of the scar / hematoma was reduced by 63.56% (length) and 67.9% (width) after the intervention and it was almost non-traceable one year after injury. The pennation angle of the fascicles underneath the scar showed a decline of 51.4% at the end of the intervention while an increase of 109.2% of the fascicles which were closer to deep aponeurosis was observed. In contrast, pennation angle of fascicles located away from the injury site were relatively unaffected. The treatment intervention resulted in a 57.9% to 77.3% decline of maximum strain per unit of MVC moment and remained similar one year after the intervention. This study provided an example of the potential use of ultrasound-based parameters to link the mechanical adaptations of the injured muscle to specific therapeutic intervention. Key pointsChanges in fascicle orientation after biceps femoris mild tear were reduced after a 28 day intervention and remained similar one year after injury.Tendon/aponeurosis strain per unit of moment of force decreased during the course of the therapeutic intervention.Future studies could utilize ultrasonography to monitor mechanical responses after various types of hamstring injury and interventions in order to improve criteria for a safe return to sport. PMID:26957929

  19. Use of Ultrasound to Monitor Biceps Femoris Mechanical Adaptations after Injury in a Professional Soccer Player

    PubMed Central

    Kellis, Eleftherios; Galanis, Nikiforos; Chrysanthou, Chrysanthos; Kofotolis, Nikolaos

    2016-01-01

    This study examined the use of ultrasound to monitor changes in the long head of the biceps femoris (BF) architecture of aprofessional soccer player with acute first-time hamstring strain. The player followed a 14 session physiotherapy treatment until return to sport. The pennation angle and aponeurosis strain of the long head of the biceps femoris (BF) were monitored at 6 occasions (up until 1 year) after injury. The size of the scar / hematoma was reduced by 63.56% (length) and 67.9% (width) after the intervention and it was almost non-traceable one year after injury. The pennation angle of the fascicles underneath the scar showed a decline of 51.4% at the end of the intervention while an increase of 109.2% of the fascicles which were closer to deep aponeurosis was observed. In contrast, pennation angle of fascicles located away from the injury site were relatively unaffected. The treatment intervention resulted in a 57.9% to 77.3% decline of maximum strain per unit of MVC moment and remained similar one year after the intervention. This study provided an example of the potential use of ultrasound-based parameters to link the mechanical adaptations of the injured muscle to specific therapeutic intervention. Key points Changes in fascicle orientation after biceps femoris mild tear were reduced after a 28 day intervention and remained similar one year after injury. Tendon/aponeurosis strain per unit of moment of force decreased during the course of the therapeutic intervention. Future studies could utilize ultrasonography to monitor mechanical responses after various types of hamstring injury and interventions in order to improve criteria for a safe return to sport. PMID:26957929

  20. Partial Tendon Release for Treatment of a Symptomatic Snapping Biceps Femoris Tendon

    PubMed Central

    Crow, Scott A.; Quach, Tony; McAllister, David R.

    2009-01-01

    Snapping of the biceps femoris tendon over the fibular head is an uncommon condition. Reported causes include an anomalous insertion of the tendon, trauma at the insertion site of the tendon, and an abnormality of the fibular head. This article reports a case of a painful snapping biceps femoris tendon in a patient without an anomalous tendon insertion or an abnormality of the fibular head. Partial release of the superior aspect of the tendon resulted in resolution of symptoms. PMID:23015904

  1. Calcific tendinitis of biceps femoris: an unusual site and cause for lateral knee pain.

    PubMed

    Chan, Warwick; Chase, Helen Emily; Cahir, John G; Walton, Neil Patrick

    2016-01-01

    A 37-year-old man presented to the acute knee and sports medicine clinic with atraumatic lateral knee pain. He had point tenderness over the lateral aspect of his knee which had not settled with anti-inflammatory medications. Imaging revealed a large opaque lesion lateral to the knee and although there was no clear mechanism, injury to the posterolateral corner was considered. An MRI subsequently revealed a rare case of calcific tendinitis to the biceps femoris tendon insertion. This condition was self-limiting and did not require interventions such as steroid injections. This is the first reported case of calcific tendinitis of biceps femoris as a cause of acute knee pain. PMID:27473032

  2. Anatomy of the long head of biceps femoris: An ultrasound study.

    PubMed

    Tosovic, D; Muirhead, J C; Brown, J M M; Woodley, S J

    2016-09-01

    Hamstring strains, particularly involving the long head of biceps femoris (BFlh) at the proximal musculotendinous junction (MTJ), are commonly experienced by athletes. With the use of diagnostic ultrasound increasing, an in-depth knowledge of normal ultrasonographic anatomy is fundamental to better understanding hamstring strain. The aim of this study was to describe the architecture of BFlh, using ultrasonography, in young men and cadaver specimens. BFlh morphology was examined in 19 healthy male participants (mean age 21.6 years) using ultrasound. Muscle, tendon and MTJ lengths were recorded and architectural parameters assessed at four standardised points along the muscle. Measurement accuracy was validated by ultrasound and dissection of BFlh in six male cadaver lower limbs (mean age 76 years). Intra-rater reliability of architectural parameters was examined for repeat scans, image analysis and dissection measurements. Distally the BFlh muscle had significantly (P < 0.05) shorter fascicles and larger pennation angles than proximal sites. Agreement between ultrasound and dissection (cadaver study) was excellent for all architectural parameters, except pennation angle (PA), and MTJ length. All other measures demonstrated good-excellent repeatability. BFlh is not uniform in architecture when imaged using ultrasound. It is likely that its distal-most segment is better suited for force production in comparison to the more proximal segments, which show excursive potential, traits which possibly contribute to the high rate of injury at the proximal MTJ. The data presented in this study provide specific knowledge of the normal ultrasonographic anatomy of BFlh, which should be of assistance in analysing BFlh injury via imaging. Clin. Anat. 29:738-745, 2016. © 2016 Wiley Periodicals, Inc. PMID:27012306

  3. Amplitude and frequency changes in surface EMG of biceps femoris during five days Bruce Protocol treadmill test.

    PubMed

    Jamaluddin, Fauzani N; Ahmad, Siti A; Noor, Samsul Bahari Mohd; Hassan, Wan Zuha Wan; Yaakob, Azhar; Adam, Yunus; Ali, Sawal H M

    2015-08-01

    Electromyography (EMG) is one of the indirect tools in indexing fatigue. Fatigue can be detected when there are changes on amplitude and frequency. However, various outcomes from literature make researchers conclude that EMG is not a reliable tool to measure fatigue. This paper investigates EMG behavior of biceps femoris in median frequency and mean absolute value during five days of Bruce Protocol treadmill test. Before that, surface EMG signals are filtered using band pass filter cut-off at 20-500Hz and are de-noised using db45 1-decimated wavelet transform. Five participants achieved more than 85% of their maximal heart rate during the running activity. The authors also consider other markers of fatigue such as performance, muscle soreness and lethargy as indicators to adaptation and maladaptation conditions. Result shows that turning points of median frequency and mean absolute value are very significant in indexing fatigue and indicators to adaptation of resistive training. PMID:26737713

  4. Influence of extended aging on beef quality characteristics and sensory perception of steaks from the biceps femoris and semimembranosus.

    PubMed

    Colle, M J; Richard, R P; Killinger, K M; Bohlscheid, J C; Gray, A R; Loucks, W I; Day, R N; Cochran, A S; Nasados, J A; Doumit, M E

    2016-09-01

    The objective was to determine the influence of post-fabrication aging (2, 14, 21, 42, and 63days) on beef quality characteristics and consumer sensory perception of biceps femoris (BF) and semimembranosus (SM) steaks. Lipid oxidation and aerobic plate counts increased (P<0.05) with longer aging periods and retail display times. An aging period by day of retail display interaction (P<0.05) was observed for a* and b* values of the BF and SM. Warner-Bratzler shear force values decreased (P<0.05) with longer aging for the SM, while no difference was observed for the BF. Consumer panel results revealed that longer aging periods increased (P<0.05) acceptability of the SM, tenderness of both muscles, and tended to increase (P=0.07) juiciness of the SM. Our results show that extended aging reduces retail color stability yet has positive effects on consumer perception of tenderness of both muscles and overall acceptability of the SM. PMID:27155799

  5. Closed proximal muscle rupture of the biceps brachii in wakeboarders.

    PubMed

    Pascual-Garrido, Cecilia; Swanson, Britta L; Bannar, Stephen M

    2012-06-01

    Closed proximal muscle rupture of the biceps brachii is a rare injury. In this report, two cases of closed proximal muscle rupture of the biceps brachii after wakeboard traumas are described. Both patients presented with a swollen arm, weakness during flexion, and a mass in the affected forearm. Magnetic resonance imaging showed displacement of the biceps brachii into the forearm. The rupture was successfully treated with muscle removal in one case and muscle repair in the other. In patients with a wakeboard trauma and similar presentations, closed proximal muscle rupture of the biceps brachii should be suspected. PMID:21877295

  6. Common Peroneal Nerve Palsy with Multiple-Ligament Knee Injury and Distal Avulsion of the Biceps Femoris Tendon

    PubMed Central

    Oshima, Takeshi; Nakase, Junsuke; Numata, Hitoaki; Takata, Yasushi

    2015-01-01

    A multiple-ligament knee injury that includes posterolateral corner (PLC) disruption often causes palsy of the common peroneal nerve (CPN), which occurs in 44% of cases with PLC injury and biceps femoris tendon rupture or avulsion of the fibular head. Approximately half of these cases do not show functional recovery. This case report aims to present a criteria-based approach to the operation and postoperative management of CPN palsy that resulted from a multiple-ligament knee injury in a 22-year-old man that occurred during judo. We performed a two-staged surgery. The first stage was to repair the injuries to the PLC and biceps femoris. The second stage involved anterior cruciate ligament reconstruction. The outcomes were excellent, with a stable knee, excellent range of motion, and improvement in the palsy. The patient was able to return to judo competition 27 weeks after the injury. To the best of our knowledge, this is the first case report describing a return to sports following CPN palsy with multiple-ligament knee injury. PMID:26064740

  7. Muscle hardness characteristics of the masseter muscle after repetitive muscle activation: comparison to the biceps brachii muscle.

    PubMed

    Kashima, Koji; Higashinaka, Shuichi; Watanabe, Naoshi; Maeda, Sho; Shiba, Ryosuke

    2004-10-01

    The purpose of this study was to compare hardness characteristics of the masseter muscle to those of the biceps brachii muscle during repetitive muscle movements. Seventeen asymptomatic female subjects participated in this study. Each subject, on separate days, undertook a 5-minute unilateral chewing gum task on the right side and a 5-minute flexion-extension exercise on the right hand with a 2kg dumbbell. Using a handheld hardness meter, muscle hardness was measured in the right masseter and in the biceps brachii muscle at eight time points (before the task, immediately after the task, and at 1, 3, 5, 10, 30, and 60 minutes after the task), and the data obtained before and after the task on each muscle were compared. Comparisons of the normalized data were also performed between the two muscles at each time point. As a result, a significant increase in muscle hardness was seen at 1 minute after the task in the biceps brachii muscle (p=0.0093). In contrast, the masseter muscle showed a tendency to lower hardness, with the lowest point of hardness occurring at 10 minutes after the task (p = 0.0160). Between the two muscles, there was a difference in the normalized data immediately after the task, and at 1, 5, and 10 minutes after the task (0.01 muscle hardness characteristics of the masseter muscle completely differed from those of the biceps brachii muscle after repetitive muscle activation. PMID:15532311

  8. Free anterolateral thigh flap raised on musculocutaneous perforators of rectus femoris muscle.

    PubMed

    Ehtesham-ul-Haq; Aslam, Ayesha; Hameed, Shahid; Ahmad, Rao Saood; Majid, Abdul; Waqas, Muhammad

    2011-08-01

    The anterolateral thigh flap (ALTF) has been in wide clinical use for the last two decades, its major disadvantage has been its variable anatomy. We are presenting a case in which no substantial perforators were found to be arising from either the lateral septum of thigh or Vastus Laterlis muscle. In this case, instead of raising another flap, we used the same skin paddle raised on the musculocutaneous perforators of rectus femoris muscle. PMID:21798144

  9. Free rectus femoris muscle transfer for one-stage reconstruction of established facial paralysis.

    PubMed

    Koshima, I; Moriguchi, T; Soeda, S; Hamanaka, T; Tanaka, H; Ohta, S

    1994-09-01

    The free vascularized rectus femoris muscle graft with a long motor nerve was used for reconstruction of unilateral established facial paralysis in one stage. The pedicle vessels were anastomosed to the recipient vessels in the ipsilateral face, and the motor nerve of the muscle, which was led through the upper lip, was sutured to the contralateral facial nerve. The advantages of this one-stage reconstruction as compared with surgery involving second-stage reconstruction are that the reconstruction can be completed in one stage and that the period required for muscle refunctioning after surgery is short. The vascular supply of the rectus femoris muscle can emanate mainly from the lateral circumflex femoral artery. In our cadaveric study, five types of variation were found for origination of a nutrient artery of the muscle. The most common type was one in which the artery derived from the descending branch of the lateral circumflex femoral artery (39 percent). The motor nerve of the rectus femoris muscle is derived from the femoral nerve under the inguinal ligament and runs downward through the intermuscular space between the sartorius muscle and the iliopsoas muscle before entering the posteromedial part of the upper third of the rectus muscle. The advantages of using the rectus muscle are as follows: (1) safety and simplicity exist with one main large arterial supply for arterial anastomosis; (2) the length of the femoral nerve (more than 20 cm) is adequate for reaching the contralateral facial nerve for suturing; (3) a simultaneous operation by two teams is possible with the patient in the supine position; (4) the force and distance of contraction are appropriate to reanimate the face; (5) the rectus muscle can be separated as a segment with appropriate lengths, size, and power for replacing lost muscles in the face; (6) the tendinous fascia in both ends provides a reliable point for anchoring sutures, which provides firmer attachment; and (7) no loss of donor

  10. Measurement of the quadriceps femoris muscle using magnetic resonance and ultrasound imaging.

    PubMed Central

    Walton, J M; Roberts, N; Whitehouse, G H

    1997-01-01

    OBJECTIVES: To define a method for measurement of the cross sectional area and volume of the quadriceps femoris muscle using magnetic resonance imaging (MRI) in conjunction with stereology, and to compare the results of measurements obtained by the MRI method with those obtained by the conventional method of static B-mode ultrasound in order to evaluate whether MRI is a reliable alternative to ultrasound. METHODS: A preliminary MRI study was undertaken on a single female volunteer in order to optimise the scanning technique and sampling design for estimating the muscle volume using the Cavalieri method. Ten healthy volunteers participated in the method comparison study. Each volunteer underwent static B-mode ultrasonography, immediately followed by MRI. The cross sectional area of the quadriceps femoris was estimated at the junction of the proximal one third and distal two thirds of the thigh, and seven systematic sections of the thigh were obtained in order to estimate muscle volume by both modalities. RESULTS: Seven sections through the muscle are required to achieve a coefficient of error of 4-5%. There was no significant difference in the cross sectional area estimates or volume estimates when ultrasound and MRI were compared. CONCLUSION: Muscle cross sectional area and volume can be measured without bias by MRI in conjunction with stereological methods and the method is a reliable alternative to static B-mode ultrasound for this purpose. Images Figure 1 Figure 4 Figure 5 PMID:9132215

  11. Glenohumeral Function of the Long Head of the Biceps Muscle

    PubMed Central

    Chalmers, Peter N.; Cip, Johannes; Trombley, Robert; Cole, Brian J.; Wimmer, Markus A.; Romeo, Anthony A.; Verma, Nikhil N.

    2014-01-01

    Background: Optimal treatment of superior labral anterior-posterior (SLAP) tears is controversial, in part because the dynamic role of the long head of the biceps muscle (LHBM) in the glenohumeral joint is unclear. The aim of this study was to determine dynamic LHBM behavior during shoulder activity by studying (1) the electromyographic activity of the LHBM during shoulder motion, (2) the effect of elbow immobilization on this activity, and (3) the effect of a load applied to the distal humerus on this activity. Hypothesis: The LHBM would not play a significant role in active glenohumeral range of motion. Study Design: Controlled laboratory study. Methods: Thirteen normal volunteers underwent surface electromyography (EMG) measurement of the LHBM, short head biceps muscle (SHBM), deltoid, infraspinatus, and brachioradialis during shoulder motion from the neutral position (0° of rotation, flexion, and abduction) to 45° of flexion, 90° of flexion, 45° of abduction, and 90° of abduction. These motions were repeated both with and without splint immobilization of the forearm and elbow at 100° of flexion and neutral rotation and with and without a 1-kg weight placed on the lateral distal humerus. Results: Mean EMG activity within the LHBM and the SHBM was low (≤11.6% ± 9.1%). LHBM activity was significant increased by flexion and abduction (P < .049 in all cases), while SHBM activity was not. EMG activity from the middle head of the deltoid was significantly increased by loading with the shoulder positioned away from the body (ie, in abduction or flexion). When compared with the unloaded state, the addition of a distal humeral load significantly increased LHBM activity in 45° of abduction (P = .028) and 90° of flexion (P = .033) despite forearm and elbow immobilization. The SHBM showed similar trends. Conclusion: In normal volunteers with forearm and elbow immobilization and application of a load to the distal humerus, LHBM EMG activity is increased by both

  12. Histochemical study on the atrophy of the quadriceps femoris muscle caused by knee joint injuries of rats.

    PubMed

    Okada, Y

    1989-03-01

    Atrophy developing in the quadriceps femoris muscle following knee injury is one of the serious problems not only in the field of orthopedics but also of rehabilitation. However the pathogenesis of this atrophy has not yet been elucidated. The author therefore produced a complex ligament injury model using the knee joints of rats in order to study the pathogenesis of this atrophy. After severing the anterior cruciate ligament, the medial collateral ligament and tibial insertion of the medial meniscus of rats, these animals were sacrificed at 4, 8 and 12 weeks. After removing the vastus lateralis muscle, vastus medialis muscle, and rectus femoris muscle, specimens of these muscles were stained for ATPase. The transection area of the muscle fibers was measured and the fiber type composition was determined. At 4 weeks the vastus medialis muscle and at 12 weeks the vastus lateralis muscle showed marked atrophy. The rectus femoris muscle exhibited the least atrophy throughout the entire observation period. In examining the atrophy of the quadriceps femoris muscle by muscle fiber type, the degree of atrophy was found to differ among the venters and even the same venter showed a different reaction depending on the elapsed time after sustaining the injury. Neither changes in the fiber type composition not neurogenic findings could be observed. PMID:2526800

  13. Effect of experimental muscle pain on maximal voluntary activation of human biceps brachii muscle.

    PubMed

    Khan, Serajul I; McNeil, Chris J; Gandevia, Simon C; Taylor, Janet L

    2011-09-01

    Muscle pain has widespread effects on motor performance, but the effect of pain on voluntary activation, which is the level of neural drive to contracting muscle, is not known. To determine whether induced muscle pain reduces voluntary activation during maximal voluntary contractions, voluntary activation of elbow flexors was assessed with both motor-point stimulation and transcranial magnetic stimulation over the motor cortex. In addition, we performed a psychophysical experiment to investigate the effect of induced muscle pain across a wide range of submaximal efforts (5-75% maximum). In all studies, elbow flexion torque was recorded before, during, and after experimental muscle pain by injection of 1 ml of 5% hypertonic saline into biceps. Injection of hypertonic saline evoked deep pain in the muscle (pain rating ∼5 on a scale from 0 to 10). Experimental muscle pain caused a small (∼5%) but significant reduction of maximal voluntary torque in the motor-point and motor cortical studies (P < 0.001 and P = 0.045, respectively; n = 7). By contrast, experimental muscle pain had no significant effect on voluntary activation when assessed with motor-point and motor cortical stimulation although voluntary activation tested with motor-point stimulation was reduced by ∼2% in contractions after pain had resolved (P = 0.003). Furthermore, induced muscle pain had no significant effect on torque output during submaximal efforts (P > 0.05; n = 6), which suggests that muscle pain did not alter the relationship between the sense of effort and production of voluntary torque. Hence, the present study suggests that transient experimental muscle pain in biceps brachii has a limited effect on central motor pathways. PMID:21737829

  14. Analysis of three different equations for predicting quadriceps femoris muscle strength in patients with COPD *

    PubMed Central

    Nellessen, Aline Gonçalves; Donária, Leila; Hernandes, Nidia Aparecida; Pitta, Fabio

    2015-01-01

    Abstract Objective: To compare equations for predicting peak quadriceps femoris (QF) muscle force; to determine the agreement among the equations in identifying QF muscle weakness in COPD patients; and to assess the differences in characteristics among the groups of patients classified as having or not having QF muscle weakness by each equation. Methods: Fifty-six COPD patients underwent assessment of peak QF muscle force by dynamometry (maximal voluntary isometric contraction of knee extension). Predicted values were calculated with three equations: an age-height-weight-gender equation (Eq-AHWG); an age-weight-gender equation (Eq-AWG); and an age-fat-free mass-gender equation (Eq-AFFMG). Results: Comparison of the percentage of predicted values obtained with the three equations showed that the Eq-AHWG gave higher values than did the Eq-AWG and Eq-AFFMG, with no difference between the last two. The Eq-AHWG showed moderate agreement with the Eq-AWG and Eq-AFFMG, whereas the last two also showed moderate, albeit lower, agreement with each other. In the sample as a whole, QF muscle weakness (< 80% of predicted) was identified by the Eq-AHWG, Eq-AWG, and Eq-AFFMG in 59%, 68%, and 70% of the patients, respectively (p > 0.05). Age, fat-free mass, and body mass index are characteristics that differentiate between patients with and without QF muscle weakness. Conclusions: The three equations were statistically equivalent in classifying COPD patients as having or not having QF muscle weakness. However, the Eq-AHWG gave higher peak force values than did the Eq-AWG and the Eq-AFFMG, as well as showing greater agreement with the other equations. PMID:26398750

  15. Acute experimentally induced neck pain does not affect fatigability of the peripheral biceps brachii muscle.

    PubMed

    Hung, Laurie Y; Maracle, Emmalee; Srbely, John Z; Brown, Stephen H M

    2014-10-01

    Evidence has shown that upper limb muscles peripheral to the cervical spine, such as the biceps brachii, can demonstrate functional deficits in the presence of chronic neck pain. However, few studies have examined how neck pain can affect the fatigability of upper limb muscles; therefore we were motivated to investigate the effects of acutely induced neuropathic neck pain on the fatigability of the biceps brachii muscle during isometric contraction to exhaustion. Topical capsaicin was used to induce neck pain in 11 healthy male participants. Surface EMG signals were recorded from the biceps brachii during an isometric elbow flexion fatigue task in which participants held a weight equivalent to 30% of their MVC until exhaustion. Two experimental sessions, one placebo and one capsaicin, were conducted separated by two days. EMG mean power frequency and average normalized activation values were calculated over the course of the fatigue task. In the presence of pain, there was no statistically significant effect on EMG parameters during fatigue of the biceps brachii. These results demonstrate that acutely induced neuropathic neck pain does not affect the fatigability, under the tested conditions, of the biceps brachii. PMID:24718930

  16. Intramuscular variation in fresh ham muscle color

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This experiment was conducted to characterize a defect involving pale muscle tissue in the superficial, ventral portion of ham muscles, resulting in two-toned appearance of cured ham products. Biceps femoris muscles (n = 200), representing 3 production systems, were obtained from the ham-boning lin...

  17. Enthesitis of the direct tendon of the rectus femoris muscle in a professional volleyball player: A case report

    PubMed Central

    Bortolotto, C.; Coscia, D.R.; Ferrozzi, G.

    2011-01-01

    Enthesitis of the direct tendon of the rectus femoris muscle is a rare pathology which mainly affects professional athletes, and it is caused by overuse and repetitive microtrauma. Athletic jumping and kicking exert a great stress on the direct tendon of the rectus femoris muscle, and volleyball and football players are therefore most frequently affected. Enthesitis may occur suddenly causing pain and functional impairment possibly associated with partial or complete tendon injuries, or it may be a chronic condition causing non-specific clinical symptoms. We present the case of a professional volleyball player who felt a sudden pain in the left side of the groin area during a training session although she had suffered no accidental injury. The pain was associated with impaired ipsilateral limb function. Tendon rupture was suspected, and magnetic resonance imaging (MRI) was performed. MRI showed a lesion at the myotendinous junction associated with marked inhomogeneity of the direct tendon. Ultrasound (US) examination confirmed the presence of both lesions and allowed a more detailed study of the pathology. This is a typical case of enthesitis which confirms that MRI should be considered the examination of choice in hip pain, particularly when the patient is a professional athlete, thanks to its panoramic visualization. However, also US is an ideal imaging technique for evaluating tendon injuries thanks to its high spatial resolution, and it can therefore be used effectively as a second line of investigation. PMID:23396666

  18. Effects of fast and slow squat exercises on the muscle activity of the paretic lower extremity in patients with chronic stroke

    PubMed Central

    Choi, Young-Ah; Kim, Jin-Seop; Lee, Dong-Yeop

    2015-01-01

    [Purpose] The purpose of this study was to investigate the effects of the speed of squat exercises on paretic lower extremity muscle activity in patients with hemiplegia following a stroke. [Subjects and Methods] Ten stroke patients performed fast and slow squat exercises for 2 seconds and 8 seconds, respectively. The muscle activities of the paretic and non-paretic sides of the rectus femoris muscle, the biceps femoris muscle, and the tibialis anterior muscle were assessed and compared using surface electromyography. [Results] The paretic side of the rectus femoris muscle showed statistically significant differences in the fast squat exercise group, which demonstrated the highest muscle activity during the rapid return to the upright position. [Conclusion] The rectus femoris muscle showed the highest muscle activity during the return to the upright position during the fast squat exercise, which indicates that the rectus femoris muscle is highly active during the fast squat exercise. PMID:26356385

  19. Development of a mathematical model for predicting electrically elicited quadriceps femoris muscle forces during isovelocity knee joint motion

    PubMed Central

    Perumal, Ramu; Wexler, Anthony S; Binder-Macleod, Stuart A

    2008-01-01

    Background Direct electrical activation of skeletal muscles of patients with upper motor neuron lesions can restore functional movements, such as standing or walking. Because responses to electrical stimulation are highly nonlinear and time varying, accurate control of muscles to produce functional movements is very difficult. Accurate and predictive mathematical models can facilitate the design of stimulation patterns and control strategies that will produce the desired force and motion. In the present study, we build upon our previous isometric model to capture the effects of constant angular velocity on the forces produced during electrically elicited concentric contractions of healthy human quadriceps femoris muscle. Modelling the isovelocity condition is important because it will enable us to understand how our model behaves under the relatively simple condition of constant velocity and will enable us to better understand the interactions of muscle length, limb velocity, and stimulation pattern on the force produced by the muscle. Methods An additional term was introduced into our previous isometric model to predict the force responses during constant velocity limb motion. Ten healthy subjects were recruited for the study. Using a KinCom dynamometer, isometric and isovelocity force data were collected from the human quadriceps femoris muscle in response to a wide range of stimulation frequencies and patterns. % error, linear regression trend lines, and paired t-tests were used to test how well the model predicted the experimental forces. In addition, sensitivity analysis was performed using Fourier Amplitude Sensitivity Test to obtain a measure of the sensitivity of our model's output to changes in model parameters. Results Percentage RMS errors between modelled and experimental forces determined for each subject at each stimulation pattern and velocity showed that the errors were in general less than 20%. The coefficients of determination between the measured

  20. Kinesiology Taping does not Modify Electromyographic Activity or Muscle Flexibility of Quadriceps Femoris Muscle: A Randomized, Placebo-Controlled Pilot Study in Healthy Volleyball Players

    PubMed Central

    Halski, Tomasz; Dymarek, Robert; Ptaszkowski, Kuba; Słupska, Lucyna; Rajfur, Katarzyna; Rajfur, Joanna; Pasternok, Małgorzata; Smykla, Agnieszka; Taradaj, Jakub

    2015-01-01

    Background Kinesiology taping (KT) is a popular method of supporting professional athletes during sports activities, traumatic injury prevention, and physiotherapeutic procedures after a wide range of musculoskeletal injuries. The effectiveness of KT in muscle strength and motor units recruitment is still uncertain. The objective of this study was to assess the effect of KT on surface electromyographic (sEMG) activity and muscle flexibility of the rectus femoris (RF), vastus lateralis (VL), and vastus medialis (VM) muscles in healthy volleyball players. Material/Methods Twenty-two healthy volleyball players (8 men and 14 women) were included in the study and randomly assigned to 2 comparative groups: “kinesiology taping” (KT; n=12; age: 22.30±1.88 years; BMI: 22.19±4.00 kg/m2) in which KT application over the RF muscle was used, and “placebo taping” (PT; n=10; age: 21.50±2.07 years; BMI: 22.74±2.67 kg/m2) in which adhesive nonelastic tape over the same muscle was used. All subjects were analyzed for resting sEMG activity of the VL and VM muscles, resting and functional sEMG activity of RF muscle, and muscle flexibility of RF muscle. Results No significant differences in muscle flexibility of the RF muscle and sEMG activity of the RF, VL, and VM muscles were registered before and after interventions in both groups, and between the KT and PT groups (p>0.05). Conclusions The results show that application of the KT to the RF muscle is not useful to improve sEMG activity. PMID:26232122

  1. The effects of kinesio taping on architecture, strength and pain of muscles in delayed onset muscle soreness of biceps brachii

    PubMed Central

    Lee, Yong Sin; Bae, Sea Hyun; Hwang, Jin Ah; Kim, Kyung Yoon

    2015-01-01

    [Purpose] This study aimed to confirm the effects of kinesio taping (KT) on muscle function and pain due to delayed onset muscle soreness (DOMS) of the biceps brachii. [Subjects and Methods] Thirty-seven subjects with induced DOMS were randomized into either Group I (control, n=19) or Group II (KT, n=18). Outcome measures were recorded before the intervention (application of KT) and at 24, 48, and 72 hours after the intervention. DOMS was induced, and muscle thickness was measured using ultrasonic radiography. Maximal voluntary isometric contraction (%MVIC) was measured via electromyography (EMG). Subjective pain was measured using a visual analogue scale (VAS). [Results] Group I exhibited a positive correlation between muscle thickness and elapsed time from intervention (24, 48, and 72 hours post induction of DOMS); they also showed a significant decrease in MVIC(%). Group II showed significant increases in muscle thickness up to the 48-hour interval post induction of DOMS, along with a significant decrease in MVIC (%). However, in contrast to Group I, Group II did not show a significant difference in muscle thickness or MVIC (%) at the 72-hour interval in comparison with the values prior to DOMS induction. [Conclusion] In adults with DOMS, activation of muscles by applying KT was found to be an effective and faster method of recovering muscle strength than rest alone. PMID:25729190

  2. The effects of kinesio taping on architecture, strength and pain of muscles in delayed onset muscle soreness of biceps brachii.

    PubMed

    Lee, Yong Sin; Bae, Sea Hyun; Hwang, Jin Ah; Kim, Kyung Yoon

    2015-02-01

    [Purpose] This study aimed to confirm the effects of kinesio taping (KT) on muscle function and pain due to delayed onset muscle soreness (DOMS) of the biceps brachii. [Subjects and Methods] Thirty-seven subjects with induced DOMS were randomized into either Group I (control, n=19) or Group II (KT, n=18). Outcome measures were recorded before the intervention (application of KT) and at 24, 48, and 72 hours after the intervention. DOMS was induced, and muscle thickness was measured using ultrasonic radiography. Maximal voluntary isometric contraction (%MVIC) was measured via electromyography (EMG). Subjective pain was measured using a visual analogue scale (VAS). [Results] Group I exhibited a positive correlation between muscle thickness and elapsed time from intervention (24, 48, and 72 hours post induction of DOMS); they also showed a significant decrease in MVIC(%). Group II showed significant increases in muscle thickness up to the 48-hour interval post induction of DOMS, along with a significant decrease in MVIC (%). However, in contrast to Group I, Group II did not show a significant difference in muscle thickness or MVIC (%) at the 72-hour interval in comparison with the values prior to DOMS induction. [Conclusion] In adults with DOMS, activation of muscles by applying KT was found to be an effective and faster method of recovering muscle strength than rest alone. PMID:25729190

  3. Voluntary and reflex control of the biceps brachii muscle in spastic-athetotic patients

    PubMed Central

    Neilson, Peter D.

    1972-01-01

    A cross-correlation technique of analysis was used to measure the transmission characteristics of tonic stretch reflex (TSR) pathways in spastic-athetoid subjects sustaining a voluntary contraction in the biceps brachii muscle. A comparison was made with the transmission characteristics of normal subjects measured by the same technique. It was found that gain and phase characteristics of spastic patients did not display the large resonant peaks present in normals. It is proposed that the resonant peaks in the TSR transmission of normal subjects were caused by long loop pathways. The absence of these peaks in the spastic patients supports the hypothesis that short-circuiting of long loop pathways by hyperactive spinal reflexes is part of the mechanism of spasticity. PMID:4343479

  4. Changes in hip joint muscle-tendon lengths with mode of locomotion.

    PubMed

    Riley, Patrick O; Franz, Jason; Dicharry, Jay; Kerrigan, D Casey

    2010-02-01

    We have reported that peak hip extension is nearly identical in walking and running, suggesting that anatomical constraints, such as flexor muscle tightness may limit the range of hip extension. To obtain a more mechanistic insight into mobility at the hip and pelvis we examined the lengths of the muscle-tendons units crossing the hip joint. Data defining the three-dimensional kinematics of 26 healthy runners at self-selected walking and running speeds were obtained. These data were used to scale and drive musculoskeletal models using OpenSIM. Muscle-tendon unit (MTU) lengths were calculated for the trailing limb illiacus, rectus femoris, gluteus maximus, and biceps femoris long head and the advancing limb biceps femoris and gluteus maximus. The magnitude and timing of MTU length peaks were each compared between walking and running. The peak length of the right (trailing limb) illiacus MTU, a pure hip flexor, was nearly identical between walking and running, while the maximum length of the rectus femoris MTU, a hip flexor and knee extensor, increased during running. The maximum length of the left (leading limb) biceps femoris was also unchanged between walking and running. Further, the timing of peak illiacus MTU length and peak contralateral biceps femoris MTU length occurred essentially simultaneously during running, at a time during gait when the hamstrings are most vulnerable to stretch injury. This latter finding suggests exploring the role for hip flexor stretching in combination with hamstring stretching to treat and/or prevent running related hamstring injury. PMID:20022251

  5. Effects of electrical stimulation or voluntary contraction for strengthening the quadriceps femoris muscles in an aged male population.

    PubMed

    Caggiano, E; Emrey, T; Shirley, S; Craik, R L

    1994-07-01

    Since musculoskeletal impairment increases with age, it is important to determine if exercise changes age-related muscle weakness. This study compared the training effects of electrical stimulation and voluntary isometric contraction, the traditional exercise, on the quadriceps femoris in males 65 years and older. Eighteen informed, nondisabled males, 72 +/- 4 years of age, participated in 12 training sessions over 4 weeks. Maximal voluntary isometric contraction (MVIC) torque was measured with a Cybex II dynamometer prior to and following training. An interclass correlation coefficient (3,1) of 0.982 demonstrated repeated reliable torque measurement. The electrical stimulation group trained at an average of 36% of pretest MVIC; the traditional exercise group trained at an average of 42% MVIC. Average (F = 14.06, p = 0.004) and peak (F = 14.32, p = 0.004) torque values were increased with both modes of training. Both methods of training using a low training load were effective in increasing torque in this older male sample. Electrical stimulation has the same potential as traditional exercise to provide improved strength for aged males. Future research should examine electrical stimulation in older persons with compromised ability to exercise using traditional methods. PMID:8081406

  6. Tenderness, sensory, and color attributes of two muscles from the M. quadriceps femoris when fabricated using a modified hot-boning technique.

    PubMed

    Jenschke, B E; Swedberg, B J; Calkins, C R

    2008-10-01

    The M. quadriceps femoris from USDA Choice (n = 12) and USDA Select (n = 12) carcasses were fabricated traditionally (COLD) or innovatively (HOT), in which the seams it shares with the top round and bottom round were separated prerigor to evaluate positional and locational effects on Warner-Bratzler shear force (WBSF), sensory attributes, and objective color. At slaughter, paired USDA Choice and USDA Select carcasses were alternately assigned either the HOT or COLD treatment. At 48 h postslaughter, subprimals were removed, vacuum-packaged, and aged for an additional 5 d. After aging, the M. quadriceps femoris was cut into 2.54-cm-thick steaks and allowed to bloom 1 h. For the M. rectus femoris (REC) and M. vastus lateralis (VAL), L* values significantly (P < 0.050) decreased when moving from the proximal to distal position within the muscle. Similarly, a* and b* values decreased in the VAL when moving from the proximal to the distal aspect. After color measurement, steaks were vacuum-packaged and frozen (-26 degrees C) until shear and sensory data were collected. Significant position (proximal to distal) and location effects (cranial to caudal) were noted for both muscles. However, treatment did not affect WBSF of the VAL. Although intramuscular variation existed, WBSF and sensory panel tenderness ratings were acceptable for the REC. Although WBSF values were greater and tenderness ratings were less than the REC, the VAL were not extremely tough and therefore could be used in enhancement applications. PMID:18539844

  7. Electromyographic analysis of thigh muscles during track cycling on a velodrome.

    PubMed

    Watanabe, Kohei; Sato, Takayuki; Mukaimoto, Takahiro; Takashima, Wataru; Yamagishi, Michio; Nishiyama, Tetsunari

    2016-08-01

    We aimed to investigate neuromuscular activation of thigh muscles during track cycling at various speeds. Eight male competitive cyclists volunteered to participate in this study. Surface electromyography of the vastus lateralis, biceps femoris and adductor magnus muscles of the bilateral legs was recorded during track cycling on velodromes with a 250-m track. The participants were instructed to maintain three different lap times: 20, 18 and 16 s. The average rectified value (ARV) was calculated from the sampled surface electromyography. Significantly higher ARVs were observed in the right compared to left leg for the biceps femoris muscle during both straight and curved sections at 18- and 16-s lap times (P < 0.05). In the biceps femoris muscle, significant changes in ARVs during the recovery phase with an increase in speed were seen in the right leg only (P < 0.05). There were no significant differences in ARVs between the straight and curved sections for all three muscles (P > 0.05). From our findings, it was suggested that during track cycling on a velodrome the laterality of the biceps femoris muscle activity is a key strategy to regulate the speed, and fixed neuromuscular strategies are adopted between straight and curved sections for thigh muscles. PMID:26571039

  8. Muscle activity in the lower limbs during push-down movement with a new active-exercise apparatus for the leg

    PubMed Central

    Tanaka, Kenta; Kamada, Hiroshi; Shimizu, Yukiyo; Aikawa, Shizu; Irie, Shun; Ochiai, Naoyuki; Sakane, Masataka; Yamazaki, Masashi

    2016-01-01

    [Purpose] Lower-limb deep vein thrombosis is a complication of orthopedic surgery. A leg-exercise apparatus named “LEX” was developed as a novel active-exercise apparatus for deep vein thrombosis prevention. Muscle activity was evaluated to assess the effectiveness of exercise with LEX in the prevention. [Subjects] Eight healthy volunteers participated in this study. [Methods] Muscle activities were determined through electromyography during exercise with LEX [LEX (+)] and during active ankle movements [LEX (−)]. The end points were peak % maximum voluntary contraction and % integrated electromyogram of rectus femoris, vastus lateralis, biceps femoris, tibialis anterior, gastrocnemius, and soleus. [Results] LEX (+) resulted in higher average values in all muscles except the tibialis anterior. Significant differences were noted in the peak of the biceps femoris and gastrocnemius and in the integrated electromyogram of the rectus femoris, vastus lateralis, gastrocnemius, and soleus. The LEX (+)/LEX (−) ratio of the peak was 2.2 for the biceps femoris and 2.0 for the gastrocnemius . The integrated electromyogram was 1.8 for the gastrocnemius, 1.5 for the rectus femoris, 1.4 for the vastus lateralis, and 1.2 for the soleus. [Conclusion] Higher muscle activity was observed with LEX (+). LEX might be a good tool for increasing lower-limb blood flow and deep vein thrombosis prevention. PMID:27134410

  9. Muscle activity in the lower limbs during push-down movement with a new active-exercise apparatus for the leg.

    PubMed

    Tanaka, Kenta; Kamada, Hiroshi; Shimizu, Yukiyo; Aikawa, Shizu; Irie, Shun; Ochiai, Naoyuki; Sakane, Masataka; Yamazaki, Masashi

    2016-03-01

    [Purpose] Lower-limb deep vein thrombosis is a complication of orthopedic surgery. A leg-exercise apparatus named "LEX" was developed as a novel active-exercise apparatus for deep vein thrombosis prevention. Muscle activity was evaluated to assess the effectiveness of exercise with LEX in the prevention. [Subjects] Eight healthy volunteers participated in this study. [Methods] Muscle activities were determined through electromyography during exercise with LEX [LEX (+)] and during active ankle movements [LEX (-)]. The end points were peak % maximum voluntary contraction and % integrated electromyogram of rectus femoris, vastus lateralis, biceps femoris, tibialis anterior, gastrocnemius, and soleus. [Results] LEX (+) resulted in higher average values in all muscles except the tibialis anterior. Significant differences were noted in the peak of the biceps femoris and gastrocnemius and in the integrated electromyogram of the rectus femoris, vastus lateralis, gastrocnemius, and soleus. The LEX (+)/LEX (-) ratio of the peak was 2.2 for the biceps femoris and 2.0 for the gastrocnemius . The integrated electromyogram was 1.8 for the gastrocnemius, 1.5 for the rectus femoris, 1.4 for the vastus lateralis, and 1.2 for the soleus. [Conclusion] Higher muscle activity was observed with LEX (+). LEX might be a good tool for increasing lower-limb blood flow and deep vein thrombosis prevention. PMID:27134410

  10. Dry Needling at Myofascial Trigger Spots of Rabbit Skeletal Muscles Modulates the Biochemicals Associated with Pain, Inflammation, and Hypoxia

    PubMed Central

    Hsieh, Yueh-Ling; Yang, Shun-An; Yang, Chen-Chia; Chou, Li-Wei

    2012-01-01

    Background and Purpose. Dry needling is an effective therapy for the treatment of pain associated with myofascial trigger point (MTrP). However, the biochemical effects of dry needling that are associated with pain, inflammation, and hypoxia are unclear. This study investigated the activities of β-endorphin, substance P, TNF-α, COX-2, HIF-1α, iNOS, and VEGF after different dosages of dry needling at the myofascial trigger spots (MTrSs) of a skeletal muscle in rabbit. Materials and Methods. Dry needling was performed either with one dosage (1D) or five dosages (5D) into the biceps femoris with MTrSs in New Zealand rabbits. Biceps femoris, serum, and dorsal root ganglion (DRG) were sampled immediately and 5 d after dry needling for β-endorphin, substance P, TNF-α, COX-2, HIF-1α, iNOS, and VEGF immunoassays. Results. The 1D treatment enhanced the β-endorphin levels in the biceps femoris and serum and reduced substance P in the biceps femoris and DRG. The 5D treatment reversed these effects and was accompanied by increase of TNF-α, COX-2, HIF-1α, iNOS, and VEGF production in the biceps femoris. Moreover, the higher levels of these biochemicals were still maintained 5 d after treatment. Conclusion. Dry needling at the MTrSs modulates various biochemicals associated with pain, inflammation, and hypoxia in a dose-dependent manner. PMID:23346198

  11. Muscle oxygen saturation heterogeneity among leg muscles during ramp exercise.

    PubMed

    Takagi, Shun; Kime, Ryotaro; Niwayama, Masatsugu; Murase, Norio; Katsumura, Toshihito

    2013-01-01

    We examined whether O(2) saturation in several leg muscles changes as exercise intensity increases. Twelve healthy young males performed 20 W/min ramp bicycle exercise until exhaustion. Pulmonary O(2) uptake (VO(2)) was monitored continuously during the experiments to determine peak oxygen uptake. Muscle O(2) saturation (SmO(2)) was also monitored continuously at the belly of the vastus lateralis (VL), rectus femoris, vastus medialis, biceps femoris, gastrocnemius lateralis, gastrocnemius medialis, and tibialis anterior by near-infrared spatial resolved spectroscopy. Although the VL muscle mainly contributes during cycling exercise, deoxygenation was enhanced not only in the VL muscle but also in the other thigh muscles and lower leg muscles with increased exercise intensity. Furthermore, SmO(2) response during ramp cycling exercise differed considerably between leg muscles. PMID:22879044

  12. Localized Electrical Impedance Myography of the Biceps Brachii Muscle during Different Levels of Isometric Contraction and Fatigue

    PubMed Central

    Li, Le; Shin, Henry; Li, Xiaoyan; Li, Sheng; Zhou, Ping

    2016-01-01

    This study assessed changes in electrical impedance myography (EIM) at different levels of isometric muscle contraction as well as during exhaustive exercise at 60% maximum voluntary contraction (MVC) until task failure. The EIM was performed on the biceps brachii muscle of 19 healthy subjects. The results showed that there was a significant difference between the muscle resistance (R) measured during the isometric contraction and when the muscle was completely relaxed. Post hoc analysis shows that the resistance increased at higher contractions (both 60% MVC and MVC), however, there were no significant changes in muscle reactance (X) during the isometric contractions. The resistance also changed during different stages of the fatigue task and there were significant decreases from the beginning of the contraction to task failure as well as between task failure and post fatigue rest. Although our results demonstrated an increase in resistance during isometric contraction, the changes were within 10% of the baseline value. These changes might be related to the modest alterations in muscle architecture during a contraction. The decrease in resistance seen with muscle fatigue may be explained by an accumulation of metabolites in the muscle tissue. PMID:27110795

  13. Localized Electrical Impedance Myography of the Biceps Brachii Muscle during Different Levels of Isometric Contraction and Fatigue.

    PubMed

    Li, Le; Shin, Henry; Li, Xiaoyan; Li, Sheng; Zhou, Ping

    2016-01-01

    This study assessed changes in electrical impedance myography (EIM) at different levels of isometric muscle contraction as well as during exhaustive exercise at 60% maximum voluntary contraction (MVC) until task failure. The EIM was performed on the biceps brachii muscle of 19 healthy subjects. The results showed that there was a significant difference between the muscle resistance (R) measured during the isometric contraction and when the muscle was completely relaxed. Post hoc analysis shows that the resistance increased at higher contractions (both 60% MVC and MVC), however, there were no significant changes in muscle reactance (X) during the isometric contractions. The resistance also changed during different stages of the fatigue task and there were significant decreases from the beginning of the contraction to task failure as well as between task failure and post fatigue rest. Although our results demonstrated an increase in resistance during isometric contraction, the changes were within 10% of the baseline value. These changes might be related to the modest alterations in muscle architecture during a contraction. The decrease in resistance seen with muscle fatigue may be explained by an accumulation of metabolites in the muscle tissue. PMID:27110795

  14. Gene expression pattern of glucose transporters in the skeletal muscles of newly hatched chicks.

    PubMed

    Shimamoto, Saki; Ijiri, Daichi; Kawaguchi, Mana; Nakashima, Kazuki; Ohtsuka, Akira

    2016-07-01

    The gene expression pattern of the glucose transporters (GLUT1, GLUT3, GLUT8, and GLUT12) among pectoralis major and minor, biceps femoris, and sartorius muscles from newly hatched chicks was examined. GLUT1 mRNA level was higher in pectoralis major muscle than in the other muscles. Phosphorylated AKT level was also high in the same muscle, suggesting a relationship between AKT and GLUT1 expression. PMID:27008100

  15. Impact of decline-board squat exercises and knee joint angles on the muscle activity of the lower limbs

    PubMed Central

    Lee, Daehee; Lee, Sangyong; Park, Jungseo

    2015-01-01

    [Purpose] This study aims to investigate how squat exercises on a decline board and how the knee joint angles affect the muscle activity of the lower limbs. [Subjects] The subjects were 26 normal adults. [Methods] A Tumble Forms wedge device was used as the decline board, and the knee joint angles were measured with a goniometer. To examine the muscle activity of the biceps femoris, rectus femoris, gastrocnemius lateralis, and tibialis anterior of the lower limbs, a comparison analysis with electromyography was conducted. [Results] The muscle activity of the biceps femoris, rectus femoris, gastrocnemius lateralis, and tibialis anterior increased with increased knee joint angles, both for squat exercises on the decline board and on a flat floor. When the knee joint angle was 45°, 60°, and 90°, the muscle activity of the rectus femoris was significantly higher and that of the tibialis anterior was significantly lower during squat exercises on the decline board than on the flat floor. When the knee joint angle was 90°, the muscle activity of the gastrocnemius lateralis was significantly lower. [Conclusion] Squat exercises on a decline board are an effective intervention to increase the muscle activity of the rectus femoris with increased knee joint angles. PMID:26357447

  16. Effects of wearing gumboots and leather lace-up boots on lower limb muscle activity when walking on simulated underground coal mine surfaces.

    PubMed

    Dobson, Jessica A; Riddiford-Harland, Diane L; Steele, Julie R

    2015-07-01

    This study aimed to investigate the effects of wearing two standard underground coal mining work boots (a gumboot and a leather lace-up boot) on lower limb muscle activity when participants walked across simulated underground coal mining surfaces. Quadriceps (rectus femoris, vastus medialis, vastus lateralis) and hamstring (biceps femoris, semitendinosus) muscle activity were recorded as twenty male participants walked at a self-selected pace around a circuit while wearing each boot type. The circuit consisted of level, inclined and declined surfaces composed of rocky gravel and hard dirt. Walking in a leather lace-up boot, compared to a gumboot, resulted in increased vastus lateralis and increased biceps femoris muscle activity when walking on sloped surfaces. Increased muscle activity appears to be acting as a slip and/or trip prevention strategy in response to challenging surfaces and changing boot features. PMID:25766420

  17. Mechanomyographic amplitude and mean power frequency versus torque relationships during isokinetic and isometric muscle actions of the biceps brachii.

    PubMed

    Beck, Travis W; Housh, Terry J; Johnson, Glen O; Weir, Joseph P; Cramer, Joel T; Coburn, Jared W; Malek, Moh H

    2004-10-01

    The purpose of this investigation was to determine the mechanomyographic (MMG) amplitude and mean power frequency (MPF) versus torque (or force) relationships during isokinetic and isometric muscle actions of the biceps brachii. Ten adults (mean +/- SD age = 21.6 +/- 1.7 years) performed submaximal to maximal isokinetic and isometric muscle actions of the dominant forearm flexors. Following determination of isokinetic peak torque (PT) and the isometric maximum voluntary contraction (MVC), the subjects randomly performed submaximal step muscle actions in 10% increments from 10% to 90% PT and MVC. Polynomial regression analyses indicated that MMG amplitude increased linearly with torque during both the isokinetic (r2 = 0.982) and isometric (r2 = 0.956) muscle actions. From 80% to 100% of isometric MVC, however, MMG amplitude appeared to plateau. Cubic models provided the best fit for the MMG MPF versus isokinetic (R2 = 0.786) and isometric (R2 = 0.940) torque relationships, although no significant increase in MMG MPF was found from 10% to 100% of isokinetic PT. For the isometric muscle actions, however, MMG MPF remained relatively stable from 10% to 50% MVC, increased from 50% to 80% MVC, and decreased from 80% to 100% MVC. The results demonstrated differences in the MMG amplitude and MPF versus torque relationships between the isokinetic and isometric muscle actions. These findings suggested that the time and frequency domains of the MMG signal may be useful for describing the unique motor control strategies that modulate dynamic versus isometric torque production. PMID:15301774

  18. The effect of temperature on proliferation and differentiation of chicken skeletal muscle satellite cells isolated from different muscle types.

    PubMed

    Harding, Rachel L; Halevy, Orna; Yahav, Shlomo; Velleman, Sandra G

    2016-04-01

    Skeletal muscle satellite cells are a muscle stem cell population that mediate posthatch muscle growth and repair. Satellite cells respond differentially to environmental stimuli based upon their fiber-type of origin. The objective of this study was to determine how temperatures below and above the in vitro control of 38°C affected the proliferation and differentiation of satellite cells isolated from the chicken anaerobic pectoralis major (p. major) or mixed fiber biceps femoris (b.femoris) muscles. The satellite cells isolated from the p. major muscle were more sensitive to both cold and hot temperatures compared to the b.femoris satellite cells during both proliferation and differentiation. The expressions of myogenic regulatory transcription factors were also different between satellite cells from different fiber types. MyoD expression, which partially regulates proliferation, was generally expressed at higher levels in p. major satellite cells compared to the b.femoris satellite cells from 33 to 43°C during proliferation and differentiation. Similarly, myogenin expression, which is required for differentiation, was also expressed at higher levels in p. major satellite cells in response to both cold and hot temperatures during proliferation and differentiation than b. femoris satellite cells. These data demonstrate that satellite cells from the anaerobic p. major muscle are more sensitive than satellite cells from the aerobic b. femoris muscle to both hot and cold thermal stress during myogenic proliferation and differentiation. PMID:27125667

  19. The growth patterns of three hindlimb muscles in the chicken.

    PubMed Central

    Helmi, C; Cracraft, J

    1977-01-01

    This study was designed to investigate the growth patterns of three hindlimb muscles of the chicken relative to the functional-biomechanical demands of increasing body size. The biceps femoris, a bipennate non-postural muscle, grew relatively faster in terms of wet and dry weight than did the parallel-fibred adductor superficialis or the unipennate adductor profundus, both postural muscles. All three muscles exhibited positive allometry (relative to body weight) in muscle length but only biceps femoris and adductor profundus showed positive allometry in cross sectional area adductor superficialis having isometric growth in this parameter. In biceps femoris and adductor superficialis the lengths of the longest and shortest fasciculi grew at equal rates, whereas in adductor profundus the shortest fasciculi grew faster than the longest. We conclude that muscle weight alone is an insufficient indicator of changing function in growing muscle. Hence, growth studies should include other functionally relevant parameters such as cross sectional area, which is proportional to the force-producing capabilities of the muscle, or fibre (fasciculus) length, which is indicative of the absolute amount of stretching or shortening that is possible and of the contraction velocity. PMID:885779

  20. Driving Sodium-Potassium Pumps With An Oscillating Electric Field: Effects On Muscle Recovery In The Human Biceps Brachii

    NASA Astrophysics Data System (ADS)

    Bovyn, Matt; Chen, Wei; Lanes, Olivia; Mast, Jason

    2013-03-01

    Dr. Chen has developed a technique called synchronization modulation, which uses an oscillating electric field to increase the rate at which the sodium-potassium pumps in the cell membrane work. Because the sodium-potassium pump is integral in the recovery of skeletal muscle fibers after an action potential, we investigated the effects of applying synchronization modulation to muscles which had already undergone fatigue due to repeated action potentials during exercise. Fatigue was induced in human subjects' biceps brachii through isometric contraction. Surface electromyography measurements of fatigue index were used to quantify how the muscle recovered over the minutes following fatigue, both when synchronization modulation was applied and when it was absent. The preliminary results were inconclusive, but it is hoped that in later work it will be shown that applying synchronization modulation is effective in increasing the rate at which the muscle recovers to its initial state. This would demonstrate not only that synchronization modulation can be successfully applied to human muscle, but also that it has many potential applications in sports medicine and novel disease treatments. Work done as part of an REU program at the University of South Florida

  1. Immediate effects of acupuncture on biceps brachii muscle function in healthy and post-stroke subjects

    PubMed Central

    2012-01-01

    Background The effects of acupuncture on muscle function in healthy subjects are contradictory and cannot be extrapolated to post-stroke patients. This study evaluated the immediate effects of manual acupuncture on myoelectric activity and isometric force in healthy and post-stroke patients. Methods A randomized clinical trial, with parallel groups, single-blinded study design, was conducted with 32 healthy subjects and 15 post-stroke patients with chronic hemiparesis. Surface electromyography from biceps brachii during maximal isometric voluntary tests was performed before and after 20-min intermittent, and manual stimulation of acupoints Quchi (LI11) or Tianquan (PC2). Pattern differentiation was performed by an automated method based on logistic regression equations. Results Healthy subjects showed a decrease in the root mean-squared (RMS) values after the stimulation of LI11 (pre: 1.392 ± 0.826 V; post: 0.612 ± 0.0.320 V; P = 0.002) and PC2 (pre: 1.494 ± 0.826 V; post: 0.623 ± 0.320 V; P = 0.001). Elbow flexion maximal isometric voluntary contraction (MIVC) was not significantly different after acupuncture stimulation of LI11 (pre: 22.2 ± 10.7 kg; post: 21.7 ± 9.5 kg; P = 0.288) or PC2 (pre: 18.8 ± 4.6 kg; post: 18.7 ± 6.0 kg; P = 0.468). Post-stroke patients did not exhibit any significant decrease in the RMS values after the stimulation of LI11 (pre: 0.627 ± 0.335 V; post: 0.530 ± 0.272 V; P = 0.187) and PC2 (pre: 0.601 ± 0.258 V; post: 0.591 ± 0.326 V; P = 0.398). Also, no significant decrease in the MIVC value was observed after the stimulation of LI11 (pre: 9.6 ± 3.9 kg; post: 9.6 ± 4.7 kg; P = 0.499) or PC2 (pre: 10.7 ± 5.6 kg; post: 10.2 ± 5.3 kg; P = 0.251). Different frequency of patterns was observed among healthy subjects and post-stroke patients groups (χ2 = 9.759; P = 0.021). Conclusion Manual acupuncture provides sufficient neuromuscular stimuli to promote immediate changes in motor unit gross recruitment without repercussion in

  2. [Amino acid composition of the rat quadriceps femoris muscle after a flight on the Kosmos-936 biosatellite].

    PubMed

    Vlasova, T F; Miroshnikova, E B; Poliakov, V V; Murugova, T P

    1982-01-01

    The amino acid composition of the quadriceps muscle of rats flown onboard the biosatellite Cosmos-936 and exposed to the ground-based synchronous control experiment was studied. The weightless rats showed changes in the amino acid concentration in the quadriceps muscle. The centrifuged flight and synchronous rats displayed an accumulation of free amino acids in the above muscle. PMID:7070040

  3. Ultrasound strain elastography in assessment of resting biceps brachii muscle stiffness in patients with Parkinson's disease: a primary observation.

    PubMed

    Gao, Jing; He, Wen; Du, Li-Juan; Li, Shuo; Cheng, Ling-Gang; Shih, George; Rubin, Jonathan

    2016-01-01

    The aim of this study was to evaluate the feasibility of ultrasound strain elastography (SE) for the assessment of resting biceps brachii muscle (BBM) stiffness in patients with Parkinson's diseases (PD). From May 2014 to December 2014, we prospectively performed SE of BBM in 14 patients with PD and 10 healthy controls. Based on the Unified Parkinson's Disease Rating Scale for scoring muscle rigidity (UPDRS, part III), muscle rigidity scores in 14 patients with PD included 3 patients with high rigidity (UPDRS III-IV) and 11 patients with low rigidity (UPDRS I-II). Ultrasound strain was represented by the deformation of the BBM and subcutaneous soft tissues that was produced by external compression with a sand bag (1.5 kg) tied onto an ultrasound transducer. Deformation was estimated with two-dimensional speckle tracking. The difference in strain ratio (SR, defined as mean BBM strain divided by mean subcutaneous soft tissue strain) between PD and healthy controls was tested by unpaired t test. The correlation between SR and muscle rigidity score was analyzed by Pearson correlation coefficient. The reliability of SR in assessment of BBM stiffness was tested using intraclass correlation coefficient. In our result, the SR in PD and healthy controls measured 2.65±0.36 and 3.30±0.27, respectively. A significant difference in SR was noted between the healthy controls and PD (P=.00011). A negative correlation was found between SR and UPDRS rigidity score (r=-0.78). Our study suggests that the SR of BBM to reference tissue can be used as a quantitative biomarker in assessing resting muscle stiffness associated with muscle rigidity in PD. PMID:27133683

  4. MUSCLE TRANSFER FROM TRICEPS TO BICEPS IN PATIENTS WITH CHRONIC INJURY OF THE UPPER TRUNK OF THE BRACHIAL PLEXUS

    PubMed Central

    Souza, Fabiano Inúcio de; Saito, Mateus; Kimura, Luiz Koiti; Júnior, Rames Mattar; Zumiotti, Arnaldo Valdir

    2015-01-01

    Objective: To evaluate the results from transposition of the triceps for elbow flexion in patients with chronic and complete injury to the upper trunk of the brachial plexus. Methods: This was a retrospective study, including only patients who had biceps grade 0 and triceps grade 5, who underwent anterior transfer of the triceps muscle, performed between 1998 and 2005. The affected side, sex, type of accident, strength of elbow flexion, complications and patient satisfaction were investigated in 11 cases. Results: 10 patients were male; the age range was from 24 to 49 years, with a mean of 33.7 years. The minimum time between injury and surgery was 21 months (range 21-74 months). The left side was affected in eight cases, and the right only in three. Good results were obtained in 10 patients, who acquired elbow flexion strength of grade 3 (two cases) and grade 4 (eight cases), while one evolved unfavorably with grade 2 strength. Two cases had complications (initial compartment syndrome and insufficient tensioning). All the patients said that they were satisfied with the procedure. Conclusion: Anterior transposition of the triceps muscle provided patient satisfaction in all cases except one, attaining strength grade 4 in eight cases, grade 3 in two cases and grade 2 in one case. PMID:27022572

  5. Spectral properties of electromyographic and mechanomyographic signals during dynamic concentric and eccentric contractions of the human biceps brachii muscle.

    PubMed

    Qi, Liping; Wakeling, James M; Ferguson-Pell, Martin

    2011-12-01

    The purpose of this study was to describe and examine the variations in recruitment patterns of motor units (MUs) in biceps brachii (BB) through a range of joint motion during dynamic eccentric and concentric contractions. Twelve healthy participants (6 females, 6 males, age=30±8.5 years) performed concentric and eccentric contractions with constant external loading at different levels. Surface electromyography (EMG) and mechanomyography (MMG) were recorded from BB. The EMGs and MMGs were decomposed into their intensities in time-frequency space using a wavelet technique. The EMG and MMG spectra were then compared using principal component analysis. Variations in total intensity, first principal component (PCI), and the angle θ formed by first component (PCI) and second component (PCII) loading scores were explained in terms of MU recruitment patterns and elbow angles. Elbow angle had a significant effect on dynamic concentric and eccentric contractions. The EMG total intensity was greater for concentric than for eccentric contractions in the present study. MMG total intensity, however, was lower during concentric than during eccentric contractions. In addition, there was no significant difference in θ between concentric and eccentric contractions for both EMG and MMG. Selective recruitment of fast MUs from BB muscle during eccentric muscle contractions was not found in the present study. PMID:22000481

  6. Effects of forward trunk lean on hamstring muscle kinematics during sprinting.

    PubMed

    Higashihara, Ayako; Nagano, Yasuharu; Takahashi, Kazumasa; Fukubayashi, Toru

    2015-01-01

    This study aimed to investigate the effects of forward trunk lean on hamstring muscle kinematics during sprinting. Eight male sprinters performed maximal-effort sprints in two trunk positions: forward lean and upright. A three-dimensional musculoskeletal model was used to compute the musculotendon lengths and velocity of the biceps femoris long head, semitendinosus, and semimembranosus muscles during the sprinting gait cycle. The musculotendon lengths of all the three hamstring muscles at foot strike and toe-off were significantly greater during the forward trunk lean sprint than during the upright trunk sprint. In addition, a positive peak musculotendon lengthening velocity was observed in the biceps femoris long head and semimembranosus muscles during the late stance phase, and musculotendon lengths at that instant were significantly greater during the forward trunk lean sprint than during the upright trunk sprint. The present study provides significant evidence that a potential for hamstring muscle strain injury involving forward trunk lean sprinting would exist during the stance phase. The results also indicate that the biceps femoris long head and semimembranosus muscles are stretched during forward trunk lean sprinting while contracting eccentrically in the late stance phase; thus, the elongation load on these muscles could be increased. PMID:25514378

  7. Evaluation of Stiffness of the Spastic Lower Extremity Muscles in Early Spinal Cord Injury by Acoustic Radiation Force Impulse Imaging

    PubMed Central

    Cho, Kang Hee

    2015-01-01

    Objective To investigate intrinsic viscoelastic changes using shear wave velocities (SWVs) of spastic lower extremity muscles in patients with early spinal cord injury (SCI) via acoustic radiation force impulse (ARFI) imaging and to evaluate correlation between the SWV values and spasticity. Methods Eighteen patients with SCI within 3 months and 10 healthy adults participated. We applied the ARFI technique to measure SWV of gastrocnemius muscle (GCM) and long head of biceps femoris muscle. Spasticity of ankle and knee joint was assessed by original Ashworth Scale. Results Ten patients with SCI had spasticity. Patients with spasticity had significantly faster SWV for GCM and biceps femoris muscle than those without spasticity (Mann-Whitney U test, p=0.007 and p=0.008) and normal control (p=0.011 and p=0.037, respectively). The SWV values of GCM correlated with the ankle spasticity (Spearman rank teat, p=0.026). There was significant correlation between the SWV values for long head of biceps femoris muscle and knee spasticity (Spearman rank teat, p=0.022). Conclusion ARFI demonstrated a difference in muscle stiffness in the GCM between patients with spastic SCI and those without spasticity. This finding suggested that stiffness of muscles increased in spastic lower extremity of early SCI patients. ARFI imaging is a valuable tool for noninvasive assessment of the stiffness of the spastic muscle and has the potential to identify pathomechanical changes of the tissue associated with SCI. PMID:26161345

  8. Comparison of hamstring muscle behavior for anterior cruciate ligament (ACL) patient and normal subject during local marching

    NASA Astrophysics Data System (ADS)

    Amineldin@Aminudin, Nurul Izzaty Bt.; Rambely, A. S.

    2014-09-01

    This study aims to investigate the hamstring muscle activity after the surgery by carrying out an electromyography experiment on the hamstring and to compare the behavior of the ACL muscle activity between ACL patient and control subject. Electromyography (EMG) is used to study the behavior of muscles during walking activity. Two hamstring muscles involved which are semitendinosus and bicep femoris. The EMG data for both muscles were recorded while the subject did maximum voluntary contraction (MVC) and marching. The study concluded that there were similarities between bicep femoris of the ACL and control subjects. The analysis showed that the biceps femoris muscle of the ACL subject had no abnormality and the pattern is as normal as the control subject. However, ACL patient has poor semitendinosus muscle strength compared to that of control subject because the differences of the forces produced. The force of semitendinosus value for control subject was two times greater than that of the ACL subject as the right semitendinosus muscle of ACL subject was used to replace the anterior cruciate ligament (ACL) that was injured.

  9. Effects of Exposure to Normobaric Hyperoxia on the Recovery of Local Muscle Fatigue in the Quadriceps Femoris of Young People

    PubMed Central

    Yokoi, Yuka; Yanagihashi, Ryuya; Morishita, Katsuyuki; Fujiwara, Takayuki; Abe, Koji

    2014-01-01

    [Purpose] Acute development of local muscle fatigue and recovery often become large issues on sports fields. This study aimed to identify the effects of normobaric hyperoxia on the recovery of local muscle fatigue. [Subjects] Eleven healthy males participated in this study, and they all completed two protocols in a random order. [Methods] Subjects performed single-leg isometric knee extension at 70% of their maximum voluntary isometric contraction (MVIC) for as long as possible. Each participant was subsequently treated with one of two recovery conditions: 20.9% O2 or 30.0% O2 for 30 minutes. Afterwards, they performed an identical isometric task to measure the extent of their recovery. The following parameters were used to assess the degrees of muscle fatigue: MVIC, endurance time, surface electromyography (sEMG) power spectra, and changes in hemoglobin concentration using near-infrared spectroscopy (NIRS). [Results] The treatment of 30.0% O2 induced a significant recovery rate in MVIC compared to the 20.9% O2. Additionally, the data revealed a significantly higher concentration of total hemoglobin after the 30.0% O2 treatment than after the 20.9% O2 treatment. [Conclusion] The results of this study suggest that recovery from acute muscle fatigue can be better facilitated under 30.0% normobaric hyperoxia than a normoxic condition. Therefore, for cases requiring quicker full recovery, treatment under 30.0% O2 environment for 30 minutes is recommended. PMID:24707107

  10. mRNA expression characteristics are different in irreversibly atrophic intrinsic muscles of the forepaw compared with reversibly atrophic biceps in a rat model of obstetric brachial plexus palsy (OBPP).

    PubMed

    Wu, Ji-Xin; Chen, Liang; Ding, Fei; Chen, Le-Zi; Gu, Yu-Dong

    2016-04-01

    In obstetric brachial plexus palsy (OBPP), irreversible muscle atrophy occurs much faster in intrinsic muscles of the hand than in the biceps. To elucidate the mechanisms involved, mRNA expression profiles of denervated intrinsic muscles of the forepaw (IMF) and denervated biceps were determined by microarray using the rat model of OBPP where atrophy of IMF is irreversible while atrophy of biceps is reversible. Relative to contralateral control, 446 dysregulated mRNAs were detected in denervated IMF and mapped to 51 KEGG pathways, and 830 dysregulated mRNAs were detected in denervated biceps and mapped to 52 KEGG pathways. In denervated IMF, 10 of the pathways were related to muscle regulation; six with down-regulated and one with up-regulated mRNAs. The remaining three pathways had both up- and down-regulated mRNAs. In denervated biceps, 13 of the pathways were related to muscle regulation, six with up-regulated and seven with down-regulated mRNAs. Five of the pathways with up-regulated mRNAs were related to regrowth and differentiation of muscle cells. Among the 23 pathways with dysregulated mRNAs, 13 were involved in regulation of neuromuscular junctions. Our results demonstrated that mRNAs expression characteristics in irreversibly atrophic denervated IMF were different from those in reversibly atrophic denervated biceps; dysregulated mRNAs in IMF were associated with inactive pathways of muscle regulation, and in biceps they were associated with active pathways of regrowth and differentiation. Lack of self-repair potential in IMF may be a major reason why atrophy of IMF becomes irreversible much faster than atrophy of biceps after denervation. PMID:26902607

  11. Muscle activation and knee biomechanics during squatting and lunging after lower extremity fatigue in healthy young women.

    PubMed

    Longpré, Heather S; Acker, Stacey M; Maly, Monica R

    2015-02-01

    Muscle activations and knee joint loads were compared during squatting and lunging before and after lower extremity neuromuscular fatigue. Electromyographic activations of the rectus femoris, vastus lateralis and biceps femoris, and the external knee adduction and flexion moments were collected on 25 healthy women (mean age 23.5 years, BMI of 23.7 kg/m(2)) during squatting and lunging. Participants were fatigued through sets of 50 isotonic knee extensions and flexions, with resistance set at 50% of the peak torque achieved during a maximum voluntary isometric contraction. Fatigue was defined as a decrease in peak isometric knee extension or flexion torque ≥25% from baseline. Co-activation indices were calculated between rectus femoris and biceps femoris; and between vastus lateralis and biceps femoris. Fatigue decreased peak isometric extension and flexion torques (p<0.05), mean vastus lateralis activation during squatting and lunging (p<0.05), and knee adduction and flexion moments during lunging (p<0.05). Quadriceps activations were greater during lunging than squatting (p<0.05). Thus, fatigue altered the recruitment strategy of the quadriceps during squatting and lunging. Lunging challenges quadriceps activation more than squatting in healthy, young women. PMID:25258248

  12. Muscular activity of lower limb muscles associated with working on inclined surfaces

    PubMed Central

    Lu, Ming-Lun; Kincl, Laurel; Lowe, Brian; Succop, Paul; Bhattacharya, Amit

    2015-01-01

    This study investigated effects of visual cues, muscular fatigue, task performance and experience of working on inclined surfaces on activity of postural muscles in the lower limbs associated with maintaining balance on three inclined surfaces—0°, 14° and 26°. Normalized electromyographic (NEMG) data were collected on 44 professional roofers bilaterally from the rectus femoris, biceps femoris, tibialii anterior, and gastrocnemii medial muscle groups. The 50th and 95th percentile normalized EMG amplitudes were used as EMG variables. Results showed that inclination angle and task performance caused a significant increase in the NEMG amplitudes of all postural muscles. Visual cues were significantly associated with a decrease in the 95th percentile EMG amplitude for the right gastrocnemius medial and tibialis anterior. Fatigue was related to a significant decrease in the NEMG amplitude for the rectus femoris. Experience of working on inclined surfaces did not have a significant effect on the NEMG amplitude. PMID:25331562

  13. ‘Serious thigh muscle strains’: beware the intramuscular tendon which plays an important role in difficult hamstring and quadriceps muscle strains

    PubMed Central

    Brukner, Peter; Connell, David

    2016-01-01

    Why do some hamstring and quadriceps strains take much longer to repair than others? Which injuries are more prone to recurrence? Intramuscular tendon injuries have received little attention as an element in ‘muscle strain’. In thigh muscles, such as rectus femoris and biceps femoris, the attached tendon extends for a significant distance within the muscle belly. While the pathology of most muscle injures occurs at a musculotendinous junction, at first glance the athlete appears to report pain within a muscle belly. In addition to the musculotendinous injury being a site of pathology, the intramuscular tendon itself is occasionally injured. These injuries have a variety of appearances on MRIs. There is some evidence that these injuries require a prolonged rehabilitation time and may have higher recurrence rates. Therefore, it is important to recognise the tendon component of a thigh ‘muscle strain’. PMID:26519522

  14. Comparative study of linear and curvilinear ultrasound probes to assess quadriceps rectus femoris muscle mass in healthy subjects and in patients with chronic respiratory disease

    PubMed Central

    Mandal, S; Suh, E; Thompson, A; Connolly, B; Ramsay, M; Harding, R; Puthucheary, Z; Moxham, J; Hart, N

    2016-01-01

    Introduction Ultrasound measurements of rectus femoris cross-sectional area (RFCSA) are clinically useful measurements in chronic obstructive pulmonary disease (COPD) and critically ill patients. Technical considerations as to the type of probe used, which affects image resolution, have limited widespread clinical application. We hypothesised that measurement of RFCSA would be similar with linear and curvilinear probes. Methods Four studies were performed to compare the use of the curvilinear probe in measuring RFCSA. Study 1 investigated agreement of RFCSA measurements using linear and curvilinear probes in healthy subjects, and in patients with chronic respiratory disease. Study 2 investigated the intra-rater and inter-rater agreement using the curvilinear probe. Study 3 investigated the agreement of RFCSA measured from whole and spliced images using the linear probe. Study 4 investigated the applicability of ultrasound in measuring RFCSA during the acute and recovery phases of an exacerbation of COPD. Results Study 1 showed demonstrated no difference in the measurement of RFCSA using the curvilinear and linear probes (308±104 mm2 vs 320±117 mm2, p=0.80; intraclass correlation coefficient (ICC)>0.97). Study 2 demonstrated high intra-rater and inter-rater reliability of RFCSA measurement with ICC>0.95 for both. Study 3 showed that the spliced image from the linear probe was similar to the whole image RFCSA (308±103.5 vs 263±147 mm2, p=0.34; ICC>0.98). Study 4 confirmed the clinical acceptability of using the curvilinear probe during an exacerbation of COPD. There were relationships observed between admission RFCSA and body mass index (r=+0.65, p=0.018), and between RFCSA at admission and physical activity levels at 4 weeks post-hospital discharge (r=+0.75, p=0.006). Conclusions These studies have demonstrated that clinicians can employ whole and spliced images from the linear probe or use images from the curvilinear probe, to measure RFCSA. This will extend

  15. The Influence of Prior Hamstring Injury on Lengthening Muscle Tissue Mechanics

    PubMed Central

    Silder, Amy; Reeder, Scott B.; Thelen, Darryl G.

    2010-01-01

    Hamstring strain injuries often occur near the proximal musculotendon junction (MTJ) of the biceps femoris. Post-injury remodeling can involve scar tissue formation, which may alter contraction mechanics and influence re-injury risk. The purpose of this study was to assess the affect of prior hamstring strain injury on muscle tissue displacements and strains during active lengthening contractions. Eleven healthy and eight subjects with prior biceps femoris injuries were tested. All previously injured subjects had since returned to sport and exhibited evidence of residual scarring along the proximal aponeurosis. Subjects performed cyclic knee flexion-extension on an MRI-compatible device using elastic and inertial loads, which induced active shortening and lengthening contractions, respectively. CINE phase-contrast imaging was used to measure tissue velocities within the biceps femoris during these tasks. Numerical integration of the velocity information was used to estimate two-dimensional tissue displacement and strain fields during muscle lengthening. The largest tissue motion was observed along the distal MTJ, with the active lengthening muscle exhibiting significantly greater and more homogeneous tissue displacements. First principal strains magnitudes were largest along the proximal MTJ for both loading conditions. The previously injured subjects exhibited less tissue motion and significantly greater strains near the proximal MTJ. We conclude that localized regions of high tissue strains during active lengthening contractions may predispose the proximal biceps femoris to injury. Furthermore, post-injury remodeling may alter the in-series stiffness seen by muscle tissue and contribute to the relatively larger localized tissue strains near the proximal MTJ, as was observed in this study. PMID:20472238

  16. Relative contributions of animal and muscle effects to variation in beef lean color stability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Beef carcasses (n = 100) were selected from a commercial processing facility. Longissimus lumborum (LM), semimembranosus (SM), biceps femoris (BF), gluteus medius (GM), triceps brachii (TB), rectus femoris (RF), vastus lateralis (VL), adductor (AD), semitendinosus (ST), infraspinatus (IS), teres ma...

  17. The Biceps Crease Interval for Diagnosing Complete Distal Biceps Tendon Ruptures

    PubMed Central

    ElMaraghy, Amr; Tsoi, K.

    2008-01-01

    Complete distal biceps tendon ruptures require prompt surgical management for optimal functional and aesthetic outcome. The need exists for a valid and reliable diagnostic tool to expedite surgical referral. We hypothesized complete distal biceps tendon ruptures result in an objectively measurable anatomic landmark (the distance between the antecubital crease of the elbow and the cusp of distal descent of the biceps muscle, or the biceps crease interval), as a result of proximal retraction of the musculotendinous complex. We established normal biceps crease interval values and biceps crease ratios between dominant and nondominant arms in 80 men with no history of biceps injury (average age, 43 years). The mean (± standard deviation) biceps crease interval for dominant and nondominant arms was 4.8 ± 0.6 cm. The mean biceps crease ratio was 1.0 ± 0.1. We measured the biceps crease interval and biceps crease ratio on 29 consecutive patients presenting with a possible complete distal biceps tendon rupture. Using a diagnostic threshold of a biceps crease interval greater than 6.0 cm or biceps crease ratio greater than 1.2, the biceps crease interval test had a sensitivity of 96% and a diagnostic accuracy of 93% for identifying complete distal biceps tendon ruptures, making it a valid and reliable tool for clinicians to identify cases requiring urgent surgical referral. Level of Evidence: Level II, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence. PMID:18551349

  18. [Preferential distal muscle involvement in case of oculopharyngeal muscular dystrophy with (GCG) 13 expansion].

    PubMed

    Nakashima, Dainari; Nakajima, Hideto; Ishida, Shimon; Sugino, Masakazu; Kimura, Fumiharu; Hanafusa, Toshiaki

    2003-09-01

    We reported a 52-year-old woman with oculopharyngeal muscular dystrophy (OPMD) harboring expanded (GCG) 13 mutation of the poly (A) binding protein 2 gene. She presented not only ptosis and dysphagia but distal dominant muscle atrophy in four extremities. CT demonstrated distal muscle atrophy with marked fat replacement in the biceps femoris, semitendinosus, membraneous, soleus, and gastrocnemius muscles. Although OPMD is considered to be a muscle disease, this patient showed even neurogenic features in the electrophysiological and pathological findings. Although previous reports indicate that OPMD is genetically homogeneous disease, some cases with OPMD may show some atypical features associated with neurogenic involvement. PMID:14727564

  19. COMPARATIVE ANALYSIS ON MUSCLE STRENGTH AMONG PATIENTS WHO UNDERWENT ARTHROSCOPIC TENOTOMY OF THE LONG HEAD OF THE BICEPS IN RELATION TO ESTHETIC DEFORMITY

    PubMed Central

    Almeida, Alexandre; Valin, Márcio Rangel; de Almeida, Nayvaldo Couto; Roveda, Gilberto; Agostini, Ana Paula

    2015-01-01

    Objective: To determine whether there was any discrepancy in elbow flexion strength among patients with and without evident clinical deformity resulting from arthroscopic tenotomy on the long head of the biceps. Method: A group of 120 patients who underwent this procedure were evaluated. After applying the exclusion criteria, 89 patients remained in the analysis. Eighteen months after the operation (median), the elbow flexion strength was measured in newtons using a digital dynamometer. Three consecutive measurements were made and the average was used. The dominant and non-dominant sides were compared. Sex, age and mean elbow flexion strength in the operated and contralateral arms of patients with and without apparent clinical deformity were evaluated. Results: The median elbow flexion strength among the patients with evident clinical deformity was 17.78 N for the dominant arm and 20.87 N for the non-dominant arm. The difference was 2.51 N. In the group without evident clinical deformity, the difference was 2.14 N. The median muscle strength in the operated arm was 17.26 N, while the median was 20.06 N in the non-operated arm, thus suggesting that there was a significant loss of muscle strength (p = 0.005). The difference in muscle strength loss between the patients with and without evident deformity was not considered statistically significant (p = 0.977). Conclusion: The patients who underwent arthroscopic tenotomy on the long head of the biceps with or without apparent clinical deformity from distal migration presented similar elbow flexion muscle strength. PMID:27047871

  20. Electromyographic analysis of lower limb muscles during the golf swing performed with three different clubs.

    PubMed

    Marta, Sérgio; Silva, Luís; Vaz, João Rocha; Castro, Maria António; Reinaldo, Gustavo; Pezarat-Correia, Pedro

    2016-01-01

    The aim of this study was to describe and compare the EMG patterns of select lower limb muscles throughout the golf swing, performed with three different clubs, in non-elite middle-aged players. Fourteen golfers performed eight swings each using, in random order, a pitching wedge, 7-iron and 4-iron. Surface electromyography (EMG) was recorded bilaterally from lower limb muscles: tibialis anterior, peroneus longus, gastrocnemius medialis, gastrocnemius lateralis, biceps femoris, semitendinosus, gluteus maximus, vastus medialis, rectus femoris and vastus lateralis. Three-dimensional high-speed video analysis was used to determine the golf swing phases. Results showed that, in average handicap golfers, the highest muscle activation levels occurred during the Forward Swing Phase, with the right semitendinosus and the right biceps femoris muscles producing the highest mean activation levels relative to maximal electromyography (70-76% and 68-73% EMG(MAX), respectively). Significant differences between the pitching wedge and the 4-iron club were found in the activation level of the left semitendinosus, right tibialis anterior, right peroneus longus, right vastus medialis, right rectus femuris and right gastrocnemius muscles. The lower limb muscles showed, in most cases and phases, higher mean values of activation on electromyography when golfers performed shots with a 4-iron club. PMID:26197882

  1. Expression profiles of myostatin, myogenin, and Myosin heavy chain in skeletal muscles of two rabbit breeds differing in growth rate.

    PubMed

    Kuang, Liangde; Xie, Xiaohong; Zhang, Xiangyu; Lei, Min; Li, Congyan; Ren, Yongjun; Zheng, Jie; Guo, Zhiqiang; Zhang, Cuixia; Yang, Chao; Zheng, Yucai

    2014-01-01

    The purpose of the present study was to compare mRNA levels of myostatin (MSTN), myogenin (MyoG), and fiber type compositions in terms of myosin heavy chain (MyHC) in skeletal muscles of two rabbit breeds with different body sizes and growth rates. Longissimus dorsi and biceps femoris muscles of 16 Californian rabbits (CW) and 16 Germany great line of ZIKA rabbits (GZ) were collected at the ages of 35d and 84d (slaughter age). The results showed that the live weights of GZ rabbits of 35d and 84d old were approximately 36% and 26% greater than those of CW rabbits, respectively. Quantitative real-time PCR analysis revealed that at the age of 84d GZ rabbits contained significantly lower MSTN mRNA level and higher MyoG mRNA level in both longissimus dorsi and biceps femoris muscles than CW rabbits, and mRNA levels of MSTN and MyoG exhibited opposite changes from the age of 35d to 84d, suggesting that GZ rabbits were subjected to less growth inhibition from MSTN at slaughter age, which occurred most possibly in skeletal muscles. Four types of fiber were identified by real-time PCR in rabbit muscles, with MyHC-1 and MyHC-2D, MyHC-2B were the major types in biceps femoris and longissimus dorsi muscles, respectively. At the age of 84d, GZ rabbits contained greater proportion of MyHC-1 and decreased proportion of MyHC-2D and decreased lactate dehydrogenase activity in biceps femoris than CW rabbits, and the results were exactly opposite in longissimus dorsi, suggesting that GZ rabbits show higher oxidative capacity in biceps femoris muscle than CW rabbits. In conclusion, the trends of mRNA levels of MSTN and fiber types in GZ rabbits' skeletal muscles might be consistent with the putative fast growth characteristic of GZ rabbits compared to CW rabbits. PMID:24813217

  2. Biceps tendinopathy

    PubMed Central

    Ibáñez, Maximiliano; Calvo, Ana Belén; Alvarez, Victoria; Lepore, Salvador; Ibáñez, Federico; Reybet, Juan Andrés

    2015-01-01

    Introduction: Tenodesis is the preferred technique in the treatment of the long head of the biceps tendon pathology in younger people, athletes, workers, and those wishing to avoid any cosmetic deformity. The aim of our study was to compare a group of patients who underwent all arthroscopic biceps tenodesis with a group of patients who underwent an open subpectoral procedure. A clinical assessment was performed and we also registered the occurrence of complications. Materials and Methods: We retrospectively reviewed 90 patients with lesions in the long head of the biceps tendon treated at our institution between January 2009 and January 2012. Group A underwent an arthroscopic technique while Group B was treated in an open fashion. Clinical assessment included appropriate scores (ASES, Rowe, Simple Shoulder Test, Constant Murley), and we also evaluated pain with Visual Analogue Scale (VAS), and personal satisfaction in terms of aesthetics and local pain at the scar. Results: Group A: Rowe 86 points, ASES 81 points, SST 9 points, Constant and Murley 87 points. VAS 2/10. Regarding scars of the portals patients were satisfied. Group B: Rowe 85 points, ASES 82 points, SST 8.5 points, Constant and Murley 85 points. VAS 3/10 (greater at the site of subpectoral approach). Aesthetic concerns about the scar was observed in 4 cases (4 women). Arm deformity (sign of Popeye) was not observed at the latest follow-up. Discussion: No statistical significant differences were found in clinical assessment between both procedures. Arthroscopic tenodesis is technically more challenging and requires an initial longer learning curve in order to perform a successful procedure. Open subpectoral tenodesis despite being a faster and simpler procedure reports discomfort regarding the scar site.

  3. Intramuscular Ganglion of the Quadriceps Femoris

    PubMed Central

    Kim, Yeung Jin; Chae, Soo Uk; Kim, Jong Yun; Jo, Hyang Jeong

    2013-01-01

    Ganglion cysts are common lesions that are most often found around the joints of the hands and feet. Ganglia around the distal femur usually occur within the synovial membrane or tendon sheath, but rarely within muscles. Several cases of intramuscular ganglions in the hand and wrist have been reported, but a ganglion cyst in the quadriceps muscle has rarely been addressed in studies. In this report, we present a 17-year-old patient with a painful movable mass in the intramuscular area of the quadriceps femoris that was diagnosed by ultrasound and treated by excision and biopsy. PMID:23508475

  4. An analysis on muscle tone of lower limb muscles on flexible flat foot

    PubMed Central

    Um, Gi-Mai; Wang, Joong-San; Park, Si-Eun

    2015-01-01

    [Purpose] The aim of this study was to examine differences in the muscle tone and stiffness of leg muscles according to types of flexible flat foot. [Subjects and Methods] For 30 subjects 10 in a normal foot group (NFG), 10 in group with both flexible flat feet (BFFG), and 10 in a group with flexible flat feet on one side (OFFG), myotonometry was used to measure the muscle tone and stiffness of the tibialis anterior muscle (TA), the rectus femoris muscle (RF), the medial gastrocnemius (MG), and the long head of the biceps femoris muscle (BF) of both lower extremities. [Results] In the measurement results, only the stiffness of TA and MG of the NFG and the BFFG showed significant differences. The muscle tone and stiffness were highest in the BFFG, followed by the OFFG and NFG, although the difference was insignificant. In the case of the OFFG, there was no significant difference in muscle tone and stiffness compared to that in the NGF and the BFFG. Furthermore, in the NFG, the non-dominant leg showed greater muscle tone and stiffness than the dominant leg, although the difference was insignificant. [Conclusion] During the relax condition, the flexible flat foot generally showed a greater muscle tone and stiffness of both lower extremities compared to the normal foot. The stiffness was particularly higher in the TA and MG muscles. Therefore, the muscle tone and stiffness of the lower extremity muscles must be considered in the treatment of flat foot. PMID:26644650

  5. BICEP's acceleration

    SciTech Connect

    Contaldi, Carlo R.

    2014-10-01

    The recent Bicep2 [1] detection of, what is claimed to be primordial B-modes, opens up the possibility of constraining not only the energy scale of inflation but also the detailed acceleration history that occurred during inflation. In turn this can be used to determine the shape of the inflaton potential V(φ) for the first time — if a single, scalar inflaton is assumed to be driving the acceleration. We carry out a Monte Carlo exploration of inflationary trajectories given the current data. Using this method we obtain a posterior distribution of possible acceleration profiles ε(N) as a function of e-fold N and derived posterior distributions of the primordial power spectrum P(k) and potential V(φ). We find that the Bicep2 result, in combination with Planck measurements of total intensity Cosmic Microwave Background (CMB) anisotropies, induces a significant feature in the scalar primordial spectrum at scales k∼ 10{sup -3} Mpc {sup -1}. This is in agreement with a previous detection of a suppression in the scalar power [2].

  6. Effects of combined exercise on changes of lower extremity muscle activation during walking in older women.

    PubMed

    Park, Jaehyun; Lee, Joongsook; Yang, Jeongok; Lee, Bomjin; Han, Dongwook

    2015-05-01

    [Purpose] The purpose of this study was to demonstrate the effects of combined exercise for a period of 12 weeks on the changes in lower extremity muscle activation during walking in older women. [Subjects] The subjects of this study were 22 elderly women who were 65 years of age or older and living in B-City. The subjects had no nervous system or muscular system diseases that might affect walking in the previous two years. [Methods] Muscle activation was measured by using surface EMG (QEMG-8, Laxtha, Daejeon, Republic of Korea). The subjects were asked to walk on an 8 m of footpath at a natural speed. In order to minimize the noise from the cable connecting the EMG measuring instrument to the electrodes, tape was used to affix the electrodes so that they would not fall off the subjects. The EMG data were analyzed by using the RMS. [Results] Muscle activation of the rectus femoris, biceps femoris, tibialis anterior, and gastrocnemius was increased significantly after combined exercise for 12 weeks. However, no increase was observed in the left biceps femoris. [Conclusion] It was demonstrated that our exercise program, which includes aerobic walking exercises, senior-robics, and muscle strengthening exercises using elastic bands, is very effective for reorganizing the normal gait pattern in the cerebral cortex and improving muscle strength. PMID:26157253

  7. Muscle force distribution during forward and backward locomotion.

    PubMed

    Błażkiewicz, Michalina

    2013-01-01

    Backward walking (BW) is a common technique employed in the treatment of a variety of orthopedic and neurological diseases. BW training may offer some benefits especially in balance and motor control ability beyond those experienced through forward walking (FW). The purpose of this study was to determine whether BW represented a simple reversal of FW and, hence muscle force distribution is the same. The study involved one male healthy student of physical education (22 years, h = 185 cm, m = 80 kg). Measurements of spatial-temporal gait parameters were conducted using eight Vicon system cameras, and Kistler plates. Noraxon EMG was used to obtain muscles activity. OpenSim software was used to compute muscle force distribution during both types of gait. During FW and BW there is small difference for force curves produced by m. gluteus maximus (RMS = 0.04), m. biceps femoris short head (RMS = 0.19) and m. tibialis anterior (RMS = 0.16). Good validation by EMG signal was obtained for m. rectus femoris, m. biceps femoris short head, m. tibialis posterior during FW and BW. For m. iliacus, only during BW good validation was achived. PMID:24215105

  8. Structure of skeletal muscles in leghorn type chicken from conservative and parent flocks.

    PubMed

    Elminowska-Wenda, Gabriela

    2007-01-01

    Intensive selection conducted within closed populations has led to the creation of specialized chicken strains that differ significantly in meat yield and reproduction performance. The effect of the selection conducted on the birds is differentiation identified not only on the molecular but also on the cellular level, among other things in the skeletal muscles. The aim of this study was to compare the structure of chosen homological skeletal muscles from Leghorn chickens (LSL), originating from parent flock, intensively selected for reproductive traits and from conservative flock (G99), unselected for many generations. The structure of musculus pectoralis superficialis and musculus biceps femoris (the thickness of the muscle fibres and the share of the fibre types in the bundle) in 8 and 20 week old chickens was compared. A significant impact of the origin on all examined slaughter parameters was recorded. Body weight before slaughter, carcass weight and the weight of breast and leg muscles in 8 weeks old LSL chicken made up from 60% to about 85% of the respective values in the G99 Leghorn. Lack of red fibres in the breast muscles of all the individuals from the parental flock (LSL) was noted, whereas in 12 individuals (among 24) from the conservative flock (G99), red fibres were observed in this muscle from 2.75% up to 7.09%. White fibres in 8 week old chicks were always thicker, both in pectoralis superficialis and biceps femoris muscle in birds with higher body weight as well as higher weight of breast and legs muscles, i.e. in chicks from conservative flock (G99), P<0.01. However, in 20 week old birds, the diameters of the white fibres were similar in both groups. Also the diameters of the red fibres in musculus biceps femoris in 8 week old chickens were higher in cockerels and pullets from conservative flock (G99). PMID:18274259

  9. Loop biceps tenotomy: an arthroscopic technique for long head of biceps tenotomy.

    PubMed

    Goubier, Jean-Noel; Bihel, Thomas; Dubois, Elodie; Teboul, Frédéric

    2014-08-01

    The long head of the biceps tendon is frequently involved in shoulder pathologies, often in relation to inflammatory or degenerative damage to the rotator cuff. Biceps tenodesis in the bicipital groove and tenotomy are the main treatment options. Tenotomy of the long head of the biceps tendon is a simpler and quicker procedure than tenodesis, and it does not require the use of implants. However, retraction of the biceps tendon, leading to Popeye deformity, and biceps muscle cramps are common complications after tenotomy. Therefore we propose an arthroscopic technique for tenotomy that limits the risk of Popeye deformity. This procedure consists of creating a loop at the severed end of the biceps tendon, which prevents the tendon from retracting into the bicipital groove. PMID:25264503

  10. Myositis Ossificans of Rectus Femoris: A Rare Case Report

    PubMed Central

    Srikanth, I Muni; Vishal, Amar; Kiran, K Ravi

    2015-01-01

    Introduction: Myositis ossificans (MO), heterotopic ossification, occurs in muscles and soft tissue. This lesion contains actively proliferating fibroblasts and osteoblasts. It commonly affects vigorous young men and more so among athletes. It occurs as a result of trauma, either acute or chronic and can also arise near joints in neurological disorders. By time of presentation, ossification is extensive and the benign nature of the lesion is usually evident on radiological studies. Most common muscles involved in MO are the flexor muscles of the arm, the hamstrings and quadriceps femoris. Case Report: We present a case of MO with isolated involvement of rectus femoris in mid-thigh and sparing of other three muscles of quadriceps femoris, with no improvement following physiotherapy and medical management requiring surgical excision for better prognosis with no recurrence. Conclusion: MO, a benign lesion, is known to affect the flexors of the arm, the hamstrings, and quadriceps femoris; it must be noted that even individual muscle can also be affected as shown in the above case presentation without involving whole group of muscles. Surgical excision is indicated if non-operative measures are not successful. PMID:27299083

  11. Use of B-mode ultrasonography for measuring femoral muscle thickness in dogs.

    PubMed

    Sakaeda, Kanako; Shimizu, Miki

    2016-06-01

    Assessment of muscle mass is important for evaluating muscle function and rehabilitation outcomes. Ultrasound has recently been successfully used to estimate muscle mass in humans by measuring muscle thickness. This study attempted to standardize procedures for measuring femoral muscle thickness ultrasonographically, as well as quantify the reliability and validity of ultrasound evaluations of muscle thickness compared to measurements made by magnetic resonance imaging (MRI) in dogs. We evaluated the quadriceps femoris (QF), biceps femoris (BF), semitendinosus (ST) and semimembranosus (SM) muscles of 10 clinically healthy Beagle dogs. Scans were taken in 5 different sections divided equally between the greater trochanter and proximal patella. MRI was performed, followed by T1-weighted and contrast-enhanced T1-weighted imaging. Muscle cross-sectional area (CSA) was measured with MRI, and muscle thickness was measured with MRI and ultrasonography. The thickness of the QF, BF and ST muscles as measured by ultrasound at slices 1-3 (from the proximal end to the middle of the femur), 2-4 (middle of the femur) and 2 (more proximal than the middle of the femur), respectively, was correlated with muscle thickness and CSA as measured by MRI. These sites showed a flat interface between muscle and transducer and were situated over belly muscle. No correlation between measurement types was seen in SM muscle. We must confirm this assessment method for various breeds, sizes, ages and muscle pathologies in dogs, thereby confirming that muscle thickness as measured ultrasonographically can reflect muscle function. PMID:26832997

  12. Use of B-mode ultrasonography for measuring femoral muscle thickness in dogs

    PubMed Central

    SAKAEDA, Kanako; SHIMIZU, Miki

    2016-01-01

    Assessment of muscle mass is important for evaluating muscle function and rehabilitation outcomes. Ultrasound has recently been successfully used to estimate muscle mass in humans by measuring muscle thickness. This study attempted to standardize procedures for measuring femoral muscle thickness ultrasonographically, as well as quantify the reliability and validity of ultrasound evaluations of muscle thickness compared to measurements made by magnetic resonance imaging (MRI) in dogs. We evaluated the quadriceps femoris (QF), biceps femoris (BF), semitendinosus (ST) and semimembranosus (SM) muscles of 10 clinically healthy Beagle dogs. Scans were taken in 5 different sections divided equally between the greater trochanter and proximal patella. MRI was performed, followed by T1-weighted and contrast-enhanced T1-weighted imaging. Muscle cross-sectional area (CSA) was measured with MRI, and muscle thickness was measured with MRI and ultrasonography. The thickness of the QF, BF and ST muscles as measured by ultrasound at slices 1–3 (from the proximal end to the middle of the femur), 2–4 (middle of the femur) and 2 (more proximal than the middle of the femur), respectively, was correlated with muscle thickness and CSA as measured by MRI. These sites showed a flat interface between muscle and transducer and were situated over belly muscle. No correlation between measurement types was seen in SM muscle. We must confirm this assessment method for various breeds, sizes, ages and muscle pathologies in dogs, thereby confirming that muscle thickness as measured ultrasonographically can reflect muscle function. PMID:26832997

  13. MRI in DNM2-related centronuclear myopathy: evidence for highly selective muscle involvement.

    PubMed

    Schessl, Joachim; Medne, Livija; Hu, Ying; Zou, Yaqun; Brown, Mark J; Huse, Jason T; Torigian, Drew A; Jungbluth, Heinz; Goebel, Hans-Hilmar; Bönnemann, Carsten G

    2007-01-01

    Dynamin 2 has recently been recognized as a causative gene for the autosomal dominant form of centronuclear myopathy (dominant centronuclear myopathy). Here we report an affected father and daughter with dynamin 2 related AD CNM with predominantly distal onset of weakness. In addition to the diagnostic central location of myonuclei the muscle biopsy also showed core-like structures. Muscle MRI in the lower leg revealed prominent involvement of the soleus, but also of the gastrocnemius and the tibialis anterior whereas in the thigh there was a consistent pattern of selective involvement of adductor longus, semimembranosus, biceps femoris, rectus femoris, and vastus intermedius with relative sparing of vastus lateralis and medialis, sartorius, gracilis, and partly of the semitendinosus. These characteristic findings on muscle MRI confirm similar findings reported for CT imaging in dynamin 2 related dominant centronuclear myopathy and may help to differentiate this disorder from central core disease and other myopathies. PMID:17134899

  14. Strength and muscle activities during the toe-gripping action: comparison of ankle angle in the horizontal plane between the sitting upright and standing positions

    PubMed Central

    Soma, Masayuki; Murata, Shin; Kai, Yoshihiro; Nakae, Hideyuki; Satou, Yousuke

    2016-01-01

    [Purpose] The aim of this study was to investigate whether toe grip strength and muscle activities are affected by the ankle angle in the horizontal plane in the sitting upright and standing positions. [Subjects] The subjects were 16 healthy young women. [Methods] We measured toe grip strength and the maximum voluntary contraction activities of the rectus femoris, biceps femoris, anterior tibialis, and medial head of the gastrocnemius. In addition, we calculated the percent integrated electromyography during foot gripping in 3 different ankle joint positions between the long axis of the foot and the line of progression on the horizontal plane, namely 10° of internal rotation, 0°, and 10° of external rotation. [Results] Two-way analysis of variance revealed significant differences. A significant main effect was observed in the measurement conditions for the percent integrated electromyography of the rectus femoris muscle and long head of the biceps femoris. However, two-way analysis of variance did not reveal any significant difference, and a significant main effect was not observed in toe grip strength. [Conclusion] These findings suggest that exerted toe grip strength is only slightly affected by the ankle angle in the horizontal plane in the sitting upright and standing positions. Therefore, the current measurement positions were shown to be optimal for measurement. PMID:27134399

  15. The effect of temperature on apoptosis and adipogenesis on skeletal muscle satellite cells derived from different muscle types

    PubMed Central

    Harding, Rachel L; Clark, Daniel L; Halevy, Orna; Coy, Cynthia S; Yahav, Shlomo; Velleman, Sandra G

    2015-01-01

    Satellite cells are multipotential stem cells that mediate postnatal muscle growth and respond differently to temperature based upon aerobic versus anaerobic fiber-type origin. The objective of this study was to determine how temperatures below and above the control, 38°C, affect the fate of satellite cells isolated from the anaerobic pectoralis major (p. major) or mixed fiber biceps femoris (b. femoris). At all sampling times, p. major and b. femoris cells accumulated less lipid when incubated at low temperatures and more lipid at elevated temperatures compared to the control. Satellite cells isolated from the p. major were more sensitive to temperature as they accumulated more lipid at elevated temperatures compared to b. femoris cells. Expression of adipogenic genes, CCAAT/enhancer-binding protein β (C/EBPβ) and proliferator-activated receptor gamma (PPARγ) were different within satellite cells isolated from the p. major or b. femoris. At 72 h of proliferation, C/EBPβ expression increased with increasing temperature in both cell types, while PPARγ expression decreased with increasing temperature in p. major satellite cells. At 48 h of differentiation, both C/EBPβ and PPARγ expression increased in the p. major and decreased in the b. femoris, with increasing temperature. Flow cytometry measured apoptotic markers for early apoptosis (Annexin-V-PE) or late apoptosis (7-AAD), showing less than 1% of apoptotic satellite cells throughout all experimental conditions, therefore, apoptosis was considered biologically not significant. The results support that anaerobic p. major satellite cells are more predisposed to adipogenic conversion than aerobic b. femoris cells when thermally challenged. PMID:26341996

  16. Immediate effects of kinematic taping on lower extremity muscle tone and stiffness in flexible flat feet

    PubMed Central

    Wang, Joong-San; Um, Gi-Mai; Choi, Jung-Hyun

    2016-01-01

    [Purpose] This study aimed to examine the immediate effects of kinematic taping on the tone and stiffness in the leg muscles of subjects with flexible flat feet. [Subjects and Methods] A total of 30 subjects, 15 in the kinematic taping and 15 in the sham taping group, were administered respective taping interventions. Subsequently, the foot pressure and the tone and stiffness in the tibialis anterior, rectus femoris, medial gastrocnemius, and the long head of the biceps femoris muscles of both the lower extremities were measured. [Results] The foot pressure of the dominant leg significantly decreased in the kinematic taping group. The muscle tone and stiffness in the rectus femoris muscle of the dominant and non-dominant leg, tibialis anterior muscle of the dominant leg, medial gastrocnemius muscle of the non-dominant leg, and the stiffness in the dominant leg significantly decreased. The muscle tone and stiffness generally increased in the sham taping group. However, no significant difference was observed between the 2 groups. [Conclusion] This study demonstrated that kinematic taping on flexible flat feet had positive effects of immediately reducing the abnormally increased foot pressure and the tone and stiffness in the lower extremity muscles. PMID:27190479

  17. Imaging of rectus femoris proximal tendinopathies.

    PubMed

    Pesquer, Lionel; Poussange, Nicolas; Sonnery-Cottet, Bertrand; Graveleau, Nicolas; Meyer, Philippe; Dallaudiere, Benjamin; Feldis, Matthieu

    2016-07-01

    The rectus femoris is the most commonly injured muscle of the anterior thigh among athletes, especially soccer players. Although the injury pattern of the muscle belly is well documented, less is known about the anatomy and specific lesions of the proximal tendons. For each head, three distinctive patterns may be encountered according to the location of the injury, which can be at the enthesis, within the tendon, or at the musculotendinous junction. In children, injuries correspond most commonly to avulsion of the anteroinferior iliac spine from the direct head and can lead to subspine impingement. Calcific tendinitis and traumatic tears may be encountered in adults. Recent studies have shown that traumatic injuries of the indirect head may be underdiagnosed and that injuries of both heads may have a surgical issue. Finally, in the case of tears, functional outcome and treatment may vary if the rupture involves one or both tendons and if the tear is partial or complete. Thus, it is mandatory for the radiologist to know the different ultrasound and magnetic resonance imaging (MRI) patterns of these lesions in order to provide accurate diagnosis and treatment. The purpose of this article is to recall the anatomy of the two heads of rectus femoris, describe a reliable method of assessment with ultrasound and MRI and know the main injury patterns, through our own experience and literature review. PMID:26956398

  18. Muscle and intensity based hamstring exercise classification in elite female track and field athletes: implications for exercise selection during rehabilitation

    PubMed Central

    Tsaklis, Panagiotis; Malliaropoulos, Nikos; Mendiguchia, Jurdan; Korakakis, Vasileios; Tsapralis, Kyriakos; Pyne, Debasish; Malliaras, Peter

    2015-01-01

    Background Hamstring injuries are common in many sports, including track and field. Strains occur in different parts of the hamstring muscle but very little is known about whether common hamstring loading exercises specifically load different hamstring components. The purpose of this study was to investigate muscle activation of different components of the hamstring muscle during common hamstring loading exercises. Methods Twenty elite female track and field athletes were recruited into this study, which had a single-sample, repeated-measures design. Each athlete performed ten hamstring loading exercises, and an electromyogram (EMG) was recorded from the biceps femoris and semitendinosus components of the hamstring. Hamstring EMG during maximal voluntary isometric contraction (MVIC) was used to normalize the mean data across ten repetitions of each exercise. An electrogoniometer synchronized to the EMG was used to determine whether peak EMG activity occurred during muscle-tendon unit lengthening, shortening, or no change in length. Mean EMG values were compared between the two recording sites for each exercise using the Student’s t-test. Results The lunge, dead lift, and kettle swings were low intensity (<50% MVIC) and all showed higher EMG activity for semitendinosus than for biceps femoris. Bridge was low but approaching medium intensity, and the TRX, hamstring bridge, and hamstring curl were all medium intensity exercises (≥50% or <80% MVIC). The Nordic, fitball, and slide leg exercises were all high intensity exercises. Only the fitball exercise showed higher EMG activity in the biceps femoris compared with the semitendinosus. Only lunge and kettle swings showed peak EMG in the muscle-tendon unit lengthening phase and both these exercises involved faster speed. Conclusion Some exercises selectively activated the lateral and medial distal hamstrings. Low, medium, and high intensity exercises were demonstrated. This information enables the clinician, strength

  19. Muscle activation patterns in the Nordic hamstring exercise: Impact of prior strain injury.

    PubMed

    Bourne, M N; Opar, D A; Williams, M D; Al Najjar, A; Shield, A J

    2016-06-01

    This study aimed to determine: (a) the spatial patterns of hamstring activation during the Nordic hamstring exercise (NHE); (b) whether previously injured hamstrings display activation deficits during the NHE; and (c) whether previously injured hamstrings exhibit altered cross-sectional area (CSA). Ten healthy, recreationally active men with a history of unilateral hamstring strain injury underwent functional magnetic resonance imaging of their thighs before and after six sets of 10 repetitions of the NHE. Transverse (T2) relaxation times of all hamstring muscles [biceps femoris long head (BFlh); biceps femoris short head (BFsh); semitendinosus (ST); semimembranosus (SM)] were measured at rest and immediately after the NHE and CSA was measured at rest. For the uninjured limb, the ST's percentage increase in T2 with exercise was 16.8%, 15.8%, and 20.2% greater than the increases exhibited by the BFlh, BFsh, and SM, respectively (P < 0.002 for all). Previously injured hamstring muscles (n = 10) displayed significantly smaller increases in T2 post-exercise than the homonymous muscles in the uninjured contralateral limb (mean difference -7.2%, P = 0.001). No muscles displayed significant between-limb differences in CSA. During the NHE, the ST is preferentially activated and previously injured hamstring muscles display chronic activation deficits compared with uninjured contralateral muscles. PMID:26059634

  20. Physical, chemical, histological and palatability characteristics of muscles from three breed-types of cattle at different times-on-feed.

    PubMed

    McKeith, F K; Savell, J W; Smith, G C; Dutson, T R; Carpenter, Z L

    1985-01-01

    Forty-five steers (9-12 months of age) of Angus (n =15), Brahman (n = 15) and Brahman × Angus (n = 15) breed-types were fed a high-energy diet and then slaughtered after 0, 112 or 224 days of feeding. At 7 days post mortem, the M. longissimus and M. biceps femoris were removed from the left side of each carcass and steaks were obtained for determination of sensory panel ratings, Warner-Bratzler shear force, sarcomere length, collagen content and collagen solubility. Tenderness ratings of steaks from the M. longissimus and M. biceps femoris from Angus were generally higher than ratings for steaks from Brahman or Brahman × Angus steers. Steaks from Brahman × Angus received higher tenderness ratings than steaks from Brahman steers in only a few comparisons. The three breed-types of cattle responded to time-on-feed differently; Brahman cattle needed to have been fed longer than Angus cattle to produce equally tender beef. With increased time-on-feed, M. longissimus tenderness increased for all breed-types, but M. biceps femoris tenderness was not related to time-on-feed. Few significant differences were observed among breed-types and among time-on-feed periods for collagen content or collagen solubility. Tenderness differences were closely correlated with the contractile state of the muscle which, in turn, was associated with weight, subcutaneous fat thickness and temperature decline of the carcass. PMID:22056075

  1. Tenoscopic Suprapectoral Biceps Tenodesis.

    PubMed

    Maier, Dirk; Izadpanah, Kaywan; Jaeger, Martin; Ogon, Peter; Südkamp, Norbert P

    2016-02-01

    Existing arthroscopic techniques of proximal biceps tenodesis may be complicated by difficulty of tendon identification, restoration of length-tension relation, cosmetic deformity, persistent biceps pain, and shoulder stiffness requiring surgical revision in a relevant proportion of cases. In this context, biceps tenoscopy, an emerging discipline of shoulder endoscopy, offers major benefits. Tenoscopy comprises endoscopic treatment of tendons and tendon sheaths. The presented technique of tenoscopic suprapectoral biceps tenodesis (TSBT) substantially facilitates tendon identification and reduces invasiveness by avoidance of unnecessary surgical involvement of the deltoid space and bursa. TSBT enables effective treatment of the biceps tendon and surrounding tissues (biceps tendon sheath, tenosynovium, transverse humeral ligament) being consistently involved in proximal biceps pathologies. The physiological length-tension relation of the musculotendinous unit is reliably maintained. Technically, the procedure of tenodesis is simplified and accelerated by redundancy of tendon exteriorization. The aforementioned benefits of TSBT may lead to superior clinical and cosmetic outcomes and lower incidences of persistent proximal biceps pain and postoperative shoulder stiffness compared with conventional techniques of arthroscopic biceps tenodesis. PMID:27073777

  2. Tenoscopic Suprapectoral Biceps Tenodesis

    PubMed Central

    Maier, Dirk; Izadpanah, Kaywan; Jaeger, Martin; Ogon, Peter; Südkamp, Norbert P.

    2016-01-01

    Existing arthroscopic techniques of proximal biceps tenodesis may be complicated by difficulty of tendon identification, restoration of length-tension relation, cosmetic deformity, persistent biceps pain, and shoulder stiffness requiring surgical revision in a relevant proportion of cases. In this context, biceps tenoscopy, an emerging discipline of shoulder endoscopy, offers major benefits. Tenoscopy comprises endoscopic treatment of tendons and tendon sheaths. The presented technique of tenoscopic suprapectoral biceps tenodesis (TSBT) substantially facilitates tendon identification and reduces invasiveness by avoidance of unnecessary surgical involvement of the deltoid space and bursa. TSBT enables effective treatment of the biceps tendon and surrounding tissues (biceps tendon sheath, tenosynovium, transverse humeral ligament) being consistently involved in proximal biceps pathologies. The physiological length-tension relation of the musculotendinous unit is reliably maintained. Technically, the procedure of tenodesis is simplified and accelerated by redundancy of tendon exteriorization. The aforementioned benefits of TSBT may lead to superior clinical and cosmetic outcomes and lower incidences of persistent proximal biceps pain and postoperative shoulder stiffness compared with conventional techniques of arthroscopic biceps tenodesis. PMID:27073777

  3. Muscle-specific modulation of vestibular reflexes with increased locomotor velocity and cadence.

    PubMed

    Dakin, Christopher J; Inglis, John Timothy; Chua, Romeo; Blouin, Jean-Sébastien

    2013-07-01

    Vestibular information is one of the many sensory signals used to stabilize the body during locomotion. When locomotor velocity increases, the influence of these signals appears to wane. It is unclear whether vestibular signals are globally attenuated with velocity or are influenced by factors such as whether a muscle is contributing to balance control. Here we investigate how vestibular sensory signals influence muscles of the leg during locomotion and what causes their attenuation with increasing locomotor velocity. We hypothesized that 1) vestibular signals influence the activity of all muscles engaged in the maintenance of medio-lateral stability during locomotion and 2) increases in both cadence and velocity would be associated with attenuation of these signals. We used a stochastic vestibular stimulus and recorded electromyographic signals from muscles of the ankle, knee, and hip. Participants walked using two cadences (52 and 78 steps/min) and two walking velocities (0.4 and 0.8 m/s). We observed phase-dependent modulation of vestibular influence over ongoing muscle activity in all recorded muscles. Within a stride, reversals of the muscle responses were observed in the biceps femoris, tibialis anterior, and rectus femoris. Vestibular-muscle coupling decreases with increases in both cadence and walking velocity. These results show that the observed vestibular suppression is muscle- and phase dependent. We suggest that the phase- and muscle-specific influence of vestibular signals on locomotor activity is organized according to each muscle's functional role in body stabilization during locomotion. PMID:23576695

  4. [Morphohistochemical study of skeletal muscles in rats after experimental flight on "Kosmos-1887"].

    PubMed

    Il'ina-Kakueva, E I

    1990-01-01

    Morphometric and histochemical methods were used to examine the soleus, gastrocnemius (medial portion), quadriceps femoris (central portion) and biceps brachii muscles of Wistar SPF rats two days after the 13-day flight on Cosmos-1887. It was found that significant atrophy developed only in the soleus muscle. The space flight did not change the percentage content of slow (type I) and fast (type II) fibers in fast twitch muscles. During two days at 1 g the slow soleus muscle developed substantial circulation disorders, which led to interstitial edema and necrotic changes. The gastrocnemius muscle showed small foci containing necrotic myofibers. Two days after recovery no glycogen aggregates were seen in myofibers, which were previously observed in other rats examined 4--8 hours after flight. An initial stage of muscle readaptation to 1 g occurred, when NAD.H2-dehydrogenase activity was decreased. PMID:2145470

  5. Lower muscle co-contraction in flutter kicking for competitive swimmers.

    PubMed

    Matsuda, Yuji; Hirano, Masami; Yamada, Yosuke; Ikuta, Yasushi; Nomura, Teruo; Tanaka, Hiroaki; Oda, Shingo

    2016-02-01

    The purpose of this study was to examine the difference in muscle activation pattern and co-contraction of the rectus and biceps femoris in flutter-kick swimming between competitive and recreational swimmers, to better understand the mechanism of repetitive kicking movements during swimming. Ten competitive and 10 recreational swimmers swam using flutter kicks at three different velocities (100%, 90%, and 80% of their maximal velocity) in a swimming flume. Surface electromyographic signals (EMG) were obtained from the rectus (RF) and biceps femoris (BF), and lower limb kinematic data were obtained at the same time. The beginning and ending of one kick cycle was defined as when the right lateral malleolus reached its highest position in the vertical axis. The offset timing of muscle activation of RF in the recreational swimmers was significantly later at all velocities than in the competitive swimmers (47-48% and 26-33% of kick time of one cycle for recreational and competitive swimmers, respectively), although the kinematic data and other activation timing of RF and BF did not differ between groups. A higher integrated EMG of RF during hip extension and knee extension induced a higher level of muscle co-contraction between RF and BF in the recreational swimmers. These results suggest that long-term competitive swimming training can induce an effective muscle activation pattern in the upper legs. PMID:26590483

  6. Muscle Activation Differs between Three Different Knee Joint-Angle Positions during a Maximal Isometric Back Squat Exercise

    PubMed Central

    Jarbas da Silva, Josinaldo; Jon Schoenfeld, Brad; Nardi, Priscyla Silva Monteiro; Pecoraro, Silvio Luis; D'Andréa Greve, Julia Maria; Hartigan, Erin

    2016-01-01

    The purpose of this study was to compare muscle activation of the lower limb muscles when performing a maximal isometric back squat exercise over three different positions. Fifteen young, healthy, resistance-trained men performed an isometric back squat at three knee joint angles (20°, 90°, and 140°) in a randomized, counterbalanced fashion. Surface electromyography was used to measure muscle activation of the vastus lateralis (VL), vastus medialis (VM), rectus femoris (RF), biceps femoris (BF), semitendinosus (ST), and gluteus maximus (GM). In general, muscle activity was the highest at 90° for the three quadriceps muscles, yet differences in muscle activation between knee angles were muscle specific. Activity of the GM was significantly greater at 20° and 90° compared to 140°. The BF and ST displayed similar activation at all joint angles. In conclusion, knee position alters muscles activation of the quadriceps and gluteus maximus muscles. An isometric back squat at 90° generates the highest overall muscle activation, yet an isometric back squat at 140° generates the lowest overall muscle activation of the VL and GM only. PMID:27504484

  7. Biceps Tenotomy Versus Tenodesis.

    PubMed

    Patel, Kushal V; Bravman, Jonathan; Vidal, Armando; Chrisman, Ashley; McCarty, Eric

    2016-01-01

    Long head biceps tendon is a common cause of anterior shoulder pain. Failure of conservative treatment may warrant surgical intervention. Surgical treatment involves long head biceps tenotomy or tenodesis. Several different techniques have been described for biceps tenodesis, including arthroscopic versus open and suprapectoral versus subpectoral. Most studies comparing tenodesis to tenotomy are limited by the level of evidence and confounding factors, such as concomitant rotator cuff tear. Many studies demonstrate similar outcomes for both procedures. Surgeon preference is likely more influential in choosing between tenotomy and tenodesis. Higher-powered studies are necessary to elucidate any differences in outcomes if present. PMID:26614471

  8. A comparison of the moment arms of pelvic limb muscles in horses bred for acceleration (Quarter Horse) and endurance (Arab)

    PubMed Central

    Crook, T C; Cruickshank, S E; McGowan, C M; Stubbs, N; Wilson, A M; Hodson-Tole, E; Payne, R C

    2010-01-01

    Selective breeding for performance has resulted in distinct breeds of horse, such as the Quarter Horse (bred for acceleration) and the Arab (bred for endurance). Rapid acceleration, seen during Quarter Horse racing, requires fast powerful muscular contraction and the generation of large joint torques, particularly by the hind limb muscles. This study compared hind limb moment arm lengths in the Quarter Horse and Arab. We hypothesized that Quarter Horse hind limb extensor muscles would have longer moment arms when compared to the Arab, conferring a greater potential for torque generation at the hip, stifle and tarsus during limb extension. Six Quarter Horse and six Arab hind limbs were dissected to determine muscle moment arm lengths for the following muscles: gluteus medius, biceps femoris, semitendinosus, vastus lateralis, gastrocnemius (medialis and lateralis) and tibialis cranialis. The moment arms of biceps femoris (acting at the hip) and gastrocnemius lateralis (acting at the stifle) were significantly longer in the Quarter Horse, although the length of the remaining muscle moment arms were similar in both breeds of horse. All the Quarter Horse muscles were capable of generating greater muscle moments owing to their greater physiological cross-sectional area (PCSA) and therefore greater isometric force potential, which suggests that PCSA is a better determinant of muscle torque than moment arm length in these two breeds of horse. With the exception of gastrocnemius and tibialis cranialis, the observed muscle fascicle length to moment arm ratio (MFL : MA ratio) was greater for the Arab horse muscles. It appears that the Arab muscles have the potential to operate at slower velocities of contraction and hence generate greater force outputs when compared to the Quarter Horse muscles working over a similar range of joint motion; this would indicate that Arab hind limb muscles are optimized to function at maximum economy rather than maximum power output. PMID

  9. A comparison of the moment arms of pelvic limb muscles in horses bred for acceleration (Quarter Horse) and endurance (Arab).

    PubMed

    Crook, T C; Cruickshank, S E; McGowan, C M; Stubbs, N; Wilson, A M; Hodson-Tole, E; Payne, R C

    2010-07-01

    Selective breeding for performance has resulted in distinct breeds of horse, such as the Quarter Horse (bred for acceleration) and the Arab (bred for endurance). Rapid acceleration, seen during Quarter Horse racing, requires fast powerful muscular contraction and the generation of large joint torques, particularly by the hind limb muscles. This study compared hind limb moment arm lengths in the Quarter Horse and Arab. We hypothesized that Quarter Horse hind limb extensor muscles would have longer moment arms when compared to the Arab, conferring a greater potential for torque generation at the hip, stifle and tarsus during limb extension. Six Quarter Horse and six Arab hind limbs were dissected to determine muscle moment arm lengths for the following muscles: gluteus medius, biceps femoris, semitendinosus, vastus lateralis, gastrocnemius (medialis and lateralis) and tibialis cranialis. The moment arms of biceps femoris (acting at the hip) and gastrocnemius lateralis (acting at the stifle) were significantly longer in the Quarter Horse, although the length of the remaining muscle moment arms were similar in both breeds of horse. All the Quarter Horse muscles were capable of generating greater muscle moments owing to their greater physiological cross-sectional area (PCSA) and therefore greater isometric force potential, which suggests that PCSA is a better determinant of muscle torque than moment arm length in these two breeds of horse. With the exception of gastrocnemius and tibialis cranialis, the observed muscle fascicle length to moment arm ratio (MFL : MA ratio) was greater for the Arab horse muscles. It appears that the Arab muscles have the potential to operate at slower velocities of contraction and hence generate greater force outputs when compared to the Quarter Horse muscles working over a similar range of joint motion; this would indicate that Arab hind limb muscles are optimized to function at maximum economy rather than maximum power output. PMID

  10. A comparative study of the electromyographic activities of lower extremity muscles during level walking and Pedalo riding

    PubMed Central

    Lee, DongGeon; Kim, YouJeong; Yun, JiHyeon; Jung, MiHye; Lee, GyuChang

    2016-01-01

    [Purpose] To analyze the electromyographic (EMG) activities of several lower extremity muscles during ground walking and pedaling using the Pedalo Reha-Bar device. [Subjects and Methods] Fifteen healthy adults aged 20–29 year participated in this study. The subjects’ surface EMG signals while walking and Pedalo Reha-Bar riding were recorded. The subjects performed 20 steps on flat ground and 20 cycles on the Pedalo Reha-Bar. During the tasks, EMG signals of the rectus femoris, biceps femoris, tibialis anterior, soleus, and gastrocnemius within a 20-second period were recorded. The mean EMG signals within the 10 seconds from 6 to 15 seconds were used for the data analysis. [Results] There was a significant increase in the bilateral use of the rectus femoris and a significant decrease in the use of the left tibialis anterior and left soleus in pedaling using the Pedalo Reha-Bar device compared to ground walking. [Conclusion] Level walking and the Pedalo Reha-Bar riding utilize different types of muscles activities. These results suggest that Pedalo Reha-Bar riding may be used for neuromuscular activation, especially of the rectus femoris. PMID:27313354

  11. Three-layered architecture of the popliteal fascia that acts as a kinetic retinaculum for the hamstring muscles.

    PubMed

    Satoh, Masahiro; Yoshino, Hiroyuki; Fujimura, Akira; Hitomi, Jiro; Isogai, Sumio

    2016-09-01

    When patients report pain in the popliteal fossa upon knee extension, the pain is usually localized in the lower region of the popliteal fossa. However, some patients complain of pain in the upper region of the popliteal fossa as the knee is flexed, which motivated us to examine the role of the popliteal fascia as the retinaculum of the hamstring muscles. Thirty-four thighs from 19 Japanese cadavers were dissected. The popliteal fascia was defined as the single aponeurotic sheet covering the popliteal fossa. We found that the fascia acted as a three-layered retinaculum for the flexor muscles of the thigh and provided a secure route for neurovascular structures to the lower leg in any kinetic position of the knee joint. The superficial layer of the popliteal fascia covering the thigh was strongly interwoven with the epimysium of biceps femoris along its lateral aspect and with that of the semimembranosus along its medial aspect, ensuring that the flexor muscles remained in their correct positions. The intermediate layer arose from the medial side of biceps femoris and merged medially with the superficial layer. The profound layer stretched transversely between the biceps femoris and the semimembranosus. Moreover, we investigated the nerve distribution in the popliteal fascia using Sihler's staining and whole-mount immunostaining for neurofilaments. The three-layered fascia was constantly innervated by branches from the posterior femoral cutaneous or saphenous nerve. The nerves were closely related and distributed to densely packed collagen fibers in the superficial layer as free or encapsulated nerve endings, suggesting that the fascia is involved in pain in the upper region of the popliteal fossa. PMID:26467331

  12. Size of quadriceps femoris may contribute to thyrotoxic periodic paralysis.

    PubMed

    Tang, Zi-Wei; He, Ying; Yao, Yu; Qiu, Li; Tian, Hao-Ming

    2015-12-01

    Thyrotoxic periodic paralysis (TPP) frequently occurs on male individuals at their third and forth decades. The major site of involvement is the proximal muscles of lower limbs. Increasing evidence has shown that the occurrence of TPP is determined by multiple factors. We hypothesized that apart from hormonal fluctuations, skeletal muscle itself may explain for the age and sex variance as well. Our study was established to explore whether the size of lower limb skeletal muscles were related to TPP. We conducted a clinical experiment including 43 patients diagnosed with TPP (Group 1) and 39 pure hyperthyroidism individuals (Group 2). Current age, body mass index (BMI), thyroid stimulating hormone (TSH), free triiodothyronine (FT3), free thyroxine (FT4), average girth of bilateral upper arm and thigh, physical activity level (PAL) were measured. We also adopted B mode ultrasound to quantify the muscle thickness (MT) of the major muscle involved in the disease, the quadriceps femoris (QF, including rectus femoris, RF; vastus intermedius, VI; vastus medialis, VM and vastus lateralis, VL). Patients were matched in TSH, FT4 and FT3. PAL was also statistically identical between groups. Age, BMI, thigh girth, the average of bilateral MT of QF were statistically different. After adjusting for age, BMI and girth, Group 1 still presented with larger MT of QF than Group 2, regardless of their current thyroid hormone level. There indeed exists an independent relationship between muscle thickness and TPP. PMID:26519100

  13. The effects of bicycle frame geometry on muscle activation and power during a wingate anaerobic test.

    PubMed

    Ricard, Mark D; Hills-Meyer, Patrick; Miller, Michael G; Michael, Timothy J

    2006-01-01

    The purpose of this study was to compare the effects of bicycle seat tube angles (STA) of (72° and 82°) on power production and EMG of the vastus laeralis (VL), vastus medialis (VM), semimembranous (SM), biceps femoris (BF) during a Wingate test (WAT). Twelve experienced cyclists performed a WAT at each STA. Repeated measures ANOVA was used to identify differences in muscular activation by STA. EMG variables were normalized to isometric maximum voluntary contraction (MVC). Paired t-tests were used to test the effects of STA on: peak power, average power, minimum power and percent power drop. Results indicated BF activation was significantly lower at STA 82° (482.9 ± 166.6 %MVC·s) compared to STA 72° (712.6 ± 265.6 %MVC·s). There were no differences in the power variables between STAs. The primary finding was that increasing the STA from 72° to 82° enabled triathletes' to maintain power production, while significantly reducing the muscular activation of the biceps femoris muscle. Key PointsRoad cyclists claim that bicycle seat tube angles between 72° and 76° are most effective for optimal performance in racing.Triathletes typically use seat tube angles greater than 76°. It is thought that a seat tube angle greater than 76° facilitates a smoother bike to run transition in the triathlon.Increasing the seat tube angle from 72 to 82 enabled triathletes' to maintain power production, while significantly reducing the muscular activation of the biceps femoris muscle.Reduced hamstring muscular activation in the triathlon frame (82 seat tube angle) may serve to reduce hamstring tightness following the bike phase of the triathlon, allowing the runner to use a longer stride length. PMID:24198678

  14. Chemical composition, quality and histochemical characteristics of individual dromedary camel (Camelus dromedarius) muscles.

    PubMed

    Kadim, I T; Al-Karousi, A; Mahgoub, O; Al-Marzooqi, W; Khalaf, S K; Al-Maqbali, R S; Al-Sinani, S S H; Raiymbek, G

    2013-03-01

    This study characterized the chemical composition, quality and histological traits of six muscles from 10 dromedary carcasses. There were significant differences in moisture, fat, protein, mineral, saturated and unsaturated fatty acid contents between muscles. The longissimus thoracis (LT) had the highest cooking loss (33.5%) and triceps brachii (TB) the lowest (29.2%). The shear force value of semitendinosus (ST), semimembranosus (SM) and biceps femoris (BF) were significantly higher than infraspinatus (IS), TB and LT. The LT had significantly higher values for L*, a*, b* than ST. The SM had the lowest MFI (65.3), while IS had the highest value (75.8). The ST significantly had the highest and lowest proportions of Type I and Type IIA muscle fibers, respectively than other muscles. This study indicated that composition, quality, and histochemical parameters varied among camel muscles and the knowledge of this variation allows for better marketing and processing of camel meat. PMID:23273465

  15. Remote Dose-Dependent Effects of Dry Needling at Distant Myofascial Trigger Spots of Rabbit Skeletal Muscles on Reduction of Substance P Levels of Proximal Muscle and Spinal Cords

    PubMed Central

    Hsieh, Yueh-Ling; Liu, Szu-Yu; Hong, Chang-Zern

    2014-01-01

    Background. Dry needling at distant myofascial trigger points is an effective pain management in patients with myofascial pain. However, the biochemical effects of remote dry needling are not well understood. This study evaluates the remote effects of dry needling with different dosages on the expressions of substance P (SP) in the proximal muscle, spinal dorsal horns of rabbits. Methods. Male New Zealand rabbits (2.5–3.0 kg) received dry needling at myofascial trigger spots of a gastrocnemius (distant muscle) in one (1D) or five sessions (5D). Bilateral biceps femoris (proximal muscles) and superficial laminaes of L5-S2, T2-T5, and C2-C5 were sampled immediately and 5 days after dry needling to determine the levels of SP using immunohistochemistry and western blot. Results. Immediately after dry needling for 1D and 5D, the expressions of SP were significantly decreased in ipsilateral biceps femoris and bilateral spinal superficial laminaes (P < .05). Five days after dry needling, these reduced immunoactivities of SP were found only in animals receiving 5D dry needling (P < .05). Conclusions. This remote effect of dry needling involves the reduction of SP levels in proximal muscle and spinal superficial laminaes, which may be closely associated with the control of myofascial pain. PMID:25276839

  16. Acute Effects of Different Methods of Stretching and Specific Warm-ups on Muscle Architecture and Strength Performance.

    PubMed

    Sá, Marcos A; Matta, Thiago T; Carneiro, Simone P; Araujo, Carolina O; Novaes, Jefferson S; Oliveira, Liliam F

    2016-08-01

    Sá, MA, Matta, TT, Carneiro, SP, Araujo, CO, Novaes, JS, and Oliveira, LF. Acute effects of different methods of stretching and specific warm-ups on muscle architecture and strength performance. J Strength Cond Res 30(8): 2324-2329, 2016-The purpose of the study was to investigate the acute effects of 2 stretching interventions, proprioceptive neuromuscular facilitation (PNF) and passive static stretching (PSS), and a specific warm-up (SW) on the strength and architecture of the vastus laterallis and biceps femoris muscles in a subsequent performance on a strength training session (STS). Musculoskeletal ultrasound images were acquired from 9 men before and immediately after stretchings or a SW, and 10 minutes after a STS. The STS consisted of the following exercises: leg extension, leg curl, leg press, and hack machine squat. The PNF resulted in lower performance for all situations. The PSS and SW improved performance for the leg press compared with the PNF and controls (CSs). For the hack machine squat, SWs resulted in higher performance than stretching conditions. The vastus lateralis muscle fascicle length (FL) increases after a STS for PNF. The biceps femoris muscle showed a higher pennation angle 10 minutes after the STS for PSS; the FL increases immediately after PSS and then decreases 10 minutes after the STS for PSS. As per our results, the SWs should be performed before STSs, whereas PNF stretching should not be prescribed because this condition impairs subsequent performance. These results may assist health professionals in prescribing resistance training. PMID:26705067

  17. Electromyographic responses of erector spinae and lower limb's muscles to dynamic postural perturbations in patients with adolescent idiopathic scoliosis.

    PubMed

    Farahpour, Nader; Ghasemi, Safoura; Allard, Paul; Saba, Mohammad Sadegh

    2014-10-01

    The aim of this study was to evaluate electromyographic (EMG) responses of erector spinae (ES) and lower limbs' muscles to dynamic forward postural perturbation (FPP) and backward postural perturbation (BPP) in patients with adolescent idiopathic scoliosis (AIS) and in a healthy control group. Ten right thoracic AIS patients (Cobb=21.6±4.4°) and 10 control adolescents were studied. Using bipolar surface electrodes, EMG activities of ES muscle at T10 (EST10) and L3 (ESL3) levels, biceps femoris (BF), gastrocnemius lateralis (G) and rectus femoris (RF) muscles in the right and the left sides during FPP and BPP were evaluated. Muscle responses were measured over a 1s time window after the onset of perturbation. In FPP test, the EMG responses of right EST10, ESL3 and BF muscles in the scoliosis group were respectively about 1.40 (p=0.035), 1.43 (p=0.07) and 1.45 (p=0.01) times greater than those in control group. Also, in BPP test, at right ESL3 muscle of the scoliosis group the EMG activity was 1.64 times higher than that in the control group (p=0.01). The scoliosis group during FPP displayed asymmetrical muscle responses in EST10 and BF muscles. This asymmetrical muscle activity in response to FPP is hypothesized to be a possible compensatory strategy rather than an inherent characteristic of scoliosis. PMID:25008019

  18. Clinical and Muscle Imaging Findings in 14 Mainland Chinese Patients with Oculopharyngodistal Myopathy

    PubMed Central

    Zhao, Juan; Liu, Jing; Xiao, Jiangxi; Du, Jing; Que, Chengli; Shi, Xin; Liang, Wei; Sun, Weiping; Zhang, Wei; Lv, He; Yuan, Yun; Wang, Zhaoxia

    2015-01-01

    Oculopharyngodistal myopathy (OPDM) is an extremely rare, adult-onset hereditary muscular disease characterized by progressive external ocular, pharyngeal, and distal muscle weakness and myopathological rimmed vacuole changes. The causative gene is currently unknown; therefore, diagnosis of OPDM is based on clinical and histopathological features and genetic exclusion of similar conditions. Moreover, variable manifestations of this disorder are reported in terms of muscle involvement and severity. We present the clinical profile and magnetic resonance imaging (MRI) changes of lower limb muscles in 14 mainland Chinese patients with OPDM, emphasizing the role of muscle MRI in disease identification and differential diagnosis. The patients came from 10 unrelated families and presented with progressive external ocular, laryngopharyngeal, facial, distal limb muscle weakness that had been present since early adulthood. Serum creatine kinase was mildly to moderately elevated. Electromyography revealed myogenic changes with inconsistent myotonic discharge. The respiratory function test revealed subclinical respiratory muscle involvement. Myopathological findings showed rimmed vacuoles with varying degrees of muscular dystrophic changes. All known genes responsible for distal and myofibrillar myopathies, vacuolar myopathies, and muscular dystrophies were excluded by PCR or targeted next-generation sequencing. Muscle MRI revealed that the distal lower legs had more severe fatty replacement than the thigh muscles. Serious involvement of the soleus and long head of the biceps femoris was observed in all patients, whereas the popliteus, gracilis and short head of biceps femoris were almost completely spared, even in advanced stages. Not only does our study widen the spectrum of OPDM in China, but it also demonstrates that OPDM has a specific pattern of muscle involvement that may provide valuable information for its differential diagnosis and show further evidence supporting

  19. Arthroscopic biceps tenodesis.

    PubMed

    Klepps, Steven; Hazrati, Yassamin; Flatow, Evan

    2002-01-01

    Surgical treatment of symptomatic pathology of the long head of the biceps tendon generally consists of either biceps tenotomy or tenodesis. Biceps tenodesis is generally recommended for younger patients and has been well described using open techniques. With advancements in arthroscopic ability and equipment, new arthroscopic techniques have recently been reported. These techniques can be especially useful when used in conjunction with other arthroscopic procedures such as distal clavicle resection, rotator cuff repair, and subacromial decompression. We present a modification of the techniques suggested by other researchers. In this technique, a bone anchor is used as a pulley at the bottom of the tunnel to pull the tendon into position. This is followed by interference screw fixation. To our knowledge, this technique has not been previously described. PMID:12426550

  20. Timing of Muscle Response to a Sudden Leg Perturbation: Comparison between Adolescents and Adults with Down Syndrome

    PubMed Central

    Valle, Maria Stella; Cioni, Matteo; Pisasale, Mariangela; Pantò, Maria Rosita; Casabona, Antonino

    2013-01-01

    Movement disturbances associated with Down syndrome reduce mechanical stability, worsening the execution of important tasks such as walking and upright standing. To compensate these deficits, persons with Down syndrome increase joint stability modulating the level of activation of single muscles or producing an agonist-antagonist co-activation. Such activations are also observed when a relaxed, extended leg is suddenly released and left to oscillate passively under the influence of gravity (Wartenberg test). In this case, the Rectus femoris of adults with Down syndrome displayed peaks of activation after the onset of the first leg flexion. With the aim to verify if these muscular reactions were acquired during the development time and to find evidences useful to give them a functional explanation, we used the Wartenberg test to compare the knee joint kinematics and the surface electromyography of the Rectus femoris and Biceps femoris caput longus between adolescents and adults with Down syndrome. During the first leg flexion, adolescents and adults showed single Rectus femoris activations while, a restricted number of participants exhibited agonist-antagonist co-activations. However, regardless the pattern of activation, adults initiated the muscle activity significantly later than adolescents. Although most of the mechanical parameters and the total movement variability were similar in the two groups, the onset of the Rectus femoris activation was well correlated with the time of the minimum acceleration variability. Thus, in adolescents the maximum mechanical stability occurred short after the onset of the leg fall, while adults reached their best joint stability late during the first flexion. These results suggest that between the adolescence and adulthood, persons with Down syndrome explore a temporal window to select an appropriate timing of muscle activation to overcome their inherent mechanical instability. PMID:24278374

  1. A 3-Dimensional Anatomic Study of the Distal Biceps Tendon

    PubMed Central

    Walton, Christine; Li, Zhi; Pennings, Amanda; Agur, Anne; Elmaraghy, Amr

    2015-01-01

    Background Complete rupture of the distal biceps tendon from its osseous attachment is most often treated with operative intervention. Knowledge of the overall tendon morphology as well as the orientation of the collagenous fibers throughout the musculotendinous junction are key to intraoperative decision making and surgical technique in both the acute and chronic setting. Unfortunately, there is little information available in the literature. Purpose To comprehensively describe the morphology of the distal biceps tendon. Study Design Descriptive laboratory study. Methods The distal biceps terminal musculature, musculotendinous junction, and tendon were digitized in 10 cadaveric specimens and data reconstructed using 3-dimensional modeling. Results The average length, width, and thickness of the external distal biceps tendon were found to be 63.0, 6.0, and 3.0 mm, respectively. A unique expansion of the tendon fibers within the distal muscle was characterized, creating a thick collagenous network along the central component between the long and short heads. Conclusion This study documents the morphologic parameters of the native distal biceps tendon. Reconstruction may be necessary, especially in chronic distal biceps tendon ruptures, if the remaining tendon morphology is significantly compromised compared with the native distal biceps tendon. Knowledge of normal anatomical distal biceps tendon parameters may also guide the selection of a substitute graft with similar morphological characteristics. Clinical Relevance A thorough description of distal biceps tendon morphology is important to guide intraoperative decision making between primary repair and reconstruction and to better select the most appropriate graft. The detailed description of the tendinous expansion into the muscle may provide insight into better graft-weaving and suture-grasping techniques to maximize proximal graft incorporation. PMID:26665092

  2. Muscular Activity and Fatigue in Lower-Limb and Trunk Muscles during Different Sit-To-Stand Tests

    PubMed Central

    Roldán-Jiménez, Cristina; Bennett, Paul; Cuesta-Vargas, Antonio I.

    2015-01-01

    Sit-to-stand (STS) tests measure the ability to get up from a chair, reproducing an important component of daily living activity. As this functional task is essential for human independence, STS performance has been studied in the past decades using several methods, including electromyography. The aim of this study was to measure muscular activity and fatigue during different repetitions and speeds of STS tasks using surface electromyography in lower-limb and trunk muscles. This cross-sectional study recruited 30 healthy young adults. Average muscle activation, percentage of maximum voluntary contraction, muscle involvement in motion and fatigue were measured using surface electrodes placed on the medial gastrocnemius (MG), biceps femoris (BF), vastus medialis of the quadriceps (QM), the abdominal rectus (AR), erector spinae (ES), rectus femoris (RF), soleus (SO) and the tibialis anterior (TA). Five-repetition STS, 10-repetition STS and 30-second STS variants were performed. MG, BF, QM, ES and RF muscles showed differences in muscle activation, while QM, AR and ES muscles showed significant differences in MVC percentage. Also, significant differences in fatigue were found in QM muscle between different STS tests. There was no statistically significant fatigue in the BF, MG and SO muscles of the leg although there appeared to be a trend of increasing fatigue. These results could be useful in describing the functional movements of the STS test used in rehabilitation programs, notwithstanding that they were measured in healthy young subjects. PMID:26506612

  3. Failure of distal biceps repair by gapping

    PubMed Central

    Copas, David; Watts, Adam C

    2016-01-01

    Background We describe the clinical, radiological and surgical findings of failed distal biceps repair by gapping and report the functional outcomes following revision repair. Methods A retrospective review of five consecutive patients was conducted. Patients presented with radial-sided forearm pain after their distal biceps fixation. All patients had less than 5 cm of retraction of the biceps muscle belly, a palpable tendon although the manoeuvre was painful with weakness on resisted supination. Flexed abducted supinated magnetic resonance imaging (FABS MRI) showed a gap between the distal end of the tendon and the footprint on the radial tuberosity. Results Mean FEA score at presentation was 44/100 (35 to 49). Mean time to re-operation was 18 months (range 4 months to 36 months). At revision, the distal end of the tendon was retracted and not making contact with the bone. All cases were revised to an in-bone endobutton repair. Mean postoperative Functional Elbow Assessment (FEA) scores undertaken at a mean of 14 months (range 5 months to 22 months) after revision improved to 95/100 (90 to 100). Conclusions Patients presenting with persistent radial sided forearm pain and weakness on provocative testing after distal biceps repair with a seemingly intact repair should be investigated with FABS MRI to look for evidence of failure of repair by gapping. Revision repair with an anatomic in-bone technique can lead to good results. PMID:27583018

  4. Aging affects spatial distribution of leg muscle oxygen saturation during ramp cycling exercise.

    PubMed

    Takagi, Shun; Kime, Ryotaro; Murase, Norio; Watanabe, Tsubasa; Osada, Takuya; Niwayama, Masatsugu; Katsumura, Toshihito

    2013-01-01

    We compared muscle oxygen saturation (SmO2) responses in several leg muscles and within a single muscle during ramp cycling exercise between elderly men (n = 8; age, 65 ± 3 years; ELD) and young men (n = 10; age, 23 ± 3 years; YNG). SmO2 was monitored at the distal site of the vastus lateralis (VLd), proximal site of the vastus lateralis (VLp), rectus femoris (RF), vastus medialis (VM), biceps femoris (BF), gastrocnemius lateralis (GL), gastrocnemius medialis (GM), and tibialis anterior (TA) by near-infrared spatial resolved spectroscopy. During submaximal exercise, significantly lower SmO2 at a given absolute work rate was observed in VLd, RF, BF, GL, and TA but not in VLp, VM, and GM in ELD than in YNG. In contrast, at all measurement sites, SmO2 at peak exercise was not significantly different between groups. These results indicate that the effects of aging on SmO2 responses are heterogeneous between leg muscles and also within a single muscle. The lower SmO2 in older men may have been caused by reduced muscle blood flow or altered blood flow distribution. PMID:23852490

  5. Breakpoints in ventilation, cerebral and muscle oxygenation, and muscle activity during an incremental cycling exercise

    PubMed Central

    Racinais, Sebastien; Buchheit, Martin; Girard, Olivier

    2014-01-01

    The aim of this study was to locate the breakpoints of cerebral and muscle oxygenation and muscle electrical activity during a ramp exercise in reference to the first and second ventilatory thresholds. Twenty-five cyclists completed a maximal ramp test on an electromagnetically braked cycle-ergometer with a rate of increment of 25 W/min. Expired gazes (breath-by-breath), prefrontal cortex and vastus lateralis (VL) oxygenation [Near-infrared spectroscopy (NIRS)] together with electromyographic (EMG) Root Mean Square (RMS) activity for the VL, rectus femoris (RF), and biceps femoris (BF) muscles were continuously assessed. There was a non-linear increase in both cerebral deoxyhemoglobin (at 56 ± 13% of the exercise) and oxyhemoglobin (56 ± 8% of exercise) concomitantly to the first ventilatory threshold (57 ± 6% of exercise, p > 0.86, Cohen's d < 0.1). Cerebral deoxyhemoglobin further increased (87 ± 10% of exercise) while oxyhemoglobin reached a plateau/decreased (86 ± 8% of exercise) after the second ventilatory threshold (81 ± 6% of exercise, p < 0.05, d > 0.8). We identified one threshold only for muscle parameters with a non-linear decrease in muscle oxyhemoglobin (78 ± 9% of exercise), attenuation in muscle deoxyhemoglobin (80 ± 8% of exercise), and increase in EMG activity of VL (89 ± 5% of exercise), RF (82 ± 14% of exercise), and BF (85 ± 9% of exercise). The thresholds in BF and VL EMG activity occurred after the second ventilatory threshold (p < 0.05, d > 0.6). Our results suggest that the metabolic and ventilatory events characterizing this latter cardiopulmonary threshold may affect both cerebral and muscle oxygenation levels, and in turn, muscle recruitment responses. PMID:24782786

  6. Skeletal muscle glucose transporter protein responses to antenatal glucocorticoids in the ovine fetus.

    PubMed

    Gray, Susan; Stonestreet, Barbara S; Thamotharan, Shanthie; Sadowska, Grazyna B; Daood, Molly; Watchko, Jon; Devaskar, Sherin U

    2006-05-01

    We investigated the effects of maternal antenatal dexamethasone (Dex) treatment given as a single course (4 doses) or multiple courses (20 doses) on fetal skeletal muscle glucose transporter (GLUT) protein concentrations at 70% of gestation (106 to 107 days with term being 145 to 150 days) in the ovine fetus. Antenatal corticosteroid administration was associated with a decrease in endogenous fetal plasma cortisol concentrations (P < 0.05), fetal hyperglycemia (P < 0.02) and hyperinsulinemia (P < 0.05). These metabolic/hormonal changes were associated with a decrease in fetal body weight (P < 0.05) in the multiple course Dex group compared with the multiple course placebo group. These perturbations were associated with an increase in fetal skeletal muscle GLUT 1 concentrations that mediate basal glucose transport in the extensor digitorum lateralis and extensor digitorum longus muscles (P < 0.05) 18 h after the last dose of Dex was given in the single course group. However, in the multiple course Dex group, a small increase in GLUT 1 was observed only in the biceps femoris. In contrast, both single and multiple courses of antenatal Dex were associated with an increase in the extensor digitorum lateralis and biceps femoris muscle GLUT 4 (insulin-responsive) concentrations (P < 0.05). We conclude that antenatal corticosteroids perturb fetal glucose/insulin homeostasis, which is associated with increases in fetal skeletal muscle glucose transporters to compensate for and attenuate the associated catabolic fetal state. These changes consist of an increase in proteins that mediate basal glucose transport (GLUT 1) to meet immediate energy requirements of the fetal skeletal muscle with an increase in basal insulin sensitivity (GLUT 4) to compensate for the Dex-induced catabolic state after exposure to multiple courses of Dex. PMID:16648290

  7. Do sarcomere length, collagen content, pH, intramuscular fat and desmin degradation explain variation in the tenderness of three ovine muscles?

    PubMed

    Starkey, Colin P; Geesink, Geert H; Collins, Damian; Hutton Oddy, V; Hopkins, David L

    2016-03-01

    The longissimus (n=118) (LL), semimembranosus (n=104) (SM) and biceps femoris (n=134) (BF) muscles were collected from lamb and sheep carcases and aged for 5days (LL and SM) and 14days (BF) to study the impact of muscle characteristics on tenderness as assessed by shear force (SF) and sensory evaluation. The impact of gender, animal age, collagen content, sarcomere length (SL), desmin degradation, ultimate pH and intramuscular fat (IMF) on tenderness was examined. The main factors which influenced SF of the LL were IMF, SL and desmin degradation, but for sensory tenderness, IMF, ultimate pH and gender were the main factors. The SF and sensory tenderness of the SM was best predicted by the degree of desmin degradation. For the BF soluble collagen and animal age both influenced SF. Different factors affect tenderness across muscles and not one prediction model applied across all muscles equally well. PMID:26613188

  8. Peak Muscle Activation, Joint Kinematics, and Kinetics during Elliptical and Stepping Movement Pattern on a Precor Adaptive Motion Trainer

    ERIC Educational Resources Information Center

    Rogatzki, Matthew J.; Kernozek, Thomas W.; Willson, John D.; Greany, John F.; Hong, Di-An; Porcari, John P.

    2012-01-01

    Kinematic, kinetic, and electromyography data were collected from the biceps femoris, rectus femoris (RF), gluteus maximus, and erector spinae (ES) during a step and elliptical exercise at a standardized workload with no hand use. Findings depicted 95% greater ankle plantar flexion (p = 0.01), 29% more knee extension (p = 0.003), 101% higher peak…

  9. Effect of the shoulder position on the biceps brachii emg in different dumbbell curls

    PubMed Central

    Oliveira, Liliam F.; Matta, Thiago T.; Alves, Daniel S.; Garcia, Marco A.C.; Vieira, Taian M.M.

    2009-01-01

    Incline Dumbbell Curl (IDC) and Dumbbell Preacher Curl (DPC) are two variations of the standard Dumbbell Biceps Curl (DBC), generally applied to optimize biceps brachii contribution for elbow flexion by fixing shoulder at a specific angle. The aim of this study is to identify changes in the neuromuscular activity of biceps brachii long head for IDC, DPC and DBC exercises, by taking into account the changes in load moment arm and muscle length elicited by each dumbbell curl protocol. A single cycle (concentric-eccentric) of DBC, IDC and DPC, was applied to 22 subjects using a submaximal load of 40% estimated from an isometric MVC test. The neuromuscular activity of biceps brachii long head was compared by further partitioning each contraction into three phases, according to individual elbow joint range of motion. Although all protocols elicited a considerable level of activation of the biceps brachii muscle (at least 50% of maximum RMS), the contribution of this muscle for elbow flexion/extension varied among exercises. The submaximal elbow flexion (concentric) elicited neuro muscular activity up to 95% of the maximum RMS value during the final phase of IDC and DBC and 80% for DPC at the beginning of the movement. All exercises showed significant less muscle activity for the elbow extension (eccentric). The Incline Dumbbell Curl and the classical Dumbbell Biceps Curl resulted in similar patterns of biceps brachii activation for the whole range of motion, whereas Dumbbell Preacher Curl elicited high muscle activation only for a short range of elbow joint angle. Key pointsThe Incline Dumbbell Curl and the Dumbbell Biceps Curl resulted in a considerable neuromuscular effort throughout the whole elbow range of motion.The Incline Dumbbell Curl and the Dumbbell Biceps Curl may be preferable for the improvement of biceps brachii force in training programs. PMID:24150552

  10. Muscle activation patterns during walking from transtibial amputees recorded within the residual limb-prosthetic interface

    PubMed Central

    2012-01-01

    Background Powered lower limb prostheses could be more functional if they had access to feedforward control signals from the user’s nervous system. Myoelectric signals are one potential control source. The purpose of this study was to determine if muscle activation signals could be recorded from residual lower limb muscles within the prosthetic socket-limb interface during walking. Methods We recorded surface electromyography from three lower leg muscles (tibilias anterior, gastrocnemius medial head, gastrocnemius lateral head) and four upper leg muscles (vastus lateralis, rectus femoris, biceps femoris, and gluteus medius) of 12 unilateral transtibial amputee subjects and 12 non-amputee subjects during treadmill walking at 0.7, 1.0, 1.3, and 1.6 m/s. Muscle signals were recorded from the amputated leg of amputee subjects and the right leg of control subjects. For amputee subjects, lower leg muscle signals were recorded from within the limb-socket interface and from muscles above the knee. We quantified differences in the muscle activation profile between amputee and control groups during treadmill walking using cross-correlation analyses. We also assessed the step-to-step inter-subject variability of these profiles by calculating variance-to-signal ratios. Results We found that amputee subjects demonstrated reliable muscle recruitment signals from residual lower leg muscles recorded within the prosthetic socket during walking, which were locked to particular phases of the gait cycle. However, muscle activation profile variability was higher for amputee subjects than for control subjects. Conclusion Robotic lower limb prostheses could use myoelectric signals recorded from surface electrodes within the socket-limb interface to derive feedforward commands from the amputee’s nervous system. PMID:22882763

  11. The effect of the weight of equipment on muscle activity of the lower extremity in soldiers.

    PubMed

    Lindner, Tobias; Schulze, Christoph; Woitge, Sandra; Finze, Susanne; Mittelmeier, Wolfram; Bader, Rainer

    2012-01-01

    Due to their profession and the tasks it entails, soldiers are exposed to high levels of physical activity and strain. This can result in overexertion and pain in the locomotor system, partly caused by carrying items of equipment. The aim of this study was to analyse the extent of muscle activity in the lower extremities caused by carrying specific items of equipment. For this purpose, the activity of selected groups of muscles caused by different items of equipment (helmet, carrying strap, backpack, and rifle) in the upper and lower leg was measured by recording dynamic surface electromyograms. Electrogoniometers were also used to measure the angle of the knee over the entire gait cycle. In addition to measuring muscle activity, the study also aimed to determine out what influence increasing weight load has on the range of motion (ROM) of the knee joint during walking. The activity of recorded muscles of the lower extremity, that is, the tibialis anterior, peroneus longus, gastrocnemius lateralis, gastrocnemius medialis, rectus femoris, and biceps femoris, was found to depend on the weight of the items of equipment. There was no evidence, however, that items of equipment weighing a maximum of 34% of their carrier's body weight had an effect on the ROM of the knee joint. PMID:22973179

  12. Ohmic cooking of whole beef muscle - Optimisation of meat preparation.

    PubMed

    Zell, Markus; Lyng, James G; Cronin, Denis A; Morgan, Desmond J

    2009-04-01

    Uniform ohmic heating of solid foods primarily depends on the uniformity of electrolyte distribution within the product. Different preparation techniques were tested in an attempt to ensure an even salt dispersion within a full beef muscle (biceps femoris). Meat pieces were soaked, injected and tumbled using a range of procedures before ohmic cooking at pasteurization temperatures. A final preparation method (multi-injection (five points) with a 3% salt solution followed by 16h tumbling) was validated. Selected quality parameters of the ohmically cooked products were compared to steam cooked products. Ohmically heated meat had a significantly (P<0.05) uniform lighter and less red colour. Cook loss was significantly lower (P<0.05) in ohmic samples and in relation to tenderness ohmic heated samples were tougher (P<0.05) though the difference was only 5.08N. Comparable cook values were attained in the ohmic and conventionally cooked products. PMID:20416569

  13. Patterns of muscle coordination during stepping responses post-stroke.

    PubMed

    Gray, V L; Pollock, C L; Wakeling, J M; Ivanova, T D; Garland, S J

    2015-12-01

    This study compared self-induced stepping reactions of seventeen participants after stroke and seventeen controls. Surface electromyographic (EMG) signals were recorded bilaterally from the soleus (SOL), tibialis anterior (TA), biceps femoris (BF) and rectus femoris (RF) muscles. Principal component analysis (PCA) was used to reduce the data into muscle activation patterns and examine group differences (paretic, non-paretic, control leg). The first principal component (PC1) explained 46.7% of the EMG signal of the stepping leg. Two PCs revealed distinct activation features for the stepping paretic leg: earlier TA onset at step initiation and earlier BF and SOL onset at mid-step. For the stance leg, PC1 explained 44.4% of the EMG signal and significant differences were found in the non-paretic leg compared to paretic (p < 0.001) and control (p < 0.001). In PC1, at step onset the BF and SOL EMG and the RF and TA EMG were increased over the latter half of the step. No PC loadings were distinct for the paretic leg during stance, however differences were found in the non-paretic leg: earlier TA burst and increased BF and SOL EMG at step initiation. The results suggest impairments in the paretic leg when stepping and compensatory strategies in the non-paretic stance leg. PMID:26475243

  14. Motoneurons of the adult marmoset can grow axons and reform motor endplates through a peripheral nerve bridge joining the locally injured cervical spinal cord to the denervated biceps brachii muscle.

    PubMed

    Emery, E; Rhrich-Haddout, F; Kassar-Duchossoy, L; Lyoussi, B; Tadié, M; Horvat, J C

    2000-12-15

    Reconnection of the injured spinal cord (SC) of the marmoset with the denervated biceps brachii muscle (BB) was obtained by using a peripheral nerve (PN) bridge. In 13 adult males, a 45 mm segment of the peroneal nerve was removed: one end was implanted unilaterally into the cervical SC of the same animal (autograft), determining a local injury, although the other end was either directly inserted into the BB (Group A) or, alternatively, sutured to its transected motor nerve, the musculocutaneous nerve (Group B). From 2-4 months post-surgery, eight out of the 10 surviving animals responded by a contraction of the BB to electrical stimulations of the PN bridge. All ten were then processed for a morphological study. As documented by retrograde axonal tracing studies using horse radish peroxidase or Fast Blue (FB), a mean number of 314 (Group A) or 45 (Group B) spinal neurons, mainly located close to the site of injury and grafting, re-expressed a capacity to grow and extend axons into the PN bridge. Most of these regenerated axons were able to grow up to the BB and form or reform functional motor endplates. Many of the spinal neurons that were retrogradely labeled with FB simultaneously displayed immunoreactivity for choline acetyl-transferase and consequently were assumed to be motoneurons. Reinnervation and regeneration of the BB were documented by methods revealing axon terminals, endplates and myofibrillary ATPase activity. Our results indicate that motoneurons of the focally injured SC of a small-sized primate can, following the example of the adult rat, re-establish a lost motor function by extending new axons all the way through a PN bridge connected to a denervated skeletal muscle. PMID:11107167

  15. Tenderization potential of Hanwoo beef muscles from carcasses with differed genders and loin intramuscular fat content levels during post mortem ageing.

    PubMed

    Park, Beom Young; Seong, Pil Nam; Ba, Hoa Van; Park, Kyoung Mi; Cho, Soo Hyun; Moon, Sung Sil; Kang, Geun Ho

    2015-06-01

    Carcasses from Hanwoo steers (n = 15) and cows (n = 15) were classified into three groups: group 1 (G1), the carcasses had 10% to < 11.5% intramuscular fat (IMF) in loin muscles; group 2 (G2), the carcasses had 13% to < 4.5% IMF in loin muscles; and group 3(G3), the carcasses had 17% to < 18.5% IMF in loin muscles. These were used to evaluate the effects of gender and carcass group on quality traits and Warner-Bratzler shear force (WBSF) of Psoas major (PM), Longissimus thoracis (LT), Longissimus lumborum (LL), Longus colli (LC), Supraspinatus (SS), Latissimus dorsi (LAD), Semimembranosus (SM), Quadriceps femoris (QF), Biceps femoris (BF) and Semitendinosus (ST) muscles. Our results showed that pH values of LT, LL, LC, BF and QF muscles were lower in steers than in cows (P < 0.05). Water holding capacity (WHC) was found higher in LC, SS, LAD and QF muscles of steers (P < 0.05). At day 2 of ageing, gender affected the WBSF values of only PM, LD and QF muscles in G1, and QF muscle in G3; however, with additional ageing, the gender effect was observed for most of the muscles. Most muscles showed ageing responses; however, the rates of ageing response significantly varied depending on gender and carcass groups. The muscles of G1 and G2 had generally higher tenderization potentials than those of G3. Furthermore, most muscles in G3 had generally lower WBSF values than in G1 and G2. These results clearly indicate that ageing has a significant effect on quality and WBSF of beef muscles, and the classification by loin IMF level may be useful for prediction of the tenderness of other muscles. PMID:25491951

  16. Altered lower leg muscle activation patterns in patients with cerebral palsy during cycling on an ergometer

    PubMed Central

    Alves-Pinto, Ana; Blumenstein, Tobias; Turova, Varvara; Lampe, Renée

    2016-01-01

    Objective Cycling on a recumbent ergometer constitutes one of the most popular rehabilitation exercises in cerebral palsy (CP). However, no control is performed on how muscles are being used during training. Given that patients with CP present altered muscular activity patterns during cycling or walking, it is possible that an incorrect pattern of muscle activation is being promoted during rehabilitation cycling. This study investigated patterns of muscular activation during cycling on a recumbent ergometer in patients with CP and whether those patterns are determined by the degree of spasticity and of mobility. Methods Electromyographic (EMG) recordings of lower leg muscle activation during cycling on a recumbent ergometer were performed in 14 adult patients diagnosed with CP and five adult healthy participants. EMG recordings were done with an eight-channel EMG system built in the laboratory. The activity of the following muscles was recorded: Musculus rectus femoris, Musculus biceps femoris, Musculus tibialis anterior, and Musculus gastrocnemius. The degree of muscle spasticity and mobility was assessed using the Modified Ashworth Scale and the Gross Motor Function Classification System, respectively. Muscle activation patterns were described in terms of onset and duration of activation as well as duration of cocontractions. Results Muscle activation in CP was characterized by earlier onsets, longer periods of activation, a higher occurrence of agonist–antagonist cocontractions, and a more variable cycling tempo in comparison to healthy participants. The degree of altered muscle activation pattern correlated significantly with the degree of spasticity. Conclusion This study confirmed the occurrence of altered lower leg muscle activation patterns in patients with CP during cycling on a recumbent ergometer. There is a need to develop feedback systems that can inform patients and therapists of an incorrect muscle activation during cycling and support the training

  17. Evaluation of muscle injury using magnetic resonance imaging

    NASA Technical Reports Server (NTRS)

    LeBlanc, A. D.; Jaweed, M.; Evans, H.

    1993-01-01

    The objective of this study was to investigate spin echo T2 relaxation time changes in thigh muscles after intense eccentric exercise in healthy men. Spin echo and calculated T2 relaxation time images of the thighs were obtained on several occasions after exercise of one limb; the contralateral limb served as control. Muscle damage was verified by elevated levels of serum creatine kinase (CK). Thirty percent of the time no exercise effect was discernible on the magnetic resonance (MR) images. In all positive MR images (70%) the semitendinosus muscle was positive, while the biceps femoris, short head, and gracilis muscles were also positive in 50% and 25% of the total cases, respectively. The peak T2 relaxation time and serum CK were correlated (r = 0.94, p<0.01); temporal changes in muscle T2 relaxation time and serum CK were similar, although T2 relaxation time remained positive after serum CK returned to background levels. We conclude that magnetic resonance imaging can serve as a useful tool in the evaluation of eccentric exercise muscle damage by providing a quantitative indicator of damage and its resolution as well as the specific areas and muscles.

  18. Effect of muscle and post-mortem rate of pH and temperature fall on antioxidant enzyme activities in beef.

    PubMed

    Pastsart, Umaporn; De Boever, Maarten; Claeys, Erik; De Smet, Stefaan

    2013-03-01

    The aim of this study was to investigate the effect of muscle, inner and outer Musculus biceps femoris (IBF and OBF respectively) and Musculus longissimus dorsi (LD), on the post-mortem rate of pH and temperature fall, and the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) during simulated retail display. At day 0 of display (2 days post-mortem), the CAT and GSH-Px activities were lower in IBF than in OBF and LD (P<0.001), and the SOD activity was lower in OBF compared to IBF and LD (P<0.001). At day 10 of display, SOD and CAT activities had decreased in all three muscles compared to day 0 (P<0.001), whereas the GSH-Px activity did increase with time of display. Across muscles, there were significant relationships between temperature fall, colour, lipid and colour stability and antioxidant enzyme activities. PMID:23273481

  19. Changes in muscle activation patterns in response to enhanced sensory input during treadmill stepping in infants born with myelomeningocele

    PubMed Central

    Pantall, Annette; Teulier, Caroline; Ulrich, Beverly D.

    2013-01-01

    Infants with myelomeningocele (MMC) increase step frequency in response to modifications to the treadmill surface. The aim was to investigate how these modifications impacted the electromyographic (EMG) patterns. We analyzed EMG from 19 infants aged 2–10 months, with MMC at the lumbosacral level. We supported infants upright on the treadmill for 12 trials, each 30 seconds long. Modifications included visual flow, unloading, weights, Velcro and lcriction. Surface electrodes recorded EMG from tibialis anterior, lateral gastrocnemius, rectus femoris and biceps femoris. We determined muscle bursts for each stride cycle and from these calculated various parameters. Results indicated that each of the five sensory conditions generated different motor patterns. Visual flow and friction which we previously reported increased step frequency impacted lateral gastrocnemius most. Weights, which significantly decreased step frequency increased burst duration and co-activity of the proximal muscles. We also observed an age effect, with all conditions increasing muscle activity in younger infants whereas in older infants visual flow and unloading stimulated most activity. In conclusion, we have demonstrated that infants with myelomeningocele at levels which impact the myotomes of major locomotor muscles find ways to respond and adapt their motor output to changes in sensory input. PMID:23158017

  20. Advances in quantitative muscle ultrasonography using texture analysis of ultrasound images.

    PubMed

    Molinari, Filippo; Caresio, Cristina; Acharya, U Rajendra; Mookiah, Muthu Rama Krishnan; Minetto, Marco Alessandro

    2015-09-01

    Musculoskeletal ultrasound imaging can be used to investigate the skeletal muscle structure in terms of architecture (thickness, cross-sectional area, fascicle length and fascicle pennation angle) and texture. Gray-scale analysis is commonly used to characterize transverse scans of the muscle. Gray mean value is used to distinguish between normal and pathologic muscles, but it depends on the image acquisition system and its settings. In this study, quantitative ultrasonography was performed on five muscles (biceps brachii, vastus lateralis, rectus femoris, medial gastrocnemius and tibialis anterior) of 20 healthy patients (10 women, 10 men) to assess the characterization performance of higher-order texture descriptors to differentiate genders and muscle types. A total of 53 features (7 first-order descriptors, 24 Haralick features, 20 Galloway features and 2 local binary pattern features) were extracted from each muscle region of interest (ROI) and were used to perform the multivariate linear regression analysis (MANOVA). Our results show that first-order descriptors, Haralick features (energy, entropy and correlation measured along different angles) and local binary pattern (LBP) energy and entropy were highly linked to the gender, whereas Haralick entropy and symmetry, Galloway texture descriptors and LBP entropy helped to distinguish muscle types. Hence, the combination of first-order and higher-order texture descriptors (Haralick, Galloway and LBP) can be used to discriminate gender and muscle types. Therefore, multi-texture analysis may be useful to investigate muscle damage and myopathic disorders. PMID:26026375

  1. The effect of swinging the arms on muscle activation and production of leg force during ski skating at different skiing speeds.

    PubMed

    Göpfert, Caroline; Lindinger, Stefan J; Ohtonen, Olli; Rapp, Walter; Müller, Erich; Linnamo, Vesa

    2016-06-01

    The study investigated the effects of arm swing during leg push-off in V2-alternate/G4 skating on neuromuscular activation and force production by the leg muscles. Nine skilled cross-country skiers performed V2-alternate skating without poles at moderate, high, and maximal speeds, both with free (SWING) and restricted arm swing (NOSWING). Maximal speed was 5% greater in SWING (P<0.01), while neuromuscular activation and produced forces did not differ between techniques. At both moderate and high speed the maximal (2% and 5%, respectively) and average (both 5%) vertical force and associated impulse (10% and 14%) were greater with SWING (all P<0.05). At high speed range of motion and angular velocity of knee flexion were 24% greater with SWING (both P<0.05), while average EMG of m. biceps femoris was 31% lower (all P<0.05) in SWING. In a similar manner, the average EMG of m. vastus medialis and m. biceps femoris were lower (17% and 32%, P<0.05) during the following knee extension. Thus, swinging the arms while performing V2-alternate can enhance both maximal speed and skiing economy at moderate and, in particularly, high speeds. PMID:27031075

  2. Ultrasound assessment of hamstring muscle size using posterior thigh muscle thickness.

    PubMed

    Abe, Takashi; Loenneke, Jeremy P; Thiebaud, Robert S

    2016-05-01

    Several studies have investigated the relationship between ultrasound-measured muscle thickness (MT) and individual muscle cross-sectional area (CSA) and muscle volume (MV) in extremity and trunk muscles; however, the hamstring muscle has not been studied. The purpose of this study was to examine the relationship between posterior thigh MT by ultrasound and the muscle CSA and MV of the hamstring obtained by magnetic resonance imaging (MRI). Ten young women aged 20-31 had MT measured by ultrasound at three sites on the medial anterior (50% of thigh length; TL) and posterior (50% and 70% of TL) aspects of the thigh. On the same day, a series of continuous muscle CSA along the thigh was measured by MRI. In each slice, the anatomical CSA of the hamstring (biceps femoris, semitendinosus and semimembranosus) and quadriceps muscle was analysed, and the CSAs at 50% and 70% of TL and maximal CSA of the hamstring (CSAmax ) were determined. MV was calculated by multiplying CSA by slice thickness. A significant correlation was observed between posterior 50% MT and 50% hamstring CSA (r = 0·848, P = 0·002) and between posterior 70% MT and 70% hamstring CSA (r = 0·679, P = 0·031). Posterior 50% MT (r = 0·732, P = 0·016) and 50% MTxTL (r = 0·873, P = 0·001) were also correlated to hamstring MV. Anterior:posterior 50% thigh MT ratio was correlated to MV ratio of quadriceps and hamstring muscles (r = 0·803, P = 0·005). Our results suggest that posterior thigh MT reflects hamstring muscle CSA and MV. The anterior:posterior MT ratio may serve as a surrogate for MV ratio of quadriceps and hamstring. PMID:25363847

  3. Walking at the preferred stride frequency minimizes muscle activity.

    PubMed

    Russell, Daniel M; Apatoczky, Dylan T

    2016-03-01

    This study determined whether walking at the preferred stride frequency minimizes muscle activity compared with other cadences at the same speed. Anthropometric measurements were recorded from 10 subjects and used to estimate their predicted resonant stride frequency. The preferred walking speed and stride frequency were determined from freely adopted walking on a treadmill. For the experimental trials the treadmill was set at each individual's preferred walking speed. Participants walked for 6 min at eight cadences prescribed by an auditory metronome: preferred stride frequency and -35, -25, -15, 0, +15, +25, +35% of predicted resonant stride frequency. Oxygen consumption was measured via gas analysis. Muscle activity of the right leg gastrocnemius (GA), tibialis anterior (TA), biceps femoris (BF) and rectus femoris (RF) muscles was recorded via electromyography (EMG). On average, participants preferred to walk with a stride frequency .07 Hz lower than their predicted resonant stride frequency, however a strong positive correlation was observed between these variables. Stride frequency had a significant and large quadratic effect on VO2 (RLR(2)=.76), and activity of the GA (RLR(2)=.66), TA (RLR(2)=.83), BF (RLR(2)=.70) and RF (RLR(2)=.78) muscles. VO2, GA and TA activity were all minimal at the preferred stride frequency and increased for faster or slower cadences. BF and RF activity were minimal across a broad range of slow frequencies including the preferred stride frequency and increased for faster frequencies. The preferred stride frequency that humans readily adopt during walking minimizes the activation of the GA, TA, BF and RF muscles, which in turn minimizes the overall metabolic cost. PMID:26979903

  4. Lower Extremity Muscle Activity During a Women's Overhand Lacrosse Shot.

    PubMed

    Millard, Brianna M; Mercer, John A

    2014-06-28

    The purpose of this study was to describe lower extremity muscle activity during the lacrosse shot. Participants (n=5 females, age 22±2 years, body height 162.6±15.2 cm, body mass 63.7±23.6 kg) were free from injury and had at least one year of lacrosse experience. The lead leg was instrumented with electromyography (EMG) leads to measure muscle activity of the rectus femoris (RF), biceps femoris (BF), tibialis anterior (TA), and medial gastrocnemius (GA). Participants completed five trials of a warm-up speed shot (Slow) and a game speed shot (Fast). Video analysis was used to identify the discrete events defining specific movement phases. Full-wave rectified data were averaged per muscle per phase (Crank Back Minor, Crank Back Major, Stick Acceleration, Stick Deceleration). Average EMG per muscle was analyzed using a 4 (Phase) × 2 (Speed) ANOVA. BF was greater during Fast vs. Slow for all phases (p<0.05), while TA was not influenced by either Phase or Speed (p>0.05). RF and GA were each influenced by the interaction of Phase and Speed (p<0.05) with GA being greater during Fast vs. Slow shots during all phases and RF greater during Crank Back Minor and Major as well as Stick Deceleration (p<0.05) but only tended to be greater during Stick Acceleration (p=0.076) for Fast vs. Slow. The greater muscle activity (BF, RF, GA) during Fast vs. Slow shots may have been related to a faster approach speed and/or need to create a stiff lower extremity to allow for faster upper extremity movements. PMID:25114727

  5. Force, work and power output of lower limb muscles during human maximal-effort countermovement jumping.

    PubMed

    Nagano, Akinori; Komura, Taku; Fukashiro, Senshi; Himeno, Ryutaro

    2005-08-01

    The purpose of this study was to simulate human maximal-effort countermovement jumping with a three-dimensional neuromusculoskeletal model. The specific aim was to investigate muscle force, work and power output of major lower limb muscles during the motion. A neuromusculoskeletal model that has nine rigid body segments, 20 degrees of freedom, 32 Hill-type lower limb muscles was developed. The neural activation input signal was represented by a series of step functions with step duration of 0.05 s. The excitation-contraction dynamics of the contractile element, the tissues around the joints to limit the joint range of motion, as well as the foot-ground interaction were implemented. A simulation was started from a standing posture. Optimal pattern of the activation input signal was searched through numerical optimization with a goal of maximizing the height reached by the mass center of body after jumping up. As a result, feasible kinematics, ground reaction force profile and muscle excitation profile were generated. It was found that monoarticular muscles had major contributions of mechanical work and power output, whereas biarticular muscles had minor contributions. Hip adductors, abductors and external rotator muscles were vigorously activated, although their mechanical work and power output was minor because of their limited length change during the motion. Joint flexor muscles such as m. iliopsoas, m. biceps femoris short head and m. tibialis anterior were activated in the beginning of the motion with an effect of facilitating the generation of a countermovement. PMID:15811607

  6. A preliminary study on the differences in male and female muscle force distribution patterns during squatting and lunging maneuvers

    PubMed Central

    Hale, Rena; Hausselle, Jerome G.; Gonzalez, Roger V.

    2014-01-01

    In the United States, 250,000 people tear their anterior cruciate ligament (ACL) annually with females at higher risk of ACL failure then males. By predicting muscle forces during low impact maneuvers we may be able to estimate possible muscle imbalances that could lead to ACL failure during highly dynamic maneuvers. The purpose of this initial study was to predict muscle forces in males and females similar in size and activity level, during squat and lunge maneuvers. We hypothesized that during basic low impact maneuvers (a) distribution of quadriceps forces are different in males and females and (b) females exhibit quadriceps dominance when compared to males. Two males and three females performed squatting and lunging maneuvers while electromyography (EMG) data, motion capture data, and ground reaction forces were collected. Nine individual muscle forces for muscles that cross the knee were estimated using an EMG-driven model. Results suggest that males activate more their rectus femoris muscle than females, who in turn activate more their vastus lateralis muscle at their maximum flexion angle, and more their vastus medialis muscle when ascending from a squat. During the lunge maneuver, males used greater biceps femoris force than females, throughout the lunge, and females exhibited higher semitendinosus force. Quadriceps dominance was evident in both males and females during the prescribed tasks, and there was no statistical difference between genders. Understanding individual muscle force distributions in males and females during low impact maneuvers may provide insights regarding failure mechanisms during highly dynamic maneuvers, when ACL injuries are more prevalent. PMID:25016289

  7. BICEP2 constrains composite inflation

    NASA Astrophysics Data System (ADS)

    Channuie, Phongpichit

    2014-07-01

    In light of BICEP2, we re-examine single field inflationary models in which the inflation is a composite state stemming from various four-dimensional strongly coupled theories. We study in the Einstein frame a set of cosmological parameters, the primordial spectral index ns and tensor-to-scalar ratio r, predicted by such models. We confront the predicted results with the joint Planck data, and with the recent BICEP2 data. We constrain the number of e-foldings for composite models of inflation in order to obtain a successful inflation. We find that the minimal composite inflationary model is fully consistent with the Planck data. However it is in tension with the recent BICEP2 data. The observables predicted by the glueball inflationary model can be consistent with both Planck and BICEP2 contours if a suitable number of e-foldings are chosen. Surprisingly, the super Yang-Mills inflationary prediction is significantly consistent with the Planck and BICEP2 observations.

  8. Spontaneous bacterial seeding of a biceps hematoma.

    PubMed

    Frye, Benjamin; Prud'homme, Joseph; Daney, Blake

    2010-11-01

    A 19-year-old male construction worker presented with an injury to his left upper arm after lifting a heavy pipe. He reported an acute onset of sharp pain followed by swelling, warmth, and weakness with elbow flexion. The diagnosis of a distal biceps tendon rupture was made and elective repair was scheduled. Seventy-two hours later, the patient presented with a spontaneous draining wound on his anterior distal humerus. The wound was draining thick purulent material. The patient underwent surgery for irrigation and debridement of his abscess. Nearly 500 cc of hematoma and purulent fluid were evacuated. A large tear of both the biceps and brachialis muscle bellies were found. Cultures were obtained that revealed the infecting organism to be Streptococcus intermedius. Human immunodeficiency virus and hepatitis-C virus testing were negative, and no history, signs, or symptoms of any cause of underlying immunodeficiency were detected. No signs or history of drug use were present. He was discharged home on culture-specific oral antibiotics. At 4-month postoperative follow-up, the patient reported no pain or limitations. He has returned to full duty at his job. Elbow range of motion was measured from 7° to 150° of flexion. Strength of elbow flexion and extension was symmetric to the uninjured side. Pronation and supination of the forearm was symmetric on both sides. He has been released from scheduled follow-up and will be seen again on an as-needed basis. PMID:21053873

  9. Bilateral Congenital Agenesis of the Long Head of the Biceps Tendon: The Beginning

    PubMed Central

    Rego Costa, Francisco; Esteves, Cátia; Melão, Lina

    2016-01-01

    The biceps brachii muscle is prone to variants but absence of the long head of the biceps (LHB) tendon is an exceptionally rare anomaly. This report concerns the fourth case of bilateral congenital absence of the LHB tendon and presents the ultrasonography (US) and magnetic resonance (MR) findings. Our case has the peculiarity of being the first in which bilateral LHB tendon agenesis is not associated with rotator cuff or labral tears. PMID:26904345

  10. The impact of altered task mechanics on timing and duration of eccentric bi-articular muscle contractions during cycling.

    PubMed

    Connick, Mark J; Li, François-Xavier

    2013-02-01

    In order to understand muscle adaptations to altered task mechanics during cycling, this study investigated the impact of altered seat height and cadence on timing and duration of gastrocnemius (GAST), biceps femoris (BF) and vastus lateralis (VL) eccentric contractions and muscle activation patterns, and cycling economy. Ten male cyclists completed 9 × 5 min of cycling at 3 seat heights and 3 cadences. Three-dimensional leg kinematics and muscle activation patterns were recorded to estimate timing of eccentric muscle contractions. Onset, offset and duration of eccentric contractions and, onset, offset and duration of muscle activation were calculated, along with cycling economy. Duration of GAST and VL eccentric contractions decreased with increasing seat height due to earlier offset of eccentric muscle contractions. Duration of BF eccentric contractions significantly increased with seat height due to a later eccentric contraction offset. Offset of GAST and BF muscle activation occurred earlier with increasing cadence. Cycling economy was significantly affected by cadence but not seat height. The results suggest that as a consequence of altered seat height, proprioceptive feedback is used to fine-tune the timing of bi-articular eccentric muscle contractions. These results may have implications for seat height self-selection. PMID:23010605

  11. All-Arthroscopic Suprapectoral Biceps Tenodesis.

    PubMed

    Nair, Rueben; Kahlenberg, Cynthia A; Patel, Ronak M; Knesek, Michael; Terry, Michael A

    2015-12-01

    Biceps tenodesis is a common treatment for pathology of the long head of the biceps tendon. Several authors have described various arthroscopic and open techniques for biceps tenodesis. Open techniques have been associated with complications such as wound infection and nerve injury. Previously described arthroscopic techniques have placed the tenodesis site within the bicipital groove, which may lead to persistent pain. We describe an all-arthroscopic suprapectoral biceps tenodesis technique that places the tenodesis site distal to the bicipital groove. This technique potentially avoids the complications associated with open tenodesis surgery while still removing the biceps tendon from the bicipital groove. PMID:27284524

  12. Reorganised anticipatory postural adjustments due to experimental lower extremity muscle pain.

    PubMed

    Shiozawa, Shinichiro; Hirata, Rogerio Pessoto; Graven-Nielsen, Thomas

    2013-12-01

    Automated movements adjusting postural control may be hampered during musculoskeletal pain leaving a risk of incomplete control of balance. This study investigated the effect of experimental muscle pain on anticipatory postural adjustments by reaction task movements. While standing, nine healthy males performed two reaction time tasks (shoulder flexion of dominant side and bilateral heel lift) before, during and after experimental muscle pain. On two different days experimental pain was induced in the m. vastus medialis (VM) or the m. tibialis anterior (TA) of the dominant side by injections of hypertonic saline (1ml, 5.8%). Isotonic saline (1ml, 0.9%) was used as control injection. Electromyography (EMG) was recorded from 13 muscles. EMG onset, EMG amplitude, and kinematic parameters (shoulder and ankle joint) were extracted. During shoulder flexion and VM pain the onset of the ipsilateral biceps femoris was significantly faster than baseline and post injection sessions. During heels lift in the VM and TA pain conditions the onset of the contralateral TA was significantly faster than baseline and post injection sessions in bilateral side. VM pain significantly reduced m. quadriceps femoris activity and TA pain significantly reduced ipsilateral VM activity and TA activity during bilateral heel lift. The EMG reaction time was delayed in bilateral soleus muscles during heels lift with VM and TA pain. The faster onset of postural muscle activity during anticipatory postural adjustments may suggest a compensatory function to maintain postural control whereas the reduced postural muscle activity during APAs may indicate a pain adaptation strategy to avoid secondary damage. PMID:24071550

  13. Coordination of two-joint rectus femoris and hamstrings during the swing phase of human walking and running.

    PubMed

    Prilutsky, B I; Gregor, R J; Ryan, M M

    1998-06-01

    It has been hypothesized previously that because a strong correlation was found between the difference in electromyographic activity (EMG) of rectus femoris (RF) and hamstrings (HA; EMG(RF)-EMG(HA)) and the difference in the resultant moments at the knee and hip (Mk-Mh) during exertion of external forces on the ground by the leg, input from skin receptors of the foot may play an important role in the control of the distribution of the resultant moments between the knee and hip by modulating activation of the two-joint RF and HA. In the present study, we examined the coordination of RF and HA during the swing phase of walking and running at different speeds, where activity of foot mechanoreceptors is not modulated by an external force. Four subjects walked at speeds of 1.8 m/s and 2.7 m/s and ran at speeds of 2.7 m/s and 3.6 m/s on a motor-driven treadmill. Surface EMG of RF, semimembranosus (SM), and long head of biceps femoris (BF) and coordinates of the four leg joints were recorded. An inverse dynamics analysis was used to calculate the resultant moments at the ankle, knee, and hip during the swing phase. EMG signals were rectified and low-pass filtered to obtain linear envelopes and then shifted in time to account for electromechanical delay between EMG and joint moments. During walking and running at all studied speeds, mean EMG envelope values of RF were statistically (P<0.05) higher in the first half of the swing (or at hip flexion/knee extension combinations of joint moments) than in the second half (or at hip extension/knee flexion combinations of joint moments). Mean EMG values of BF and SM were higher (P<0.05) in the second half of the swing than in the first half. EMG and joint moment peaks were substantially higher (P<0.05) in the swing phase of walking at 2.7 m/s than during the swing phase of running at the same speed. Correlation coefficients calculated between the differences (EMG(RF)-EMG(HA)) and (Mk-Mh), taken every 1% of the swing phase, were

  14. Vitamin K2 in different bovine muscles and breeds.

    PubMed

    Rødbotten, Rune; Gundersen, Thomas; Vermeer, Cees; Kirkhus, Bente

    2014-05-01

    Meat is a natural source of vitamin K, a vitamin associated with reduced bone loss and prevention of osteoporosis. Whether vitamin K content varies between breeds and muscles in cattle is not known. In the present study, contents of vitamin K1 (phylloquinone) and K2 (menaquinone, MK) were analysed in three different muscles from steers of two different breeds, Norwegian Red and Jersey, respectively. Results showed that MK4 was the most dominant of the vitamin K2 analogues, while only traces were found of MK6 and MK7. Both breeds had higher levels of MK4 in M. biceps femoris (BF) and M. longissimus dorsi (LD) compared to M. psoas major (PM). The results also showed significantly higher MK4 levels in muscles from Jersey compared to Norwegian Red. Furthermore, MK4 was not associated with intramuscular fat, suggesting a physiological role for MK4 in skeletal muscle cells. There were no association between vitamin K content and tenderness. PMID:24508562

  15. Muscular coordination of biceps brachii and brachioradialis in elbow flexion with respect to hand position

    PubMed Central

    Kleiber, Tim; Kunz, Leo; Disselhorst-Klug, Catherine

    2015-01-01

    Contribution of synergistic muscles toward specific movements over multi joint systems may change with varying position of distal or proximal joints. Purpose of this study is to reveal the relationship of muscular coordination of brachioradialis and biceps brachii during elbow flexion with respect to hand position and biomechanical advantages and disadvantages of biceps brachii. A group of 16 healthy subjects has been advised to perform 20 repetitions of single elbow flexion movements in different hand positions (pronated, neutral, and supinated). With a speed of 20°/s, simultaneously sEMG of biceps brachii and brachioradialis and kinematics of the movement were recorded in a motion analysis laboratory. Normalized to MVC the sEMG amplitudes of both muscles contributing to elbow flexion movements were compared in pronated, supinated, and neutral hand position over elbow joint angle. Significant differences in the contribution of brachioradialis were found in pronated hand position compared to supinated and neutral hand position while the muscular activity of biceps brachii shows no significant changes in any hand position. In conclusion, a statistical significant dependency of the inter-muscular coordination between biceps brachii and brachioradialis during elbow flexion with respect to hand position has been observed depending on a biomechanical disadvantage of biceps brachii. PMID:26300781

  16. Changes in Muscle Activity and Kinematics of Highly Trained Cyclists During Fatigue

    PubMed Central

    Dingwell, Jonathan B.; Joubert, Jason E.; Diefenthaeler, Fernando; Trinity, Joel D.

    2010-01-01

    Muscle fatigue may alter kinematics and contribute to repetitive strain injuries. This study quantified how both localized muscle fatigue and movement kinematics change over time during exhaustive cycling. Seven highly trained cyclists rode a stationary bicycle ergometer at 100% of their VO2max until voluntary exhaustion. Cycling kinematics and EMG activity from select lower extremity muscles were recorded. Cross-correlations were computed to quantify how EMG median frequencies (MDF) changed with changes in movement kinematics. All athletes maintained both cadence and power output for ~90% of the trial duration. Significant sustained muscle fatigue occurred in 18 of 28 muscles tested, most prominently in the biceps femoris (p = 0.020) and gastrocnemius (p = 0.018). Kinematics and MDF both fluctuated non-monotonically as subjects fatigued. Changes in MDF significantly preceded changes in mean trunk lean (p = 0.009) and hip angles (p = 0.025), and trunk lean range of motion (p = 0.029). Fluctuations in MDF were positively correlated with fluctuations in mean trunk lean (p = 0.009) and knee splay angles (p = 0.011), and with trunk lean (p = 0.002) and ankle (p = 0.001) range of motion. These results therefore establish a direct link between changes in muscle fatigue state and subsequent changes in movement kinematics during cycling.. PMID:18990638

  17. Altered muscle coordination when pedaling with independent cranks

    PubMed Central

    Hug, François; Boumier, Florian; Dorel, Sylvain

    2013-01-01

    Pedaling with independent cranks ensures each leg cycles independently of the other, and thus eliminates the contribution of the contralateral leg during the upstroke phase. Consequently the subject is required to actively pull-up the pedal to complete the cycle. The present study aimed to determine the acute effect of the use of independent cranks on muscle coordination during a submaximal pedaling exercise. Ten healthy males were asked to perform submaximal pedaling exercises at 100 Watts with normal fixed cranks (control condition) or independent cranks. Both 2-D pedal forces and electromyographic (EMG) SIGNALS of 10 lower limb muscles were recorded. When the mean EMG activity across the cycle was considered, the use of independent cranks significantly increased the activity level compared to control for Tibialis anterior (TA) (P = 0.0017; +336 ± 302%), Gastrocnemius medialis (GM) (P = 0.0005; +47 ± 25%), Rectus femoris (RF) (P = 0.005; +123 ± 153%), Biceps femoris (BF)—long head (P = 0.0001; +162 ± 97%), Semimembranosus (SM) (P = 0.0001; +304 ± 192%), and Tensor fascia latae (P = 0.0001; +586 ± 262%). The analysis of the four pedaling sectors revealed that the increased activity of hip and knee flexors mainly occurred during the top dead center and the upstroke phase. In addition, a high inter-individual variability was found in the way the participants adapted to pedaling with independent cranks. The present results showed that the enforced pull-up action required when using independent cranks was achieved by increasing the activation of hip and knee flexors. Further studies are needed to determine whether training with independent cranks has the potential to induce long-term changes in muscle coordination, and, if so, whether these changes are beneficial for cycling performance. PMID:24009587

  18. Changes in muscle activity after performing the FIFA 11+ programme part 2 for 4 weeks.

    PubMed

    Takata, Yasushi; Nakase, Junsuke; Inaki, Anri; Mochizuki, Takafumi; Numata, Hitoaki; Oshima, Takeshi; Kinuya, Seigo; Tsuchiya, Hiroyuki

    2016-10-01

    Changes in muscle activity were evaluated by positron emission tomography-computed tomography (PET-CT) after performing part 2 of the Fédération Internationale de Football Association's 11+ programme (11+) for 4 weeks. Eleven males performed part 2 of the 11+ for 20 min before and after 37 MBq of (18)F-fluorodeoxyglucose (FDG) was injected intravenously. PET-CT images were obtained 50 min after FDG injection. The participants were then instructed to perform part 2 of the 11+ 3 times per week for 4 consecutive weeks, after which another set of PET-CT images was obtained following the same procedure. Regions of interest were defined within 30 muscles. The standardised uptake value (SUV) of FDG by muscle tissue per unit volume was calculated, and FDG accumulation was compared between pre- and post-training PET-CT results. Performing part 2 of the 11+ for 4 weeks increased mean SUV in the sartorius, semimembranosus, biceps femoris, abductor hallucis, and flexor hallucis brevis muscles (P < 0.05). In conclusion, routinely performing part 2 of the 11+ for 4 weeks increased glucose uptake related to muscle activity in the hamstrings and hallux muscles. We speculate that there is some possibility of this change of muscle activity contributing to a decrease in sports-related injuries. PMID:26911842

  19. The Influence of an Unstable Surface on Trunk and Lower Extremity Muscle Activities during Variable Bridging Exercises

    PubMed Central

    Kim, Jung-hyun; Kim, Young; Chung, Yijung

    2014-01-01

    [Purpose] The aim of this study was to investigate the influence of an unstable surface on trunk and lower extremity muscle activities during various types of bridging exercises. [Subjects] Thirty healthy female adults voluntarily participated in this study. [Methods] All subjects were asked to perform 3 different bridging exercises (bridging exercise, single leg lift bridging exercise, single leg cross bridging exercise) with and without an unstable surface. The trunk and lower extremity muscle activities were measured by using surface electromyography during bridging exercise. [Results] During the bridging exercise (BE), single leg lift bridging exercise (LBE), and single leg cross bridging exercise (CBE), the muscle activities of the external oblique muscle (EO), erector spinae (ES), and biceps femoris (BF) were significantly higher on an unstable surface than on a stable surface. The muscle activities of the EO on both sides, contralateral BF, and ipsilateral ES were significantly higher during LBE than during BE and CBE. [Conclusion] Use of an unstable surface increases muscle activity of the trunk and lower extremities, and single leg lift bridging exercise increases the muscle activity of the EO on both sides, ipsilateral ES, and contralateral BF. PMID:24764625

  20. Influence of type of muscle on volatile compounds throughout the manufacture of Celta dry-cured ham.

    PubMed

    Bermúdez, Roberto; Franco, Daniel; Carballo, Javier; Lorenzo, José M

    2015-12-01

    The effect of muscle type on volatile compounds throughout the manufacture of Celta dry-cured ham was studied. Thirty Celta ham were taken from the fresh pieces, after the end of the salting stage, after 120 days of post-salting, after the end of drying-ripening stage, and after 165 and 330 days of "bodega" step. The volatile compounds from semimembranosus (SM) and biceps femoris (BF) muscles were extracted by using headspace-solid phase microextraction (SPME) and analysed by gas chromatographic/mass spectrometry (GC/MS). Fifty-five volatile compounds were identified and quantified. The number of volatile compounds increased during the different steps of the process, reaching at 550 days of process 39 and 40 volatile compounds in SM and BF muscles, respectively. Results indicated that the most abundant chemical family in flavour at the end of the manufacturing process were esters in the two muscles studied, followed by aliphatic hydrocarbons and aldehydes. During the manufacturing process, an increase in the total amount of volatile compounds was observed, being this increase more marked in samples from BF muscle (from 550.7 to 1118.9 × 10(6) area units) than in samples from SM muscle (from 459.3 to 760.4 × 10(6) area units). Finally, muscle type displayed significant (P < 0.05) differences for four esters, two alcohols, one aldehyde, one ketone and four aliphatic hydrocarbons. PMID:25331495

  1. Muscle activation during exercise in severe acute hypoxia: role of absolute and relative intensity.

    PubMed

    Torres-Peralta, Rafael; Losa-Reyna, José; González-Izal, Miriam; Perez-Suarez, Ismael; Calle-Herrero, Jaime; Izquierdo, Mikel; Calbet, José A L

    2014-12-01

    The aim of this study was to determine the influence of severe acute hypoxia on muscle activation during whole body dynamic exercise. Eleven young men performed four incremental cycle ergometer tests to exhaustion breathing normoxic (FIO2=0.21, two tests) or hypoxic gas (FIO2=0.108, two tests). Surface electromyography (EMG) activities of rectus femoris (RF), vastus medialis (VL), vastus lateralis (VL), and biceps femoris (BF) were recorded. The two normoxic and the two hypoxic tests were averaged to reduce EMG variability. Peak VO2 was 34% lower in hypoxia than in normoxia (p<0.05). The EMG root mean square (RMS) increased with exercise intensity in all muscles (p<0.05), with greater effect in hypoxia than in normoxia in the RF and VM (p<0.05), and a similar trend in VL (p=0.10). At the same relative intensity, the RMS was greater in normoxia than in hypoxia in RF, VL, and BF (p<0.05), with a similar trend in VM (p=0.08). Median frequency increased with exercise intensity (p<0.05), and was higher in hypoxia than in normoxia in VL (p<0.05). Muscle contraction burst duration increased with exercise intensity in VM and VL (p<0.05), without clear effects of FIO2. No significant FIO2 effects on frequency domain indices were observed when compared at the same relative intensity. In conclusion, muscle activation during whole body exercise increases almost linearly with exercise intensity, following a muscle-specific pattern, which is adjusted depending on the FIO2 and the relative intensity of exercise. Both VL and VM are increasingly involved in power output generation with the increase of intensity and the reduction in FIO2. PMID:25225839

  2. Lower Extremity Muscle Activity During a Women’s Overhand Lacrosse Shot

    PubMed Central

    Millard, Brianna M.; Mercer, John A.

    2014-01-01

    The purpose of this study was to describe lower extremity muscle activity during the lacrosse shot. Participants (n=5 females, age 22±2 years, body height 162.6±15.2 cm, body mass 63.7±23.6 kg) were free from injury and had at least one year of lacrosse experience. The lead leg was instrumented with electromyography (EMG) leads to measure muscle activity of the rectus femoris (RF), biceps femoris (BF), tibialis anterior (TA), and medial gastrocnemius (GA). Participants completed five trials of a warm-up speed shot (Slow) and a game speed shot (Fast). Video analysis was used to identify the discrete events defining specific movement phases. Full-wave rectified data were averaged per muscle per phase (Crank Back Minor, Crank Back Major, Stick Acceleration, Stick Deceleration). Average EMG per muscle was analyzed using a 4 (Phase) × 2 (Speed) ANOVA. BF was greater during Fast vs. Slow for all phases (p<0.05), while TA was not influenced by either Phase or Speed (p>0.05). RF and GA were each influenced by the interaction of Phase and Speed (p<0.05) with GA being greater during Fast vs. Slow shots during all phases and RF greater during Crank Back Minor and Major as well as Stick Deceleration (p<0.05) but only tended to be greater during Stick Acceleration (p=0.076) for Fast vs. Slow. The greater muscle activity (BF, RF, GA) during Fast vs. Slow shots may have been related to a faster approach speed and/or need to create a stiff lower extremity to allow for faster upper extremity movements. PMID:25114727

  3. Whole-body vibration effects on the muscle activity of upper and lower body muscles during the baseball swing in recreational baseball hitters.

    PubMed

    Reyes, Gabriel F; Dickin, D Clark; Crusat, Nolan J K; Dolny, Dennis G

    2011-11-01

    The purpose of this study was to evaluate the effects of whole-body vibration (WBV) on the muscle recruitment of selected upper and lower body muscles during the baseball swing. Participants were recreationally trained males (n = 16, 22 +/- 2 years, 181.4 +/- 7.4 cm, 84.7 +/- 9.0 kg), with previous baseball experience. Subjects participated in three randomized sessions on separate days, consisting of three sets of five swings offa hitting tee. Exercises (upper and lower body dynamic and static movements) with or without WBVexposure were performed between swing sets. During each swing, the gastrocnemius, biceps femoris, gluteus maximus, pectoralis major, latissimus dorsi, and triceps brachii were evaluated for electromyographic (EMG) activity. EMG values were normalized to EMG measured during maximal voluntary isometric contraction. Statistical analysis revealed no significant differences in EMG activity across the three treatments. In addition, the results displayed a specific muscle recruitment order during the swing, starting with the lower body followed by the upper body muscles. This study was the first to report the recruitment order during the baseball swing. Although acute exposure to WBV did not significantly alter the muscle recruitment, these results may prove useful for practitioners looking to enhance baseball swing performance. PMID:22303781

  4. Relationship between skin temperature and muscle activation during incremental cycle exercise.

    PubMed

    Priego Quesada, Jose I; Carpes, Felipe P; Bini, Rodrigo R; Salvador Palmer, Rosario; Pérez-Soriano, Pedro; Cibrián Ortiz de Anda, Rosa M

    2015-02-01

    While different studies showed that better fitness level adds to the efficiency of the thermoregulatory system, the relationship between muscular effort and skin temperature is still unknown. Therefore, the present study assessed the relationship between neuromuscular activation and skin temperature during cycle exercise. Ten physically active participants performed an incremental workload cycling test to exhaustion while neuromuscular activations were recorded (via surface electromyography - EMG) from rectus femoris, vastus lateralis, biceps femoris and gastrocnemius medialis. Thermographic images were recorded before, immediately after and 10 min after finishing the cycling test, at four body regions of interest corresponding to the muscles where neuromuscular activations were monitored. Frequency band analysis was conducted to assess spectral properties of EMG signals in order to infer on priority in recruitment of motor units. Significant inverse relationship between changes in skin temperature and changes in overall neuromuscular activation for vastus lateralis was observed (r<-0.5 and p<0.04). Significant positive relationship was observed between skin temperature and low frequency components of neuromuscular activation from vastus lateralis (r>0.7 and p<0.01). Participants with larger overall activation and reduced low frequency component for vastus lateralis activation presented a better adaptive response of their thermoregulatory system by showing fewer changes in skin temperature after incremental cycling test. PMID:25660627

  5. BICEP2 III: Instrumental systematics

    SciTech Connect

    Ade, P. A. R.

    2015-11-23

    In a companion paper, we have reported a >5σ detection of degree scale B-mode polarization at 150 GHz by the Bicep2 experiment. Here we provide a detailed study of potential instrumental systematic contamination to that measurement. We focus extensively on spurious polarization that can potentially arise from beam imperfections. We present a heuristic classification of beam imperfections according to their symmetries and uniformities, and discuss how resulting contamination adds or cancels in maps that combine observations made at multiple orientations of the telescope about its boresight axis. We introduce a technique, which we call "deprojection," for filtering the leading order beam-induced contamination from time-ordered data, and show that it reduces power in Bicep2's actual and null-test BB spectra consistent with predictions using high signal-to-noise beam shape measurements. We detail the simulation pipeline that we use to directly simulate instrumental systematics and the calibration data used as input to that pipeline. Finally, we present the constraints on BB contamination from individual sources of potential systematics. We find that systematics contribute BB power that is a factor of ~10× below Bicep2's three-year statistical uncertainty, and negligible compared to the observed BB signal. Lastly, the contribution to the best-fit tensor/scalar ratio is at a level equivalent to r = (3–6) × 10–3.

  6. BICEP2 III: Instrumental Systematics

    NASA Astrophysics Data System (ADS)

    BICEP2 Collaboration; Ade, P. A. R.; Aikin, R. W.; Barkats, D.; Benton, S. J.; Bischoff, C. A.; Bock, J. J.; Brevik, J. A.; Buder, I.; Bullock, E.; Dowell, C. D.; Duband, L.; Filippini, J. P.; Fliescher, S.; Golwala, S. R.; Halpern, M.; Hasselfield, M.; Hildebrandt, S. R.; Hilton, G. C.; Irwin, K. D.; Karkare, K. S.; Kaufman, J. P.; Keating, B. G.; Kernasovskiy, S. A.; Kovac, J. M.; Kuo, C. L.; Leitch, E. M.; Lueker, M.; Netterfield, C. B.; Nguyen, H. T.; O'Brient, R.; Ogburn, R. W., IV; Orlando, A.; Pryke, C.; Richter, S.; Schwarz, R.; Sheehy, C. D.; Staniszewski, Z. K.; Sudiwala, R. V.; Teply, G. P.; Tolan, J. E.; Turner, A. D.; Vieregg, A. G.; Wong, C. L.; Yoon, K. W.

    2015-12-01

    In a companion paper, we have reported a >5σ detection of degree scale B-mode polarization at 150 GHz by the BICEP2 experiment. Here we provide a detailed study of potential instrumental systematic contamination to that measurement. We focus extensively on spurious polarization that can potentially arise from beam imperfections. We present a heuristic classification of beam imperfections according to their symmetries and uniformities, and discuss how resulting contamination adds or cancels in maps that combine observations made at multiple orientations of the telescope about its boresight axis. We introduce a technique, which we call "deprojection," for filtering the leading order beam-induced contamination from time-ordered data, and show that it reduces power in BICEP2's actual and null-test BB spectra consistent with predictions using high signal-to-noise beam shape measurements. We detail the simulation pipeline that we use to directly simulate instrumental systematics and the calibration data used as input to that pipeline. Finally, we present the constraints on BB contamination from individual sources of potential systematics. We find that systematics contribute BB power that is a factor of ∼10× below BICEP2's three-year statistical uncertainty, and negligible compared to the observed BB signal. The contribution to the best-fit tensor/scalar ratio is at a level equivalent to r = (3-6) × 10-3.

  7. BICEP2 III: Instrumental systematics

    DOE PAGESBeta

    Ade, P. A. R.

    2015-11-23

    In a companion paper, we have reported a >5σ detection of degree scale B-mode polarization at 150 GHz by the Bicep2 experiment. Here we provide a detailed study of potential instrumental systematic contamination to that measurement. We focus extensively on spurious polarization that can potentially arise from beam imperfections. We present a heuristic classification of beam imperfections according to their symmetries and uniformities, and discuss how resulting contamination adds or cancels in maps that combine observations made at multiple orientations of the telescope about its boresight axis. We introduce a technique, which we call "deprojection," for filtering the leading ordermore » beam-induced contamination from time-ordered data, and show that it reduces power in Bicep2's actual and null-test BB spectra consistent with predictions using high signal-to-noise beam shape measurements. We detail the simulation pipeline that we use to directly simulate instrumental systematics and the calibration data used as input to that pipeline. Finally, we present the constraints on BB contamination from individual sources of potential systematics. We find that systematics contribute BB power that is a factor of ~10× below Bicep2's three-year statistical uncertainty, and negligible compared to the observed BB signal. Lastly, the contribution to the best-fit tensor/scalar ratio is at a level equivalent to r = (3–6) × 10–3.« less

  8. Utility for production of massaged products of selected wild boar muscles originating from wetlands and an arable area.

    PubMed

    Zochowska-Kujawska, J; Lachowicz, K; Sobczak, M; Bienkiewicz, G

    2010-07-01

    Percentages of muscle fibre types, area of intramuscular fatty tissue (IMF) and changes in hardness, rheological properties as well as mean fibre cross-sectional area (CSA), and endomysium thickness of muscles from wild boars hunted in two different ecosystems (arable area vs. wetlands) were evaluated. Three muscles: Biceps femoris (BF), Semimembranosus (SM), and Longissimus (L) subjected to massaging (or not) for 4h were studied. Fibre type percentage and structural elements: mean muscle fibre cross-sectional area (CSA), endomysium thickness, and amount of intramuscular fat (IMF) were measured using a computer image analysis programme. Fibre properties of muscles from wild boars originating from arable areas did not differ from those of wild boars from wetlands. Muscles of wild boars hunted in the arable area of the forest contained significantly higher amounts of intramuscular fat and lower values of hardness, viscous and elastic moduli than the corresponding muscles of animals from the marshy area. Of the muscles tested, BF with its higher percentage of red fibres and fibre CSA, thicker endomysium and lower amount of IMF compared to SM and L muscles, was tougher and more elastic and viscous than the other two muscles. Muscle massaging resulted in an increase in the fibre CSA and decrease in thickness of the endomysium and as a consequence reduced hardness and augmented the viscous and elastic modules of the muscles. Muscles with higher amounts of intramuscular fat, lower values of textural parameters and percentage of red fibres as well as smaller structural elements showed higher susceptibility to massaging. Muscles from animals hunted on wetlands compared to those from wild boar shot on the arable land and BF compared to SM and L, were slightly less susceptible to mechanical tenderization. PMID:20416815

  9. Post-mortem oxidative stability of three yak (Bos grunniens) muscles as influenced by animal age.

    PubMed

    Wen, Wenting; Luo, Xiaolin; Xia, Baixue; Guan, Jiuqiang; Nie, Yuanyang; Li, Lu; Duan, Jingyue; Suman, Surendranath P; Sun, Qun

    2015-07-01

    The influence of animal age and muscle source on the oxidative stability of yak steaks was examined. Longissimus thoracis (LT) muscles from yaks of different age groups (0.5, 1.5, 2.5, and 3.5 years), and three muscle sources of LT, Psoas major (PM), and Biceps femoris (BF) from yaks of 0.5, 1.5, and 2.5 years, were evaluated for metmyoglobin content, activity of antioxidant enzymes, and antioxidant capacity. Oxidative stability was influenced (P<0.05) by muscle source and animal age. LT steaks from 0.5, 1.5, and 2.5 year old yaks exhibited lower (P<0.05) metmyoglobin content than their PM and BF counterparts. Furthermore, LT steaks from 3.5 year old yaks demonstrated lower (P<0.05) metmyoglobin content and greater (P<0.05) activities of antioxidant enzymes than LT steaks from other age groups. These results indicated the necessity to develop muscle- and age-specific processing strategies to improve color and oxidative stability of yak meat. PMID:25839885

  10. Muscle imaging in patients with tubular aggregate myopathy caused by mutations in STIM1

    PubMed Central

    Tasca, Giorgio; D'Amico, Adele; Monforte, Mauro; Nadaj-Pakleza, Aleksandra; Vialle, Marc; Fattori, Fabiana; Vissing, John; Ricci, Enzo; Bertini, Enrico

    2015-01-01

    Tubular aggregate myopathy is a genetically heterogeneous disease characterized by tubular aggregates as the hallmark on muscle biopsy. Mutations in STIM1 have recently been identified as one genetic cause in a number of tubular aggregate myopathy cases. To characterize the pattern of muscle involvement in this disease, upper and lower girdles and lower limbs were imaged in five patients with mutations in STIM1, and the scans were compared with two patients with tubular aggregate myopathy not caused by mutations in STIM1. A common pattern of involvement was found in STIM1-mutated patients, although with variable extent and severity of lesions. In the upper girdle, the subscapularis muscle was invariably affected. In the lower limbs, all the patients showed a consistent involvement of the flexor hallucis longus, which is very rarely affected in other muscle diseases, and a diffuse involvement of thigh and posterior leg with sparing of gracilis, tibialis anterior and, to a lesser extent, short head of biceps femoris. Mutations in STIM1 are associated with a homogeneous involvement on imaging despite variable clinical features. Muscle imaging can be useful in identifying STIM1-mutated patients especially among other forms of tubular aggregate myopathy. PMID:26255678

  11. Age and Diet Affect Gene Expression Profile in Canine Skeletal Muscle

    PubMed Central

    Middelbos, Ingmar S.; Vester, Brittany M.; Karr-Lilienthal, Lisa K.; Schook, Lawrence B.; Swanson, Kelly S.

    2009-01-01

    We evaluated gene transcription in canine skeletal muscle (biceps femoris) using microarray analysis to identify effects of age and diet on gene expression. Twelve female beagles were used (six 1-year olds and six 12-year olds) and they were fed one of two experimental diets for 12 months. One diet contained primarily plant-based protein sources (PPB), whereas the second diet contained primarily animal-based protein sources (APB). Affymetrix GeneChip Canine Genome Arrays were used to hybridize extracted RNA. Age had the greatest effect on gene transcription (262 differentially expressed genes), whereas the effect of diet was relatively small (22 differentially expressed genes). Effects of age (regardless of diet) were most notable on genes related to metabolism, cell cycle and cell development, and transcription function. All these genes were predominantly down-regulated in geriatric dogs. Age-affected genes that were differentially expressed on only one of two diets were primarily noted in the PPB diet group (144/165 genes). Again, genes related to cell cycle (22/35) and metabolism (15/19) had predominantly decreased transcription in geriatric dogs, but 6/8 genes related to muscle development had increased expression. Effects of diet on muscle gene expression were mostly noted in geriatric dogs, but no consistent patterns in transcription were observed. The insight these data provide into gene expression profiles of canine skeletal muscle as affected by age, could serve as a foundation for future research pertaining to age-related muscle diseases. PMID:19221602

  12. Muscle imaging in patients with tubular aggregate myopathy caused by mutations in STIM1.

    PubMed

    Tasca, Giorgio; D'Amico, Adele; Monforte, Mauro; Nadaj-Pakleza, Aleksandra; Vialle, Marc; Fattori, Fabiana; Vissing, John; Ricci, Enzo; Bertini, Enrico

    2015-11-01

    Tubular aggregate myopathy is a genetically heterogeneous disease characterized by tubular aggregates as the hallmark on muscle biopsy. Mutations in STIM1 have recently been identified as one genetic cause in a number of tubular aggregate myopathy cases. To characterize the pattern of muscle involvement in this disease, upper and lower girdles and lower limbs were imaged in five patients with mutations in STIM1, and the scans were compared with two patients with tubular aggregate myopathy not caused by mutations in STIM1. A common pattern of involvement was found in STIM1-mutated patients, although with variable extent and severity of lesions. In the upper girdle, the subscapularis muscle was invariably affected. In the lower limbs, all the patients showed a consistent involvement of the flexor hallucis longus, which is very rarely affected in other muscle diseases, and a diffuse involvement of thigh and posterior leg with sparing of gracilis, tibialis anterior and, to a lesser extent, short head of biceps femoris. Mutations in STIM1 are associated with a homogeneous involvement on imaging despite variable clinical features. Muscle imaging can be useful in identifying STIM1-mutated patients especially among other forms of tubular aggregate myopathy. PMID:26255678

  13. Effect of ski simulator training on kinematic and muscle activation of the lower extremities

    PubMed Central

    Moon, Jeheon; Koo, Dohoon; Kim, Kitae; Shin, Insik; Kim, Hyeyoung; Kim, Jinhae

    2015-01-01

    [Purpose] This study aimed to verify the effectiveness of an augmented reality-based ski simulator through analyzing the changes in movement patterns as well as the engagement of major muscles of the lower body. [Subjects] Seven subjects participated in the study. All were national team-level athletes studying at “K” Sports University in Korea who exhibited comparable performance levels and had no record of injuries in the preceding 6 months (Age 23.4 ± 3.8 years; Height 172.6 ± 12.1 cm; Weight 72.3 ± 16.2 kg; Experience 12.3 ± 4.8 years). [Methods] A reality-based ski simulator developed by a Korean manufacturer was used for the study. Three digital video cameras and a wireless electromyography system were used to perform 3-dimensional motion analysis and measure muscle activation level. [Results] Left hip angulation was found to increase as the frequency of the turns increased. Electromyography data revealed that the activation level of the quadriceps group’s extension muscles and the biceps femoris group’s flexing muscles had a crossing pattern. [Conclusion] Sustained training using an augmented reality-based ski simulator resulted in movements that extended the lower body joints, which is thought to contribute to increasing muscle fatigue. PMID:26357449

  14. The modified norwegian method of biceps tenodesis.

    PubMed

    Foad, Abdullah; Faruqui, Sami; Hanna, Courtney C

    2014-02-01

    This technical note describes a method of biceps tenodesis called the Modified Norwegian Method that is an all-arthroscopic, intra-articular, bony biceps tenodesis that uses a suture shuttle passer through an anterosuperolateral portal. It allows for easy passage of suture through the long head of the biceps tendon while one is viewing through the posterior portal. We believe this method to be a very reasonable and simple method of biceps tenodesis that has complication rates similar to those described for subpectoral and other methods of fixation. PMID:24843845

  15. Muscle activation during various hamstring exercises.

    PubMed

    McAllister, Matt J; Hammond, Kelley G; Schilling, Brian K; Ferreria, Lucas C; Reed, Jacob P; Weiss, Lawrence W

    2014-06-01

    The dorsal muscles of the lower torso and extremities have often been denoted the "posterior chain." These muscles are used to support the thoracic and lumbar spine and peripheral joints, including the hip, knee, and ankle on the dorsal aspect of the body. This study investigated the relative muscle activity of the hamstring group and selected surrounding musculature during the leg curl, good morning, glute-ham raise, and Romanian deadlift (RDL). Twelve healthy, weight-trained men performed duplicate trials of single repetitions at 85% 1-repetition maximum for each lift in random order, during which surface electromyography and joint angle data were obtained. Repeated measures analysis of variance across the 4 exercises was performed to compare the activity from the erector spinae (ES), gluteus medius (GMed), semitendinosus (ST), biceps femoris (BF), and medial gastrocnemius (MGas). Significant differences (p ≤ 0.05) were noted in eccentric muscle activity between exercise for the MGas (p < 0.027), ST (p < 0.001), BF (p < 0.001), and ES (p = 0.032), and in concentric muscle activity, for the ES (p < 0.001), BF (p = 0.010), ST (p = 0.009), MGas (p < 0.001), and the GMed (p = 0.018). Bonferroni post hoc analysis revealed significant pairwise differences during eccentric actions for the BF, ST, and MGas. Post hoc analysis also revealed significant pairwise differences during concentric actions for the ES, BF, ST, MGas, and GMed. Each of these showed effect sizes that are large or greater. The main findings of this investigation are that the ST is substantially more active than the BF among all exercises, and hamstring activity was maximized in the RDL and glute-ham raise. Therefore, athletes and coaches who seek to maximize the involvement of the hamstring musculature should consider focusing on the glute-ham raise and RDL. PMID:24149748

  16. Focusing on Increasing Velocity during Heavy Resistance Knee Flexion Exercise Boosts Hamstring Muscle Activity in Chronic Stroke Patients.

    PubMed

    Vinstrup, Jonas; Calatayud, Joaquin; Jakobsen, Markus D; Sundstrup, Emil; Andersen, Lars L

    2016-01-01

    Background. Muscle strength is markedly reduced in stroke patients, which has negative implications for functional capacity and work ability. Different types of feedback during strength training exercises may alter neuromuscular activity and functional gains. Objective. To compare levels of muscle activity during conditions of blindfolding and intended high contraction speed with a normal condition of high-intensity knee flexions. Methods. Eighteen patients performed unilateral machine knee flexions with a 10-repetition maximum load. Surface electromyography (EMG) was recorded from the quadrics and hamstring muscles and normalized to maximal EMG (nEMG) of the nonparetic limb. Results. For the paretic leg, the speed condition showed higher values of muscle activity compared with the normal and blindfolded conditions for both biceps femoris and semitendinosus. Likewise, the speed condition showed higher co-contraction values compared with the normal and blindfolded conditions for the vastus lateralis. No differences were observed between exercise conditions for the nonparetic leg. Conclusion. Chronic stroke patients are capable of performing heavy resistance training with intended high speed of contraction. Focusing on speed during the concentric phase elicited higher levels of muscle activity of the hamstrings compared to normal and blindfolded conditions, which may have implications for regaining fast muscle strength in stroke survivors. PMID:27525118

  17. Focusing on Increasing Velocity during Heavy Resistance Knee Flexion Exercise Boosts Hamstring Muscle Activity in Chronic Stroke Patients

    PubMed Central

    Jakobsen, Markus D.

    2016-01-01

    Background. Muscle strength is markedly reduced in stroke patients, which has negative implications for functional capacity and work ability. Different types of feedback during strength training exercises may alter neuromuscular activity and functional gains. Objective. To compare levels of muscle activity during conditions of blindfolding and intended high contraction speed with a normal condition of high-intensity knee flexions. Methods. Eighteen patients performed unilateral machine knee flexions with a 10-repetition maximum load. Surface electromyography (EMG) was recorded from the quadrics and hamstring muscles and normalized to maximal EMG (nEMG) of the nonparetic limb. Results. For the paretic leg, the speed condition showed higher values of muscle activity compared with the normal and blindfolded conditions for both biceps femoris and semitendinosus. Likewise, the speed condition showed higher co-contraction values compared with the normal and blindfolded conditions for the vastus lateralis. No differences were observed between exercise conditions for the nonparetic leg. Conclusion. Chronic stroke patients are capable of performing heavy resistance training with intended high speed of contraction. Focusing on speed during the concentric phase elicited higher levels of muscle activity of the hamstrings compared to normal and blindfolded conditions, which may have implications for regaining fast muscle strength in stroke survivors. PMID:27525118

  18. Impact of season on the fatty acid profiles of male and female blesbok (Damaliscus pygargus phillipsi) muscles.

    PubMed

    Neethling, J; Britz, T J; Hoffman, L C

    2014-12-01

    This study quantified the impact of season on fatty acid profiles of male and female blesbok muscles (longissimus thoracis et lumborum, biceps femoris, semimembranosus, semitendinosus, infraspinatus, and supraspinatus). Eight mature blesbok were harvested per season (winter and spring). Gender and muscle type influenced (p<0.05) the fatty acid profiles of blesbok muscles, while season only influenced the C18:3ω3 (α-linolenic acid, ALA) percentages and therefore the total omega-3 poly-unsaturated fatty acids (total ω3 PUFA). Female muscles had higher C16:0 (palmitic acid) (21.01%±0.256 vs. 19.05%±0.296) and total MUFA percentages, while male muscles had higher (p<0.05) C18:2ω6c, C20:5ω3, total ω3 PUFA (11.08%±0.382 vs. 8.50%±0.367), and total PUFA (43.03%±0.904 vs. 29.59%±1.164) percentages, contributing to higher poly-unsaturated to saturated fatty acid ratios (PUFA:SFA ratios). Differences in fatty acid profiles were attributed more to gender and anatomical location of muscles, than seasonal differences in diets. PMID:25089783

  19. Lower Extremity Muscle Activation and Kinematics of Catchers When Throwing Using Various Squatting and Throwing Postures

    PubMed Central

    Peng, Yi-Chien; Lo, Kuo-Cheng; Wang, Lin-Hwa

    2015-01-01

    This study investigated the differences in joint motions and muscle activities of the lower extremities involved in various squatting postures. The motion capture system with thirty-one reflective markers attached on participants was used for motion data collection. The electromyography system was applied over the quadriceps, biceps femoris, tibialis anterior, and gastrocnemius muscles of the pivot and stride leg. The joint extension and flexion in wide squatting are greater than in general squatting (p = 0.005). Knee joint extension and flexion in general squatting are significantly greater than in wide squatting (p = 0.001). The adduction and abduction of the hip joint in stride passing are significantly greater than in step squatting (p = 0.000). Furthermore, the adduction and abduction of the knee joint in stride passing are also significantly greater than in step squatting (p = 0.000). When stride passing is performed, the muscle activation of the hamstring of the pivot foot in general squatting is significantly greater than in wide squatting (p < 0.05), and this difference continues to the stride period. Most catchers use a general or wide squatting width, exclusive of a narrow one. Therefore, the training design for strengthening the lower extremity muscles should consider the appropriateness of the common squat width to enhance squat-up performance. For lower limb muscle activation, wide squatting requires more active gastrocnemius and tibialis anterior muscles. Baseball players should extend the knee angle of the pivot foot before catching the ball. Key points Common squatting width can enhance squat-up performance through strengthening lower body muscle. Wide squatting width might improve lower body muscle activation, leading to more effective communication between the brain and the muscle group. The benefit might be improved coordination of lower body muscle. Common and wide squatting width might be cycled through training to enhance the strengthen and

  20. Lower Extremity Muscle Activation and Kinematics of Catchers When Throwing Using Various Squatting and Throwing Postures.

    PubMed

    Peng, Yi-Chien; Lo, Kuo-Cheng; Wang, Lin-Hwa

    2015-09-01

    This study investigated the differences in joint motions and muscle activities of the lower extremities involved in various squatting postures. The motion capture system with thirty-one reflective markers attached on participants was used for motion data collection. The electromyography system was applied over the quadriceps, biceps femoris, tibialis anterior, and gastrocnemius muscles of the pivot and stride leg. The joint extension and flexion in wide squatting are greater than in general squatting (p = 0.005). Knee joint extension and flexion in general squatting are significantly greater than in wide squatting (p = 0.001). The adduction and abduction of the hip joint in stride passing are significantly greater than in step squatting (p = 0.000). Furthermore, the adduction and abduction of the knee joint in stride passing are also significantly greater than in step squatting (p = 0.000). When stride passing is performed, the muscle activation of the hamstring of the pivot foot in general squatting is significantly greater than in wide squatting (p < 0.05), and this difference continues to the stride period. Most catchers use a general or wide squatting width, exclusive of a narrow one. Therefore, the training design for strengthening the lower extremity muscles should consider the appropriateness of the common squat width to enhance squat-up performance. For lower limb muscle activation, wide squatting requires more active gastrocnemius and tibialis anterior muscles. Baseball players should extend the knee angle of the pivot foot before catching the ball. Key pointsCommon squatting width can enhance squat-up performance through strengthening lower body muscle.Wide squatting width might improve lower body muscle activation, leading to more effective communication between the brain and the muscle group. The benefit might be improved coordination of lower body muscle.Common and wide squatting width might be cycled through training to enhance the strengthen and

  1. Two-stage muscle activity responses in decisions about leg movement adjustments during trip recovery.

    PubMed

    Potocanac, Zrinka; Pijnappels, Mirjam; Verschueren, Sabine; van Dieën, Jaap; Duysens, Jacques

    2016-01-01

    Studies on neural decision making mostly investigated fast corrective adjustments of arm movements. However, fast leg movement corrections deserve attention as well, since they are often required to avoid falling after balance perturbations. The present study aimed at elucidating the mechanisms behind fast corrections of tripping responses by analyzing the concomitant leg muscle activity changes. This was investigated in seven young adults who were tripped in between normal walking trials and took a recovery step by elevating the tripped leg over the obstacle. In some trials, a forbidden landing zone (FZ) was presented behind the obstacle, at the subjects' preferred foot landing position, forcing a step correction. Muscle activity of the tripped leg gastrocnemius medialis (iGM), tibialis anterior (iTA), rectus femoris (iRF), and biceps femoris (iBF) muscles was compared between normal trips presented before any FZ appearance, trips with a FZ, and normal trips presented in between trips with a FZ ("catch" trials). When faced with a real or expected (catch trials) FZ, subjects shortened their recovery steps. The underlying changes in muscle activity consisted of two stages. The first stage involved reduced iGM activity, occurring at a latency shorter than voluntary reaction, followed by reduced iTA and increased iBF and iGM activities occurring at longer latencies. The fast response was not related to step shortening, but longer latency responses clearly were functional. We suggest that the initial response possibly acts as a "pause," allowing the nervous system to integrate the necessary information and prepare the subsequent, functional movement adjustment. PMID:26561597

  2. Patterns of strain and activation in the thigh muscles of goats across gaits during level locomotion.

    PubMed

    Gillis, Gary B; Flynn, John P; McGuigan, Polly; Biewener, Andrew A

    2005-12-01

    Unlike homologous muscles in many vertebrates, which appear to function similarly during a particular mode of locomotion (e.g. red muscle in swimming fish, pectoralis muscle in flying birds, limb extensors in jumping and swimming frogs), a major knee extensor in mammalian quadrupeds, the vastus lateralis, appears to operate differently in different species studied to date. In rats, the vastus undergoes more stretching early in stance than shortening in later stance. In dogs, the reverse is true; more substantial shortening follows small amounts of initial stretching. And in horses, while the vastus strain trajectory is complex, it is characterized mainly by shortening during stance. In this study, we use sonomicrometry and electromyography to study the vastus lateralis and biceps femoris of goats, with three goals in mind: (1) to see how these muscles work in comparison to homologous muscles studied previously in other taxa; (2) to address how speed and gait impact muscle actions and (3) to test whether fascicles in different parts of the same muscle undergo similar length changes. Results indicate that the biceps femoris undergoes substantial shortening through much of stance, with higher strains in walking and trotting [32-33% resting length (L0)] than galloping (22% L0). These length changes occur with increasing biceps EMG intensities as animals increase speed from walking to galloping. The vastus undergoes a stretch-shorten cycle during stance. Stretching strains are higher during galloping (15% L0) than walking and trotting (9% L0). Shortening strains follow a reverse pattern and are greatest in walking (24% L0), intermediate in trotting (20% L0) and lowest during galloping (17% L0). As a result, the ratio of stretching to shortening increases from below 0.5 in walking and trotting to near 1.0 during galloping. This increasing ratio suggests that the vastus does relatively more positive work than energy absorption at the slower speeds compared with galloping

  3. Muscle-specific colour stability of blesbok (Damaliscus pygargus phillipsi) meat.

    PubMed

    Neethling, Nikki E; Suman, Surendranath P; Sigge, Gunnar O; Hoffman, Louwrens C

    2016-09-01

    The increasing demand for meat from alternative species, such as blesbok (Damaliscus pygargus phillipsi), gives rise to the need for characterizing the quality attributes of fresh meat from these species. While muscle-specific colour stability has been extensively studied in conventional livestock, limited information is available on this phenomenon in game meat. Therefore, the objective of this study was to examine the colour stability of three major blesbok muscles, infraspinatus (IS), longissimus thoracis et lumborum (LTL) and biceps femoris (BF). Instrumental colour, surface myoglobin redox forms, and biochemical attributes influencing colour stability were measured on 2.5-cm steaks from blesbok IS, LTL, and BF during refrigerated storage under aerobic conditions for eight days. IS steaks consistently demonstrated higher (P≤0.05) redness, colour stability, and chroma than the LTL and BF steaks. These findings suggested that blesbok IS muscle is more colour-stable than its LTL and BF counterparts. The game industry may employ muscle-specific strategies to improve marketability of fresh blesbok meat. PMID:27136392

  4. Individual Muscle use in Hamstring Exercises by Soccer Players Assessed using Functional MRI.

    PubMed

    Fernandez-Gonzalo, R; Tesch, P A; Linnehan, R M; Kreider, R B; Di Salvo, V; Suarez-Arrones, L; Alomar, X; Mendez-Villanueva, A; Rodas, G

    2016-06-01

    This study used functional magnetic resonance imaging (fMRI) to compare individual muscle use in exercises aimed at preventing hamstring injuries. Thirty-six professional soccer players were randomized into 4 groups, each performing either Nordic hamstring, flywheel leg curl, Russian belt or conic-pulley exercise. MRIs were performed before and immediately after a bout of 4 sets of 8 repetitions. Pre-post exercise differences in contrast shift (T2) were analyzed for the long (BFLh) and short head (BFSh) of biceps femoris, semitendinosus (ST), semimembranosus (SM) and gracilis (GR) muscles. Flywheel leg curl increased (P<0.001) T2 of GR (95%), ST (65%), BFSh (51%) and BFLh (14%). After the Nordic hamstring, GR (39%), ST (16%) and BFSh (14%) showed increased T2 (P<0.001). Russian belt and conic-pulley exercise produced subtle (P<0.02) T2 increases of ST (9 and 6%, respectively) and BFLh (7 and 6%, respectively). Russian belt increased T2 of SM (7%). Among exercises examined, flywheel leg curl showed the most substantial hamstring and GR muscle use. However, no single exercise executed was able to increase T2 of all hamstring and synergist muscles analyzed. It is therefore suggested that multiple exercises must be carried out to bring in, and fully activate all knee flexors and hip extensors. PMID:27116347

  5. The influence of visual information on multi-muscle control during quiet stance: a spectral analysis approach.

    PubMed

    Danna-Dos-Santos, Alessander; Degani, Adriana M; Boonstra, Tjeerd W; Mochizuki, Luis; Harney, Allison M; Schmeckpeper, Megan M; Tabor, Lori C; Leonard, Charles T

    2015-02-01

    Standing upright requires the coordination of neural drives to a large set of muscles involved in controlling human bipedal stance (i.e., postural muscles). The coordination may deteriorate in situations where standing is performed under more challenging circumstances, such as standing on a smaller base of support or not having adequate visual information. The present study investigates the role of common neural inputs in the organization of multi-muscle synergies and the effects of visual input disruption to this mechanism of control. We analyzed the strength and distribution of correlated neural inputs (measured by intermuscular coherence) to six postural muscles previously recognized as components of synergistic groups involved in the maintenance of the body's vertical positioning. Two experimental conditions were studied: quiet bipedal stance performed with opened eyes (OEs) and closed eyes (CEs). Nine participants stood quietly for 30 s while the activity of the soleus, biceps femoris, lumbar erector spinae, tibialis anterior, rectus femoris, and rectus abdominis muscles were recorded using surface electrodes. Intermuscular (EMG-EMG) coherence was estimated for 12 muscle pairs formed by these muscles, including pairs formed solely by either posterior, anterior, or mixed (one posterior and one anterior) muscles. Intermuscular coherence was only found to be significant for muscle pairs formed solely by either posterior or anterior muscles, and no significant coherence was found for mixed muscle pairs. Significant intermuscular coherence was only found within a distinct frequency interval bounded between 1 and 10 Hz when visual input was available (OEs trials). The strength of correlated neural inputs was similar across muscle pairs located in different joints but executing a similar function (pushing body either backward or forward) suggesting that synergistic postural groups are likely formed based on their functional role instead of their anatomical location

  6. Glenoid labrum tears related to the long head of the biceps.

    PubMed

    Andrews, J R; Carson, W G; McLeod, W D

    1985-01-01

    Tears of the glenoid labrum were observed in 73 baseball pitchers and other throwing athletes who underwent arthroscopic examination of the dominant shoulder. Most of the tears were located over the anterosuperior portion of the glenoid labrum near the origin of the tendon of the long head of the biceps muscle into the glenoid. At arthroscopy, the tendon of the long head of the biceps appeared to originate through and be continuous with the superior portion of the glenoid labrum. In many cases it appeared to have pulled the anterosuperior portion of the labrum off the glenoid. This observation was verified at arthroscopy by viewing the origin of the biceps tendon into the glenoid labrum as the muscle was electrically stimulated. With stimulation of the muscle, the tendinous portion became quite taut, particularly near its attachment to the glenoid labrum, and actually lifted the labrum off the glenoid. Three-dimensional high-speed cinematography with computer analysis revealed that the moment acting about the elbow joint to extend the joint through an arc of about 50 degrees was in excess of 600 inch-pounds. The extremely high velocity of elbow extension which is generated must be decelerated through the final 30 degrees of elbow extension. Of the muscles of the arm that provide the large deceleration forces in the follow-through phase of throwing, only the biceps brachii traverses both the elbow joint and the shoulder joint. Additional forces are generated in the biceps tendon in its function as a "shunt" muscle to stabilize the glenohumeral joint during the throwing act.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:4051091

  7. Sensitivity of subject-specific models to Hill muscle-tendon model parameters in simulations of gait.

    PubMed

    Carbone, V; van der Krogt, M M; Koopman, H F J M; Verdonschot, N

    2016-06-14

    Subject-specific musculoskeletal (MS) models of the lower extremity are essential for applications such as predicting the effects of orthopedic surgery. We performed an extensive sensitivity analysis to assess the effects of potential errors in Hill muscle-tendon (MT) model parameters for each of the 56 MT parts contained in a state-of-the-art MS model. We used two metrics, namely a Local Sensitivity Index (LSI) and an Overall Sensitivity Index (OSI), to distinguish the effect of the perturbation on the predicted force produced by the perturbed MT parts and by all the remaining MT parts, respectively, during a simulated gait cycle. Results indicated that sensitivity of the model depended on the specific role of each MT part during gait, and not merely on its size and length. Tendon slack length was the most sensitive parameter, followed by maximal isometric muscle force and optimal muscle fiber length, while nominal pennation angle showed very low sensitivity. The highest sensitivity values were found for the MT parts that act as prime movers of gait (Soleus: average OSI=5.27%, Rectus Femoris: average OSI=4.47%, Gastrocnemius: average OSI=3.77%, Vastus Lateralis: average OSI=1.36%, Biceps Femoris Caput Longum: average OSI=1.06%) and hip stabilizers (Gluteus Medius: average OSI=3.10%, Obturator Internus: average OSI=1.96%, Gluteus Minimus: average OSI=1.40%, Piriformis: average OSI=0.98%), followed by the Peroneal muscles (average OSI=2.20%) and Tibialis Anterior (average OSI=1.78%) some of which were not included in previous sensitivity studies. Finally, the proposed priority list provides quantitative information to indicate which MT parts and which MT parameters should be estimated most accurately to create detailed and reliable subject-specific MS models. PMID:27131851

  8. Raman spectroscopic study of acute oxidative stress induced changes in mice skeletal muscles

    NASA Astrophysics Data System (ADS)

    Sriramoju, Vidyasagar; Alimova, Alexandra; Chakraverty, Rahul; Katz, A.; Gayen, S. K.; Larsson, L.; Savage, H. E.; Alfano, R. R.

    2008-02-01

    The oxidative stress due to free radicals is implicated in the pathogenesis of tissue damage in diseases such as muscular dystrophy, Alzheimer dementia, diabetes mellitus, and mitochrondrial myopathies. In this study, the acute oxidative stress induced changes in nicotinamide adenine dinucleotides in mouse skeletal muscles are studied in vitro using Raman spectroscopy. Mammalian skeletal muscles are rich in nicotinamide adenine dinucleotides in both reduced (NADH) and oxidized (NAD) states, as they are sites of aerobic and anaerobic respiration. The relative levels of NAD and NADH are altered in certain physiological and pathological conditions of skeletal muscles. In this study, near infrared Raman spectroscopy is used to identify the molecular fingerprints of NAD and NADH in five-week-old mice biceps femoris muscles. A Raman vibrational mode of NADH is identified in fresh skeletal muscle samples suspended in buffered normal saline. In the same samples, when treated with 1% H IIO II for 5 minutes and 15 minutes, the Raman spectrum shows molecular fingerprints specific to NAD and the disappearance of NADH vibrational bands. The NAD bands after 15 minutes were more intense than after 5 minutes. Since NADH fluoresces and NAD does not, fluorescence spectroscopy is used to confirm the results of the Raman measurements. Fluorescence spectra exhibit an emission peak at 460 nm, corresponding to NADH emission wavelength in fresh muscle samples; while the H IIO II treated muscle samples do not exhibit NADH fluorescence. Raman spectroscopy may be used to develop a minimally invasive, in vivo optical biopsy method to measure the relative NAD and NADH levels in muscle tissues. This may help to detect diseases of muscle, including mitochondrial myopathies and muscular dystrophies.

  9. Muscle coordination during breaststroke swimming: Comparison between elite swimmers and beginners.

    PubMed

    Vaz, João R; Olstad, Bjørn Harald; Cabri, Jan; Kjendlie, Per-Ludvik; Pezarat-Correia, Pedro; Hug, François

    2016-10-01

    The present study aimed to compare muscle coordination strategies of the upper and lower limb muscles between beginners and elite breaststroke swimmers. Surface electromyography (EMG) of eight muscles was recorded in 16 swimmers (8 elite, 8 beginners) during a 25 m swimming breaststroke at 100% of maximal effort. A decomposition algorithm was used to identify the muscle synergies that represent the temporal and spatial organisation of muscle coordination. Between-groups indices of similarity and lag times were calculated. Individual muscle patterns were moderately to highly similar between groups (between-group indices range: 0.61 to 0.84). Significant differences were found in terms of lag time for pectoralis major (P < 0.05), biceps brachii, rectus femoris and tibialis anterior (P < 0.01), indicating an earlier activation for these muscles in beginners compared to elites (range: -13.2 to -3.8% of the swimming cycle). Three muscle synergies were identified for both beginners and elites. Although their composition was similar between populations, the third synergy exhibited a high within-group variability. Moderate to high indices of similarity were found for the shape of synergy activation coefficients (range: 0.63 to 0.88) but there was a significant backward shift (-8.4% of the swimming cycle) in synergy #2 for beginners compared to elites. This time shift suggested differences in the global arm-to-leg coordination. These results indicate that the synergistic organisation of muscle coordination during breaststroke swimming is not profoundly affected by expertise. However, specific timing adjustments were observed between lower and upper limbs. PMID:26878097

  10. COMPARISON OF TRUNK AND LOWER EXTREMITY MUSCLE ACTIVITY AMONG FOUR STATIONARY EQUIPMENT DEVICES: UPRIGHT BIKE, RECUMBENT BIKE, TREADMILL, AND ELLIPTIGO®

    PubMed Central

    Baker, Ryan; Gibson, Chris; Kearney, Andrew; Busemeyer, Tommy

    2016-01-01

    Background Stationary equipment devices are often used to improve fitness. The ElliptiGO® was recently developed that blends the elements of an elliptical trainer and bicycle, allowing reciprocal lower limb pedaling in an upright position. However, it is unknown whether the muscle activity used for the ElliptiGO® is similar to walking or cycling. To date, there is no information comparing muscle activity for exercise on the treadmill, stationary upright and recumbent bikes, and the ElliptiGO®. Purpose/Hypothesis The purpose of this study was to assess trunk and lower extremity muscle activity among treadmill walking, cycling (recumbent and upright) and the ElliptiGO® cycling. It was hypothesized that the ElliptiGO® and treadmill would elicit similar electromyographic muscle activity responses compared to the stationary bike and recumbent bike during an exercise session. Study Design Cohort, repeated measures Methods Twelve recreationally active volunteers participated in the study and were assigned a random order of exercise for each of the four devices (ElliptiGO®, stationary upright cycle ergometer, recumbent ergometer, and a treadmill). Two-dimensional video was used to monitor the start and stop of exercise and surface electromyography (SEMG) were used to assess muscle activity during two minutes of cycling or treadmill walking at 40-50% heart rate reserve (HRR). Eight muscles on the dominant limb were used for analysis: gluteus maximus (Gmax), gluteus medius (Gmed), biceps femoris (BF), lateral head of the gastrocnemius (LG), tibialis anterior (TA), rectus femoris (RF). Two trunk muscles were assessed on the same side; lumbar erector spinae at L3-4 level (LES) and rectus abdominus (RA). Maximal voluntary isometric contractions (MVIC) were determined for each muscle and SEMG data were expressed as %MVIC in order to normalize outputs. Results The %MVIC for RF during ElliptiGO® cycling was higher than recumbent cycling. The LG muscle activity was highest

  11. Design, development and testing of a low-cost sEMG system and its use in recording muscle activity in human gait.

    PubMed

    Supuk, Tamara Grujic; Skelin, Ana Kuzmanic; Cic, Maja

    2014-01-01

    Surface electromyography (sEMG) is an important measurement technique used in biomechanical, rehabilitation and sport environments. In this article the design, development and testing of a low-cost wearable sEMG system are described. The hardware architecture consists of a two-cascade small-sized bioamplifier with a total gain of 2,000 and band-pass of 3 to 500 Hz. The sampling frequency of the system is 1,000 Hz. Since real measured EMG signals are usually corrupted by various types of noises (motion artifacts, white noise and electromagnetic noise present at 50 Hz and higher harmonics), we have tested several denoising techniques, both on artificial and measured EMG signals. Results showed that a wavelet-based technique implementing Daubechies5 wavelet and soft sqtwolog thresholding is the most appropriate for EMG signals denoising. To test the system performance, EMG activities of six dominant muscles of ten healthy subjects during gait were measured (gluteus maximus, biceps femoris, sartorius, rectus femoris, tibialis anterior and medial gastrocnemius). The obtained EMG envelopes presented against the duration of gait cycle were compared favourably with the EMG data available in the literature, suggesting that the proposed system is suitable for a wide range of applications in biomechanics. PMID:24811078

  12. Design, Development and Testing of a Low-Cost sEMG System and Its Use in Recording Muscle Activity in Human Gait

    PubMed Central

    Supuk, Tamara Grujic; Skelin, Ana Kuzmanic; Cic, Maja

    2014-01-01

    Surface electromyography (sEMG) is an important measurement technique used in biomechanical, rehabilitation and sport environments. In this article the design, development and testing of a low-cost wearable sEMG system are described. The hardware architecture consists of a two-cascade small-sized bioamplifier with a total gain of 2,000 and band-pass of 3 to 500 Hz. The sampling frequency of the system is 1,000 Hz. Since real measured EMG signals are usually corrupted by various types of noises (motion artifacts, white noise and electromagnetic noise present at 50 Hz and higher harmonics), we have tested several denoising techniques, both on artificial and measured EMG signals. Results showed that a wavelet—based technique implementing Daubechies5 wavelet and soft sqtwolog thresholding is the most appropriate for EMG signals denoising. To test the system performance, EMG activities of six dominant muscles of ten healthy subjects during gait were measured (gluteus maximus, biceps femoris, sartorius, rectus femoris, tibialis anterior and medial gastrocnemius). The obtained EMG envelopes presented against the duration of gait cycle were compared favourably with the EMG data available in the literature, suggesting that the proposed system is suitable for a wide range of applications in biomechanics. PMID:24811078

  13. Profunda Femoris Artery Perforator Propeller Flap: A Valid Method to Cover Complicated Ischiatic Pressure Sores.

    PubMed

    Scalise, Alessandro; Tartaglione, Caterina; Bolletta, Elisa; Pierangeli, Marina; Di Benedetto, Giovanni

    2015-08-01

    We report the case of a 50-year-old paraplegic man with a complicated grade III/IV ischiatic pressure sore treated with a propeller flap based on the first perforator of the profunda femoris artery. Our aim was to surgically reconstruct an ischiatic pressure sore in a patient with ankylosis using a fasciocutaneous perforator propeller flap obtained from the posterior region of the thigh. Our decision to perform a profunda femoris artery perforator propeller flap reconstruction was mainly due to the anatomical contiguity of the flap with the site of the lesion and the good quality of the skin harvested from the posterior region of the thigh. The use of the perforator fasciocutaneous flap represents a muscle-sparing technique, providing a better long-term result in surgical reconstruction. The choice of the 180-degree propeller flap was due to its ability to provide a good repair of the pressure ulcer and to pass over the ischiatic prominence in the patient in the forced decubitus position. The operatory course did not present any kind of complication. Using this reconstructive treatment, we have obtained complete coverage of the ischiatic pressure sore. PMID:26495200

  14. Profunda Femoris Artery Perforator Propeller Flap: A Valid Method to Cover Complicated Ischiatic Pressure Sores

    PubMed Central

    Tartaglione, Caterina; Bolletta, Elisa; Pierangeli, Marina; Di Benedetto, Giovanni

    2015-01-01

    Summary: We report the case of a 50-year-old paraplegic man with a complicated grade III/IV ischiatic pressure sore treated with a propeller flap based on the first perforator of the profunda femoris artery. Our aim was to surgically reconstruct an ischiatic pressure sore in a patient with ankylosis using a fasciocutaneous perforator propeller flap obtained from the posterior region of the thigh. Our decision to perform a profunda femoris artery perforator propeller flap reconstruction was mainly due to the anatomical contiguity of the flap with the site of the lesion and the good quality of the skin harvested from the posterior region of the thigh. The use of the perforator fasciocutaneous flap represents a muscle-sparing technique, providing a better long-term result in surgical reconstruction. The choice of the 180-degree propeller flap was due to its ability to provide a good repair of the pressure ulcer and to pass over the ischiatic prominence in the patient in the forced decubitus position. The operatory course did not present any kind of complication. Using this reconstructive treatment, we have obtained complete coverage of the ischiatic pressure sore. PMID:26495200

  15. Functional and muscle morphometric effects of ACL reconstruction. A prospective CT study with 1 year follow-up.

    PubMed

    Lindström, M; Strandberg, S; Wredmark, T; Felländer-Tsai, L; Henriksson, M

    2013-08-01

    Computed tomography (CT) was used to explore if changes in muscle cross-sectional area and quality after anterior cruciate ligament (ACL) injury and reconstruction would be related to knee function. Fourteen females and 23 males (16-54 years) underwent clinical tests, subjective questionnaires, and CT 1 week before and 1 year after ACL surgery with semitendinosus-gracilis (STG) graft and rehabilitation. Postoperatively, knee laxity was decreased and functional knee measures and subjective patient scores improved. The most obvious remaining deficit was the quadriceps atrophy, which was significantly larger if the right leg was injured. Right-leg injury also tended to cause larger compensatory hypertrophy of the combined knee flexor and tibial internal rotator muscles (preoperatively). The quadriceps atrophy was significantly correlated with the scores and functional tests, the latter also being related to the remaining size of the gracilis muscle. Biceps femoris hypertrophy and, in males only, semimembranosus hypertrophy was observed following the ACL reconstruction. The lack of semimembranosus hypertrophy in the women could, via tibial internal rotation torque deficit, contribute to the less favorable functional and subjective outcome recorded for the women. The results indicate that the quadriceps, the combined knee flexor/tibial internal rotator muscles, side of ACL injury, and sex are important to consider in rehabilitation after STG graft. PMID:22107159

  16. Electromechanical delay of the hamstrings during eccentric muscle actions in males and females: Implications for non-contact ACL injuries.

    PubMed

    De Ste Croix, Mark B A; ElNagar, Youssif O; Iga, John; James, David; Ayala, Francisco

    2015-12-01

    Sex differences in neuromuscular functioning has been proposed as one of the factors behind an increased relative risk of non-contact anterior cruciate ligament (ACL) injury in females. The aim of this study was to explore sex differences in electromechanical delay (EMD) of the hamstring muscles during eccentric muscle actions and during a range of movement velocities. This study recruited 110 participants (55 males, 55 females) and electromyography of the semitendinosus, semimembranosus and biceps femoris was determined during eccentric actions at 60, 120 and 240°/s. No significant sex differences were observed irrespective of muscle examined or movement velocity. Irrespective of sex EMD significantly increased with increasing movement velocity (P < 0.01). There was no significant difference in the EMD of the 3 muscles examined. Our findings suggest that during eccentric actions of the hamstrings that there are no sex differences, irrespective of movement velocity. This would suggest that other factors are probably responsible for the increased relative risk of non-contact ACL injury in females compared to males. PMID:26522999

  17. THE EFFECTS OF APONEUROSIS GEOMETRY ON STRAIN INJURY SUSCEPTIBILITY EXPLORED WITH A 3D MUSCLE MODEL

    PubMed Central

    Rehorn, Michael R.; Blemker, Silvia S.

    2010-01-01

    In the musculoskeletal system, some muscles are injured more frequently than others. For example, the biceps femoris longhead (BFLH) is the most commonly injured hamstring muscle. It is thought that acute injuries result from large strains within the muscle tissue, but the mechanism behind this type of strain injury is still poorly understood. The purpose of this study was to build computational models to analyze the stretch distributions within the BFLH muscle and to explore the effects of aponeurosis geometry on the magnitude and location of peak stretches within the model. We created a three-dimensional finite element (FE) model of the BFLH based on magnetic resonance (MR) images. We also created a series of simplified models with a similar geometry to the MR-based model. We analyzed the stretches predicted by the MR-based model during lengthening contractions to determine the region of peak local fiber stretch. The peak along-fiber stretch was 1.64 and was located adjacent to the proximal myotendinous junction (MTJ). In contrast, the average along-fiber stretch across all the muscle tissue was 0.95. By analyzing the simple models, we found that varying the dimensions of the aponeuroses (width, length, and thickness) had a substantial impact on the location and magnitude of peak stretches within the muscle. Specifically, the difference in widths between the proximal and distal aponeurosis in the BFLH contributed most to the location and magnitude of peak stretch, as decreasing the proximal aponeurosis width by 80% increased peak average stretches along the proximal MTJ by greater than 60% while slightly decreasing stretches along the distal MTJ. These results suggest that the aponeurosis morphology of the BFLH plays a significant role in determining stretch distributions throughout the muscle. Furthermore, this study introduces the new hypothesis that aponeurosis widths may be important in determining muscle injury susceptibility. PMID:20541207

  18. Muscle Activation and Estimated Relative Joint Force During Running with Weight Support on a Lower-Body Positive-Pressure Treadmill.

    PubMed

    Jensen, Bente R; Hovgaard-Hansen, Line; Cappelen, Katrine L

    2016-08-01

    Running on a lower-body positive-pressure (LBPP) treadmill allows effects of weight support on leg muscle activation to be assessed systematically, and has the potential to facilitate rehabilitation and prevent overloading. The aim was to study the effect of running with weight support on leg muscle activation and to estimate relative knee and ankle joint forces. Runners performed 6-min running sessions at 2.22 m/s and 3.33 m/s, at 100%, 80%, 60%, 40%, and 20% body weight (BW). Surface electromyography, ground reaction force, and running characteristics were measured. Relative knee and ankle joint forces were estimated. Leg muscles responded differently to unweighting during running, reflecting different relative contribution to propulsion and antigravity forces. At 20% BW, knee extensor EMGpeak decreased to 22% at 2.22 m/s and 28% at 3.33 m/s of 100% BW values. Plantar flexors decreased to 52% and 58% at 20% BW, while activity of biceps femoris muscle remained unchanged. Unweighting with LBPP reduced estimated joint force significantly although less than proportional to the degree of weight support (ankle). It was concluded that leg muscle activation adapted to the new biomechanical environment, and the effect of unweighting on estimated knee force was more pronounced than on ankle force. PMID:26957520

  19. Effect of an Eight-Week Ballroom Dancing Program on Muscle Architecture in Older Adults Females.

    PubMed

    Cepeda, Christina C P; Lodovico, Angélica; Fowler, Neil; Rodacki, André L F

    2015-10-01

    Aging is related to a progressive remodeling of the neuromuscular system, which includes muscle mass, strength, and power reductions. This study investigated the effect of an eight-week dance program on fascicle pennation angle, fascicle length, and thickness of the vastus lateralis (VL), tibialis anterior (TA), biceps femoris (BF), and gastrocnemius medialis (GM) muscles using ultrasound images. Thirty-four healthy older women were randomly assigned to either a dancing (DG: n = 19, 69.1 ± 6.5 years, 72.5 ± 11.7 kg) or control group (CG: n = 15, 71.5 ± 7.4 years, 70.9 ± 9.3 kg). After training, the DG showed greater (p < .05) thickness for VL (16%), TA (17%), BF (19%), and GM (15%); pennation angle for VL (21%), TA (23%), BF (21%), and GM (17%); and fascicle length for VL (11%), TA (12%), BF (10%), and GM (10%). These findings suggest that dance training was effective to change the lower limb muscle architecture in older female adults. PMID:25642640

  20. The effect of backpack heaviness on trunk-lower extremity muscle activities and trunk posture.

    PubMed

    Al-Khabbaz, Yusuf S S M; Shimada, Tomoaki; Hasegawa, Masashi

    2008-08-01

    The purpose of the present study is to analyze trunk-lower extremity muscle activities and trunk postural changes during the carriage of different backpacks. Nineteen male university students (21+/-3 years) participated in the experiment's four standing modes: (1) unloaded standing, (2) 10% body weight (BW) load (in the form of a backpack), (3) 15% BW load and (4) 20% BW load. Bilateral rectus abdominis, erector spinae, vastus medialis and biceps femoris muscle activities were recorded using surface electromyography (SEMG), while trunk inclination, side flexion and rotation were measured by using VICON 250 during all standing modes. The results showed that rectus abdominis muscle activities increased progressively and disproportionably as the backpack load increased. As for the trunk posture, almost the same backward inclination was adapted even with increasing backpack heaviness. Twenty percent BW backpack causes the most significant muscular and postural changes so it should be avoided. However, it is recommended to study other backpack factors such as frequency of usage, usage time, type of the backpack and age to come up with a complete usage recommendation. PMID:18329270

  1. Effects of the lower extremities muscle activation during muscular strength training on an unstable platform with magneto-rheological dampers

    NASA Astrophysics Data System (ADS)

    Piao, YongJun; Choi, YounJung; Kim, JungJa; Kwan, TaeKyu; Kim, Nam-Gyun

    2009-03-01

    Adequate postural balance depends on the spatial and temporal integration of vestibular, visual, and somatosensory information. Especially, the musculoskeletal function (range of joint, flexibility of spine, muscular strength) is essential in maintaining the postural balance. Muscular strength training methods include the use of commercialized devices and repeatable resistance training tools (rubber band, ball, etc). These training systems cost high price and can't control of intensity. Thus we suggest a new training system which can adjust training intensity and indicate the center of pressure of a subject while the training was passively controlled by applying controlled electric current to the Magneto- Rheological damper. And we performed experimental studies on the muscular activities in the lower extremities during maintaining, moving and pushing exercises on an unstable platform with Magneto rheological dampers. A subject executed the maintaining, moving and pushing exercises which were displayed in a monitor. The electromyographic signals of the eight muscles in lower extremities were recorded and analyzed in the time and frequency domain: the muscles of interest were rectus femoris, biceps femoris, tensor fasciae latae, vastus lateralis, vastus medialis, gastrocnemius, tibialis anterior, and soleus. The experimental results showed the difference of muscular activities at the four moving exercises and the nine maintaining exercises. The rate of the increase in the muscular activities was affected by the condition of the unstable platform with MR dampers for the maintaining and moving exercises. The experimental results suggested the choice of different maintaining and moving exercises could selectively train different muscles with varying intensity. Furthermore, the findings also suggested the training using this system can improve the ability of postural balance.

  2. Motoneuronal and muscle synergies involved in cat hindlimb control during fictive and real locomotion: a comparison study.

    PubMed

    Markin, Sergey N; Lemay, Michel A; Prilutsky, Boris I; Rybak, Ilya A

    2012-04-01

    We compared the activity profiles and synergies of spinal motoneurons recorded during fictive locomotion evoked in immobilized decerebrate cat preparations by midbrain stimulation to the activity profiles and synergies of the corresponding hindlimb muscles obtained during forward level walking in cats. The fictive locomotion data were collected in the Spinal Cord Research Centre, University of Manitoba, and provided by Dr. David McCrea; the real locomotion data were obtained in the laboratories of M. A. Lemay and B. I. Prilutsky. Scatterplot representation and minimum spanning tree clustering algorithm were used to identify the possible motoneuronal and muscle synergies operating during both fictive and real locomotion. We found a close similarity between the activity profiles and synergies of motoneurons innervating one-joint muscles during fictive locomotion and the profiles and synergies of the corresponding muscles during real locomotion. However, the activity patterns of proximal nerves controlling two-joint muscles, such as posterior biceps and semitendinosus (PBSt) and rectus femoris (RF), were not uniform in fictive locomotion preparations and differed from the activity profiles of the corresponding two-joint muscles recorded during forward level walking. Moreover, the activity profiles of these nerves and the corresponding muscles were unique and could not be included in the synergies identified in fictive and real locomotion. We suggest that afferent feedback is involved in the regulation of locomotion via motoneuronal synergies controlled by the spinal central pattern generator (CPG) but may also directly affect the activity of motoneuronal pools serving two-joint muscles (e.g., PBSt and RF). These findings provide important insights into the organization of the spinal CPG in mammals, the motoneuronal and muscle synergies engaged during locomotion, and their afferent control. PMID:22190626

  3. Motoneuronal and muscle synergies involved in cat hindlimb control during fictive and real locomotion: a comparison study

    PubMed Central

    Markin, Sergey N.; Lemay, Michel A.; Prilutsky, Boris I.

    2012-01-01

    We compared the activity profiles and synergies of spinal motoneurons recorded during fictive locomotion evoked in immobilized decerebrate cat preparations by midbrain stimulation to the activity profiles and synergies of the corresponding hindlimb muscles obtained during forward level walking in cats. The fictive locomotion data were collected in the Spinal Cord Research Centre, University of Manitoba, and provided by Dr. David McCrea; the real locomotion data were obtained in the laboratories of M. A. Lemay and B. I. Prilutsky. Scatterplot representation and minimum spanning tree clustering algorithm were used to identify the possible motoneuronal and muscle synergies operating during both fictive and real locomotion. We found a close similarity between the activity profiles and synergies of motoneurons innervating one-joint muscles during fictive locomotion and the profiles and synergies of the corresponding muscles during real locomotion. However, the activity patterns of proximal nerves controlling two-joint muscles, such as posterior biceps and semitendinosus (PBSt) and rectus femoris (RF), were not uniform in fictive locomotion preparations and differed from the activity profiles of the corresponding two-joint muscles recorded during forward level walking. Moreover, the activity profiles of these nerves and the corresponding muscles were unique and could not be included in the synergies identified in fictive and real locomotion. We suggest that afferent feedback is involved in the regulation of locomotion via motoneuronal synergies controlled by the spinal central pattern generator (CPG) but may also directly affect the activity of motoneuronal pools serving two-joint muscles (e.g., PBSt and RF). These findings provide important insights into the organization of the spinal CPG in mammals, the motoneuronal and muscle synergies engaged during locomotion, and their afferent control. PMID:22190626

  4. Comparative Analysis of Muscle Transcriptome between Pig Genotypes Identifies Genes and Regulatory Mechanisms Associated to Growth, Fatness and Metabolism

    PubMed Central

    Ayuso, Miriam; Fernández, Almudena; Núñez, Yolanda; Benítez, Rita; Isabel, Beatriz; Barragán, Carmen; Fernández, Ana Isabel; Rey, Ana Isabel; Medrano, Juan F.; Cánovas, Ángela; González-Bulnes, Antonio; López-Bote, Clemente; Ovilo, Cristina

    2015-01-01

    Iberian ham production includes both purebred (IB) and Duroc-crossbred (IBxDU) Iberian pigs, which show important differences in meat quality and production traits, such as muscle growth and fatness. This experiment was conducted to investigate gene expression differences, transcriptional regulation and genetic polymorphisms that could be associated with the observed phenotypic differences between IB and IBxDU pigs. Nine IB and 10 IBxDU pigs were slaughtered at birth. Morphometric measures and blood samples were obtained and samples from Biceps femoris muscle were employed for compositional and transcriptome analysis by RNA-Seq technology. Phenotypic differences were evident at this early age, including greater body size and weight in IBxDU and greater Biceps femoris intramuscular fat and plasma cholesterol content in IB newborns. We detected 149 differentially expressed genes between IB and IBxDU neonates (p < 0.01 and Fold-Change > 1. 5). Several were related to adipose and muscle tissues development (DLK1, FGF21 or UBC). The functional interpretation of the transcriptomic differences revealed enrichment of functions and pathways related to lipid metabolism in IB and to cellular and muscle growth in IBxDU pigs. Protein catabolism, cholesterol biosynthesis and immune system were functions enriched in both genotypes. We identified transcription factors potentially affecting the observed gene expression differences. Some of them have known functions on adipogenesis (CEBPA, EGRs), lipid metabolism (PPARGC1B) and myogenesis (FOXOs, MEF2D, MYOD1), which suggest a key role in the meat quality differences existing between IB and IBxDU hams. We also identified several polymorphisms showing differential segregation between IB and IBxDU pigs. Among them, non-synonymous variants were detected in several transcription factors as PPARGC1B and TRIM63 genes, which could be associated to altered gene function. Taken together, these results provide information about candidate

  5. Acute Calcific Tendinitis of the Rectus Femoris: A Case Series

    PubMed Central

    IKobayashi, Hideo; Kaneko, Haruka; Homma, Yasuhiro; Baba, Tomonori; Kaneko, Kazuo

    2015-01-01

    Introduction: Periarticular calcific tendinitis is a common cause of Orthopedic outpatient referral. Calcific tendinitis of the rectus femoris, however, is very rare and not well known. Due to its rarity, correct diagnosis and prompt treatment are not fully understood. Case Report: Two females (38 and 40 years old) of acute calcific tendinitis of the rectus femoris with the good clinical course without any operative treatment were presented. The pain was managed with oral non-steroidal antiinflammatory drugs and/or local steroid injection. Interval radiographic assessment showed complete resorption of the calcification. Conclusion: Establishing the correct diagnosis and initiating prompt treatment are shown to be important in achieving resolution of symptoms and in avoiding unnecessary investigations. PMID:27299063

  6. Composite inflation confronts BICEP2 and PLANCK

    NASA Astrophysics Data System (ADS)

    Karwan, Khamphee; Channuie, Phongpichit

    2014-06-01

    We examine observational constraints on single-field inflation in which the inflaton is a composite field stemming from a four-dimensional strongly interacting field theory. We confront the predictions with the Planck and very recent BICEP2 data. In the large non-minimal coupling regions, we discover for the minimal composite inflationary model that the predictions lie well inside the joint 68% CL for the Planck data, but is in tension with the recent BICEP2 observations. In the case of the glueball inflationary model, the predictions satisfy the Planck results. However, this model can produce a large tensor-to-scalar ratio consistent with the recent BICEP2 observations if the number of e-foldings is slightly smaller than the range commonly used. For a super Yang-Mills paradigm, we discover that the predictions satisfy the Planck data, and surprisingly a large tensor-to-scalar ratio consistent with the BICEP2 results can also be produced for an acceptable range of the number of e-foldings and of the confining scale. In the small non-minimal coupling regions, all of the models can satisfy the BICEP2 results. However, the predictions of the glueball and superglueball inflationary models cannot satisfy the observational bound on the amplitude of the curvature perturbation launched by Planck, and the techni-inflaton self-coupling in the minimal composite inflationary model is constrained to be extremely small.

  7. Hydatid cyst of biceps brachii associated with peripheral neuropathy

    PubMed Central

    Tuna, Serkan; Duymus, Tahir Mutlu; Yanik, Hakan Serhat; Durakbasa, Mehmet Oguz; Mutlu, Serhat; Erdem, Sevki

    2015-01-01

    Introduction Hydatidosis represents the most significant parasitic disorder in the Mediterranean countries and leads to major problems through unfavorable effects on the public health and national economy. Localization of the primary cyst hydatid infection in the extremity is rare and biceps brachii localization is also rarely reported in the literature. Presentation of case A 43-year-old woman, who presented with the complaints of mass and pain in the left arm and numbness of the hand. Laboratory investigations, X-ray and magnetic resonance (MRI) findings revealed hydatid cyst of the biceps brachi muscle. The mass was totally excised and the diagnosis was confirmed by the macroscopic images of the mass and the pathologic results. After the surgery, the patient had an improvement in the nerve compression findings including numbness of the hand and the upper extremity and pain. Discussion Localization of a primary cyst hydatid infection in the upper extremity is rare and there are no reports of peripheral neuropathy secondary to mass effect. Even if the pre-surgical electromyelography performed for the nerve conduction study reveals a normal result, the potential for the hydatid cysts to cause nerve compression should be taken into consideration in such patients. Conclusion Cases of concomitant neurologic findings and complaints secondary to peripheral nerve compression are very rare. The clinical findings should not be ruled out even if the EMG result is negative. PMID:25682195

  8. Effect of feeding palm oil by-products based diets on muscle fatty acid composition in goats.

    PubMed

    Abubakr, Abdelrahim; Alimon, Abdul Razak; Yaakub, Halimatun; Abdullah, Norhani; Ivan, Michael

    2015-01-01

    The present study aims to evaluate the effects of feeding palm oil by-products based diets on different muscle fatty acid profiles in goats. Thirty-two Cacang × Boer goats were randomly assigned to four dietary treatments: (1) control diet (CD), (2) 80% decanter cake diet (DCD), (3) 80% palm kernel cake diet (PKCD) and (4) CD plus 5% palm oil (PO) supplemented diet (CPOD). After 100 days of feeding, four goats from each group were slaughtered and longissimus dorsi (LD), infraspinatus (IS) and biceps femoris (BF) were sampled for analysis of fatty acids. Goats fed the PKCD had higher (P<0.05) concentration of lauric acid (C12:0) than those fed the other diets in all the muscles tested. Compared to the other diets, the concentrations of palmitic acid (C16:0) and stearic acid (C18:0) were lower (P<0.05) and that of linoleic acid (C18:2 n-6) was higher (P<0.05) in the muscles from goats fed the CD. It was concluded that palm kernel cake and decanter cake can be included in the diet of goats up to 80% with more beneficial than detrimental effects on the fatty acid profile of their meat. PMID:25789610

  9. Effect of canola oil emulsion injection on processing characteristics and consumer acceptability of three muscles from mature beef.

    PubMed

    Pietrasik, Z; Wang, H; Janz, J A M

    2013-02-01

    The study was undertaken to investigate the impact of the combined effect of blade tenderization and canola oil emulsion injection on processing yield and eating quality-related parameters of selected loin and hip muscles (longissimus lumborum, LL, biceps femoris, BF and semimembranosus, SM) from over thirty month (OTM) cattle. Canola oil emulsion injection significantly reduced shear force, increased sensory scores for juiciness and tenderness, and made connective tissue less perceptible. Targeted levels of omega-3 fatty acids can be achieved by the inclusion of canola oil containing marinades/emulsions at levels sufficient to retain omega-3 fatty acids in cooked product. All consumer acceptability attributes of OTM muscles were improved with the use of canola oil emulsion injection treatments without compromising colour although slightly decreasing oxidative stability of BF muscle. Injection of omega-3 oil emulsions in combination with blade tenderization can be effectively utilized to enrich injected products in essential fatty acids and enhance eating quality of OTM beef. PMID:23089241

  10. Effect of Feeding Palm Oil By-Products Based Diets on Muscle Fatty Acid Composition in Goats

    PubMed Central

    Abubakr, Abdelrahim; Alimon, Abdul Razak; Yaakub, Halimatun; Abdullah, Norhani; Ivan, Michael

    2015-01-01

    The present study aims to evaluate the effects of feeding palm oil by-products based diets on different muscle fatty acid profiles in goats. Thirty-two Cacang × Boer goats were randomly assigned to four dietary treatments: (1) control diet (CD), (2) 80% decanter cake diet (DCD), (3) 80% palm kernel cake diet (PKCD) and (4) CD plus 5% palm oil (PO) supplemented diet (CPOD). After 100 days of feeding, four goats from each group were slaughtered and longissimus dorsi (LD), infraspinatus (IS) and biceps femoris (BF) were sampled for analysis of fatty acids. Goats fed the PKCD had higher (P<0.05) concentration of lauric acid (C12:0) than those fed the other diets in all the muscles tested. Compared to the other diets, the concentrations of palmitic acid (C16:0) and stearic acid (C18:0) were lower (P<0.05) and that of linoleic acid (C18:2 n-6) was higher (P<0.05) in the muscles from goats fed the CD. It was concluded that palm kernel cake and decanter cake can be included in the diet of goats up to 80% with more beneficial than detrimental effects on the fatty acid profile of their meat. PMID:25789610

  11. The Effects of Inclination (Up and Down) of the Treadmill on the Electromyogram Activities of the Forelimb and Hind limb Muscles at a Walk and a Trot in Thoroughbred Horses

    PubMed Central

    TAKAHASHI, Toshiyuki; MATSUI, Akira; MUKAI, Kazutaka; OHMURA, Hajime; HIRAGA, Atsushi; AIDA, Hiroko

    2014-01-01

    ABSTRACT It is important to know the effects of the inclination of a slope on the activity of each muscle, because training by running on a sloped track is commonly used for Thoroughbred racehorses. The effects of incline (from −6 to +6%) on the forelimbs and hind limbs during walking and trotting on a treadmill were evaluated by an integrated electromyogram (iEMG). The muscle activities in the forelimbs (5 horses) and hind limbs (4 horses) were measured separately. Two stainless steel wires were inserted into each of the brachiocephalicus (Bc), biceps brachii (BB), splenius (Sp), and pectoralis descendens (PD) in the forelimb experiment and into the longissimus dorsi (LD), vastus lateralis (VL), gluteus medius (GM), and biceps femoris (BF) in the hind limb experiment. The EMG recordings were taken at a sampling rate of 1,000 Hz. At a walk, the iEMG values for the forelimb were not significantly different under any of the inclinations. In the hind limb, the iEMG values for the GM and BF significantly decreased as the inclination decreased. At a trot, the iEMG values for the Bc in the forelimb significantly decreased as the inclination of the treadmill decreased. In the hind limb, the iEMG values for the LD, GM, and BF significantly decreased as the inclination decreased. Uphill exercise increased the iEMG values for the Bc, LD, GM, and BF, while downhill exercise resulted in little increase in the iEMG values. It was concluded that the effects of inclination on the muscle activities were larger for the uphill exercises, and for the hind limb muscles compared with the forelimb muscles. PMID:25558180

  12. The Effects of Inclination (Up and Down) of the Treadmill on the Electromyogram Activities of the Forelimb and Hind limb Muscles at a Walk and a Trot in Thoroughbred Horses.

    PubMed

    Takahashi, Toshiyuki; Matsui, Akira; Mukai, Kazutaka; Ohmura, Hajime; Hiraga, Atsushi; Aida, Hiroko

    2014-01-01

    It is important to know the effects of the inclination of a slope on the activity of each muscle, because training by running on a sloped track is commonly used for Thoroughbred racehorses. The effects of incline (from -6 to +6%) on the forelimbs and hind limbs during walking and trotting on a treadmill were evaluated by an integrated electromyogram (iEMG). The muscle activities in the forelimbs (5 horses) and hind limbs (4 horses) were measured separately. Two stainless steel wires were inserted into each of the brachiocephalicus (Bc), biceps brachii (BB), splenius (Sp), and pectoralis descendens (PD) in the forelimb experiment and into the longissimus dorsi (LD), vastus lateralis (VL), gluteus medius (GM), and biceps femoris (BF) in the hind limb experiment. The EMG recordings were taken at a sampling rate of 1,000 Hz. At a walk, the iEMG values for the forelimb were not significantly different under any of the inclinations. In the hind limb, the iEMG values for the GM and BF significantly decreased as the inclination decreased. At a trot, the iEMG values for the Bc in the forelimb significantly decreased as the inclination of the treadmill decreased. In the hind limb, the iEMG values for the LD, GM, and BF significantly decreased as the inclination decreased. Uphill exercise increased the iEMG values for the Bc, LD, GM, and BF, while downhill exercise resulted in little increase in the iEMG values. It was concluded that the effects of inclination on the muscle activities were larger for the uphill exercises, and for the hind limb muscles compared with the forelimb muscles. PMID:25558180

  13. Influence of angular velocity on vastus lateralis and rectus femoris oxygenation dynamics during knee extension exercises.

    PubMed

    Denis, Romain; Wilkinson, Jennifer; De Vito, Giuseppe

    2011-09-01

    The purpose of this study was to investigate whether changes in angular velocity would alter vastus lateralis (VL) and rectus femoris (RF) oxygenation status during maximal isokinetic knee extension exercises. Eleven recreationally active male participants randomly performed ten maximal knee extensions at 30, 60, 120 and 240° s(-1). Tissue oxygenation index (TOI) and total haemoglobin concentration ([tHb]) were acquired from the VL and RF muscles by means of near-infrared spectroscopy (NIRS). Breath-by-breath pulmonary oxygen consumption (VO(2p)) was recorded throughout the tests. Peak torque and VO(2p) significantly decreased as a function of velocity (P<0·05). Interestingly, RF and VL TOI significantly increased as a function of velocity (P<0·05), whereas [tHb] significantly decreased as a function of velocity (P<0·05). A greater number of muscle fibre recruited at slow velocity, where the torque and VO(2p) were the highest, might explain the lower VL and RF TOI observed herein. Furthermore, the increase in local blood flow (suggested by [tHb] changes) during isokinetic knee extension exercises performed at slow angular velocity might have been induced by a higher intramuscular pressure during the contraction phases as well as a greater microcirculatory vasodilatation during relaxation phases. Implementing slow-velocity isokinetic exercises in rehabilitation or other training programmes could delay the short-term anoxia generated by such exercises and result in muscle metabolism enhancement. PMID:21771253

  14. Selective bilateral activation of leg muscles after cutaneous nerve stimulation during backward walking

    PubMed Central

    Massaad, Firas; Jansen, Karen; Bruijn, Sjoerd M.; Duysens, Jacques

    2012-01-01

    During human locomotion, cutaneous reflexes have been suggested to function to preserve balance. Specifically, cutaneous reflexes in the contralateral leg's muscles (with respect to the stimulus) were suggested to play an important role in maintaining stability during locomotor tasks where stability is threatened. We used backward walking (BW) as a paradigm to induce unstable gait and analyzed the cutaneous reflex activity in both ipsilateral and contralateral lower limb muscles after stimulation of the sural nerve at different phases of the gait cycle. In BW, the tibialis anterior (TA) reflex activity in the contralateral leg was markedly higher than TA background EMG activity during its stance phase. In addition, in BW a substantial reflex suppression was observed in the ipsilateral biceps femoris during the stance-swing transition in some participants, while for medial gastrocnemius the reflex activity was equal to background activity in both legs. To test whether the pronounced crossed responses in TA could be related to instability, the responses were correlated with measures of stability (short-term maximum Lyapunov exponents and step width). These measures were higher for BW compared with forward walking, indicating that BW is less stable. However, there was no significant correlation between these measures and the amplitude of the crossed TA responses in BW. It is therefore proposed that these crossed responses are related to an attempt to briefly slow down (TA decelerates the center of mass in the single-stance period) in the light of unexpected perturbations, such as provided by the sural nerve stimulation. PMID:22773779

  15. Influence of Posture on Pulmonary O2 Uptake Kinetics, Muscle Deoxygenation and Myolectrical Activity During Heavy-Intensity Exercise

    PubMed Central

    Denis, Romain; Perrey, Stéphane

    2006-01-01

    The aim of the present study was to test the hypothesis that compared to upright posture, slower oxygen uptake (VO2) kinetics resulting from exercise at the same relative metabolic load in the supine posture will be associated with increased muscle de-oxygenation and greater myoelectrical activity. Nine subjects completed one 12-min heavy-intensity constant-load exercises in each of the supine and upright postures on an electronically braked cycle ergometer at a same gain in metabolism per unit increase in work intensity (10.8 ± 1.3 vs. 11.8 ± 1.1 mlO2·min-1·W-1 in upright and supine, respectively) on separate days. Breath-by-breath VO2 kinetics were analyzed with a double exponential model to characterize the primary and slow component phases. Myoelectrical activity (RMS) of the vastus lateralis (VL), rectus femoris, and biceps femoris muscles was recorded at different epochs of the exercise. Oxygenation of the VL muscle was recorded continuously by near-infrared spectroscopy. In supine compared with upright cycling, the primary time constant of VO2 kinetics was significantly increased (32.7 ± 10.7 s vs. 23.5 ± 6.7 s, respectively) while the absolute magnitude of VO2 slow component was decreased (p < 0.05) but not the relative amplitude. VL de-oxygenation was higher (p < 0.05) in supine cycling throughout the exercising period whereas RMS values for all muscles did not change appreciably over time. Our findings suggest that lowered oxygen supply induced by supine heavy exercise, alters oxidative metabolism dynamics and increases muscle de-oxygenation. However, cycling supine did not increase markedly the rate of muscle fatigue. Key Points Hydrostatic pressure gradients in blood vessels oriented longitudinally in the body are lesser in supine than in upright posture. Lowered oxygen supply induced with supine exercise slows oxidative metabolism dynamics and increases muscle de-oxygenation during heavy exercise. Compared to upright, supine exercise did not

  16. Muscle Activation During Exercise in Severe Acute Hypoxia: Role of Absolute and Relative Intensity

    PubMed Central

    Torres-Peralta, Rafael; Losa-Reyna, José; González-Izal, Miriam; Perez-Suarez, Ismael; Calle-Herrero, Jaime; Izquierdo, Mikel

    2014-01-01

    Abstract Torres-Peralta, Rafael, José Losa-Reyna, Miriam González-Izal, Ismael Perez-Suarez, Jaime Calle-Herrero, Mikel Izquierdo, and José A.L. Calbet. Muscle activation during exercise in severe acute hypoxia: Role of absolute and relative intensity. High Alt Med Biol 15:472–482, 2014.—The aim of this study was to determine the influence of severe acute hypoxia on muscle activation during whole body dynamic exercise. Eleven young men performed four incremental cycle ergometer tests to exhaustion breathing normoxic (FIo2=0.21, two tests) or hypoxic gas (FIo2=0.108, two tests). Surface electromyography (EMG) activities of rectus femoris (RF), vastus medialis (VL), vastus lateralis (VL), and biceps femoris (BF) were recorded. The two normoxic and the two hypoxic tests were averaged to reduce EMG variability. Peak Vo2 was 34% lower in hypoxia than in normoxia (p<0.05). The EMG root mean square (RMS) increased with exercise intensity in all muscles (p<0.05), with greater effect in hypoxia than in normoxia in the RF and VM (p<0.05), and a similar trend in VL (p=0.10). At the same relative intensity, the RMS was greater in normoxia than in hypoxia in RF, VL, and BF (p<0.05), with a similar trend in VM (p=0.08). Median frequency increased with exercise intensity (p<0.05), and was higher in hypoxia than in normoxia in VL (p<0.05). Muscle contraction burst duration increased with exercise intensity in VM and VL (p<0.05), without clear effects of FIo2. No significant FIo2 effects on frequency domain indices were observed when compared at the same relative intensity. In conclusion, muscle activation during whole body exercise increases almost linearly with exercise intensity, following a muscle-specific pattern, which is adjusted depending on the FIo2 and the relative intensity of exercise. Both VL and VM are increasingly involved in power output generation with the increase of intensity and the reduction in FIo2. PMID:25225839

  17. Arthroscopic Surgical Techniques for the Management of Proximal Biceps Injuries.

    PubMed

    Werner, Brian C; Holzgrefe, Russell E; Brockmeier, Stephen F

    2016-01-01

    Current arthroscopic surgical techniques for the management of proximal biceps tendon disorders encompass 3 commonly advocated procedures: proximal biceps anchor reattachment (superior labrum anterior to posterior or SLAP repair), biceps tenotomy, and arthroscopic biceps tenodesis. The indications for each procedure vary based on injury pattern, symptomatic presentation, concomitant pathologic abnormality, and most notably, patient factors, such as age, functional demand, and specific sport or activity participation. Outcomes after SLAP repair are generally favorable, although recent studies have found biceps tenodesis to be the preferred treatment for certain patient populations. PMID:26614472

  18. Outlet biceps tenodesis: a new technique for treatment of biceps long head tendon injury.

    PubMed

    Lemos, David; Esquivel, Amanda; Duncan, Douglas; Marsh, Stephanie; Lemos, Stephen

    2013-05-01

    Degeneration and tearing of the long head of the biceps brachii tendon (LHBT) are common intra-articular findings, and surgical intervention including tenodesis or tenotomy is beneficial. A new arthroscopic shoulder technique may be performed through an anterior portal while one is viewing from a posterior portal: (1) Visualize the intra-articular biceps tendon. (2) Identify the segment of the LHBT to be enlarged. (3) Use a tissue modulation wand to enlarge the tendon. (4) Evaluate the diameter of the enlarged segment. It should be twice the original diameter. (5) Cut the biceps tendon at the proximal end of the enlarged segment. (6) View the tendon within the tunnel. (7) Identify and cut the remaining stump of the biceps tendon. Seventeen cadaveric shoulders were used to compare the pullout force, stiffness, and displacement of outlet tenodesis versus tenotomy. There was a significant increase in pullout force for the outlet tenodesis group when compared with tenotomy. This technique is used to operatively treat LHBT intra-articular pathology in patients who would benefit from tenotomy and traditional biceps tenodesis and may minimize the retraction of the biceps tendon distally. PMID:23875155

  19. Chronic Hyperinsulinemia Increases Myoblast Proliferation in Fetal Sheep Skeletal Muscle.

    PubMed

    Brown, Laura D; Wesolowski, Stephanie R; Kailey, Jenai; Bourque, Stephanie; Wilson, Averi; Andrews, Sasha E; Hay, William W; Rozance, Paul J

    2016-06-01

    Insulin is an important fetal growth factor. However, chronic experimental hyperinsulinemia in the fetus fails to accelerate linear and lean mass growth beyond normal rates. Mechanisms preventing accelerated lean mass accretion during hyperinsulinemia are unknown. To address potential mechanisms, late-gestation fetal sheep were infused with iv insulin and glucose to produce euglycemic hyperinsulinemia (INS) or saline for 7-9 days. Fetal substrate uptake and protein metabolic rates were measured. INS fetuses had 1.5-fold higher insulin concentrations (P < .0001) and equivalent glucose concentrations. INS fetuses had 20% more Pax7(+) nuclei in the biceps femoris, which indicates the potential for hyperinsulinemia to increase the number of myoblasts within late-gestation fetal skeletal muscle. Additionally, the percentage of Pax7(+) myoblasts that expressed Ki-67 was 1.3-fold higher and expression of myogenic regulatory factors was 50% lower in INS fetuses (MYF5 and MYOG [myogenin], P < .005), which indicates a shift toward myoblast proliferation over differentiation. There were no differences for fetal body, organ, or muscle weights, although INS placentas weighed 28% less (P < .05). Protein synthesis and accretion rates did not change in INS fetuses, nor did fiber muscle size. Essential amino acid concentrations were lower in the INS group (P < .05) except for tryptophan. Umbilical blood flow, net total amino acids, and O2 uptakes rates did not differ between groups. Arterial O2 content was 33% lower (P < .005) and norepinephrine was 100% higher in the INS fetuses (P < .01), all of which are factors that may counteract fetal protein accretion during hyperinsulinemia despite an increase in myoblast proliferation. PMID:27049667

  20. Multi-muscle control during bipedal stance: an EMG-EMG analysis approach.

    PubMed

    Danna-Dos-Santos, Alessander; Boonstra, Tjeerd W; Degani, Adriana M; Cardoso, Vinicius S; Magalhaes, Alessandra T; Mochizuki, Luis; Leonard, Charles T

    2014-01-01

    Posture and postural reactions to mechanical perturbations require the harmonic modulation of the activity of multiple muscles. This precision can become suboptimal in the presence of neuromuscular disorders and result in higher fall risk and associated levels of comorbidity. This study was designed to investigate neurophysiological principles related to the generation and distribution of inputs to skeletal muscles previously recognized as a synergistic group. Specifically, we investigated the current hypothesis that correlated neural inputs, as measured by intermuscular coherence, are the mechanism used by the central nervous system to coordinate the formation of postural muscle synergies. This hypothesis was investigated by analyzing the strength and distribution of correlated neural inputs to postural muscles during the execution of a quiet stance task. Nine participants, 4 females and 5 males, mean age 29.2 years old (±6.1 SD), performed the task of standing while holding a 5-kg barbell in front of their bodies at chest level. Subjects were asked to maintain a standing position for 10 s while the activity of three postural muscles was recorded by surface electrodes: soleus (SOL), biceps femoris (BF), and lumbar erector spinae (ERE). EMG-EMG coherence was estimated for three muscle pairs (SOL/BF, SOL/ERE, and BF/ERE). Our choice of studying these muscles was made based on the fact that they have been reported as components of a functional (synergistic) muscle group that emerges during the execution of bipedal stance. In addition, an isometric contraction can be easily induced in this muscle group by simply adding a weight to the body's anterior aspect. The experimental condition elicited a significant increase in muscle activation levels for all three muscles (p < 0.01 for all muscles). EMG-EMG coherence analysis revealed significant coherence within two distinct frequency bands, 0-5 and 5-20 Hz. Significant coherence within the later frequency band was also

  1. Muscle glycogen levels and blood metabolites in reindeer (Rangifer tarandus tarandus L.) after transport and lairage.

    PubMed

    Wiklund, E; Andersson, A; Malmfors, G; Lundström, K

    1996-01-01

    A total of 66 reindeer cows and calves were included in a study on the effects of supplementary feeding, transport and lairage on muscle glycogen content, ultimate pH and blood metabolite values. Thirty reindeer (10 not transported, 20 transported 800 km) received no supplementary feed (groups A-C), another 30 animals (10 not transported, 20 transported 1000 km) were given a supplementary reindeer feed mixture 2 months prior to slaughter (groups D-F) and six animals, which had been part of a feeding experiment, were fed for 5 months and slaughtered at the research unit. Glycogen determinations and pH measurements were made in m. longissimus, m. biceps femoris and m. triceps brachii. Blood samples were collected at slaughter and muscle samples were taken 30 min after slaughter. Ultimate pH was measured 30 hr post mortem. The glycogen content in the muscles of groups A-C was very low (100-200 mmol/kg). In groups D-G, the glycogen content was equivalent to normal beef muscle values (300-500 mmol/kg). The values of the blood metabolites urea and creatinine, both of which could indicate protein catabolism caused by stress, were significantly (p < 0.05) higher in animals not having received supplemental feed (groups A-C). Alkaline phosphatase values were significantly (p < 0.05) higher in supplemental fed animals (groups D-G), indicating that their nutritional status was good. Total protein values were significantly (p < 0.05) higher in groups A, D, E and F compared to the other groups. Lorry transport did not significantly (p > 0.05) reduce the muscle glycogen content. Lairage (groups C and F) showed no negative effect on the parameters examined. These results suggest that the animals' physical condition and nutritional status have a considerable effect on their ability to tolerate various stress factors, such as lorry transport and lairage. PMID:22060679

  2. Cortical motor representation of the rectus femoris does not differ between the left and right hemisphere.

    PubMed

    Ward, Sarah; Bryant, Adam L; Pietrosimone, Brian; Bennell, Kim L; Clark, Ross; Pearce, Alan J

    2016-06-01

    Transcranial magnetic stimulation (TMS) involves non-invasive magnetic stimulation of the brain, and can be used to explore the corticomotor excitability and motor representations of skeletal muscles. However there is a lack of motor mapping studies in the lower limb and few conducted in healthy cohorts. The cortical motor representations of muscles can vary between individuals in terms of center position and area despite having a general localized region within the motor cortex. It is important to characterize the normal range for these variables in healthy cohorts to be able to evaluate changes in clinical populations. TMS was used in this cross-sectional study to assess the active motor threshold (AMT) and cortical representation area for rectus femoris in 15 healthy individuals (11M/4F 27.3±5.9years). No differences were found between hemispheres (Left vs. Right P=0.130) for AMT. In terms of y-axis center position no differences were found between hemispheres (Left vs. Right P=0.539), or for the x-axis center position (Left vs. Right P=0.076). Similarly, no differences in calculated area of the motor representation were found (Left vs. Right P=0.699) indicating symmetry between hemispheres. PMID:26999234

  3. Ultrasound Assessment of the Rectus Femoris Cross-Sectional Area: Subject Position Implications.

    PubMed

    Hacker, Eileen Danaher; Peters, Tara; Garkova, Miglena

    2016-09-01

    Ultrasonic measurement of the rectus femoris (RF) is a novel, proxy measure for muscle strength. The impact of hip flexion/head of bed positioning on RF cross-sectional area (CSA) has not been fully explored. This study describes and compares differences in RF CSA across four degrees of hip flexion. This repeated-measures, comparative study enrolled healthy, pre-menopausal women (n = 20). RF CSA of the dominant leg was measured using the SonoSite M-Turbo ultrasound system with the head of bed at 0°, 20°, 30°, and 60°. One-way repeated measures indicated significant differences in RF CSA, F(3, 17) = 14.18, p < .001, with variation in hip flexion/head of bed elevation and significant RF CSA differences between: (a) 0° and 20°, (b) 0° and 30°, (c) 0° and 60°, and (d) 20° and 60°. Standardizing patient positioning when conducting ultrasonic measurement of RF CSA is vital for researchers who assess muscle mass. PMID:27090872

  4. Force-generating capacities and fatigability of the quadriceps femoris in relation to different exercise modes.

    PubMed

    Ullrich, Boris; Brüggemann, Gert-Peter

    2008-09-01

    In this study, we examined whether different exercise modes provoke functional differences in maximal and explosive force-generating capacities and fatigability of the quadriceps femoris (QF). Additionally, the interaction of different functional capacities was studied in competitive athletes. Ten competitive tennis players and 10 endurance athletes participated in the study. Pre-exercise force-generating capacities were determined during maximal voluntary isometric knee extensions (MVC). Fatigability of the QF was studied using sustained isometric contractions with target loads of 20% and 40% of pre-exercise MVC. Postexercise MVCs were conducted 20 seconds, 1 minute, and 3 minutes post task failure. Muscle activation of the QF during the fatiguing exercises and postexercise MVCs was estimated using surface electromyography. Higher explosive force-generating capacities, but no differences in absolute moments, were detected in tennis players compared with endurance athletes. Fatigability of the QF during both fatiguing tasks was approximately the same in both athletic populations. This was indicated by minor group differences in endurance time, postexercise MVC production, and electromyography (EMG)-estimated muscle activation during fatigue. Variability in endurance time was not significantly associated with pre-exercise force-generating capacities in these competitive athletes. In both athletic populations, recovery of MVC was significantly slower after the fatiguing contraction with 20% of MVC compared with that with 40% of MVC. These results may enhance understanding of plasticity of the neuromuscular system and yield interesting information for the optimization of athletic training programs. Explosive strength training might enhance endurance athletes' explosiveness without decreasing muscle fatigue resistance. The exercise profile of competitive tennis is suggested to act as a sufficient trigger to reach high neuromuscular fatigue resistance but may be

  5. The role of biceps brachii and brachioradialis for the control of elbow flexion and extension movements.

    PubMed

    von Werder, Sylvie Charlotte Frieda Anneliese; Disselhorst-Klug, Catherine

    2016-06-01

    How do synergistic muscles interact, when their contraction aims at stabilizing and fine-tuning a movement, which is induced by the antagonistic muscle? The aim of the study was to analyze the interaction of biceps and brachioradialis during fine-tuning control tasks in comparison to load bearing ones. The surface electromyogram of biceps, brachioradialis and triceps were examined in 15 healthy subjects in dynamic flexion and extension movements with different combinations of contraction levels, joint angles and angular velocities. The measurements were conducted in two configurations, where the torque due to an external load opposes the rotational direction of the elbow flexion (load bearing tasks) or the elbow extension (fine-tuning tasks). Whereas during load bearing control tasks, similar muscular activation of biceps and brachioradialis was observed for all joint angles, angular velocities and external loads, during fine-tuning control tasks a significant difference of the muscular activation of both flexors was observed for 1kg, F(3.639,47.305)=2.864, p=0.037, and 5kg of external load, F(1.570,21.976)=6.834, p=0.008. The results confirm the synergistic muscular activation of both flexors during load bearing tasks, but suggest different control strategies for both flexors when they comprise a fine-tuning control task. PMID:27061680

  6. Anomalous biceps origin from the rotator cuff

    PubMed Central

    Banerjee, Samik; Patel, Vipul R

    2015-01-01

    Variations in the origin of the long head of biceps tendon (LHBT) have been described in literature; however, its clinical significance remains uncertain. We describe in this report, the history, physical examination and the arthroscopic findings in a patient who had an anomalous origin of the LHBT from the rotator cuff, resulting in restriction of range of motion. This anomalous origin of the long head of biceps tendon causing capsular contracture and restriction of movements leading to secondary internal impingement, has not been extensively reported in the literature. Shoulder arthroscopists should be aware that, although, an uncommon clinical condition, the aberrant congenital origin of the LHBT from the rotator cuff can rarely become pathologic in middle age and lead to shoulder dysfunction. In such cases, release of the anomalous band may be required, along with the treatment of other concomitant intraarticular pathologies in the glenohumeral joint. PMID:25593361

  7. Arthroscopic Biceps Tenodesis From a Superior Viewing Portal in the Shoulder.

    PubMed

    Tarleton, Andrew A; Zhou, Liang; O'Brien, Michael J; Savoie, Felix H

    2015-08-01

    The purpose of this report is to describe our modification of the Verma-Trenhaile biceps tenodesis technique using a superior viewing portal that allows placement of the tenodesis site at the top of the pectoralis major tendon with interference screw fixation. The advantages of this technique include the following: (1) There is no need to exteriorize the tendon through the skin. (2) Viewing from superiorly allows a panoramic view of the groove all the way to the pectoralis major tendon insertion. (3) This panoramic view allows a more complete view of the biceps down to the muscle-tendon junction beneath the pectoralis major tendon. (4) The improved visualization permits the drill hole to be contained within the constraints of the groove. Short-term follow-up shows favorable results clinically, and no major complications have been associated with this technique. PMID:26759782

  8. Arthroscopic Biceps Tenodesis From a Superior Viewing Portal in the Shoulder

    PubMed Central

    Tarleton, Andrew A.; Zhou, Liang; O'Brien, Michael J.; Savoie, Felix H.

    2015-01-01

    The purpose of this report is to describe our modification of the Verma-Trenhaile biceps tenodesis technique using a superior viewing portal that allows placement of the tenodesis site at the top of the pectoralis major tendon with interference screw fixation. The advantages of this technique include the following: (1) There is no need to exteriorize the tendon through the skin. (2) Viewing from superiorly allows a panoramic view of the groove all the way to the pectoralis major tendon insertion. (3) This panoramic view allows a more complete view of the biceps down to the muscle-tendon junction beneath the pectoralis major tendon. (4) The improved visualization permits the drill hole to be contained within the constraints of the groove. Short-term follow-up shows favorable results clinically, and no major complications have been associated with this technique. PMID:26759782

  9. Biceps Tenodesis for Type II SLAP Tears.

    PubMed

    Tayrose, Gregory A; Karas, Spero G; Bosco, Joseph

    2015-06-01

    Tears of the superior glenoid labrum are a common cause of shoulder pain and disability, especially in overhead athletes such as pitchers, swimmers, and volleyball players. Type II SLAP lesions have been the most clinically important superior labral pathology, and the management of this lesion has been a very controversial topic. Currently, there are no high level studies in the literature to guide treatment. While the few level 3 and level 4 evidence studies that are available following arthroscopic repair of type II SLAP lesions all report reasonable overall patient satisfaction, persistent postoperative pain is common and associated with a low return to pre-injury level of sports participation. There has been a recent school of thought that biceps tenodesis, which maintains the length-tension relationship of the long head of biceps, should be the procedure of choice for patients with isolated type II SLAP lesions. The current paper reviews the role biceps tenodesis plays in the management of type II SLAP tears. PMID:26517164

  10. [Proximal and distal biceps tendon rupture--an indication for surgery?].

    PubMed

    Klonz, A; Eggers, C; Reilmann, H

    1998-09-01

    We reviewed 77 conservatively and 164 operatively treated cases of rupture of the long head of the biceps documented in the literature. Refixation offers a small but relatively constant improvement of flexion and supination power and thus reduces the number of cases with remaining light or marked weakness by one third. Deformity by the slipped muscle can be corrected effectively. As complications are uncommon surgery should be recommended to young and active patients and should at least be offered to less active patients. Thirteen patients were re-examined after operative repair for distal biceps tendon avulsion and 277 reported cases were reviewed. After conservative management (n = 20) the power of flexion remains reduced by 30%-40%, that of supination by more than 50%. The loss of flexion power, as well as the deformity can be nicely diminished by attachment of the distal biceps to the brachialis muscle (n = 22). There are no complications documented regarding this procedure. The anatomic reinsertion (n = 248) additionally reduces the loss of supination power to 0%-25%, but bears a higher risk of complications. The double-incision technique (n = 105 of 248) does not necessarily decrease this risk. There are as many nerve injuries reported as with the single-anterior approach. Additionally we are faced with the problem of radioulnar synostosis. The use of suture anchors provides a nice way of fixation of the tendon but does not facilitate the approach to the tuberosity. The distal biceps tendon rupture should be treated operatively. The adequate method of repair is to be determined individually. PMID:9816985

  11. [Biceps tendon: diagnosis, therapy and results after proximal and distal rupture].

    PubMed

    Klonz, A; Reilmann, H

    2000-03-01

    Ruptures of the long head of the M. biceps humeri are commonly caused by degenerative changes within the tendon. They are associated with pathologies of the subacromial space. The loss of power regarding elbow flexion and supination amounts to 8 to 21% after conservative treatment. Refixation offers a small but evident improvement of flexion and supination power. Especially endurance is improved. The number of cases with remaining light or marked weakness is reduced by more than 50%. Deformity by the slipped muscle can be corrected effectively. Function of the glenohumeral joint can only be improved if associated subacromial problems are identified and treated simultaneously. As complications are uncommon surgery should be recommended to young and active patients and should at least be offered to less active patients. Ruptures of the distal tendon are less common. Thirteen patients were re-examined after operative repair for distal biceps tendon avulsion and 277 reported cases were reviewed. After conservative management (n = 20) the power of flexion will remain reduced by 30%-40%, that of supination by more than 50%. The loss of flexion power, as well as the deformity can be diminished by attachment of the distal biceps to the brachialis muscle (n = 22). The anatomic re-insertion (n = 248) additionally reduces the loss of supination power to 0%-25%, but bears a higher risk of complications. Using the 'double-incision technique' (n = 105 of 248) does not decrease the risk of naval lesions but increases the incidence of radioulnar synostosis. The use of suture anchors provides a nice way of fixation of the tendon but does not facilitate the approach to the tuberosity. The distal biceps tendon rupture should be treated operatively. The adequate method of repair is to be determined individually. PMID:10798230

  12. The relationship between muscularity, muscle:bone ratio and cut dimensions in male and female lamb carcasses and the measurement of muscularity using image analysis.

    PubMed

    Hopkins, D L

    1996-12-01

    Dorsal images of 57 whole lamb carcasses (mean 22.5 kg, SD 2.3 kg) were obtained on a slaughter chain using a video camera. The lambs represented two sexes (29 cryptorchids, 28 ewes) and one genotype (Poll Dorset × Border Leicester × Merino). Cryptorchid carcasses were significantly (P < 0.05) leaner than ewe carcasses at a common weight but there was little difference in dimensional measurements of M. longissimus thoracis et lumborum (LL). The cryptorchid carcasses had a significantly better conformation (based on the EUROP system) even when adjusted to the same carcass weight and subcutaneous fat level. From the hindleg and chump the following muscles were dissected and weighed: M. semimembranosus, M. adductor femoris, M. semitendinosus, M. biceps femoris, and M. quadriceps femoris. The femur was weighed, the length measured and a muscularity value calculated as described by Purchas et al. (1991 Meat Sci., 30, 181). There was no significant effect of sex on muscularity or muscle to bone ratio (M:B). Cryptorchid carcasses produced heavier (P < 0.05) round and midloin cuts but lighter (P < 0.05) chump and ribloin cuts. Overall there was no significant sex effect on the yield of hindquarter cuts. Correlation showed a significant (P < 0.001) association between LL area and muscularity, with a lower correlation between round and topside cross-sectional area and muscularity. Neither muscle cross-sectional area nor muscularity was significantly related to M:B ratios. Muscularity increased with increasing carcass weight (P < 0.001) but M:B did not. Prediction of muscularity was significantly (P < 0.05) improved by adding to hot carcass weight a measure of the combined width across the hind legs at interval three, as taken from video images, there being five equally-spaced intervals from the groin to the gambrel. A similar result was achieved by using carcass width at the third interval of five-eventy spaced intervals between the minimum shoulder width and the point of

  13. [Proximal and distal ruptures of the biceps brachii tendon].

    PubMed

    Klonz, A; Loitz, D; Reilmann, H

    2003-09-01

    Proximal ruptures. Ruptures of the long head of the M. biceps humeri are commonly caused by degenerative changes within the tendon. Non-operative treatment gives good results, the loss of power regarding elbow flexion and supination amounts to only 8-21%. Refixation may be indicated for cosmetic reasons and offers a small but evident improvement of flexion and supination power. Deformity of the slipped muscle can be corrected effectively. Residual complaints after conservative treatment often result from associated subacromial problems. Distal ruptures. Ruptures of the distal tendon should be treated operatively. The loss of power after conservative treatment is evident (30-40% for flexion, >50% for supination). Extra-anatomical tenodesis to the brachialis muscle or anatomical fixation to the radial tuberosity can be applied. Flexion power and cosmesis can be addressed by both techniques. If supination strength is to be restored, the tendon has to be fixed anatomically. Preparation of the tuberosity bears the risk of heterotopic ossification or nerve damage. Mini-open techniques, using only a limited anterior approach, may decrease risks. PMID:14959750

  14. Quantifying the Elastic Property of Nine Thigh Muscles Using Magnetic Resonance Elastography

    PubMed Central

    Chakouch, Mashhour K.; Charleux, Fabrice; Bensamoun, Sabine F.

    2015-01-01

    Background Pathologies of the muscles can manifest different physiological and functional changes. To adapt treatment, it is necessary to characterize the elastic property (shear modulus) of single muscles. Previous studies have used magnetic resonance elastography (MRE), a technique based on MRI technology, to analyze the mechanical behavior of healthy and pathological muscles. The purpose of this study was to develop protocols using MRE to determine the shear modulus of nine thigh muscles at rest. Methods Twenty-nine healthy volunteers (mean age = 26 ± 3.41 years) with no muscle abnormalities underwent MRE tests (1.5 T MRI). Five MRE protocols were developed to quantify the shear moduli of the nine following thigh muscles at rest: rectus femoris (RF), vastus medialis (VM), vastus intermedius (VI), vastus lateralis (VL), sartorius (Sr), gracilis (Gr), semimembranosus (SM), semitendinosus (ST), and biceps (BC). In addition, the shear modulus of the subcutaneous adipose tissue was analyzed. Results The gracilis, sartorius, and semitendinosus muscles revealed a significantly higher shear modulus (μ_Gr = 6.15 ± 0.45 kPa, μ_ Sr = 5.15 ± 0.19 kPa, and μ_ ST = 5.32 ± 0.10 kPa, respectively) compared to other tissues (from μ_ RF = 3.91 ± 0.16 kPa to μ_VI = 4.23 ± 0.25 kPa). Subcutaneous adipose tissue had the lowest value (μ_adipose tissue = 3.04 ± 0.12 kPa) of all the tissues tested. Conclusion The different elasticities measured between the tissues may be due to variations in the muscles' physiological and architectural compositions. Thus, the present protocol could be applied to injured muscles to identify their behavior of elastic property. Previous studies on muscle pathology found that quantification of the shear modulus could be used as a clinical protocol to identify pathological muscles and to follow-up effects of treatments and therapies. These data could also be used for modelling purposes. PMID:26397730

  15. MRI-Based Regional Muscle Use during Hamstring Strengthening Exercises in Elite Soccer Players.

    PubMed

    Mendez-Villanueva, Alberto; Suarez-Arrones, Luis; Rodas, Gil; Fernandez-Gonzalo, Rodrigo; Tesch, Per; Linnehan, Richard; Kreider, Richard; Di Salvo, Valter

    2016-01-01

    The present study examined site-specific hamstring muscles use with functional magnetic resonance imaging (MRI) in elite soccer players during strength training. Thirty-six players were randomized into four groups, each performing either Nordic hamstring, flywheel leg-curl, Russian belt or the hip-extension conic-pulley exercise. The transverse relaxation time (T2) shift from pre- to post-MRI were calculated for the biceps femoris long (BFl) and short (BFs) heads, semitendinosus (ST) and semimembranosus (SM) muscles at proximal, middle and distal areas of the muscle length. T2 values increased substantially after flywheel leg-curl in all regions of the BFl (from 9±8 to 16±8%), BFs (41±6-71±11%), and ST (60±1-69±7%). Nordic hamstring induced a substantial T2 increase in all regions of the BFs (13±8-16±5%) and ST (15±7-17±5%). T2 values after the Russian belt deadlift substantially increased in all regions of the BFl (6±4-7±5%), ST (8±3-11±2%), SM (6±4-10±4%), and proximal and distal regions of BFs (6±6-8±5%). T2 values substantially increased after hip-extension conic-pulley only in proximal and middle regions of BFl (11±5-7±5%) and ST (7±3-12±4%). The relevance of such MRI-based inter- and intra-muscle use in designing more effective resistance training for improving hamstring function and preventing hamstring injuries in elite soccer players should be explored with more mechanistic studies. PMID:27583444

  16. Postmortem degradation of skeletal muscle proteins: a novel approach to determine the time since death.

    PubMed

    Pittner, Stefan; Monticelli, Fabio C; Pfisterer, Alexander; Zissler, Angela; Sänger, Alexandra M; Stoiber, Walter; Steinbacher, Peter

    2016-03-01

    Estimating the time since death is a very important aspect in forensic sciences which is pursued by a variety of methods. The most precise method to determine the postmortem interval (PMI) is the temperature method which is based on the decrease of the body core temperature from 37 °C. However, this method is only useful in the early postmortem phase (~0-36 h). The aim of the present work is to develop an accurate method for PMI determination beyond this present limit. For this purpose, we used sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), Western blotting, and casein zymography to analyze the time course of degradation of selected proteins and calpain activity in porcine biceps femoris muscle until 240 h postmortem (hpm). Our results demonstrate that titin, nebulin, desmin, cardiac troponin T, and SERCA1 degraded in a regular and predictable fashion in all samples investigated. Similarly, both the native calpain 1 and calpain 2 bands disintegrate into two bands subsequently. This degradation behavior identifies muscular proteins and enzymes as promising substrates for future molecular-based PMI determination technologies. PMID:26041514

  17. Strength Training to Contraction Failure Increases Voluntary Activation of the Quadriceps Muscle Shortly After Total Knee Arthroplasty

    PubMed Central

    Mikkelsen, Elin Karin; Jakobsen, Thomas Linding; Holsgaard-Larsen, Anders; Andersen, Lars Louis; Bandholm, Thomas

    2016-01-01

    ABSTRACT Objective The objective of this study was to investigate voluntary activation of the quadriceps muscle during one set of knee extensions performed until contraction failure in patients shortly after total knee arthroplasty. Design This was a cross-sectional study of 24 patients with total knee arthroplasty. One set of knee extensions was performed until contraction failure, using a predetermined 10 repetition maximum loading. In the operated leg, electromyographic (EMG) activity of the lateral and medial vastus, semitendinosus, and biceps femoris muscles was recorded during the set. Muscle activity (%EMGmax) and median power frequency of the EMG power spectrum were calculated for each repetition decile (10%–100% contraction failure). Results Muscle activity increased significantly over contractions from a mean of 90.0 and 93.6 %EMGmax (lateral vastus and medial vastus, respectively) at 10% contraction failure to 99.3 and 105.5 %EMGmax at 100% contraction failure (P = 0.009 and 0.004). Median power frequency decreased significantly over contractions from a mean of 66.8 and 64.2 Hz (lateral vastus and medial vastus, respectively) at 10% contraction failure to 59.9 and 60.1 Hz at 100% contraction failure (P = 0.0006 and 0.0187). Conclusion In patients shortly after total knee arthroplasty, 10 repetition maximum–loaded knee extensions performed in one set until contraction failure increases voluntary activation of the quadriceps muscle during the set. Clinical Trials Gov-identifier: NCT01713140 to the abstract to increase trial transparency. PMID:26339729

  18. Intrauterine growth-restricted sheep fetuses exhibit smaller hindlimb muscle fibers and lower proportions of insulin-sensitive Type I fibers near term.

    PubMed

    Yates, Dustin T; Cadaret, Caitlin N; Beede, Kristin A; Riley, Hannah E; Macko, Antoni R; Anderson, Miranda J; Camacho, Leticia E; Limesand, Sean W

    2016-06-01

    Intrauterine growth restriction (IUGR) reduces muscle mass and insulin sensitivity in offspring. Insulin sensitivity varies among muscle fiber types, with Type I fibers being most sensitive. Differences in fiber-type ratios are associated with insulin resistance in adults, and thus we hypothesized that near-term IUGR sheep fetuses exhibit reduced size and proportions of Type I fibers. Placental insufficiency-induced IUGR fetuses were ∼54% smaller (P < 0.05) than controls and exhibited hypoxemia and hypoglycemia, which contributed to 6.9-fold greater (P < 0.05) plasma norepinephrine and ∼53% lower (P < 0.05) plasma insulin concentrations. IUGR semitendinosus muscles contained less (P < 0.05) myosin heavy chain-I protein (MyHC-I) and proportionally fewer (P < 0.05) Type I and Type I/IIa fibers than controls, but MyHC-II protein concentrations, Type II fibers, and Type IIx fibers were not different. IUGR biceps femoris muscles exhibited similar albeit less dramatic differences in fiber type proportions. Type I and IIa fibers are more responsive to adrenergic and insulin regulation than Type IIx and may be more profoundly impaired by the high catecholamines and low insulin in our IUGR fetuses, leading to their proportional reduction. In both muscles, fibers of each type were uniformly smaller (P < 0.05) in IUGR fetuses than controls, which indicates that fiber hypertrophy is not dependent on type but rather on other factors such as myoblast differentiation or protein synthesis. Together, our findings show that IUGR fetal muscles develop smaller fibers and have proportionally fewer Type I fibers, which is indicative of developmental adaptations that may help explain the link between IUGR and adulthood insulin resistance. PMID:27053651

  19. All-Arthroscopic Suprapectoral versus Open Subpectoral Tenodesis of the Long Head of the Biceps Brachii

    PubMed Central

    Gombera, M. Mustafa; Kahlenberg, Cynthia A.; Nair, Rueben; Saltzman, Matthew D.; Terry, Michael A.

    2015-01-01

    Objectives: Pathology of the long head of the biceps tendon is a recognized source of shoulder pain in adults that can be treated with tenotomy or tenodesis when non-operative measures are not effective. It is not clear whether arthroscopic or open biceps tenodesis has a clinical advantage. To date, we are not aware of any studies that directly compare clinical outcomes between an arthroscopic and an open technique for tenodesis of the long head of the biceps brachii. The purpose of this study was to determine whether a difference in outcomes and complications exists between matched cohorts after biceps tenodesis utilizing an open subpectoral versus an all-arthroscopic suprapectoral technique. Methods: A prospective database was reviewed for patients undergoing an all-arthroscopic suprapectoral or open subpectoral biceps tenodesis. Adult patients with a minimum 18-month follow-up were included. Patients undergoing a concomitant rotator cuff or labral repair were excluded. The groups were matched to age within 3 years, sex, and time to follow-up within 3 months. Pain improvement, development of a popeye deformity, muscle cramping, post-operative ASES scores, satisfaction scores, and complications were evaluated. Results: Forty-six patients (23 all-arthroscopic, 23 open) patients with an average age of 57.2 years (range, 45-70) were evaluated at a mean 28.7 months (range, 18-42) follow-up. No patients in either group developed a popeye deformity or complained of arm cramping. There was no significant difference in mean ASES scores between the open and all-arthroscopic groups (92.7 vs. 88.9, P = 0.42, Table 1). Similarly, there was no significant difference between patient satisfaction scores (8.9 vs. 9.1, P = 0.73). Eighteen patients (78.3%) in the arthroscopic cohort and sixteen patients (69.6%) in the open cohort fully returned to athletic activity (P = 0.50). There were no complications in the all-arthroscopic group. There were two complications in the open group

  20. Biceps Lesion Associated With Rotator Cuff Tears

    PubMed Central

    Jeong, Ho Yeon; Kim, Jung Youn; Cho, Nam Su; Rhee, Yong Girl

    2016-01-01

    Background: Various tenodesis methods are being used for long head of the biceps tendon lesions. However, there is no consensus on the most appropriate surgical method. Hypothesis: There are significant differences in incidence of cosmetic deformity and persistent bicipital pain between open subpectoral and arthroscopic intracuff tenodesis groups. Study Design: Cohort study; Level of evidence, 3. Methods: This study included 72 patients who underwent biceps tenodesis and rotator cuff repair between January 2009 and May 2014 and who were followed for at least 1 year. Open subpectoral tenodesis was performed in 39 patients (group A), and arthroscopic intracuff tenodesis was performed in 33 patients (group B). Results: In group A, the mean visual analog scale (VAS) score for pain during motion and mean University of California, Los Angeles (UCLA) and Constant scores significantly improved from 4.6, 18.6, and 64.5 preoperatively to 1.9, 30.5, and 86.5 at last follow-up, respectively (P < .001 for all). In group B, these scores significantly improved from 5.1, 17.6, and 62.9 preoperatively to 1.8, 31.5, and 85.9 at last follow-up, respectively (P < .001 for all). Popeye deformity was noted in 2 (5.2%) patients from group A and 5 (15.6%) patients from group B (P = .231). Additionally, persistent bicipital tenderness was noted in 1 (2.6%) patient from group A and 8 (24.2%) patients from group B (P = .012). Conclusion: Both open subpectoral tenodesis and arthroscopic intracuff tenodesis show good clinical outcomes for long head of the biceps tendon lesions. However, open subpectoral tenodesis may be more appropriate, considering the low incidence of Popeye deformity and tenderness. PMID:27231699

  1. Variation in palatability and biochemical traits within and among eleven beef muscles.

    PubMed

    Rhee, M S; Wheeler, T L; Shackelford, S D; Koohmaraie, M

    2004-02-01

    The objective of this study was to determine the extent of variation in, and relationships among, biochemical and palatability traits within and among 11 major beef muscles. Longissimus thoracis et lumborum (LD), psoas major (PM), gluteus medius (GM), semimembranosus (SM), adductor (AD), biceps femoris (BF), semitendinosus (ST), rectus femoris (RF), triceps brachii (TB), infraspinatus (IS), and supraspinatus (SS) from one side of 31 Charolais x MARC III steer carcasses were vacuum-packaged, stored at 2 degrees C until 14 d postmortem, and then frozen at -30 degrees C. The 2.54-cm-thick steaks were obtained from two or three locations within muscles in order to assess biochemical traits and Warner-Bratzler shear force, and from near the center for sensory trait evaluation. The PM was most tender and was followed by IS in both shear force and tenderness rating (P < 0.05). The other muscles were not ranked the same by shear force and tenderness rating. The BF had the lowest (P < 0.05) tenderness rating. The PM, GM, and LD had lower (P < 0.05) collagen concentration (2.7 to 4.5 mg/g muscle) than muscles from the chuck and round (5.9 to 9.0 mg/g), except for the AD (4.9 mg/g). Desmin proteolysis was highest (P < 0.05) for BF and LD (60.7 and 60.1% degraded), and was lowest (P < 0.05) for PM (20.2%). The PM, TB, IS, RF, and ST had relatively long sarcomere lengths (> 2.1 microm), whereas the GM had the shortest (P < 0.05) sarcomere length (1.7 microm). Cooking loss was lowest (P < 0.05) for BF (18.7%) and was followed by LD and IS (20.7%); it was highest (P < 0.05) for ST (27.4%). Across all muscles, tenderness rating was highly correlated (r > 0.60) with shear force, connective tissue rating, sarcomere length, and collagen content. Within a muscle, correlations among all traits were generally highest in LD and lowest in AD. Within muscle, location effects were detected (P < 0.05) for shear force (PM, ST, BF, SM, and RF), sarcomere length (PM, ST, BF, LD, SS, IS, SM, and

  2. Contributions to enhanced activity in rectus femoris in response to Lokomat-applied resistance.

    PubMed

    Klarner, Taryn; Blouin, J-S; Carpenter, M G; Lam, T

    2013-03-01

    The application of resistance during the swing phase of locomotion is a viable approach to enhance activity in the rectus femoris (RF) in patients with neurological damage. Increased muscle activity is also accompanied by changes in joint angle and stride frequency, consequently influencing joint angular velocity, making it difficult to attribute neuromuscular changes in RF to resistance. Thus, the purpose of this study was to evaluate the effects of resistance on RF activity while constraining joint trajectories. Participants walked in three resistance conditions; 0 % (no resistance), 5 and 10 % of their maximum voluntary contraction (MVC). Visual and auditory biofeedback was provided to help participants maintain the same knee joint angle and stride frequency as during baseline walking. Lower limb joint trajectories and RF activity were recorded. Increasing the resistance, while keeping joint trajectories constant with biofeedback, independently enhanced swing phase RF activity. Therefore, the observed effects in RF are related to resistance, independent of any changes in joint angle. Considering resistance also affects stride frequency, a second experiment was conducted to evaluate the independent effects of resistance and stride frequency on RF activity. Participants walked in four combinations of resistance at 0 and 10 %MVC and natural and slow stride frequency conditions. We observed significant increases in RF activity with increased resistance and decreased stride frequency, confirming the independent contribution of resistance on RF activity as well as the independent effect of stride frequency. Resistance and stride frequency may be key parameters in gait rehabilitation strategies where either of these may be manipulated to enhance swing phase flexor muscle activity in order to maximize rehabilitation outcomes. PMID:23183638

  3. Arthroscopic tenodesis of the long head of the biceps.

    PubMed

    Harwin, Steven F; Birns, Michael E; Mbabuike, Jean-Jacques; Porter, David A; Galano, Gregory J

    2014-11-01

    The long head of the biceps (LHB) is commonly implicated in shoulder pathology due to its anatomic course and intimacy with the rotator cuff and superior labrum of the glenoid. Treatment of tendinosis of the LHB may be required secondary to partial thickness tears, instability/subluxation, associated rotator cuff tears, or SLAP (superior labrum, anterior to posterior) lesions. Treatment options include open or arthroscopic techniques for tenodesis vs tenotomy. Controversy exists in the orthopedic literature regarding the preferred procedure. The all-arthroscopic biceps tenodesis technique is a viable and reproducible option for treatment. This article provides a review of the all-arthroscopic biceps tenodesis technique using proximal interference screw fixation and its subsequent postoperative regimen. All-arthroscopic biceps tenodesis maintains elbow flexion and supination power, minimizes cosmetic deformities, and leads to less fatigue soreness after active flexion. Thus, arthroscopic biceps tenodesis should be offered and encouraged as a treatment option for younger, active patients. PMID:25361357

  4. Avulsion fracture of the straight and reflected heads of rectus femoris.

    PubMed

    Deehan, D J; Beattie, T F; Knight, D; Jongschaap, H

    1992-09-01

    We present a rare case of avulsion fracture of the reflected head of rectus femoris. This occurred in a 13-year-old male footballer. Diagnosis was made with pelvic radiology and treatment was bed rest and analgesia. PMID:1449579

  5. Light sterile neutrinos after BICEP-2

    SciTech Connect

    Archidiacono, Maria; Hannestad, Steen; Fornengo, Nicolao; Gariazzo, Stefano; Giunti, Carlo; Laveder, Marco E-mail: fornengo@to.infn.it E-mail: giunti@to.infn.it E-mail: marco.laveder@pd.infn.it

    2014-06-01

    The recent discovery of B-modes in the polarization pattern of the Cosmic Microwave Background by the BICEP2 experiment has important implications for neutrino physics. We revisit cosmological bounds on light sterile neutrinos and show that they are compatible with all current cosmological data provided that the mass is relatively low. Using CMB data, including BICEP-2, we find an upper bound of m{sub s} < 0.85 eV (2σ Confidence Level). This bound is strengthened to 0.48 eV when HST measurements of H{sub 0} are included. However, the inclusion of SZ cluster data from the Planck mission and weak gravitational measurements from the CFHTLenS project favours a non-zero sterile neutrino mass of 0.44{sup +0.11}{sub −0.16} eV. Short baseline neutrino oscillations, on the other hand, indicate a new mass state around 1.2 eV. This mass is highly incompatible with cosmological data if the sterile neutrino is fully thermalised (Δχ{sup 2} > 10). However, if the sterile neutrino only partly thermalises it can be compatible with all current data, both cosmological and terrestrial.

  6. Building the BICEP3 Test Cryostat

    NASA Astrophysics Data System (ADS)

    Walker, Samantha; Kuo, Chao-Lin; Thompson, Keith L.; Grayson, James; Karpel, Ethan; Monticue, Val; Kuo Group/Bicep3 Collaboration Team

    2016-03-01

    BICEP3, a ground-based telescope stationed in the South Pole, currently employs a cryostat to observe the polarization of the Cosmic Microwave Background, the earliest light in the Universe, by using devices that take advantage of the superconductivity transition of titanium. The cryostat consists of staggered temperature stages at 300 K, 50 K, 4 K, 2 K, 350 mK, and 250 mK that are maintained by both a pulse tube and three stage helium (He4-He3-He3) sorption refrigerator. However, currently the helium refrigerator is experiencing unanticipated heat loading which is decreasing the fridge cycle hold time and thus the number of hours that BICEP3 can observe for in a given period of time. To address this issue, this past summer I worked at Stanford University to construct a thermally-similar cryostat that will be used to test the thermal conductivities of its various internal components at subKelvin temperatures and determine the source of this heat loading.

  7. Leg and trunk muscle coordination and postural sway during increasingly difficult standing balance tasks in young and older adults.

    PubMed

    Donath, Lars; Kurz, Eduard; Roth, Ralf; Zahner, Lukas; Faude, Oliver

    2016-09-01

    Ageing impairs body balance and increases older adults' fall risk. Balance training can improve intrinsic fall risk factors. However, age comparisons of muscle activity responses during balance tasks are lacking. This study investigated relative muscle activity, muscle coordination and postural sway during various recommended static balance training tasks. Muscle activity (%MVC), amplitude ratios (AR) and co-activity (CAI) were determined during standing tasks for 30s (1: double limb stance on a foam surface, eyes open; 2: double limb stance on firm ground, eyes closed; 3: double limb stance, feet in step position on a foam surface, eyes open; 4: double limb stance, feet in step position on firm ground, eyes closed; 5: single limb stance on firm ground, eyes open) in 20 healthy young adults (24±2 y) and 20 older adults (73±6 y). Surface electromyography (SEMG) was applied (SENIAM guidelines) to ankle (tibialis anterior, soleus, medial gastrocnemius, peroneus longus) and thigh (vastus lateralis, vastus medialis, biceps femoris, semitendinosus) muscles (non-dominant leg). Electrodes over trunk (multifidus and internal oblique) muscles were applied bilaterally. Two- to six-fold higher levels of relative muscle activity were found in older adults for ankle (0.0002muscles. Co-activation was elevated in young adults for the trunk (0.001muscle coordination patterns during all stance conditions at the ankle (0.06<ηp(2)<0.28) and the trunk (0.14<ηp(2)<0.23). Older adults had higher electrophysiological costs for all stance conditions. Muscle coordination showed inverse activity patterns at the ankle and trunk. Optimal balance and strength training programs should take into account age-specific alterations in muscle activity. PMID:27451322

  8. Selection of Reference Genes for Gene Expression Studies Related to Intramuscular Fat Deposition in Capra hircus Skeletal Muscle

    PubMed Central

    Zhu, Wuzheng; Lin, Yaqiu; Liao, Honghai; Wang, Yong

    2015-01-01

    The identification of suitable reference genes is critical for obtaining reliable results from gene expression studies using quantitative real-time PCR (qPCR) because the expression of reference genes may vary considerably under different experimental conditions. In most cases, however, commonly used reference genes are employed in data normalization without proper validation, which may lead to incorrect data interpretation. Here, we aim to select a set of optimal reference genes for the accurate normalization of gene expression associated with intramuscular fat (IMF) deposition during development. In the present study, eight reference genes (PPIB, HMBS, RPLP0, B2M, YWHAZ, 18S, GAPDH and ACTB) were evaluated by three different algorithms (geNorm, NormFinder and BestKeeper) in two types of muscle tissues (longissimus dorsi muscle and biceps femoris muscle) across different developmental stages. All three algorithms gave similar results. PPIB and HMBS were identified as the most stable reference genes, while the commonly used reference genes 18S and GAPDH were the most variably expressed, with expression varying dramatically across different developmental stages. Furthermore, to reveal the crucial role of appropriate reference genes in obtaining a reliable result, analysis of PPARG expression was performed by normalization to the most and the least stable reference genes. The relative expression levels of PPARG normalized to the most stable reference genes greatly differed from those normalized to the least stable one. Therefore, evaluation of reference genes must be performed for a given experimental condition before the reference genes are used. PPIB and HMBS are the optimal reference genes for analysis of gene expression associated with IMF deposition in skeletal muscle during development. PMID:25794179

  9. The Effect of Monochromatic Infrared Photo Energy on the Irritability of Myofascial Trigger Spot of Rabbit Skeletal Muscle

    PubMed Central

    Kuan, Ta-Shen; Lin, Yu-Ching; Lien, Wei-Chih; Hsieh, Pei-Chun; Chung, Yu-Ting; Lin, Sheng-Hsiang; Chou, Li-Wei

    2015-01-01

    Objective. To determine whether the vasodilatation effect of monochromatic infrared photo energy (MIRE) had the potential for the treatment of myofascial trigger spot (MTrS) in rabbits. Design. A randomized-controlled animal study. Subjects. Twelve adult New Zealand rabbits. Methods. For each rabbit, a MTrS (equivalent to a myofascial trigger point in humans) in one side of the biceps femoris muscle was randomly selected for MIRE treatment (experimental side), while another MTrS in the other side (control side) received a sham treatment. The intervention consisted of a daily 40 minutes treatment, three times per week for 2 weeks. The prevalence of endplate noise (EPN) loci in the MTrS was assessed before, immediately after, and one week after the completion of the 2-week treatment. Results. MIRE could suppress the prevalence of EPN in the MTrS. The degree of reduction in EPN prevalence in the MTrS between the experimental side and the control side was significantly different immediately after MIRE treatment, but not significantly different one week after MIRE treatment. Conclusion. Our study suggests that MIRE may be a useful therapeutic option for the management of the myofascial trigger point in humans. PMID:26442122

  10. Disorders of the long head of the biceps tendon.

    PubMed

    Mellano, Chris R; Shin, Jason J; Yanke, Adam B; Verma, Nikhil N

    2015-01-01

    The functional importance of the long head of the biceps tendon is a source of debate. Despite the controversy concerning its functional role, the long head of the biceps tendon is a recognized pain generator in the shoulder. Because long head of the biceps tendinopathy is commonly associated with other shoulder pathologies, a thorough assessment and examination are critical to making the correct diagnosis and choosing a management plan. If nonsurgical treatment has failed, biceps tenotomy and biceps tenodesis can provide pain relief. Biceps tenodesis is reserved for young, higher demand patients; requires more rehabilitation time; and has a higher cost. All-arthroscopic proximal tenodesis and distal open subpectoral tenodesis have advantages and disadvantages. Although recent midterm reports suggest slightly better revision and complication rates with subpectoral tenodesis, more studies are needed to verify these findings. Persistent shoulder symptoms after biceps tenodesis commonly occur secondary to missed or untreated associated shoulder pathologies but also may result from mechanical failure of the tenodesis. PMID:25745939

  11. Development of estimation system of knee extension strength using image features in ultrasound images of rectus femoris

    NASA Astrophysics Data System (ADS)

    Murakami, Hiroki; Watanabe, Tsuneo; Fukuoka, Daisuke; Terabayashi, Nobuo; Hara, Takeshi; Muramatsu, Chisako; Fujita, Hiroshi

    2016-04-01

    The word "Locomotive syndrome" has been proposed to describe the state of requiring care by musculoskeletal disorders and its high-risk condition. Reduction of the knee extension strength is cited as one of the risk factors, and the accurate measurement of the strength is needed for the evaluation. The measurement of knee extension strength using a dynamometer is one of the most direct and quantitative methods. This study aims to develop a system for measuring the knee extension strength using the ultrasound images of the rectus femoris muscles obtained with non-invasive ultrasonic diagnostic equipment. First, we extract the muscle area from the ultrasound images and determine the image features, such as the thickness of the muscle. We combine these features and physical features, such as the patient's height, and build a regression model of the knee extension strength from training data. We have developed a system for estimating the knee extension strength by applying the regression model to the features obtained from test data. Using the test data of 168 cases, correlation coefficient value between the measured values and estimated values was 0.82. This result suggests that this system can estimate knee extension strength with high accuracy.

  12. In vivo measurements of biceps brachii and triceps brachii fascicle lengths using extended field-of-view ultrasound.

    PubMed

    Nelson, Christa M; Dewald, Julius P A; Murray, Wendy M

    2016-06-14

    Muscle fascicle lengths are commonly measured in vivo using static 2D ultrasound. However, static ultrasound is best suited for muscles with shorter, pennate fascicles, in which entire fascicles can be viewed in one static image. An informal review of data from cadaver dissections suggests that over 60% of muscles in the upper and lower limbs have optimal lengths longer than the field-of-view of standard ultrasound transducers. Extended field-of-view ultrasound (EFOV) has been validated for measurement of fascicle lengths, but has yet to be implemented in the upper extremity in humans. In this study, EFOV ultrasound was used to measure the lengths of fascicles sampled from the anterior portion of the biceps brachii (long head) and the distal half of the triceps brachii (lateral head). Data were collected from both limbs of eleven healthy subjects in three elbow postures under passive conditions. Image analysis was completed via Image J. Fascicle length measurements were highly reliable, with intra-class correlations ranging from .92 to .95 for biceps and .81-.92 for triceps (p<.001). Systematic, significant differences in measured lengths, consistent with muscle function, were observed between elbow positions. In vivo measurements for both muscles in this study were within the range of cadaver data. This work establishes the feasibility and reliability of EFOV ultrasound for measurement of the long fascicles of muscles in the upper limb. PMID:27083062

  13. The BICEP/Keck CMB polarization program: Status and results

    NASA Astrophysics Data System (ADS)

    Steinbach, Bryan

    2016-06-01

    The BICEP/Keck program is searching for the imprint of inflationary gravitational waves on the Cosmic Microwave Background polarization with 5000 detectors in sub 1-m aperture telescopes observing at 95, 150 and 220GHz. Combining BICEP/Keck data with Planck polarization data, we constrain the tensor to scalar ratio (r) to be less than 0.09 at 95% confidence, for the first time exceeding the strength of the constraint from CMB temperature data. In this talk we report on this result, along with the quality of polarized 220GHz observations at the South Pole and the deployment of the BICEP-3 camera.

  14. Management of distal biceps and triceps ruptures.

    PubMed

    Blackmore, Susan M; Jander, Ryan M; Culp, Randall W

    2006-01-01

    The management of distal biceps and triceps ruptures is reviewed. Epidemiology, clinical presentation, evaluation, surgical management, nonoperative management, and rehabilitation rationale and techniques are presented. Although various surgical repair techniques are used, none has been shown to produce superior clinical outcomes. The literature is lacking information to provide evidence-based decisions regarding rehabilitation strategies. Prospective studies comparing types and timing of repairs and timing and techniques for a postoperative program are needed. As that information is not yet available, the rehabilitation plan outlined in this article is based on timetables for healing tissue, strength of repair, prevention of complications, consideration of patient's medical history and injury history, and review of the literature. Familiarity with the different treatment options assists the surgeon and therapist tailor a therapy program that is optimal for each individual patient. PMID:16713863

  15. BICEP2 in corpuscular description of inflation

    SciTech Connect

    Dvali, G.; Gomez, C.

    2015-03-15

    A corpuscular quantum description of inflation shows that there is no fundamental problem with trans-Planckian excursions of the inflaton field up to about 100 Planck masses, with the upper bound coming from the corpuscular quantum effects. In this description, the r parameter measures the ratio of occupation numbers of gravitons versus inflatons, which, according to BICEP2, was roughly a half at the time of 60 e-foldings prior to the end of inflation. We stress that in a non-Wilsonian UV self-completion of gravity, any trans-Planckian mode coupled to the inflaton is a black hole. Unlike the Wilsonian case, integrating them out gives an exponentially suppressed effect and is unable to prevent trans-Planckian excursions of the inflaton field.

  16. Inflationary tensor perturbations after BICEP2.

    PubMed

    Caligiuri, Jerod; Kosowsky, Arthur

    2014-05-16

    The measurement of B-mode polarization of the cosmic microwave background at large angular scales by the BICEP experiment suggests a stochastic gravitational wave background from early-Universe inflation with a surprisingly large amplitude. The power spectrum of these tensor perturbations can be probed both with further measurements of the microwave background polarization at smaller scales and also directly via interferometry in space. We show that sufficiently sensitive high-resolution B-mode measurements will ultimately have the ability to test the inflationary consistency relation between the amplitude and spectrum of the tensor perturbations, confirming their inflationary origin. Additionally, a precise B-mode measurement of the tensor spectrum will predict the tensor amplitude on solar system scales to 20% accuracy for an exact power-law tensor spectrum, so a direct detection will then measure the running of the tensor spectral index to high precision. PMID:24877926

  17. Hamstring Fatigue and Muscle Activation Changes During Six Sets of Nordic Hamstring Exercise in Amateur Soccer Players.

    PubMed

    Marshall, Paul W M; Lovell, Ric; Knox, Michael F; Brennan, Scott L; Siegler, Jason C

    2015-11-01

    The Nordic hamstring exercise (NHE) is a bodyweight movement commonly prescribed to increase eccentric hamstring strength and reduce the incidence of strain injury in sport. This study examined hamstring fatigue and muscle activation responses throughout 6 sets of 5 repetitions of the NHE. Ten amateur-level soccer players performed a single session of 6 sets of 5 repetitions of NHE. Maximal eccentric and concentric torque output (in newton meters) was measured after every set. Hamstrings electromyograms (EMG) were measured during all maximal contractions and exercise repetitions. Hamstring maximal eccentric torque was reduced throughout the range of motion after only a single set of NHE between 7.9 and 17.1% (p ≤ 0.05), with further reductions in subsequent sets. Similarly, maximal concentric torque reductions between 7.8 and 17.2% were observed throughout the range of motion after 1 set of NHE (p ≤ 0.05). During the descent phase of the NHE repetitions, hamstring muscle activity progressively increased as the number of sets performed increased. These increases were observed in the first half of the range of motion. During the ascent phase, biceps femoris muscle activity but not medial hamstrings was reduced from the start of exercise during latter sets of repetitions. These data provide unique insight into the extent of fatigue induced from a bodyweight only exercise after a single set of 5 repetitions. Strength and conditioning coaches need to be aware of the speed and extent of fatigue induced from NHE, particularly in practical settings in which this exercise is now prescribed before sport-specific training sessions (i.e., the FIFA-11 before soccer training). PMID:25886019

  18. Effect of muscle and intensity of finishing diet on meat quality of foals slaughtered at 15 months.

    PubMed

    Franco, Daniel; Lorenzo, José M

    2014-01-01

    The effect of muscle and intensity of finishing diet on meat quality of foals slaughtered at 15 months was study. For this work, a total of twenty one foals and six muscles: longissimus dorsi (LD), semimembranosus (SM), semitendinosus (ST), biceps femoris (BF), triceps brachii (TB) and Psoas major & minor (PM) from two different intensities of finishing diet (1.5 vs. 3 kg/day) were analysed. Meat quality (chemical composition, colour characteristics, and textural traits), fatty and amino acid profile and mineral composition were studied. In general the factor muscle had more effect on all traits measured in this study than finishing effect, especially in the fatty acids and mineral composition. SM muscle showed the highest percentage of protein in both finishing groups (22.34 and 21.74% for 3 and 1.5 kg of commercial feeding, respectively). The intramuscular fat content in the analysed muscles ranged between 0.15% (LD in 1.5 group) and 1.83% (PM in 3.0 group). The highest values of iron heme that were obtained in TB muscle (2.46 mg/100 g meat) are a considerable source of bioavailable iron content. The three most abundant fatty acids in both groups and for all muscles studied were oleic acid, palmitoleic acid and linoleic acid. From a healthy point of view, muscles from foals finishing with a minor amount of commercial fodder were the best. The best nutritional value was reached for PM and ST with 14.73% of total omega 3 and the highest polyunsaturated/saturated ratio (1.10), respectively. Concerning amino acid profile, values of essential/non-essential ratio were significantly higher (P<0.001) in muscles of 1.5 diet group foals (0.856) than the other group (0.833). Finally, potassium (243 mg/100 g) and phosphorous (202 mg/100 g) were the two main minerals, followed by sodium (54 mg/100 g) and magnesium (26 mg/100 g). PMID:23933631

  19. Spontaneous medial dislocation of the tendon of the long biceps brachii. An anatomic study of prevalence and pathomechanics.

    PubMed

    Petersson, C J

    1986-10-01

    Medial displacement of the tendon of the long biceps brachii muscle was analyzed in a dissection study on autopsy in 77 subjects, 42 men and 35 women. The tendon was found to be medially displaced in five shoulders in five different subjects (6.5%). Medial displacement of the tendon was always found in connection with full-thickness supraspinatus tendon ruptures. It is a common belief that the tendon is always displaced medially to the lesser tubercle riding over the subscapularis tendon. In the present series, this condition was found only in one case; in the other shoulders the tendon had slipped medially to the lesser tubercle under the subscapularis tendon, which was partially internally ruptured. In patients with rotator cuff lesions, medial displacement of the long biceps tendon might be one reason for pain over the front of the shoulder. PMID:3769261

  20. BICEP2, the curvature perturbation and supersymmetry

    NASA Astrophysics Data System (ADS)

    Lyth, David H.

    2014-11-01

    The tensor fraction r simeq 0.16 found by BICEP2 corresponds to a Hubble parameter H simeq 1.0 × 1014 GeV during inflation. This has two implications for the (single-field) slow-roll inflation hypothesis. First, the inflaton perturbation must account for much more than 10% of the curvature perturbation ζ, which barring fine-tuning means that it accounts for practically all of it. It follows that a curvaton-like mechanism for generating ζ requires an alternative to slow roll such as k-inflation. Second, accepting slow-roll inflation, the excursion of the inflaton field is at least of order Planck scale. As a result, the flatness of the inflaton presumably requires a shift symmetry. I point out that if such is the case, the resulting potential is likely to have at least approximately the quadratic form suggested in 1983 by Linde, which is known to be compatible with the observed r as well as the observed spectral index ns. The shift symmetry does not require supersymmetry. Also, the big H may rule out a GUT by restoring the symmetry and producing fatal cosmic strings. The absence of a GUT would correspond to the absence of superpartners for the Standard Model particles, which indeed have yet to be found at the LHC.

  1. BICEP2, the curvature perturbation and supersymmetry

    SciTech Connect

    Lyth, David H.

    2014-11-01

    The tensor fraction r ≅ 0.16 found by BICEP2 corresponds to a Hubble parameter H ≅ 1.0 × 10{sup 14} GeV during inflation. This has two implications for the (single-field) slow-roll inflation hypothesis. First, the inflaton perturbation must account for much more than 10% of the curvature perturbation ζ, which barring fine-tuning means that it accounts for practically all of it. It follows that a curvaton-like mechanism for generating ζ requires an alternative to slow roll such as k-inflation. Second, accepting slow-roll inflation, the excursion of the inflaton field is at least of order Planck scale. As a result, the flatness of the inflaton presumably requires a shift symmetry. I point out that if such is the case, the resulting potential is likely to have at least approximately the quadratic form suggested in 1983 by Linde, which is known to be compatible with the observed r as well as the observed spectral index n{sub s}. The shift symmetry does not require supersymmetry. Also, the big H may rule out a GUT by restoring the symmetry and producing fatal cosmic strings. The absence of a GUT would correspond to the absence of superpartners for the Standard Model particles, which indeed have yet to be found at the LHC.

  2. Behaviour of the electrical impedance myography in isometric contraction of biceps brachii at different elbow joint angles

    NASA Astrophysics Data System (ADS)

    Coutinho, A. B. B.; Jotta, B.; Pino, A. V.; Souza, M. N.

    2012-12-01

    Electrical impedance myography (EIM) can be understood as an experimental technique applied to evaluate bioelectrical impedance associated to the muscular activity. With the development of technique, some studies are trying to associate the EIM parameters with the morphological and physiological changes that occur in the muscle during contraction. In this context this work sought to associate EIM parameters observed during isometric contractions of the biceps brachii muscle at different elbow joint angles with the correspondent muscular force. Differently from previous works that did not observe significant correlation between those data, our findings point to high correlations between the some EIM resistive parameters and the muscle force. Despite the need of further investigation, our results indicated that EIM technique can be used to estimate muscle force in a noninvasive way.

  3. Distal biceps reconstruction 13 years post-injury

    PubMed Central

    Burrus, M. Tyrrell

    2015-01-01

    Distal biceps tendon ruptures are relatively rare injuries most commonly caused by an eccentric contraction of the biceps brachii. The majority of complete ruptures receive early surgical intervention, however, some patients do present in a delayed fashion. There are many surgical options at this time for acute and chronic injuries, and this case report describes an Achilles allograft reconstruction in a male who sustained a complete tear 13 years prior to presentation. At 12-month follow up, he had regained full function of his dominant extremity as evidence by returning to work with no limitations and by a Disabilities of the Arm, Shoulder, and Hand (DASH) score of zero. We are unaware of a successfully surgically reconstructed distal biceps tendon of this chronicity. As the literature on this subject is sparse, this case report gives credence to the idea that certain patients with a chronic distal biceps rupture should be considered for operative reconstruction and not relegated to continued failed conservative treatment. Discussed are the surgical treatment options and controversies for chronic distal biceps ruptures, and we review various outcome studies using different surgical techniques. PMID:25829956

  4. The Gluteus Medius Vs. Thigh Muscles Strength Ratio and Their Relation to Electromyography Amplitude During a Farmer’s Walk Exercise

    PubMed Central

    Stastny, Petr; Lehnert, Michal; Zaatar, Amr; Svoboda, Zdenek; Xaverova, Zuzana; Pietraszewski, Przemysław

    2015-01-01

    The strength ratio between hamstrings and quadriceps (H/Q) is associated with knee injuries as well as hip abductor muscle (HAB) weakness. Sixteen resistance trained men (age, 32.5 ± 4.2 years) performed 5 s maximal isometric contractions at 75° of knee flexion/extension and 15° of hip abduction on a dynamometer. After this isometric test they performed a Farmer’s walk exercise to find out if the muscle strength ratio predicted the electromyography amplitude expressed as a percentage of maximum voluntary isometric contraction (%MVIC). The carried load represented a moderate intensity of 75% of the exercise six repetitions maximum (6RM). Electromyography data from the vastus medialis (VM), vastus lateralis (VL), biceps femoris (BF) and gluteus medius (Gmed) on each leg were collected during the procedure. The groups selected were participants with H/Q ≥ 0.5, HQ < 0.5, HAB/H ≥ 1, HAB/H < 1, HAB/Q ≥ 0.5 and HAB/Q < 0.5. One way ANOVA showed that Gmed activity was significantly greater in the group with HAB/H < 1 (42 ± 14 %MVIC) as compared to HAB/H ≥ 1 (26 ± 10 %MVIC) and HAB/Q < 0.5 (47 ± 19 %MVIC) compared to HAB/Q ≥ 0.5 (26 ± 12 %MVIC). The individuals with HAB/H < 1 were found to have greater activation of their Gmed during the Farmer’s walk exercise. Individuals with HAB/Q < 0.5 had greater activation of the Gmed. Gmed strength ratios predict the muscle involvement when a moderate amount of the external load is used. The Farmer’s walk is recommended as an exercise which can strengthen the gluteus medius, especially for individuals with a HAB/H ratio < 1 and HAB/Q < 0.5. PMID:25964819

  5. Avulsion fracture of the straight and reflected heads of rectus femoris.

    PubMed Central

    Deehan, D J; Beattie, T F; Knight, D; Jongschaap, H

    1992-01-01

    We present a rare case of avulsion fracture of the reflected head of rectus femoris. This occurred in a 13-year-old male footballer. Diagnosis was made with pelvic radiology and treatment was bed rest and analgesia. Images Fig. 1 Fig. 2 PMID:1449579

  6. The Significance of Rectus Femoris for the Favorable Functional Outcome After Total Femur Replacement

    PubMed Central

    Nakayama, Takayuki; Shimoji, Takashi; Ae, Keisuke; Tanizawa, Taisuke; Gokita, Tabu

    2016-01-01

    Background: In treatment of tumors, we usually reconstruct after resection of the entire femur using only metallic modular endoprostheses among many procedures and defined it as a total femur replacement. We studied the interrelation between the preservation of rectus femoris and the functional outcome after total femur replacement. Methods: We rated the functional outcomes of 21 patients who underwent total femur replacement. We categorized the subjects into 2 groups: group A (rectus femoris preserved) and group B (rectus femoris unpreserved). We examined them based on the Mann-Whitney U test between the 2 groups in average through the Musculoskeletal Tumor Society functional scores. Results: The average score of group A was 20 of 25 (11–25; 80%), whereas the average score of group B was 10 of 25 (4–13; 40%). There was significant difference between the groups (P = 0.00168877). Conclusion: We found that the preservation of rectus femoris is imperative for achieving the favorable functional outcome in total femur replacement.

  7. BICEP2/Keck Array. IV. Optical Characterization and Performance of the BICEP2 and Keck Array Experiments

    NASA Astrophysics Data System (ADS)

    Ade, P. A. R.; Aikin, R. W.; Barkats, D.; Benton, S. J.; Bischoff, C. A.; Bock, J. J.; Bradford, K. J.; Brevik, J. A.; Buder, I.; Bullock, E.; Dowell, C. D.; Duband, L.; Filippini, J. P.; Fliescher, S.; Golwala, S. R.; Halpern, M.; Hasselfield, M.; Hildebrandt, S. R.; Hilton, G. C.; Hui, H.; Irwin, K. D.; Kang, J. H.; Karkare, K. S.; Kaufman, J. P.; Keating, B. G.; Kefeli, S.; Kernasovskiy, S. A.; Kovac, J. M.; Kuo, C. L.; Leitch, E. M.; Lueker, M.; Megerian, K. G.; Netterfield, C. B.; Nguyen, H. T.; O’Brient, R.; Ogburn, R. W., IV; Orlando, A.; Pryke, C.; Richter, S.; Schwarz, R.; Sheehy, C. D.; Staniszewski, Z. K.; Sudiwala, R. V.; Teply, G. P.; Thompson, K.; Tolan, J. E.; Turner, A. D.; Vieregg, A. G.; Weber, A. C.; Wong, C. L.; Yoon, K. W.; bicep2, The; Keck Array Collaborations

    2015-06-01

    bicep2 and the Keck Array are polarization-sensitive microwave telescopes that observe the cosmic microwave background (CMB) from the South Pole at degree angular scales in search of a signature of inflation imprinted as B-mode polarization in the CMB. bicep2 was deployed in late 2009, observed for three years until the end of 2012 at 150 GHz with 512 antenna-coupled transition edge sensor bolometers, and has reported a detection of B-mode polarization on degree angular scales. The Keck Array was first deployed in late 2010 and will observe through 2016 with five receivers at several frequencies (95, 150, and 220 GHz). bicep2 and the Keck Array share a common optical design and employ the field-proven bicep1 strategy of using small-aperture, cold, on-axis refractive optics, providing excellent control of systematics while maintaining a large field of view. This design allows for full characterization of far-field optical performance using microwave sources on the ground. Here we describe the optical design of both instruments and report a full characterization of the optical performance and beams of bicep2 and the Keck Array at 150 GHz.

  8. Free biceps tendon autograft to augment arthroscopic rotator cuff repair.

    PubMed

    Obma, Padraic R

    2013-01-01

    Arthroscopic rotator cuff repairs have become the standard of treatment for all sizes of tears over the past several years. Current healing rates reported in the literature are quite good, but improving the healing potential of rotator cuff repairs remains a challenging problem. There has been an increase recently in the use of augmentation of rotator cuff repairs with xenografts or synthetics for large and massive tears. Biceps tenodesis is often indicated as part of the treatment plan while one is performing rotator cuff surgery. A subpectoral biceps tenodesis provides a source of autograft to augment rotator cuff repairs of all sizes. Two techniques are presented to augment rotator cuff repairs with a free biceps tendon autograft. This is a novel idea in an attempt to improve healing rates and long-term results of rotator cuff repairs of all sizes. PMID:24400197

  9. Tomographic elastography of contracting skeletal muscles from their natural vibrations

    NASA Astrophysics Data System (ADS)

    Sabra, Karim G.; Archer, Akibi

    2009-11-01

    Conventional elastography techniques require an external mechanical or radiation excitation to measure noninvasively the viscoelastic properties of skeletal muscles and thus monitor human motor functions. We developed instead a passive elastography technique using only an array of skin-mounted accelerometers to record the low-frequency vibrations of the biceps brachii muscle naturally generated during voluntary contractions and to determine their two-dimensional directionality. Cross-correlating these recordings provided travel-times measurements of these muscle vibrations between multiple sensor pairs. Travel-time tomographic inversions yielded spatial variations of their propagation velocity during isometric elbow flexions which indicated a nonuniform longitudinal stiffening of the biceps.

  10. BICEP2. II. Experiment and three-year Data Set

    NASA Astrophysics Data System (ADS)

    BICEP2 Collaboration; Ade, P. A. R.; Aikin, R. W.; Amiri, M.; Barkats, D.; Benton, S. J.; Bischoff, C. A.; Bock, J. J.; Brevik, J. A.; Buder, I.; Bullock, E.; Davis, G.; Day, P. K.; Dowell, C. D.; Duband, L.; Filippini, J. P.; Fliescher, S.; Golwala, S. R.; Halpern, M.; Hasselfield, M.; Hildebrandt, S. R.; Hilton, G. C.; Irwin, K. D.; Karkare, K. S.; Kaufman, J. P.; Keating, B. G.; Kernasovskiy, S. A.; Kovac, J. M.; Kuo, C. L.; Leitch, E. M.; Llombart, N.; Lueker, M.; Netterfield, C. B.; Nguyen, H. T.; O'Brient, R.; Ogburn, R. W., IV; Orlando, A.; Pryke, C.; Reintsema, C. D.; Richter, S.; Schwarz, R.; Sheehy, C. D.; Staniszewski, Z. K.; Story, K. T.; Sudiwala, R. V.; Teply, G. P.; Tolan, J. E.; Turner, A. D.; Vieregg, A. G.; Wilson, P.; Wong, C. L.; Yoon, K. W.

    2014-09-01

    We report on the design and performance of the BICEP2 instrument and on its three-year data set. BICEP2 was designed to measure the polarization of the cosmic microwave background (CMB) on angular scales of 1°-5°(l = 40-200), near the expected peak of the B-mode polarization signature of primordial gravitational waves from cosmic inflation. Measuring B-modes requires dramatic improvements in sensitivity combined with exquisite control of systematics. The BICEP2 telescope observed from the South Pole with a 26 cm aperture and cold, on-axis, refractive optics. BICEP2 also adopted a new detector design in which beam-defining slot antenna arrays couple to transition-edge sensor (TES) bolometers, all fabricated on a common substrate. The antenna-coupled TES detectors supported scalable fabrication and multiplexed readout that allowed BICEP2 to achieve a high detector count of 500 bolometers at 150 GHz, giving unprecedented sensitivity to B-modes at degree angular scales. After optimization of detector and readout parameters, BICEP2 achieved an instrument noise-equivalent temperature of 15.8 μ {K}\\sqrt{{s}}. The full data set reached Stokes Q and U map depths of 87.2 nK in square-degree pixels (5.'2 μK) over an effective area of 384 deg2 within a 1000 deg2 field. These are the deepest CMB polarization maps at degree angular scales to date. The power spectrum analysis presented in a companion paper has resulted in a significant detection of B-mode polarization at degree scales.

  11. BICEP2. II. Experiment and three-year data set

    SciTech Connect

    Ade, P. A. R.; Aikin, R. W.; Bock, J. J.; Brevik, J. A.; Filippini, J. P.; Golwala, S. R.; Hildebrandt, S. R.; Amiri, M.; Davis, G.; Halpern, M.; Hasselfield, M.; Barkats, D.; Benton, S. J.; Bischoff, C. A.; Buder, I.; Bullock, E.; Day, P. K.; Dowell, C. D.; Duband, L.; Fliescher, S.; Collaboration: Bicep2 Collaboration; and others

    2014-09-01

    We report on the design and performance of the BICEP2 instrument and on its three-year data set. BICEP2 was designed to measure the polarization of the cosmic microwave background (CMB) on angular scales of 1°-5°(ℓ = 40-200), near the expected peak of the B-mode polarization signature of primordial gravitational waves from cosmic inflation. Measuring B-modes requires dramatic improvements in sensitivity combined with exquisite control of systematics. The BICEP2 telescope observed from the South Pole with a 26 cm aperture and cold, on-axis, refractive optics. BICEP2 also adopted a new detector design in which beam-defining slot antenna arrays couple to transition-edge sensor (TES) bolometers, all fabricated on a common substrate. The antenna-coupled TES detectors supported scalable fabrication and multiplexed readout that allowed BICEP2 to achieve a high detector count of 500 bolometers at 150 GHz, giving unprecedented sensitivity to B-modes at degree angular scales. After optimization of detector and readout parameters, BICEP2 achieved an instrument noise-equivalent temperature of 15.8 μK√s. The full data set reached Stokes Q and U map depths of 87.2 nK in square-degree pixels (5.'2 μK) over an effective area of 384 deg{sup 2} within a 1000 deg{sup 2} field. These are the deepest CMB polarization maps at degree angular scales to date. The power spectrum analysis presented in a companion paper has resulted in a significant detection of B-mode polarization at degree scales.

  12. A Predictive Mathematical Model of Muscle Forces for Children with Cerebral Palsy

    ERIC Educational Resources Information Center

    Lee, Samuel C. K.; Ding, Jun; Prosser, Laura A.; Wexler, Anthony S.; Binder-Macleod, Stuart A.

    2009-01-01

    Aim: The purpose of this study was to determine if our previously developed muscle model could be used to predict forces of the quadriceps femoris and triceps surae muscles of children with spastic diplegic cerebral palsy (CP). Method: Twenty-two children with CP (12 males, 10 females; mean age 10y, SD 2y, range 7-13y; Gross Motor Function…

  13. An Examination of Muscle Activation and Power Characteristics While Performing the Deadlift Exercise With Straight and Hexagonal Barbells.

    PubMed

    Camara, Kevin D; Coburn, Jared W; Dunnick, Dustin D; Brown, Lee E; Galpin, Andrew J; Costa, Pablo B

    2016-05-01

    Camara, KD, Coburn, JW, Dunnick, DD, Brown, LE, Galpin, AJ, and Costa, PB. An examination of muscle activation and power characteristics while performing the deadlift exercise with straight and hexagonal barbells. J Strength Cond Res 30(5): 1183-1188, 2016-The deadlift exercise is commonly performed to develop strength and power, and to train the lower-body and erector spinae muscle groups. However, little is known about the acute training effects of a hexagonal barbell vs. a straight barbell when performing deadlifts. Therefore, the purpose of this study was to examine the hexagonal barbell in comparison with the straight barbell by analyzing electromyography (EMG) from the vastus lateralis, biceps femoris, and erector spinae, as well as peak force, peak power, and peak velocity using a force plate. Twenty men with deadlifting experience volunteered to participate in the study. All participants completed a 1 repetition maximum (1RM) test with each barbell on 2 separate occasions. Three repetitions at 65 and 85% 1RM were performed with each barbell on a third visit. The results revealed that there was no significant difference for 1RM values between the straight and hexagonal barbells (mean ± SD in kg = 181.4 ± 27.3 vs. 181.1 ± 27.6, respectively) (p > 0.05). Significantly greater normalized EMG values were found from the vastus lateralis for both the concentric (1.199 ± 0.22) and eccentric (0.879 ± 0.31) phases of the hexagonal-barbell deadlift than those of the straight-barbell deadlift (0.968 ± 0.22 and 0.559 ± 1.26), whereas the straight-barbell deadlift led to significantly greater EMG values from the bicep femoris during the concentric phase (0.835 ± 0.19) and the erector spinae (0.753 ± 0.28) during the eccentric phase than the corresponding values for the hexagonal-barbell deadlift (0.723 ± 0.20 and 0.614 ± 0.21) (p ≤ 0.05). In addition, the hexagonal-barbell deadlift demonstrated significantly greater peak force (2,553.20 ± 371.52 N), peak

  14. Differential Changes with Age in Multiscale Entropy of Electromyography Signals from Leg Muscles during Treadmill Walking

    PubMed Central

    Kang, Hyun Gu; Dingwell, Jonathan B.

    2016-01-01

    Age-related gait changes may be due to the loss of complexity in the neuromuscular system. This theory is disputed due to inconsistent results from single-scale analyses. Also, behavioral adaptations may confound these changes. We examined whether EMG dynamics during gait is less complex in older adults over a range of timescales using the multiscale entropy method, and whether slower walking attenuates this effect. Surface EMG was measured from the left vastus lateralis (VL), biceps femoris (BF), gastrocnemius (GA), and tibialis anterior (TA) in 17 young and 18 older adults as they walked on a treadmill for 5 minutes at 0.8x-1.2x of preferred speed. Sample entropy (SE) and the complexity index (CI) of the EMG signals were calculated after successive coarse-graining to extract dynamics at timescales of 27 to 270 Hz, with m = 2 and r = 0.15 SD. SE and CI were lower across the timescales in older adults in VL and BF, but higher in GA (all p<0.001); these results held for VL and GA even after accounting for longer EMG burst durations in older adults. CI was higher during slower walking speed in VL and BF (p<0.001). Results were mostly similar for m = 3 and r = 0.01–0.35. Smaller r was more sensitive to age-related differences. The decrease in complexity with aging in the timescales studied was limited to proximal muscles, particularly VL. The increase in GA may be driven by other factors. Walking slower may reflect a behavioral adaptation that allows the nervous system to function with greater complexity. PMID:27570974

  15. Differential Changes with Age in Multiscale Entropy of Electromyography Signals from Leg Muscles during Treadmill Walking.

    PubMed

    Kang, Hyun Gu; Dingwell, Jonathan B

    2016-01-01

    Age-related gait changes may be due to the loss of complexity in the neuromuscular system. This theory is disputed due to inconsistent results from single-scale analyses. Also, behavioral adaptations may confound these changes. We examined whether EMG dynamics during gait is less complex in older adults over a range of timescales using the multiscale entropy method, and whether slower walking attenuates this effect. Surface EMG was measured from the left vastus lateralis (VL), biceps femoris (BF), gastrocnemius (GA), and tibialis anterior (TA) in 17 young and 18 older adults as they walked on a treadmill for 5 minutes at 0.8x-1.2x of preferred speed. Sample entropy (SE) and the complexity index (CI) of the EMG signals were calculated after successive coarse-graining to extract dynamics at timescales of 27 to 270 Hz, with m = 2 and r = 0.15 SD. SE and CI were lower across the timescales in older adults in VL and BF, but higher in GA (all p<0.001); these results held for VL and GA even after accounting for longer EMG burst durations in older adults. CI was higher during slower walking speed in VL and BF (p<0.001). Results were mostly similar for m = 3 and r = 0.01-0.35. Smaller r was more sensitive to age-related differences. The decrease in complexity with aging in the timescales studied was limited to proximal muscles, particularly VL. The increase in GA may be driven by other factors. Walking slower may reflect a behavioral adaptation that allows the nervous system to function with greater complexity. PMID:27570974

  16. Toxic heavy metals in the muscle of roe deer (Capreolus capreolus)--food toxicological significance.

    PubMed

    Lehel, József; Laczay, Péter; Gyurcsó, Adrienn; Jánoska, Ferenc; Majoros, Szilvia; Lányi, Katalin; Marosán, Miklós

    2016-03-01

    The study was performed on 20 (10 males, 10 females) roe deer (Capreolus capreolus) to investigate the concentration of cadmium, lead, mercury, and arsenic in the muscle tissue. They reside in forest and meadow, about 50 km distance from industrial activities and traffic. Samples were taken from the musculus biceps femoris of each deer without external contamination after shooting during the regular hunting season on a hunting area close to Eger in Hungary. The determination of heavy metal contents was carried out by inductively coupled plasma optical emission spectrometry (ICP-OES). The statistical analysis was performed by statistical package for the social sciences (SPSS) version 11.0. The measured residue concentration of cadmium was below the limit of detection in the roe deer meat indicating no health risk for the consumers. The average lead concentration (0.48 ± 0.21 mg/kg wet weight) exceeded the regulated maximum limit, but its calculated weekly intake was below the provisional tolerable weekly intake (PTWI). The residue level of mercury is not regulated and the average mercury content of roe deer meat (0.87 ± 0.40 mg/kg wet weight) was about half of PTWI, but the consumption of meat with the highest detected concentrations results in higher PTWI than recommended. The measured concentration of arsenic (0.27 ± 0.20 mg/kg wet weight) in the roe deer meat may not pose any health risk for the human consumers according to the PTWI set by the World Health Organization. PMID:26507733

  17. Proximal coracobrachialis tendon rupture, subscapularis tendon rupture, and medial dislocation of the long head of the biceps tendon in an adult after traumatic anterior shoulder dislocation.

    PubMed

    Saltzman, Bryan M; Harris, Joshua D; Forsythe, Brian

    2015-01-01

    Rupture of the coracobrachialis is a rare entity, in isolation or in combination with other muscular or tendinous structures. When described, it is often a result of direct trauma to the anatomic area resulting in rupture of the muscle belly. The authors present a case of a 57-year-old female who suffered a proximal coracobrachialis tendon rupture from its origin at the coracoid process, with concomitant subscapularis tear and medial dislocation of the long head of biceps tendon after first time traumatic anterior shoulder dislocation. Two weeks after injury, magnetic resonance imaging suggested the diagnosis, which was confirmed during combined arthroscopic and open technique. Soft-tissue tenodesis of coracobrachialis to the intact short head of the biceps, tenodesis of the long head of biceps to the intertubercular groove, and double-row anatomic repair of the subscapularis were performed. The patient did well postoperatively, and ultimately at 6 months follow-up, she was without pain, and obtained 160° of active forward elevation, 45° of external rotation, internal rotation to T8, 5/5 subscapularis and biceps strength. Scoring scales had improved from the following preoperative to final follow-up: American Shoulder and Elbow Surgeons, 53.33-98.33; constant, 10-100; visual analogue scale-pain, 4-0. DASH score was 5. PMID:25937715

  18. Proximal coracobrachialis tendon rupture, subscapularis tendon rupture, and medial dislocation of the long head of the biceps tendon in an adult after traumatic anterior shoulder dislocation

    PubMed Central

    Saltzman, Bryan M.; Harris, Joshua D.; Forsythe, Brian

    2015-01-01

    Rupture of the coracobrachialis is a rare entity, in isolation or in combination with other muscular or tendinous structures. When described, it is often a result of direct trauma to the anatomic area resulting in rupture of the muscle belly. The authors present a case of a 57-year-old female who suffered a proximal coracobrachialis tendon rupture from its origin at the coracoid process, with concomitant subscapularis tear and medial dislocation of the long head of biceps tendon after first time traumatic anterior shoulder dislocation. Two weeks after injury, magnetic resonance imaging suggested the diagnosis, which was confirmed during combined arthroscopic and open technique. Soft-tissue tenodesis of coracobrachialis to the intact short head of the biceps, tenodesis of the long head of biceps to the intertubercular groove, and double-row anatomic repair of the subscapularis were performed. The patient did well postoperatively, and ultimately at 6 months follow-up, she was without pain, and obtained 160° of active forward elevation, 45° of external rotation, internal rotation to T8, 5/5 subscapularis and biceps strength. Scoring scales had improved from the following preoperative to final follow-up: American Shoulder and Elbow Surgeons, 53.33-98.33; constant, 10-100; visual analogue scale-pain, 4-0. DASH score was 5. PMID:25937715

  19. Creatine Loading, Resistance Exercise Performance, and Muscle Mechanics.

    ERIC Educational Resources Information Center

    Stevenson, Scott W.; Dudley, Gary A.

    2001-01-01

    Examined whether creatine (CR) monohydrate loading would alter resistance exercise performance, isometric strength, or in vivo contractile properties of the quadriceps femoris muscle compared with placebo loading in resistance-trained athletes. Overall, CR loading did not provide an ergogenic benefit for the unilateral dynamic knee extension…

  20. Tensors, BICEP2 results, prior dependence, and dust

    NASA Astrophysics Data System (ADS)

    Cortês, Marina; Liddle, Andrew R.; Parkinson, David

    2015-09-01

    We investigate the prior dependence on the inferred spectrum of primordial tensor perturbations, in light of recent results from BICEP2 and taking into account a possible dust contribution to polarized anisotropies. We highlight an optimized parametrization of the tensor power spectrum, and adoption of a logarithmic prior on its amplitude AT, leading to results that transform more evenly under change of pivot scale. In the absence of foregrounds the tension between the results of BICEP2 and Planck drives the tensor spectral index nT to be blue tilted in a joint analysis, which would be in contradiction to the standard inflation prediction (nT<0 ). When foregrounds are accounted for, the BICEP2 results no longer require nonstandard inflationary parameter regions. We present limits on primordial AT and nT, adopting foreground scenarios put forward by Mortonson and Seljak and motivated by Planck 353 GHz observations, and assess what dust contribution leaves a detectable cosmological signal. We find that if there is sufficient dust for the signal to be compatible with standard inflation, then the primordial signal is too weak to be robustly detected by BICEP2 if Planck+WMAP upper limits from temperature and E -mode polarization are correct.

  1. Outcomes of biceps tenodesis in an active duty population.

    PubMed

    Jacobs, Jeremy M; Jackson, Keith L; Pniewski, Josh E; Dickston, Michelle L; Abell, Brian E; Mueller, Terry L; Bojescul, John A

    2015-01-01

    Pathology affecting the long head of the biceps tendon and its insertion is a frequent cause of shoulder pain in the active duty military population. The purpose of this investigation was to evaluate functional outcomes of subpectoral biceps tenodesis in an active duty population. A retrospective case series of 22 service members who underwent biceps tenodesis was performed and Shoulder Pain and Disability Indexes (SPADI) and Disabilities of the Arm, Shoulder and Hand (DASH) scores were obtained preoperatively and at 6 months. Additionally, a review of each subject's physical profile was performed 6 months after surgery to determine continued physical limitations and one's ability to deploy. There was a statistically significant improvement in SPADI and DASH scores comparing preoperative versus postoperative outcomes. Although five subjects (22%) continued to have a restriction to performing push-ups on the Army Physical Fitness Test, all were deemed deployable from a physical standpoint. The results of this review suggest that active duty personnel undergoing biceps tenodesis have significant functional improvement at 6 months. Additionally, very few have long-term physical limitations or deployment restrictions. PMID:25988691

  2. Editorial Commentary: Open Versus Arthroscopic Biceps Tenodesis--You Choose.

    PubMed

    Harris, Joshua D

    2016-02-01

    In a Level IV evidence systematic review of 16 studies comparing arthroscopic and open biceps tenodesis, both techniques showed good or excellent short-term subjective and objective clinical outcomes in 98% of subjects. Ultimately, technique selection may be based on surgeon preference. In open tenodesis, one should avoid vigorous medial retraction to mitigate the risk of nerve injury. PMID:26814399

  3. BICEP2 and Keck array: upgrades and improved beam characterization

    NASA Astrophysics Data System (ADS)

    Buder, I.; Ade, P. A. R.; Ahmed, Z.; Aikin, R. W.; Alexander, K. D.; Amiri, M.; Barkats, D.; Benton, S. J.; Bischoff, C. A.; Bock, J. J.; Bonetti, J. A.; Brevik, J. A.; Bullock, E.; Burger, B.; Crill, B. P.; Davis, G.; Dowell, C. D.; Duband, L.; Filippini, J. P.; Fliescher, S.; Golwala, S. R.; Gordon, M. S.; Halpern, M.; Hasselfield, M.; Hildebrandt, S. R.; Hilton, G. C.; Hristov, V. V.; Hui, H.; Irwin, K. D.; Karkare, K. S.; Kaufman, J. P.; Keating, B. G.; Kefeli, S.; Kernasovskiy, S. A.; Kovac, J. M.; Kuo, C. L.; Leitch, E. M.; Lueker, M.; Mason, P.; Megerian, K. G.; Netterfield, C. B.; Nguyen, H. T.; O'Brient, R.; Ogburn, R. W.; Orlando, A.; Pryke, C.; Reintsema, C. D.; Richter, S.; Schwarz, R.; Sheehy, C. D.; Staniszewski, Z. K.; Sudiwala, R. V.; Teply, G. P.; Thompson, K. L.; Tolan, J. E.; Turner, A. D.; Vieregg, A. G.; Weber, A. C.; Wiebe, D. V.; Wilson, P.; Wong, C. L.; Yoon, K. W.

    2014-08-01

    Searching for evidence of inflation by measuring B-modes in the cosmic microwave background (CMB) polarization at degree angular scales remains one of the most compelling experimental challenges in cosmology. BICEP2 and the Keck Array are part of a program of experiments at the South Pole whose main goal is to achieve the sensitivity and systematic control necessary for measurements of the tensor-to-scalar ratio at σ(r) ~0:01. Beam imperfections that are not sufficiently accounted for are a potential source of spurious polarization that could interfere with that goal. The strategy of BICEP2 and the Keck Array is to completely characterize their telescopes' polarized beam response with a combination of in-lab, pre-deployment, and on-site calibrations. We Sereport the status of these experiments, focusing on continued improved understanding of their beams. Far-field measurements of the BICEP2 beam with a chopped thermal source, combined with analysis improvements, show that the level of residual beam-induced systematic errors is acceptable for the goal of σ(r) ~ 0:01 measurements. Beam measurements of the Keck Array side lobes helped identify a way to reduce optical loading with interior cold baffles, which we installed in late 2013. These baffles reduced total optical loading, leading to a ~ 10% increase in mapping speed for the 2014 observing season. The sensitivity of the Keck Array continues to improve: for the 2013 season it was 9:5 μK _/s noise equivalent temperature (NET). In 2014 we converted two of the 150-GHz cameras to 100 GHz for foreground separation capability. We have shown that the BICEP2 and the Keck Array telescope technology is sufficient for the goal of σ(r) ~ 0:01 measurements. Furthermore, the program is continuing with BICEP3, a 100-GHz telescope with 2560 detectors.

  4. Distal biceps tendon injuries--current treatment options.

    PubMed

    Quach, Tony; Jazayeri, Reza; Sherman, Orrin H; Rosen, Jeffrey E

    2010-01-01

    Three percent of all biceps tendon ruptures occur at the distal aspect, where the tendon inserts into the radial tuberosity. Distal bicep tendon ruptures typically occur in middle-aged males after an eccentric extension load is applied to the elbow. Patients usually complain of a sudden, sharp, and painful tearing sensation in the antecubital region, with a palpable defect. The biceps squeeze and hook tests are specific maneuvers by which to diagnose distal biceps ruptures on physical examination. Magnetic resonance imaging (MRI) or ultrasound maybe be helpful to distinguish between partial and complete tears. Anatomic studies suggest there are two distinct insertions for the short and long heads of the distal biceps. The short head may be a more powerful flexor, and the long head may be a more powerful supinator. Nonoperative treatment typically results in loss of flexion and supination strength and endurance. Early anatomic re-attachment is the goal. Surgical approaches include one- or two-incision techniques, and tendon fixation methods include the use of suture anchors, bone tunnels, an endobutton, or biotenodesis screws. Biomechanical studies have shown that endobuttons have higher load-to-failure strengths, compared to the other fixation methods. However, clinical studies have demonstrated that patients do well regardless of surgical approach or fixation method. Possible complications include nerve injuries, heterotopic ossification, postoperative fracture, tendon rerupture, complex regional pain syndrome, and wound infection. Partial ruptures are significantly less common and initially can be treated conservatively. Chronic tears are more difficult to treat because of possible tendon retraction and poor tissue quality. Tendon grafts using semitendinosus, fascia lata, hamstring, Achilles (calcaneal), or flexor carpi radialis have been successfully used for length restoration in these cases. PMID:20632985

  5. Firing rate analysis using decompostion-enhanced spike triggered averaging in the quadriceps femoris.

    PubMed

    Conwit, R A; Tracy, B; Cowl, A; McHugh, M; Stashuk, D; Brown, W F; Metter, E J

    1998-10-01

    Electromyographic signals detected from the quadriceps femoris during various constant force contractions were decomposed to identify individual motor unit discharges and mean firing rates (FRs). Subject and group mean FRs were calculated for each force level. Mean FR values and FR variability increased with force. Individual, subject, and group mean FRs showed slight increases until 30% of maximum voluntary contraction and larger increases thereafter. Findings are discussed in relation to motor unit recruitment, frequency modulation, and fatigue. PMID:9736067

  6. On the effect of thermal agents in the response of the brachial biceps at different contraction levels.

    PubMed

    Garcia, Larissa Martins; Soares, Alcimar Barbosa; Simieli, Camila; Boratino, Alessandra Vairo Peres; Guirro, Rinaldo Roberto de Jesus

    2014-12-01

    The objective of this study was to assess electromyographic features of the brachial biceps muscle after the application of cryotherapy and short-wave diathermy. Sixty healthy volunteers participated in the study and were equally divided into three groups: cryotherapy - application of ice packs for 30 min; short-wave diathermy for 20 min; and control. The thermal agents were applied to the anterior and posterior regions of the non-dominant arm. The electromyographic (EMG) signal from the brachial biceps was recorded before and after the application of thermal agents during flexion of the elbow joint at 25%, 50%, 75% of a maximum voluntary isometric contraction defined at least two days before the actual experiments (MVICbl). The volunteers also were asked to execute a free MVIC before and after the application of the thermal agents (MVIC free). A linear regression model with mixed effects (random and fixed) was used. Intra-group analysis showed a reduction in root mean square (RMS) at MVIC free, with no change in the median frequency of the EMG signal at any contraction level for the short-wave diathermy group. An increase on RMS values and a decrease on median frequencies were found after the application of cryotherapy for all contraction levels. The results imply that cryotherapy plays an important role on changing neuromuscular responses at various levels of muscle contraction. Therapists should be aware of that and carefully consider its use prior to activities in which neuromuscular precision is required. PMID:25148950

  7. Operator performance and localized muscle fatigue in a simulated space vehicle control task

    NASA Technical Reports Server (NTRS)

    Lewis, J. L., Jr.

    1979-01-01

    Fourier transforms in a special purpose computer were utilized to obtain power spectral density functions from electromyograms of the biceps brachii, triceps brachii, brachioradialis, flexor carpi ulnaris, brachialis, and pronator teres in eight subjects performing isometric tracking tasks in two directions utilizing a prototype spacecraft rotational hand controller. Analysis of these spectra in general purpose computers aided in defining muscles involved in performing the task, and yielded a derived measure potentially useful in predicting task termination. The triceps was the only muscle to show significant differences in all possible tests for simple effects in both tasks and, overall, was the most consistently involved of the six muscles. The total power monitored for triceps, biceps, and brachialis dropped to minimal levels across all subjects earlier than for other muscles. However, smaller variances existed for the biceps, brachioradialis, brachialis, and flexor carpi ulnaris muscles and could provide longer predictive times due to smaller standard deviations for a greater population range.

  8. Model-independent fit to Planck and BICEP2 data

    NASA Astrophysics Data System (ADS)

    Barranco, Laura; Boubekeur, Lotfi; Mena, Olga

    2014-09-01

    Inflation is the leading theory to describe elegantly the initial conditions that led to structure formation in our Universe. In this paper, we present a novel phenomenological fit to the Planck, WMAP polarization (WP) and the BICEP2 data sets using an alternative parametrization. Instead of starting from inflationary potentials and computing the inflationary observables, we use a phenomenological parametrization due to Mukhanov, describing inflation by an effective equation of state, in terms of the number of e-folds and two phenomenological parameters α and β. Within such a parametrization, which captures the different inflationary models in a model-independent way, the values of the scalar spectral index ns, its running and the tensor-to-scalar ratio r are predicted, given a set of parameters (α ,β). We perform a Markov Chain Monte Carlo analysis of these parameters, and we show that the combined analysis of Planck and WP data favors the Starobinsky and Higgs inflation scenarios. Assuming that the BICEP2 signal is not entirely due to foregrounds, the addition of this last data set prefers instead the ϕ2 chaotic models. The constraint we get from Planck and WP data alone on the derived tensor-to-scalar ratio is r <0.18 at 95% C.L., value which is consistent with the one quoted from the BICEP2 Collaboration analysis, r =0.16-0.05+0-06, after foreground subtraction. This is not necessarily at odds with the 2σ tension found between Planck and BICEP2 measurements when analyzing data in terms of the usual ns and r parameters, given that the parametrization used here, for the preferred value ns≃0.96, allows only for a restricted parameter space in the usual (ns,r) plane.

  9. Inflation after false vacuum decay: new evidence from BICEP2

    SciTech Connect

    Bousso, Raphael; Harlow, Daniel; Senatore, Leonardo E-mail: dharlow@princeton.edu

    2014-12-01

    Last year we argued that if slow-roll inflation followed the decay of a false vacuum in a large landscape, the steepening of the scalar potential between the inflationary plateau and the barrier generically leads to a potentially observable suppression of the scalar power spectrum at large distances. Here we revisit this analysis in light of the recent BICEP2 results. Assuming that both the BICEP2 B-mode signal and the Planck analysis of temperature fluctuations hold up, we find that the data now discriminate more sharply between our scenario and ΛCDM. Nonzero tensor modes exclude standard ΛCDM with notable but not yet conclusive confidence: at ∼3.8σ if r = 0.2, or at ∼ 3.5σ if r = 0.15. Of the two steepening models of our previous work, one is now ruled out by existing bounds on spatial curvature. The other entirely reconciles the tension between BICEP2 and Planck. Upcoming EE polarization measurements have the potential to rule out unmodified ΛCDM decisively. Next generation Large Scale Structure surveys can further increase the significance. More precise measurements of BB at low ℓ will help distinguish our scenario from other explanations. If steepening is confirmed, the prospects for detecting open curvature increase but need not be large.

  10. Inflation after false vacuum decay: new evidence from BICEP2

    NASA Astrophysics Data System (ADS)

    Bousso, Raphael; Harlow, Daniel; Senatore, Leonardo

    2014-12-01

    Last year we argued that if slow-roll inflation followed the decay of a false vacuum in a large landscape, the steepening of the scalar potential between the inflationary plateau and the barrier generically leads to a potentially observable suppression of the scalar power spectrum at large distances. Here we revisit this analysis in light of the recent BICEP2 results. Assuming that both the BICEP2 B-mode signal and the Planck analysis of temperature fluctuations hold up, we find that the data now discriminate more sharply between our scenario and ΛCDM. Nonzero tensor modes exclude standard ΛCDM with notable but not yet conclusive confidence: at ~3.8σ if r = 0.2, or at ~ 3.5σ if r = 0.15. Of the two steepening models of our previous work, one is now ruled out by existing bounds on spatial curvature. The other entirely reconciles the tension between BICEP2 and Planck. Upcoming EE polarization measurements have the potential to rule out unmodified ΛCDM decisively. Next generation Large Scale Structure surveys can further increase the significance. More precise measurements of BB at low l will help distinguish our scenario from other explanations. If steepening is confirmed, the prospects for detecting open curvature increase but need not be large.

  11. Long head of biceps: from anatomy to treatment.

    PubMed

    Sarmento, M

    2015-01-01

    The long head of the biceps (LHB), tendinous structure of the proximal brachial biceps, has its well-known anatomy, which contrasts with its current functional characterization. Various forms of proximal anchor and intra-articular route, important for the correct interpretation of its contribution to the pathology of the shoulder as well as the treatment methodology, are described. Knowledge of its biomechanics results mainly from cadaveric studies that contradict each other. Already the few studies in vivo indicate a depressant and stabilizing action, anterior, for the humeral head. Its pathology is rarely isolated because it is almost always correlated with rotator cuff or labrum pathology. It can be divided into 3 major groups (inflammatory, instability and traumatic) and subdivided according to its location. The anterior shoulder pain is the initial symptom of pathology of LHB Its perfect characterization is dependent on the associated injuries. Clinical tests are multiple and only their combination allows better sensitivity and specificity for LHB pathology. The arthro-MRI and dynamic ultrasound are able to increase proper diagnostic of the pathology of LHB. Treatment ranges from conservative and surgical. The latter includes the repair, tenotomy and tenodesis of LHB which can be performed by open or arthroscopic methodology. The author intends to review existing literature on all aspects related to the long head of the biceps from anatomy to treatment, presenting the latest results. PMID:25351662

  12. BICEP2/SPUD: Searching for Inflation with Degree Scale Polarimetry from the South Pole

    NASA Technical Reports Server (NTRS)

    Nguyen, Hien Trong; Kovac, John; Adec, Peter; Aikin, Randol; Benton, Steve; Bock, Jamie; Brevik, Justus; Carlstrom, John; Dowell, Darren; Duband, Lionel; Golwala, Sunil; Halpern, Mark; Hasselfield, Matthew; Irwin, Kent; Jones, William; Kaufman, Jonathan; Keating, Brian; Kuo, Chao-Lin; Lange, Andrew; Matsumura, Tomotake; Netterfield, Barth; Pryke, Clem; Ruhl, John; Sheehy, Chris; Sudiwala, Rashmi

    2008-01-01

    BICEP2/SPUD is the new powerful upgrade of the existing BICEP1 experiment, a bolometric receiver to study the polarization of the cosmic microwave background radiation, which has been in operation at the South Pole since January 2006. BICEP2 will provide an improvement up to 10 times mapping speed at 150 GHz compared to BICEP1, using the same BICEP telescope mount. SPUD, a series of compact, mechanically-cooled receivers deployed on the DASI mount at the Pole, will provide similar mapping speed in to BICEP2 in three bands, 100, 150, and 220 GHz. The new system will use large TES focal plane arrays to provide unprecedented sensitivity and excellent control of foreground contamination.

  13. A simple means of increasing muscle size after spinal cord injury: a pilot study.

    PubMed

    Dudley, G A; Castro, M J; Rogers, S; Apple, D F

    1999-09-01

    This study tested that hypothesis that skeletal muscle within a year of spinal cord injury (SCI) would respond to intermittent high force loading by showing an increase in size. Three males about 46 weeks post clinically complete SCI underwent surface electrical stimulation of their left or right m. quadriceps femoris 2 days per week for 8 weeks to evoke 4 sets of ten isometric or dynamic actions each session. Conditioning increased average cross-sectional area of m. quadriceps femoris, assessed by magnetic resonance imaging, by 20+/-1% (p = 0.0103). This reversed 48 weeks of atrophy such that m. quadriceps femoris 54 weeks after SCI was the same size as when the patients were first studied 6 weeks after injury. The results suggest that skeletal muscle is remarkably responsive to intermittent, high force loading after almost one year of little if any contractile activity. PMID:10483812

  14. Does the rectus femoris nerve block improve knee recurvatum in adult stroke patients? A kinematic and electromyographic study.

    PubMed

    Gross, R; Delporte, L; Arsenault, L; Revol, P; Lefevre, M; Clevenot, D; Boisson, D; Mertens, P; Rossetti, Y; Luauté, J

    2014-02-01

    Knee recurvatum (KR) during gait is common in hemiplegic patients. Quadriceps spasticity has been postulated as a cause of KR in this population. The aim of this study was to assess the role of rectus femoris spasticity in KR by using selective motor nerve blocks of the rectus femoris nerve in hemiparetic stroke patients. The data from six adult, post-stroke hemiplegic patients who underwent a rectus femoris nerve block for a stiff-knee gait were retrospectively analyzed. An extensive clinical and functional evaluation was performed and gait was assessed by motion analysis (kinematic, kinetic and electromyographic parameters) before and during the block realized using 2% lidocaine injected under a neurostimulation and ultrasonographic targeting procedure. The main outcome measures were the peak knee extension in stance and peak knee extensor moment obtained during gait analysis. No serious adverse effect of the nerve block was observed. The block allowed a reduction of rectus femoris overactivity in all patients. Peak knee extension and extensor moment in stance did not improve in any patient, but peak knee flexion during the swing phase was significantly higher after block (mean: 31.2° post, 26.4 pre, p < 0.05). Our results provide arguments against the hypothesis that the spasticity of the rectus femoris contributes to KR. PMID:24286615

  15. A newly discovered muscle: The tensor of the vastus intermedius.

    PubMed

    Grob, K; Ackland, T; Kuster, M S; Manestar, M; Filgueira, L

    2016-03-01

    The quadriceps femoris is traditionally described as a muscle group composed of the rectus femoris and the three vasti. However, clinical experience and investigations of anatomical specimens are not consistent with the textbook description. We have found a second tensor-like muscle between the vastus lateralis (VL) and the vastus intermedius (VI), hereafter named the tensor VI (TVI). The aim of this study was to clarify whether this intervening muscle was a variation of the VL or the VI, or a separate head of the extensor apparatus. Twenty-six cadaveric lower limbs were investigated. The architecture of the quadriceps femoris was examined with special attention to innervation and vascularization patterns. All muscle components were traced from origin to insertion and their affiliations were determined. A TVI was found in all dissections. It was supplied by independent muscular and vascular branches of the femoral nerve and lateral circumflex femoral artery. Further distally, the TVI combined with an aponeurosis merging separately into the quadriceps tendon and inserting on the medial aspect of the patella. Four morphological types of TVI were distinguished: Independent-type (11/26), VI-type (6/26), VL-type (5/26), and Common-type (4/26). This study demonstrated that the quadriceps femoris is architecturally different from previous descriptions: there is an additional muscle belly between the VI and VL, which cannot be clearly assigned to the former or the latter. Distal exposure shows that this muscle belly becomes its own aponeurosis, which continues distally as part of the quadriceps tendon. PMID:26732825

  16. Influence of "in series" elastic resistance on muscular performance during a biceps-curl set on the cable machine.

    PubMed

    García-López, David; Herrero, Azael J; González-Calvo, Gustavo; Rhea, Matthew R; Marín, Pedro J

    2010-09-01

    This study aimed to investigate the role of elastic resistance (ER) applied "in series" to a pulley-cable (PC) machine on the number of repetitions performed, kinematics parameters, and perceived exertion during a biceps-curl set to failure with a submaximal load (70% of the 1 repetition maximum). Twenty-one undergraduate students (17 men and 4 women) performed, on 2 different days, 1 biceps-curl set on the PC machine. Subjects were randomly assigned to complete 2 experimental conditions in a cross-over fashion: conventional PC mode or ER + PC mode. Results indicate ER applied "in series" to a PC machine significantly reduces (p < 0.05) the maximal number of repetitions and results in a smooth and consistent decline in mean acceleration throughout the set, in comparison to the conventional PC mode. Although no significant differences were found concerning intrarepetition kinematics, the ER trended to reduce (18.6%) the peak acceleration of the load. With a more uniformly distributed external resistance, a greater average muscle tension could have been achieved throughout the range of movement, leading to greater fatigue that could explain the lower number of maximal repetitions achieved. The application of force in a smooth, consistent fashion during each repetition of an exercise, while avoiding active deceleration, is expected to enhance the benefits of the resistance exercise, especially for those seeking greater increases in muscular hypertrophy. PMID:20703162

  17. Radiostereometric Evaluation of Tendon Elongation after Distal Biceps Repair

    PubMed Central

    Marshall, Nathan; Keller, Robert A.; Guest, John-Michael; Moutzouros, Vasilios

    2016-01-01

    Objectives: Operative repair of distal biceps tendon ruptures have shown successful outcomes. However, little is known about the amount of tendon or repair site lengthening or creep. Treatment algorithms in regards to repair fixation, immobilization, initiation of activity and physical therapy are largely made on previous tendon healing principles and anecdotal findings. The purpose of our study was to evaluate distal biceps tendon repair via intratendinous radiostereometric analysis to evaluate tendon lengthening/creep at different time intervals of healing. Methods: Ten patients were recruited who sustained a distal biceps rupture requiring operative repair. Distal biceps repairs were performed using an endobutton only, single incision technique. Intraoperatively, two 2-mm tantalum beads with laser-etched holes were sutured to the distal biceps tendon. One bead was placed at the radius tendon interface and the other placed 1cm proximal to the first bead. Beads were evaluated via both CT scans immediately post-operatively and at 16 weeks and x-rays obtained at time 0 and then at 4, 8, and 16 weeks. Measurements were made using the endobutton to bead and bead-to-bead distances in order to assess repair site elongation as well as tendon elongation over time. Following final follow-up, patients underwent a DASH questionnaire and ultrasound to confirm the integrity of the tendon. Results: Ten patients were included in the study. Nine patients had complete ruptures with one having a partial rupture that underwent completion and subsequent repair. All patients showed statistically significant lengthening after surgery. The mean amount of lengthening after surgery was 21.8 mm (range 10.1-29.7 mm, p < 0.05). The repair site lengthened a mean of 12.5 mm (range 8.8-17.0 mm, p <0.05) and the tendon lengthened a mean of 9.4 mm (range: 4.0-18.8 mm, p<0.05) from surgery to final follow-up. The greatest change in lengthening was noted between time 0 and week 4 (mean: 11.8 mm

  18. A cadaver knee simulator to evaluate the biomechanics of rectus femoris transfer.

    PubMed

    Anderson, Michael C; Brown, Nicholas A T; Bachus, Kent N; Macwilliams, Bruce A

    2009-07-01

    A cadaver knee simulator has been developed to model surgical transfer of the rectus femoris. The simulator allows knee specimens six degrees of freedom and is capable of modeling both the swing and stance phases of human gait. Experiments were conducted using a mechanical hinge analog of the knee to verify that time, flexion angle, and knee extension force measurements recorded when using the simulator were not influenced by its design or operation. A ballistic double pendulum model was used to model the swing phase of gait, and the contributions of hip and ankle torques and hamstrings cocontraction were included when modeling the stance phase of gait. When modeling swing, range of motion and time to peak knee flexion in swing for the hinge knee were similar to those of in vivo test subjects. Measurements of hinge knee extension force when modeling stance under various biomechanical conditions matched those predicted using an analytical model. Future studies using cadaver knee specimens will apply techniques described in this paper to further our understanding of changes in knee biomechanics caused by rectus femoris transfer surgery. PMID:19403312

  19. Effects of a multichannel dynamic functional electrical stimulation system on hemiplegic gait and muscle forces

    PubMed Central

    Qian, Jing-guang; Rong, Ke; Qian, Zhenyun; Wen, Chen; Zhang, Songning

    2015-01-01

    [Purpose] The purpose of the study was to design and implement a multichannel dynamic functional electrical stimulation system and investigate acute effects of functional electrical stimulation of the tibialis anterior and rectus femoris on ankle and knee sagittal-plane kinematics and related muscle forces of hemiplegic gait. [Subjects and Methods] A multichannel dynamic electrical stimulation system was developed with 8-channel low frequency current generators. Eight male hemiplegic patients were trained for 4 weeks with electric stimulation of the tibia anterior and rectus femoris muscles during walking, which was coupled with active contraction. Kinematic data were collected, and muscle forces of the tibialis anterior and rectus femoris of the affected limbs were analyzed using a musculoskelatal modeling approach before and after training. A paired sample t-test was used to detect the differences between before and after training. [Results] The step length of the affected limb significantly increased after the stimulation was applied. The maximum dorsiflexion angle and maximum knee flexion angle of the affected limb were both increased significantly during stimulation. The maximum muscle forces of both the tibia anterior and rectus femoris increased significantly during stimulation compared with before functional electrical stimulation was applied. [Conclusion] This study established a functional electrical stimulation strategy based on hemiplegic gait analysis and musculoskeletal modeling. The multichannel functional electrical stimulation system successfully corrected foot drop and altered circumduction hemiplegic gait pattern. PMID:26696734

  20. Nonsingular bouncing cosmologies in light of BICEP2

    SciTech Connect

    Cai, Yi-Fu; Quintin, Jerome; Saridakis, Emmanuel N.; Wilson-Ewing, Edward E-mail: jquintin@physics.mcgill.ca E-mail: wilson-ewing@phys.lsu.edu

    2014-07-01

    We confront various nonsingular bouncing cosmologies with the recently released BICEP2 data and investigate the observational constraints on their parameter space. In particular, within the context of the effective field approach, we analyze the constraints on the matter bounce curvaton scenario with a light scalar field, and the new matter bounce cosmology model in which the universe successively experiences a period of matter contraction and an ekpyrotic phase. Additionally, we consider three nonsingular bouncing cosmologies obtained in the framework of modified gravity theories, namely the Hořava-Lifshitz bounce model, the f(T) bounce model, and loop quantum cosmology.

  1. Dark matter chaotic inflation in light of BICEP2

    SciTech Connect

    Mukaida, Kyohei; Nakayama, Kazunori E-mail: kazunori@hep-th.phys.s.u-tokyo.ac.jp

    2014-08-01

    We propose an economical model in which a singlet {sub 2}-odd scalar field accounts for the primordial inflation and the present dark matter abundance simultaneously in the light of recent BICEP2 result. Interestingly, the reheating temperature and the thermal dark matter abundance are closely connected by the same interaction between the singlet scalar and the standard model Higgs. In addition, the reheating temperature turns out to be quite high, T{sub R} ∼> 10{sup 12} GeV, and hence the thermal leptogenesis is compatible with this model. Therefore, it can be one of the simplest cosmological scenarios.

  2. Arthroscopic suprapectoral tenodesis of the long head biceps: reproducing an anatomic length-tension relationship.

    PubMed

    David, Tal S; Schildhorn, Jeffrey C

    2012-09-01

    Tenodesis is an accepted treatment option in the management of pathology involving the long head of the biceps (LHB). Among the common causes for revision surgery after tenodesis are residual pain within the bicipital groove, cramping, early biceps fatigue, and biceps deformity. Most technical descriptions of arthroscopic biceps tenodesis involve fixation of the LHB tendon within or proximal to the intertubercular sulcus and thus fail to address the described sources of pain within this proximal anatomic location. Suprapectoral tenodesis offers the surgeon the ability to remove the LHB from within the bicipital groove by fixating the biceps more distally. Cramping, early fatigue, and biceps deformity have been described when the appropriate length-tension relation of the biceps tendon has not been restored after LHB tenodesis. Our described procedure allows for a more consistent restoration of the anatomic length-tension relation of the LHB, therefore reducing the symptoms associated with this variable. This all-arthroscopic, suprapectoral biceps tenodesis with interference fixation addresses the most common causes for revision surgery and offers a comprehensive solution for LHB pathology. PMID:23766967

  3. Intravenous maternal -arginine administration to twin-bearing ewes, during late pregnancy, is associated with increased fetal muscle mTOR abundance and postnatal growth in twin female lambs.

    PubMed

    Sales, F; Sciascia, Q; van der Linden, D S; Wards, N J; Oliver, M H; McCoard, S A

    2016-06-01

    The aims of this study were to determine whether parenteral Arg administered to well-fed twin-bearing ewes from 100 to 140 d of pregnancy influences fetal skeletal muscle growth, the abundance and activation of mechanistic target of rapamycin (mTOR) protein, and postnatal muscle growth of the offspring. Ewes fed 100% of NRC-recommended nutrient requirements for twin-bearing ewes were administered an intravenous bolus of either 345 μmol Arg HCl/kg BW or saline solution (Control) 3 times per day. At 140 d of pregnancy (P140), a group of 11 Control and 9 Arg-treated ewes were euthanized and hind leg muscles and longissimus dorsi (LD) were excised and weighed. A sample of LD was snap frozen in liquid nitrogen for later analysis of free AA (FAA) concentration, mTOR abundance and phosphorylation, and biochemical indices (DNA, RNA, and protein content). For the remaining 25 ewes (Arg, = 13, and Control, = 12), Arg administration was continued until the initiation of parturition and ewes were allowed to lamb. Lambs were weaned at postnatal Day 82 and grazed on pasture until postnatal day 153 (PN153), when a subset of 20 lambs ( = 10 per group) was euthanized. At P140, only the psoas major was heavier in the Arg-administered group compared with the Control group. Female lambs from ewes supplemented with Arg (Arg-F) had increased abundance of total mTOR, RNA concentration, and RNA:DNA ratio in LD compared with female lambs from Control ewes (Con-F), whereas males did not differ. At PN153, Arg-F were heavier than Con-F and had heavier LD and plantaris and a trend for heavier psoas major muscles compared with Con-F. In contrast, BW and individual muscle weights did not differ in male lambs. Lambs from Arg-treated ewes had heavier semimembranosus and tended to have heavier biceps femoris compared with Control lambs. The RNA concentration in LD was greater in Arg-F compared with Con-F, and DNA concentration was greater in the Arg group compared with the Control group. In

  4. New insight of some extracellular matrix molecules in beef muscles. Relationships with sensory qualities.

    PubMed

    Dubost, A; Micol, D; Lethias, C; Listrat, A

    2016-05-01

    The aim of this study was to highlight the relationships between decorin, tenascin-X and type XIV collagen, three minor molecules of extracellular matrix (ECM), with some structural parameters of connective tissue and its content in total collagen, its cross-links (CLs) and its proteoglycans (PGs). In addition, we have evaluated impact of these minor molecules on beef quality traits. The relative abundance of these molecules was evaluated by western blot analysis in Longissimus thoracis (LT) and Biceps femoris (BF) muscles from Aberdeen Angus and Blond d'Aquitaine beef breeds. Decorin and tenascin-X were more abundant in BF than in LT (1.8 v. 0.5 arbitrary units (AU), respectively, P<0.001, and 1.0 v. 0.6 AU, P<0.05). There was no muscle effect for collagen XIV content. Decorin and tenascin-X relative abundance were positively correlated with perimysium and endomysium areas and with collagen characteristics (total, insoluble and CLs). Decorin was negatively correlated with total PG content and positively with tenascin-X. Collagen XIV was correlated with any of parameters measured. To assess the impact of decorin, tenascin-X and collagen XIV and of their ratios to total collagen and PGs on shear force and quality traits we realized, respectively, a multiple-linear regression analysis and a Pearson's correlation analysis. Decorin and tenascin-X relative abundance were, respectively, negatively and positively involved in juiciness. Decorin relative abundance was also negatively involved in abnormal flavour and positively in overall liking. The ratio of decorin to total collagen and PGs was negatively correlated to juiciness, together with collagen XIV ratio to total PGs. The ratios of decorin, tenascin-X and collagen XIV to total PGs were positively correlated to sensory tenderness, negatively to abnormal beef flavour and positively to overall liking. The ratio of decorin to total collagen was also negatively correlated to abnormal flavour and positively to overall

  5. Tendinopathy of the long head of the biceps tendon: histopathologic analysis of the extra-articular biceps tendon and tenosynovium

    PubMed Central

    Streit, Jonathan J; Shishani, Yousef; Rodgers, Mark; Gobezie, Reuben

    2015-01-01

    Background Bicipital tendinitis is a common cause of anterior shoulder pain, but there is no evidence that acute inflammation of the extra-articular long head of the biceps (LHB) tendon is the root cause of this condition. We evaluated the histologic findings of the extra-articular portion of the LHB tendon and synovial sheath in order to compare those findings to known histologic changes seen in other tendinopathies. Methods Twenty-six consecutive patients (mean age 45.4±13.7 years) underwent an open subpectoral biceps tenodesis for anterior shoulder pain localized to the bicipital groove. Excised tendons were sent for histologic analysis. Specimens were graded using a semiquantitative scoring system to evaluate tenocyte morphology, the presence of ground substance, collagen bundle characteristics, and vascular changes. Results Chronic inflammation was noted in only two of 26 specimens, and no specimen demonstrated acute inflammation. Tenocyte enlargement and proliferation, characterized by increased roundness and size of the cell and nucleus with proteoglycan matrix expansion and myxoid degenerative changes, was found in all 26 specimens. Abundant ground substance, collagen bundle changes, and increased vascularization were visualized in all samples. Conclusion Anterior shoulder pain attributed to the biceps tendon does not appear to be due to an inflammatory process in most cases. The histologic findings of the extra-articular portion of the LHB tendon and synovial sheath are similar to the pathologic findings in de Quervain tenosynovitis at the wrist, and may be due to a chronic degenerative process similar to this and other tendinopathies of the body. PMID:25792859

  6. Keck array and BICEP3: spectral characterization of 5000+ detectors

    NASA Astrophysics Data System (ADS)

    Karkare, K. S.; Ade, P. A. R.; Ahmed, Z.; Aikin, R. W.; Alexander, K. D.; Amiri, M.; Barkats, D.; Benton, S. J.; Bischoff, C. A.; Bock, J. J.; Bonetti, J. A.; Brevik, J. A.; Buder, I.; Bullock, E. W.; Burger, B.; Connors, J.; Crill, B. P.; Davis, G.; Dowell, C. D.; Duband, L.; Filippini, J. P.; Fliescher, S. T.; Golwala, S. R.; Gordon, M. S.; Grayson, J. A.; Halpern, M.; Hasselfield, M.; Hildebrandt, S. R.; Hilton, G. C.; Hristov, V. V.; Hui, H.; Irwin, K. D.; Kang, J. H.; Karpel, E.; Kefeli, S.; Kernasovskiy, S. A.; Kovac, J. M.; Kuo, C. L.; Leitch, E. M.; Lueker, M.; Mason, P.; Megerian, K. G.; Netterfield, C. B.; Nguyen, H. T.; O'Brient, R.; Ogburn, R. W.; Pryke, C. L.; Reintsema, C. D.; Richter, S.; Schwarz, R.; Sheehy, C. D.; Staniszewski, Z. K.; Sudiwala, R. V.; Teply, G. P.; Thompson, K. L.; Tolan, J. E.; Turner, A. D.; Vieregg, A.; Weber, A.; Wong, C. L.; Wu, W. L. K.; Yoon, K. W.

    2014-08-01

    The inflationary paradigm of the early universe predicts a stochastic background of gravitational waves which would generate a B-mode polarization pattern in the cosmic microwave background (CMB) at degree angular scales. Precise measurement of B-modes is one of the most compelling observational goals in modern cosmology. Since 2011, the Keck Array has deployed over 2500 transition edge sensor (TES) bolometer detectors at 100 and 150 GHz to the South Pole in pursuit of degree-scale B-modes, and Bicep3 will follow in 2015 with 2500 more at 100 GHz. Characterizing the spectral response of these detectors is important for controlling systematic effects that could lead to leakage from the temperature to polarization signal, and for understanding potential coupling to atmospheric and astrophysical emission lines. We present complete spectral characterization of the Keck Array detectors, made with a Martin-Puplett Fourier Transform Spectrometer at the South Pole, and preliminary spectra of Bicep3 detectors taken in lab. We show band centers and effective bandwidths for both Keck Array bands, and use models of the atmosphere at the South Pole to cross check our absolute calibration. Our procedure for obtaining interferograms in the field with automated 4-axis coupling to the focal plane represents an important step towards efficient and complete spectral characterization of next-generation instruments more than 10000 detectors.

  7. Increased Post-Operative Stiffness after Arthroscopic Suprapectoral Biceps Tenodesis

    PubMed Central

    Werner, Brian C.; Pehlivan, Hakan C.; Hart, Joseph M.; Carson, Eric W.; Diduch, David R.; Miller, Mark D.; Brockmeier, Stephen F.

    2014-01-01

    Objectives: Biceps tenodesis can be performed open or arthroscopically and can be positioned in a suprapectoral or subpectoral position. Suprapectoral tenodesis can be carried out arthroscopically, whereas the subpectoral tenodesis is performed as an open procedure. The goal of this study is to compare the incidence of postoperative stiffness between arthroscopic suprapectoral and open subpectoral biceps tenodesis and evaluate risk factors for its occurrence. Methods: Study Design: The charts of all patients who underwent arthroscopic or open biceps tenodesis who were a minimum of two years post-procedure were reviewed. Patients with preoperative frozen shoulder, prior shoulder surgery, or massive rotator cuff tears which required longer post-operative immobilization were excluded. Post-operative stiffness was defined as persistent range of motion deficit (<100oof forward flexion and abduction; <40o of internal or external rotation) and pain resulting in a diagnosis of post-operative frozen shoulder and requiring either an injection, lysis of adhesions/manipulation, or both. Analysis: Means were calculated for continuous variables and compared using Students t test. Frequencies for categorical variables were compared using chi square tests. Results: We identified 249 consecutive biceps tenodeses from 2008-11 (106 arthroscopic, 143 open) that met inclusion and exclusion criteria. A significantly increased incidence of post-operative stiffness was found in the arthroscopic tenodesis cohort as compared to the open cohort (17.9% vs. 5.6%, p=0.002). The groups were otherwise well matched. (Table I). Further analysis was performed comparing patients with and without post-operative stiffness within the arthroscopic cohort. (Table II) Female gender (63.2% vs 33.3%, p = 0.016) and smoking (36.8% vs 16.1%, p = 0.040) were independent risk factors for post-operative stiffness after arthroscopic tenodesis. Location of the tenodesis from the top of the humeral head as measured

  8. Tissue reactivity and suture handling characteristics of “jimat” against silk and chromic gut in cat thigh muscle: A comparative study

    PubMed Central

    Bekele, Tilahun; Bhokre, A. P.; Tesfaye, Abreha

    2015-01-01

    Aim: This study was conducted to evaluate and compare the tissue reactivity and suture handling characteristics of chromic gut, silk, and ‘jimat’ suture materials in cat thigh muscle. Materials and Methods: This experimental study was conducted from November, 2013 to April, 2014 in Kombolcha Animal Diseases Survey, Research and Diagnostic Laboratory, Kombolcha, Ethiopia. A total of 36 local breed male cats were randomly assigned into chromic gut, silk, and “jimat” groups of 12 cats each as A, B, and C, respectively. The hind leg muscle biceps femoris was incised and sutured with suture materials according to their groups. The muscle samples with its suture were collected at six different days interval i.e. 1, 3, 7, 14, 21, and 28 and processed histopathologically to assess the degree of leukocytic infiltration and fibrous and granulation tissue formation (GTF). In addition, all suture materials were evaluated intraoperatively about their handling characteristics, by rating the precision of knot tying, square knot positioning, and resistance to knot slippage. The statistical analysis was done with two-way ANOVA, Kruskal–Wallis, and Chi-square tests. Results: The histopathology showed that “jimat” thread (2.4±1.2) had produced least leukocytic infiltration than chromic gut (4.5±1.9) and silk (4.3±1.5) sutures during the study period. Higher GTF was seen at day 3 (6 [100%]), 7 (6 [100%]) and day 14 (4 [66.7%]) in all sutures, whereas “jimat” showed significantly (p<0.05) higher fibrous tissue formation (10 [83.3%]) than others. Moreover, “jimat” suture had equal suture handling characteristics (p>0.05) with both chromic gut and silk. Conclusion: The result indicated that a single strand “jimat” thread appears to be the most satisfactory suture material as regards to both tissue reaction and suture handling characteristics for skeletal muscle approximation in cats and provided that studies on its carcinogenic effects should be done. PMID

  9. The muscle activation patterns of lower limb during stair climbing at different backpack load.

    PubMed

    Yali, Han; Aiguo, Song; Haitao, Gao; Songqing, Zhu

    2015-01-01

    Stair climbing under backpack load condition is a challenging task. Understanding muscle activation patterns of lower limb during stair climbing with load furthers our understanding of the factors involved in joint pathology and the effects of treatment. At the same time, stair climbing under backpack load requires adjustments of muscle activations and increases joint moment compared to level walking, which with muscle activation patterns are altered as a result of using an assistive technology, such as a wearable exoskeleton leg for human walking power augmentation. Therefore, the aim of this study was to analyze lower limb muscles during stair climbing under different backpack load. Nine healthy volunteers ascended a four-step staircase at different backpack load (0 kg, 10 kg, 20 kg, 30 kg). Electromyographic (EMG) signals were recorded from four lower limb muscles (gastrocnemius, tibialis anterior, hamstring, rectus femoris). The results showed that muscle activation amplitudes of lower limb increase with increasing load during stair climbing, the maximum RMS of gastrocnemius are greater than tibialis anterior, hamstring and rectus femoris whether stair climbing or level walking under the same load condition. However, the maximum RMS of hamstring are smaller than gastrocnemius, tibialis anterior and rectus femoris. The study of muscle activation under different backpack load during stair climbing can be used to design biomechanism and explore intelligent control based on EMG for a wearable exoskeleton leg for human walking power augmentation. PMID:26899302

  10. Actions of Two Bi-Articular Muscles of the Lower Extremity: A Review

    PubMed Central

    Landin, Dennis; Thompson, Melissa; Reid, Meghan

    2016-01-01

    The extremities of the human body contain several bi-articular muscles. The actions produced by muscles at the joints they cross are greatly influenced by joint moment arms and muscle length. These factors are dynamic and subject to change as joint angles are altered. Therefore, to more completely understand the actions of such muscles, the angles of both joints must be manipulated. This report reviews investigations, which have explored the actions of two bi-articular muscles of the lower extremities (gastrocnemius and rectus femoris) as the joints they cross are moved into various combinations of angles. The findings have both clinical and physical performance ramifications. PMID:27298656

  11. Actions of Two Bi-Articular Muscles of the Lower Extremity: A Review.

    PubMed

    Landin, Dennis; Thompson, Melissa; Reid, Meghan

    2016-07-01

    The extremities of the human body contain several bi-articular muscles. The actions produced by muscles at the joints they cross are greatly influenced by joint moment arms and muscle length. These factors are dynamic and subject to change as joint angles are altered. Therefore, to more completely understand the actions of such muscles, the angles of both joints must be manipulated. This report reviews investigations, which have explored the actions of two bi-articular muscles of the lower extremities (gastrocnemius and rectus femoris) as the joints they cross are moved into various combinations of angles. The findings have both clinical and physical performance ramifications. PMID:27298656

  12. Interictal conduction slowing in muscle fibers in hypokalemic periodic paralysis.

    PubMed

    Troni, W; Doriguzzi, C; Mongini, T

    1983-11-01

    Conduction velocity in muscle fibers of the short head of biceps brachii was reduced between attacks in all the affected members of a family suffering from hypokalemic periodic paralysis. This finding represents a further evidence of a primary alteration of sarcolemmal function in this disease. Interictal conduction slowing in muscle fibers is consistent with the prevailing pathophysiologic hypothesis, which considers an increased membrane permeability to sodium ions as the fundamental defect underlying all forms of familial periodic paralysis. PMID:6685247

  13. Optimizing Muscle Parameters in Musculoskeletal Modeling Using Monte Carlo Simulations

    NASA Technical Reports Server (NTRS)

    Hanson, Andrea; Reed, Erik; Cavanagh, Peter

    2011-01-01

    Astronauts assigned to long-duration missions experience bone and muscle atrophy in the lower limbs. The use of musculoskeletal simulation software has become a useful tool for modeling joint and muscle forces during human activity in reduced gravity as access to direct experimentation is limited. Knowledge of muscle and joint loads can better inform the design of exercise protocols and exercise countermeasure equipment. In this study, the LifeModeler(TM) (San Clemente, CA) biomechanics simulation software was used to model a squat exercise. The initial model using default parameters yielded physiologically reasonable hip-joint forces. However, no activation was predicted in some large muscles such as rectus femoris, which have been shown to be active in 1-g performance of the activity. Parametric testing was conducted using Monte Carlo methods and combinatorial reduction to find a muscle parameter set that more closely matched physiologically observed activation patterns during the squat exercise. Peak hip joint force using the default parameters was 2.96 times body weight (BW) and increased to 3.21 BW in an optimized, feature-selected test case. The rectus femoris was predicted to peak at 60.1% activation following muscle recruitment optimization, compared to 19.2% activation with default parameters. These results indicate the critical role that muscle parameters play in joint force estimation and the need for exploration of the solution space to achieve physiologically realistic muscle activation.

  14. [Marinesco-Sjögren syndrome--report of two patients in a family with muscle CT study].

    PubMed

    Higuchi, S; Taku, K; Fukuhara, N; Hozumi, I; Yamazaki, M

    1993-01-01

    Two patients with Marinesco-Sjögren syndrome in a family were characterized by autosomal recessive inheritance, congenital cataract, cerebellar ataxia, mental retardation, short stature and variable skeletal abnormalities. Muscle biopsy specimens showed replacement of muscle fibers by fat and fibrous tissue, a marked variation of fiber size and a rimmed vacuole formation. Nerve biopsy specimens showed a reduced number of myelinated nerve fibers in the sural nerves. Muscle CT revealed atrophy of the quadriceps femoris, semitendinosus, gastrocnemius and soleus muscles. Accordingly, extensor muscles in the thighs were more preferentially involved than flexor muscles in the legs. PMID:8334784

  15. Initial Performance of Bicep3: A Degree Angular Scale 95 GHz Band Polarimeter

    NASA Astrophysics Data System (ADS)

    Wu, W. L. K.; Ade, P. A. R.; Ahmed, Z.; Alexander, K. D.; Amiri, M.; Barkats, D.; Benton, S. J.; Bischoff, C. A.; Bock, J. J.; Bowens-Rubin, R.; Buder, I.; Bullock, E.; Buza, V.; Connors, J. A.; Filippini, J. P.; Fliescher, S.; Grayson, J. A.; Halpern, M.; Harrison, S. A.; Hilton, G. C.; Hristov, V. V.; Hui, H.; Irwin, K. D.; Kang, J.; Karkare, K. S.; Karpel, E.; Kefeli, S.; Kernasovskiy, S. A.; Kovac, J. M.; Kuo, C. L.; Megerian, K. G.; Netterfield, C. B.; Nguyen, H. T.; O'Brient, R.; Ogburn, R. W.; Pryke, C.; Reintsema, C. D.; Richter, S.; Sorensen, C.; Staniszewski, Z. K.; Steinbach, B.; Sudiwala, R. V.; Teply, G. P.; Thompson, K. L.; Tolan, J. E.; Tucker, C. E.; Turner, A. D.; Vieregg, A. G.; Weber, A. C.; Wiebe, D. V.; Willmert, J.; Yoon, K. W.

    2016-08-01

    Bicep3 is a 550-mm aperture telescope with cold, on-axis, refractive optics designed to observe at the 95-GHz band from the South Pole. It is the newest member of the Bicep/ Keck family of inflationary probes specifically designed to measure the polarization of the cosmic microwave background (CMB) at degree angular scales. Bicep3 is designed to house 1280 dual-polarization pixels, which, when fully populated, totals to ˜ 9× the number of pixels in a single Keck 95-GHz receiver, thus further advancing the Bicep/ Keck program's 95 GHz mapping speed. Bicep3 was deployed during the austral summer of 2014-2015 with nine detector tiles, to be increased to its full capacity of 20 in the second season. After instrument characterization, measurements were taken, and CMB observation commenced in April 2015. Together with multi-frequency observation data from Planck, Bicep2, and the Keck Array, Bicep3 is projected to set upper limits on the tensor-to-scalar ratio to r lesssim 0.03 at 95 % C.L.

  16. Initial Performance of uc(Bicep3): A Degree Angular Scale 95 GHz Band Polarimeter

    NASA Astrophysics Data System (ADS)

    Wu, W. L. K.; Ade, P. A. R.; Ahmed, Z.; Alexander, K. D.; Amiri, M.; Barkats, D.; Benton, S. J.; Bischoff, C. A.; Bock, J. J.; Bowens-Rubin, R.; Buder, I.; Bullock, E.; Buza, V.; Connors, J. A.; Filippini, J. P.; Fliescher, S.; Grayson, J. A.; Halpern, M.; Harrison, S. A.; Hilton, G. C.; Hristov, V. V.; Hui, H.; Irwin, K. D.; Kang, J.; Karkare, K. S.; Karpel, E.; Kefeli, S.; Kernasovskiy, S. A.; Kovac, J. M.; Kuo, C. L.; Megerian, K. G.; Netterfield, C. B.; Nguyen, H. T.; O'Brient, R.; Ogburn, R. W.; Pryke, C.; Reintsema, C. D.; Richter, S.; Sorensen, C.; Staniszewski, Z. K.; Steinbach, B.; Sudiwala, R. V.; Teply, G. P.; Thompson, K. L.; Tolan, J. E.; Tucker, C. E.; Turner, A. D.; Vieregg, A. G.; Weber, A. C.; Wiebe, D. V.; Willmert, J.; Yoon, K. W.

    2015-12-01

    uc(Bicep3) is a 550-mm aperture telescope with cold, on-axis, refractive optics designed to observe at the 95-GHz band from the South Pole. It is the newest member of the uc(Bicep)/Keck family of inflationary probes specifically designed to measure the polarization of the cosmic microwave background (CMB) at degree angular scales. uc(Bicep3) is designed to house 1280 dual-polarization pixels, which, when fully populated, totals to ˜ 9× the number of pixels in a single Keck 95-GHz receiver, thus further advancing the uc(Bicep)/Keck program's 95 GHz mapping speed. uc(Bicep3) was deployed during the austral summer of 2014-2015 with nine detector tiles, to be increased to its full capacity of 20 in the second season. After instrument characterization, measurements were taken, and CMB observation commenced in April 2015. Together with multi-frequency observation data from Planck, uc(Bicep2), and the Keck Array, uc(Bicep3) is projected to set upper limits on the tensor-to-scalar ratio to r ≲ 0.03 at 95 % C.L.

  17. BICEP3: a 95GHz refracting telescope for degree-scale CMB polarization

    NASA Astrophysics Data System (ADS)

    Ahmed, Z.; Amiri, M.; Benton, S. J.; Bock, J. J.; Bowens-Rubin, R.; Buder, I.; Bullock, E.; Connors, J.; Filippini, J. P.; Grayson, J. A.; Halpern, M.; Hilton, G. C.; Hristov, V. V.; Hui, H.; Irwin, K. D.; Kang, J.; Karkare, K. S.; Karpel, E.; Kovac, J. M.; Kuo, C. L.; Netterfield, C. B.; Nguyen, H. T.; O'Brient, R.; Ogburn, R. W.; Pryke, C.; Reintsema, C. D.; Richter, S.; Thompson, K. L.; Turner, A. D.; Vieregg, A. G.; Wu, W. L. K.; Yoon, K. W.

    2014-08-01

    Bicep3 is a 550 mm-aperture refracting telescope for polarimetry of radiation in the cosmic microwave background at 95 GHz. It adopts the methodology of Bicep1, Bicep2 and the Keck Array experiments | it possesses sufficient resolution to search for signatures of the inflation-induced cosmic gravitational-wave background while utilizing a compact design for ease of construction and to facilitate the characterization and mitigation of systematics. However, Bicep3 represents a significant breakthrough in per-receiver sensitivity, with a focal plane area 5x larger than a Bicep2/Keck Array receiver and faster optics (f=1:6 vs. f=2:4). Large-aperture infrared-reflective metal-mesh filters and infrared-absorptive cold alumina filters and lenses were developed and implemented for its optics. The camera consists of 1280 dual-polarization pixels; each is a pair of orthogonal antenna arrays coupled to transition-edge sensor bolometers and read out by multiplexed SQUIDs. Upon deployment at the South Pole during the 2014-15 season, Bicep3 will have survey speed comparable to Keck Array 150 GHz (2013), and will signifcantly enhance spectral separation of primordial B-mode power from that of possible galactic dust contamination in the Bicep2 observation patch

  18. Effects of feed deprivation on the AMPK signaling pathway in skeletal muscle of broiler chickens.

    PubMed

    Hu, Xiyi; Liu, Lei; Song, Zhigang; Sheikhahmadi, Ardashir; Wang, Yufeng; Buyse, Johan

    2016-01-01

    The 5'-adenosine monophosphate-activated protein kinase (AMPK) plays a key role in rapid metabolic adaptations to maintain energy homeostasis in poultry. It remains unclear if AMPK is involved in muscular energy metabolism in broiler chickens. Hence, in the present study, seven-day-old male broilers were equally divided into three groups: fed ad libitum (control); feed-deprived for 24h (S24); feed-deprived for 24h and then refed for 24h (S24R24). Compared to the control group, the plasma levels of glucose, insulin, T3 and triglycerides in the S24 group were significantly lower (P<0.05), whereas the uric acid levels were significantly higher (P<0.01). Except for glucose, refeeding for 24h reversed the fasting-induced alterations in plasma metabolite. Fasting decreased the liver kinase B1 (LKB1), AMPK alpha 2 subunit (AMPKα2), and fatty acid synthase (FAS) mRNA levels (P<0.05) in M. pectoralis major (PM). Feed deprivation did not affect the phosphorylated AKT, mammalian target of rapamycin (mTOR) and ribosomal protein S6 kinase (p70S6K) in PM (P>0.05), but upregulated carnitine palmitoyltransferase 1 (CPT1) gene expression and increased phosphorylated LKB1 (0.05muscle returned to control group levels after 24h refeeding. In M. biceps femoris (BF), the AMPKα2 and FAS mRNA levels were decreased by fasting compared to control (P<0.05), whereas CPT1 mRNA and phosphorylated LKB1 and AMPK protein levels were increased. Refeeding for 24h reversed the changes in AMPKα2 and CPT1 gene expression and phosphorylated AMPKα2 subunit. Fasting did not affect the AKT, mTOR and p70S6K in both PM and BF muscles (P>0.05). However, refeeding after 24h of fasting increased the phosphorylated mTOR level in BF muscle which was in parallel with increased plasma insulin concentration. It was likely that increased phospho-mTOR level in the BF muscle was

  19. Bilateral medial displacement of the biceps tendon of origin: repair using polypropylene mesh and staples.

    PubMed

    Barnes, D M

    2013-09-01

    A three-year-old male greyhound was presented with acute onset right forelimb lameness because of medial displacement of the biceps tendon of origin. Ultrasonographic examination confirmed the diagnosis, and a concomitant partial tear of the medial glenohumeral ligament was detected during arthroscopy. To stabilise the biceps tendon, polypropylene mesh was fixed across the intertubercular groove to replace the torn transverse humeral retinaculum. Recovery was uneventful and lameness resolved. Fifteen months later, the dog was presented with medial displacement of the biceps tendon of origin of the left shoulder, and was treated successfully using the same technique. PMID:23614688

  20. Isocurvature perturbations and tensor mode in light of Planck and BICEP2

    SciTech Connect

    Kawasaki, Masahiro; Yokoyama, Shuichiro; Sekiguchi, Toyokazu; Takahashi, Tomo E-mail: toyokazu.sekiguchi@helsinki.fi E-mail: shu@icrr.u-tokyo.ac.jp

    2014-08-01

    We investigate the degeneracy of the isocurvature perturbations and the primordial gravitational waves, by using recent observations of the cosmic microwave background (CMB) reported by Planck and BICEP2 collaborations. We show that the tension in the bound on the tensor-to-scalar ratio r between Planck and BICEP2 can be resolved by introducing the anti-correlated isocurvature perturbations. Quantitatively, we find that with the anti-correlated isocurvature perturbations the constraints on r from Planck alone and BICEP2 results can be consistent at 68 % C.L.

  1. Quantifying the BICEP2-Planck tension over gravitational waves.

    PubMed

    Smith, Kendrick M; Dvorkin, Cora; Boyle, Latham; Turok, Neil; Halpern, Mark; Hinshaw, Gary; Gold, Ben

    2014-07-18

    The recent BICEP2 measurement of B-mode polarization in the cosmic microwave background (r = 0.2(-0.05)(+0.07)), a possible indication of primordial gravity waves, appears to be in tension with the upper limit from WMAP (r < 0.13 at 95% C.L.) and Planck (r < 0.11 at 95% C.L.). We carefully quantify the level of tension and show that it is very significant (around 0.1% unlikely) when the observed deficit of large-scale temperature power is taken into account. We show that measurements of TE and EE power spectra in the near future will discriminate between the hypotheses that this tension is either a statistical fluke or a sign of new physics. We also discuss extensions of the standard cosmological model that relieve the tension and some novel ways to constrain them. PMID:25083631

  2. Radiative inflation and dark energy RIDEs again after BICEP2

    SciTech Connect

    Bari, Pasquale Di; King, Stephen F.; Merle, Alexander; Luhn, Christoph; Schmidt-May, Angnis E-mail: S.F.King@soton.ac.uk E-mail: A.Merle@soton.ac.uk

    2014-08-01

    Following the ground-breaking measurement of the tensor-to-scalar ratio r=0.20{sup +0.07}{sub -0.05} by the BICEP2 collaboration, we perform a statistical analysis of a model that combines Radiative Inflation with Dark Energy (RIDE) based on the M{sup 2}|Φ|{sup 2}ln(|Φ|{sup 2}/Λ{sup 2}) potential and compare its predictions to those based on the traditional chaotic inflation M{sup 2}|Φ|{sup 2} potential. We find a best-fit value in the RIDE model of r=0.18 as compared to r=0.17 in the chaotic model, with the spectral index being n{sub S}=0.96 in both models.

  3. BICEP2, non-Bunch-Davies and entanglement

    NASA Astrophysics Data System (ADS)

    Mahajan, Namit

    2015-04-01

    BICEP2 result on the tensor to scalar ratio r indicates a blue tilt in the primordial gravitational wave spectrum. This blue tilt and the observed large value r = 0.2 are difficult to accommodate within the single field inflationary scenarios under standard conditions. Non-Bunch-Davies vacuum states have been proposed as a possibility. Such vacua are known to lead to pathologies. In this note we point out that it is known that these states ought to be interpreted as excited/squeezed states built over the standard Bunch-Davies vacuum in order to avoid pathological issues. We discuss the associated entanglement properties due to de Sitter horizon, and how such an approach may be more natural in the context of inflation. In particular, we suggest to employ entanglement considerations in de Sitter background to study the nature and intrinsic properties of modified initial states.

  4. Joint analysis of BICEP2/keck array and Planck Data.

    PubMed

    Ade, P A R; Aghanim, N; Ahmed, Z; Aikin, R W; Alexander, K D; Arnaud, M; Aumont, J; Baccigalupi, C; Banday, A J; Barkats, D; Barreiro, R B; Bartlett, J G; Bartolo, N; Battaner, E; Benabed, K; Benoît, A; Benoit-Lévy, A; Benton, S J; Bernard, J-P; Bersanelli, M; Bielewicz, P; Bischoff, C A; Bock, J J; Bonaldi, A; Bonavera, L; Bond, J R; Borrill, J; Bouchet, F R; Boulanger, F; Brevik, J A; Bucher, M; Buder, I; Bullock, E; Burigana, C; Butler, R C; Buza, V; Calabrese, E; Cardoso, J-F; Catalano, A; Challinor, A; Chary, R-R; Chiang, H C; Christensen, P R; Colombo, L P L; Combet, C; Connors, J; Couchot, F; Coulais, A; Crill, B P; Curto, A; Cuttaia, F; Danese, L; Davies, R D; Davis, R J; de Bernardis, P; de Rosa, A; de Zotti, G; Delabrouille, J; Delouis, J-M; Désert, F-X; Dickinson, C; Diego, J M; Dole, H; Donzelli, S; Doré, O; Douspis, M; Dowell, C D; Duband, L; Ducout, A; Dunkley, J; Dupac, X; Dvorkin, C; Efstathiou, G; Elsner, F; Enßlin, T A; Eriksen, H K; Falgarone, E; Filippini, J P; Finelli, F; Fliescher, S; Forni, O; Frailis, M; Fraisse, A A; Franceschi, E; Frejsel, A; Galeotta, S; Galli, S; Ganga, K; Ghosh, T; Giard, M; Gjerløw, E; Golwala, S R; González-Nuevo, J; Górski, K M; Gratton, S; Gregorio, A; Gruppuso, A; Gudmundsson, J E; Halpern, M; Hansen, F K; Hanson, D; Harrison, D L; Hasselfield, M; Helou, G; Henrot-Versillé, S; Herranz, D; Hildebrandt, S R; Hilton, G C; Hivon, E; Hobson, M; Holmes, W A; Hovest, W; Hristov, V V; Huffenberger, K M; Hui, H; Hurier, G; Irwin, K D; Jaffe, A H; Jaffe, T R; Jewell, J; Jones, W C; Juvela, M; Karakci, A; Karkare, K S; Kaufman, J P; Keating, B G; Kefeli, S; Keihänen, E; Kernasovskiy, S A; Keskitalo, R; Kisner, T S; Kneissl, R; Knoche, J; Knox, L; Kovac, J M; Krachmalnicoff, N; Kunz, M; Kuo, C L; Kurki-Suonio, H; Lagache, G; Lähteenmäki, A; Lamarre, J-M; Lasenby, A; Lattanzi, M; Lawrence, C R; Leitch, E M; Leonardi, R; Levrier, F; Lewis, A; Liguori, M; Lilje, P B; Linden-Vørnle, M; López-Caniego, M; Lubin, P M; Lueker, M; Macías-Pérez, J F; Maffei, B; Maino, D; Mandolesi, N; Mangilli, A; Maris, M; Martin, P G; Martínez-González, E; Masi, S; Mason, P; Matarrese, S; Megerian, K G; Meinhold, P R; Melchiorri, A; Mendes, L; Mennella, A; Migliaccio, M; Mitra, S; Miville-Deschênes, M-A; Moneti, A; Montier, L; Morgante, G; Mortlock, D; Moss, A; Munshi, D; Murphy, J A; Naselsky, P; Nati, F; Natoli, P; Netterfield, C B; Nguyen, H T; Nørgaard-Nielsen, H U; Noviello, F; Novikov, D; Novikov, I; O'Brient, R; Ogburn, R W; Orlando, A; Pagano, L; Pajot, F; Paladini, R; Paoletti, D; Partridge, B; Pasian, F; Patanchon, G; Pearson, T J; Perdereau, O; Perotto, L; Pettorino, V; Piacentini, F; Piat, M; Pietrobon, D; Plaszczynski, S; Pointecouteau, E; Polenta, G; Ponthieu, N; Pratt, G W; Prunet, S; Pryke, C; Puget, J-L; Rachen, J P; Reach, W T; Rebolo, R; Reinecke, M; Remazeilles, M; Renault, C; Renzi, A; Richter, S; Ristorcelli, I; Rocha, G; Rossetti, M; Roudier, G; Rowan-Robinson, M; Rubiño-Martín, J A; Rusholme, B; Sandri, M; Santos, D; Savelainen, M; Savini, G; Schwarz, R; Scott, D; Seiffert, M D; Sheehy, C D; Spencer, L D; Staniszewski, Z K; Stolyarov, V; Sudiwala, R; Sunyaev, R; Sutton, D; Suur-Uski, A-S; Sygnet, J-F; Tauber, J A; Teply, G P; Terenzi, L; Thompson, K L; Toffolatti, L; Tolan, J E; Tomasi, M; Tristram, M; Tucci, M; Turner, A D; Valenziano, L; Valiviita, J; Van Tent, B; Vibert, L; Vielva, P; Vieregg, A G; Villa, F; Wade, L A; Wandelt, B D; Watson, R; Weber, A C; Wehus, I K; White, M; White, S D M; Willmert, J; Wong, C L; Yoon, K W; Yvon, D; Zacchei, A; Zonca, A

    2015-03-13

    We report the results of a joint analysis of data from BICEP2/Keck Array and Planck. BICEP2 and Keck Array have observed the same approximately 400  deg^{2} patch of sky centered on RA 0 h, Dec. -57.5°. The combined maps reach a depth of 57 nK deg in Stokes Q and U in a band centered at 150 GHz. Planck has observed the full sky in polarization at seven frequencies from 30 to 353 GHz, but much less deeply in any given region (1.2  μK deg in Q and U at 143 GHz). We detect 150×353 cross-correlation in B modes at high significance. We fit the single- and cross-frequency power spectra at frequencies ≥150  GHz to a lensed-ΛCDM model that includes dust and a possible contribution from inflationary gravitational waves (as parametrized by the tensor-to-scalar ratio r), using a prior on the frequency spectral behavior of polarized dust emission from previous Planck analysis of other regions of the sky. We find strong evidence for dust and no statistically significant evidence for tensor modes. We probe various model variations and extensions, including adding a synchrotron component in combination with lower frequency data, and find that these make little difference to the r constraint. Finally, we present an alternative analysis which is similar to a map-based cleaning of the dust contribution, and show that this gives similar constraints. The final result is expressed as a likelihood curve for r, and yields an upper limit r_{0.05}<0.12 at 95% confidence. Marginalizing over dust and r, lensing B modes are detected at 7.0σ significance. PMID:25815919

  5. Joint Analysis of BICEP2/Keck Array and Planck Data

    NASA Astrophysics Data System (ADS)

    BICEP2/Keck and Planck Collaborations; Ade, P. A. R.; Aghanim, N.; Ahmed, Z.; Aikin, R. W.; Alexander, K. D.; Arnaud, M.; Aumont, J.; Baccigalupi, C.; Banday, A. J.; Barkats, D.; Barreiro, R. B.; Bartlett, J. G.; Bartolo, N.; Battaner, E.; Benabed, K.; Benoît, A.; Benoit-Lévy, A.; Benton, S. J.; Bernard, J.-P.; Bersanelli, M.; Bielewicz, P.; Bischoff, C. A.; Bock, J. J.; Bonaldi, A.; Bonavera, L.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Boulanger, F.; Brevik, J. A.; Bucher, M.; Buder, I.; Bullock, E.; Burigana, C.; Butler, R. C.; Buza, V.; Calabrese, E.; Cardoso, J.-F.; Catalano, A.; Challinor, A.; Chary, R.-R.; Chiang, H. C.; Christensen, P. R.; Colombo, L. P. L.; Combet, C.; Connors, J.; Couchot, F.; Coulais, A.; Crill, B. P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R. D.; Davis, R. J.; de Bernardis, P.; De Rosa, A.; de Zotti, G.; Delabrouille, J.; Delouis, J.-M.; Désert, F.-X.; Dickinson, C.; Diego, J. M.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Dowell, C. D.; Duband, L.; Ducout, A.; Dunkley, J.; Dupac, X.; Dvorkin, C.; Efstathiou, G.; Elsner, F.; Enßlin, T. A.; Eriksen, H. K.; Falgarone, E.; Filippini, J. P.; Finelli, F.; Fliescher, S.; Forni, O.; Frailis, M.; Fraisse, A. A.; Franceschi, E.; Frejsel, A.; Galeotta, S.; Galli, S.; Ganga, K.; Ghosh, T.; Giard, M.; Gjerløw, E.; Golwala, S. R.; González-Nuevo, J.; Górski, K. M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Gudmundsson, J. E.; Halpern, M.; Hansen, F. K.; Hanson, D.; Harrison, D. L.; Hasselfield, M.; Helou, G.; Henrot-Versillé, S.; Herranz, D.; Hildebrandt, S. R.; Hilton, G. C.; Hivon, E.; Hobson, M.; Holmes, W. A.; Hovest, W.; Hristov, V. V.; Huffenberger, K. M.; Hui, H.; Hurier, G.; Irwin, K. D.; Jaffe, A. H.; Jaffe, T. R.; Jewell, J.; Jones, W. C.; Juvela, M.; Karakci, A.; Karkare, K. S.; Kaufman, J. P.; Keating, B. G.; Kefeli, S.; Keihänen, E.; Kernasovskiy, S. A.; Keskitalo, R.; Kisner, T. S.; Kneissl, R.; Knoche, J.; Knox, L.; Kovac, J. M.; Krachmalnicoff, N.; Kunz, M.; Kuo, C. L.; Kurki-Suonio, H.; Lagache, G.; Lähteenmäki, A.; Lamarre, J.-M.; Lasenby, A.; Lattanzi, M.; Lawrence, C. R.; Leitch, E. M.; Leonardi, R.; Levrier, F.; Lewis, A.; Liguori, M.; Lilje, P. B.; Linden-Vørnle, M.; López-Caniego, M.; Lubin, P. M.; Lueker, M.; Macías-Pérez, J. F.; Maffei, B.; Maino, D.; Mandolesi, N.; Mangilli, A.; Maris, M.; Martin, P. G.; Martínez-González, E.; Masi, S.; Mason, P.; Matarrese, S.; Megerian, K. G.; Meinhold, P. R.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mitra, S.; Miville-Deschênes, M.-A.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Moss, A.; Munshi, D.; Murphy, J. A.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C. B.; Nguyen, H. T.; Nørgaard-Nielsen, H. U.; Noviello, F.; Novikov, D.; Novikov, I.; O'Brient, R.; Ogburn, R. W.; Orlando, A.; Pagano, L.; Pajot, F.; Paladini, R.; Paoletti, D.; Partridge, B.; Pasian, F.; Patanchon, G.; Pearson, T. J.; Perdereau, O.; Perotto, L.; Pettorino, V.; Piacentini, F.; Piat, M.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Ponthieu, N.; Pratt, G. W.; Prunet, S.; Pryke, C.; Puget, J.-L.; Rachen, J. P.; Reach, W. T.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.; Renzi, A.; Richter, S.; Ristorcelli, I.; Rocha, G.; Rossetti, M.; Roudier, G.; Rowan-Robinson, M.; Rubiño-Martín, J. A.; Rusholme, B.; Sandri, M.; Santos, D.; Savelainen, M.; Savini, G.; Schwarz, R.; Scott, D.; Seiffert, M. D.; Sheehy, C. D.; Spencer, L. D.; Staniszewski, Z. K.; Stolyarov, V.; Sudiwala, R.; Sunyaev, R.; Sutton, D.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J. A.; Teply, G. P.; Terenzi, L.; Thompson, K. L.; Toffolatti, L.; Tolan, J. E.; Tomasi, M.; Tristram, M.; Tucci, M.; Turner, A. D.; Valenziano, L.; Valiviita, J.; van Tent, B.; Vibert, L.; Vielva, P.; Vieregg, A. G.; Villa, F.; Wade, L. A.; Wandelt, B. D.; Watson, R.; Weber, A. C.; Wehus, I. K.; White, M.; White, S. D. M.; Willmert, J.; Wong, C. L.; Yoon, K. W.; Yvon, D.; Zacchei, A.; Zonca, A.; Bicep2/Keck; Planck Collaborations

    2015-03-01

    We report the results of a joint analysis of data from BICEP2/Keck Array and Planck. BICEP2 and Keck Array have observed the same approximately 400 deg2 patch of sky centered on RA 0 h, Dec. -57.5 ° . The combined maps reach a depth of 57 nK deg in Stokes Q and U in a band centered at 150 GHz. Planck has observed the full sky in polarization at seven frequencies from 30 to 353 GHz, but much less deeply in any given region (1.2 μ K deg in Q and U at 143 GHz). We detect 150 ×353 cross-correlation in B modes at high significance. We fit the single- and cross-frequency power spectra at frequencies ≥150 GHz to a lensed-Λ CDM model that includes dust and a possible contribution from inflationary gravitational waves (as parametrized by the tensor-to-scalar ratio r), using a prior on the frequency spectral behavior of polarized dust emission from previous Planck analysis of other regions of the sky. We find strong evidence for dust and no statistically significant evidence for tensor modes. We probe various model variations and extensions, including adding a synchrotron component in combination with lower frequency data, and find that these make little difference to the r constraint. Finally, we present an alternative analysis which is similar to a map-based cleaning of the dust contribution, and show that this gives similar constraints. The final result is expressed as a likelihood curve for r, and yields an upper limit r0.05<0.12 at 95% confidence. Marginalizing over dust and r, lensing B modes are detected at 7.0 σ significance.

  6. Detection of degree-scale B-mode polarization and studying cosmic polarization rotation with the BICEP1 and BICEP2 telescopes

    NASA Astrophysics Data System (ADS)

    Kaufman, Jonathan Philip

    The BICEP1 and BICEP2 telescopes studied the temperature and polarization of the Cosmic Microwave Background (CMB) from 2006 -- 2008 and 2010 -- 2012, respectively, producing the deepest maps of polarization created to date. From BICEP2 three-year data, we detect B-mode polarization at the degree-scale above the expectation from lensed-ΛCDM to greater than 5sigma significance, consistent with that expected from gravitational waves created during Inflation. Instrumental systematic effects have been characterized and ruled out, and galactic foreground contamination is disfavored by the data. Additionally, correlations between temperature and B-mode polarization and between E-mode and B-mode polarization show evidence of polarization rotation of --1° to 5sigma significance; however, adding systematic uncertainty reduces this significance to ˜ 2sigma. These measurements, combined with other CMB and astrophysical measurements, point to possible parity violating physics like cosmic birefringence, but more precise calibration techniques are required to break the degeneracy between cosmic polarization rotation and systematic effects. Improved calibration is possible with current generation technology and may be achieved within the next few years. In this work, I present experimental and analysis techniques employed for BICEP1 and BICEP2 to measure B-mode polarization and temperature and polarization correlations, as well as the scientific motivation, results, and a path forward for future measurements.

  7. EMG analysis of human postural responses during parabolic flight microgravity episodes

    NASA Technical Reports Server (NTRS)

    Layne, Charles S.; Spooner, Brian S.

    1990-01-01

    Anticipatory postural activity in the trunk and legs precedes rapid shoulder flexion in unit gravity. The hypothesis that anticipatory activity is a component of a single neural command for arm movement was tested by monitoring the surface electromyographic activity of the biceps femoris, paraspinals, and deltoid muscles of three subjects during the microgravity phase of parabolic flight. If part of a single command, anticipatory postural activity would be expected to remain intact despite the absence of the body's center of gravity in a reduced gravity environment. However, in at least 75 percent of the microgravity trials anticipatory biceps femoris activity was absent, indicating a separation of postural and agonist muscle activity. Such a finding suggests that anticipatory postural biceps femoris activity may be initiated independently of agonist (deltoid) activity.

  8. Spontaneous distal biceps tendon ruptures: are they related to statin administration?

    PubMed

    Savvidou, Christiana; Moreno, Rodrigo

    2012-01-01

    The purpose of this study is to identify a possible correlation between statin administration and incidence of spontaneous distal biceps tendon ruptures. We retrospectively reviewed 104 patients with distal biceps tendon rupture that were treated surgically from 2004 to 2010, 102 males and two females with mean age 47 years (range, 22-78). Patients were divided based on the mechanism of injury and statin administration. After statistical analysis, it was found nearly two times more likely to have spontaneous distal biceps tendon rupture with use of statins. Patients in Group 1 (spontaneous tendon rupture) compared to Group 2 (provoked tendon rupture) were older, had weaker postoperative strength but similar postoperative ROM. Patients taking statins compared to those that were not taking statins were older, had same postoperative strength and similar postoperative ROM. Based on the results of our study we conclude that there is a trend of association of spontaneous distal biceps tendon ruptures with statin administration. PMID:22745079

  9. Mimetic F(R) inflation confronted with Planck and BICEP2/Keck Array data

    NASA Astrophysics Data System (ADS)

    Odintsov, S. D.; Oikonomou, V. K.

    2016-05-01

    In this paper we demonstrate that in the context of mimetic F(R) gravity with Lagrange multiplier, it is possible to realize cosmologies which are compatible with the recent BICEP2/Keck Array data. We provide some characteristic examples for which the predicted scalar to tensor ratio can be quite smaller in comparison to the upper limit imposed by the BICEP2/Keck Array observations.

  10. The Painful Long Head of the Biceps Brachii: Nonoperative Treatment Approaches.

    PubMed

    Wilk, Kevin E; Hooks, Todd R

    2016-01-01

    The long head of the biceps has garnered increased attention and interest due to the high prevalence of pain that can be a primary condition or occur secondary to shoulder dysfunction. The successful treatment of biceps tendinopathy is dependent on an accurate diagnosis and recognizing all causative factors. The treatment program will be individualized with a rehabilitation program designed to restore strength and flexibility and restore normal tendon mechanics. PMID:26614470

  11. Spontaneous resorption of calcification at the long head of the biceps tendon

    PubMed Central

    Amri, Adriansyah; Nakai, Sho; Hara, Michiharu; Yamanaka, Issei; Hamawaki, Jun-ichi

    2015-01-01

    Calcific tendinitis of the long head of the biceps tendon is a rare cause of shoulder pain. Calcium deposits are often spontaneously resorbed or reduced in size in the rotator cuff tendons, which represent the most common sites of calcific tendinitis around the shoulder. To our knowledge, no case of spontaneous resorption of calcification in the long head of the biceps tendon has been reported in the literature. Here, we report one such case and describe its successful treatment using a conservative approach.

  12. Does the Dumbbell-Carrying Position Change the Muscle Activity in Split Squats and Walking Lunges?

    PubMed Central

    Lehnert, Michal; Zaatar, Amr M.Z.; Svoboda, Zdenek; Xaverova, Zuzana

    2015-01-01

    Abstract Stastny, P, Lehnert, M, Zaatar, AMZ, Svoboda, Z, and Xaverova, Z. Does the dumbbell-carrying position change the muscle activity in split squats and walking lunges? J Strength Cond Res 29(11): 3177–3187, 2015—The forward walking lunge (WL) and split squat (SSq) are similar exercises that have differences in the eccentric phase, and both can be performed in the ipsilateral or contralateral carrying conditions. This study aimed to determine the effects of dumbbell-carrying position on the kinematics and electromyographic (EMG) amplitudes of the gluteus medius (Gmed), vastus medialis (VM), vastus lateralis (VL), and biceps femoris during WLs and SSqs. The resistance-trained (RT) and the non–resistance-trained (NT) groups (both n = 14) performed ipsilateral WLs, contralateral WLs, ipsilateral SSqs, and contralateral SSqs in a randomized order in a simulated training session. The EMG amplitude, expressed as a percentage of the maximal voluntary isometric contraction (%MVIC), and the kinematics, expressed as the range of motion (ROM) of the hip and knee, were measured during 5 repetition maximum for both legs. The repeated measure analyses of variance showed significant differences between the RT and NT groups. The NT group showed a smaller knee flexion ROM (p < 0.001, η2 = 0.36) during both types of WLs, whereas the RT group showed a higher eccentric Gmed amplitude (p < 0.001, η2 = 0.46) during all exercises and a higher eccentric VL amplitude (p < 0.001, η2 = 0.63) during contralateral WLs. Further differences were found between contralateral and ipsilateral WLs in both the RT (p < 0.001, η2 = 0.69) and NT groups (p < 0.001, η2 = 0.80), and contralateral WLs resulted in higher eccentric Gmed amplitudes. Contralateral WLs highly activated the Gmed (90% MVIC); therefore, this exercise can increase the Gmed maximal strength. The ipsilateral loading condition did not increase the Gmed or VM activity in the RT or NT group. PMID:25968228

  13. Biceps tenoscopy in arthroscopic treatment of primary synovial chondromatosis of the shoulder.

    PubMed

    Maier, Dirk; Izadpanah, Kaywan; Jaeger, Martin; Ogon, Peter; Südkamp, Norbert P

    2014-08-01

    Primary synovial chondromatosis (PSC) of the shoulder is a rare condition and usually necessitates operative therapy. Arthroscopic partial synovectomy with removal of loose osteochondromas may be regarded as the current surgical treatment of choice. However, involvement of the biceps tendon sheath (BTS) occurs in almost half of the patients and required additional open surgery in all previously reported cases. We successfully performed tenoscopy of the BTS and long head of the biceps tendon during arthroscopic treatment of PSC in a 26-year-old male competitive wrestler. Biceps tenoscopy enabled minimally invasive partial (teno)synovectomy and removal of all osteochondromas within the BTS. The symptoms of PSC fully subsided within 2 postoperative weeks. There were no functional restrictions at the 3-month follow-up examination. These preliminary results support the feasibility, safety, and efficacy of biceps tenoscopy as a complement in arthroscopic treatment of PSC of the shoulder, dispensing with the need for additional open surgery. The spectrum of indications for biceps tenoscopy has still to be defined. Conceivable indications are proposed. This first report of a diagnostic and interventional biceps tenoscopy entails a detailed step-by-step description of the surgical technique. PMID:25264517

  14. Analysis of upper arm muscle activation using surface electromyography signals during drum playing.

    PubMed

    Chong, Hyun Ju; Kwon, Chun-Ki; Kang, Hyun-Joo; Kim, Soo Ji

    2016-06-01

    This study measured surface electromyography of the biceps brachii and triceps brachii during repeated drum playing with and without a drumstick to better understand activation of the upper arm muscles and inform the use of instrument playing for motor rehabilitation. A total of 40 healthy college students participated in this study. All participants were asked to strike a drum with their hand and with a drumstick at three different levels of stroke: soft, medium, and strong. The stroke order was randomly assigned to participants. A sound level meter was used to record the intensity of the drum playing. Surface electromyography signals were recorded at every hit during drum playing both with and without the drumstick in each of the three stroke conditions. The results demonstrated that the highest muscle activation was observed in both biceps brachii and triceps brachii with strong drum playing with and without the drumstick. A two-way repeated measures analysis of variance showed that there was a significant main effect for stroke intensity in muscle activation and produced sound level. While higher activation of the triceps brachii was observed for drum playing without a drumstick, no significant differences were found between the biceps brachii and sound level. This study demonstrated via surface electromyography data that greater muscle activation of the biceps brachii and triceps brachii does not occur with the use of drumsticks in drum playing. With the drum sound controlled, drum playing by hand can be an effective therapeutic intervention for the upper arm muscles. PMID:27419114

  15. Analysis of upper arm muscle activation using surface electromyography signals during drum playing

    PubMed Central

    Chong, Hyun Ju; Kwon, Chun-Ki; Kang, Hyun-Joo; Kim, Soo Ji

    2016-01-01

    This study measured surface electromyography of the biceps brachii and triceps brachii during repeated drum playing with and without a drumstick to better understand activation of the upper arm muscles and inform the use of instrument playing for motor rehabilitation. A total of 40 healthy college students participated in this study. All participants were asked to strike a drum with their hand and with a drumstick at three different levels of stroke: soft, medium, and strong. The stroke order was randomly assigned to participants. A sound level meter was used to record the intensity of the drum playing. Surface electromyography signals were recorded at every hit during drum playing both with and without the drumstick in each of the three stroke conditions. The results demonstrated that the highest muscle activation was observed in both biceps brachii and triceps brachii with strong drum playing with and without the drumstick. A two-way repeated measures analysis of variance showed that there was a significant main effect for stroke intensity in muscle activation and produced sound level. While higher activation of the triceps brachii was observed for drum playing without a drumstick, no significant differences were found between the biceps brachii and sound level. This study demonstrated via surface electromyography data that greater muscle activation of the biceps brachii and triceps brachii does not occur with the use of drumsticks in drum playing. With the drum sound controlled, drum playing by hand can be an effective therapeutic intervention for the upper arm muscles. PMID:27419114

  16. Arthroscopic Labrum Reconstruction in the Hip Using the Indirect Head of Rectus Femoris as a Local Graft: Surgical Technique.

    PubMed

    Sharfman, Zachary T; Amar, Eyal; Sampson, Thomas; Rath, Ehud

    2016-04-01

    The importance of the acetabular labrum has been well documented for the health and function of the hip joint. Labral reconstruction has proven effective but often requires the use of a cadaveric allograft or auto graft from the fascia lata or gracilis. The indirect head of the rectus femoris is in close proximity with the anterior superior acetabulum, which is the most common site of labral tears. Using the indirect head of the rectus femoris as a local graft minimizes surgical invasiveness by mitigating the need to harvest the graft from a different location, in case of an autograft, and by minimizing donor site morbidity and damage to local tissues. The graft is harvested and fixed to the acetabular rim through the same arthroscopic portals. Hip labral reconstruction using the reflected head of the rectus femoris tendon is a minimally invasive surgical procedure that restores stability to the hip joint, is applicable in all patients undergoing hip labral reconstruction, and offers decreased tissue morbidity compared with other grafting techniques. PMID:27462534

  17. Revised cosmological parameters after BICEP 2 and BOSS

    NASA Astrophysics Data System (ADS)

    Das, Santanu; Mukherjee, Suvodip; Souradeep, Tarun

    2015-02-01

    Estimation of parameters of the 'standard' model of cosmology have dramatically improved over past few decades due to increasingly exquisite measurements made by Cosmic Microwave Background (CMB) experiments. Recent data from Planck matches well with the minimal ΛCDM model. A likelihood analysis using Planck, WMAP and a selection of high resolution experiments (highL), tensor to scalar ratio r0.002 is found to be <0.11 when dns/d ln k = 0. Planck also imposes an upper bound on neutrino mass ∑ mν<0.23 eV using Planck + WMAP + highL + BAO likelihood. However, recently results from BICEP 2 claims the detection of r= 0.2+0.07-0.05 from polarization spectra. Further, results from SDSS-III BOSS large scale galaxy survey constrains the total neutrino mass to ∑ mν=0.36 ± 0.10 eV . It is important to study the consequences of these new measurements on other cosmological parameters. In this paper we assess the revised constraints on cosmological parameters in light of these two measurements that are in some tension with the constraints from Planck. The sensitivity of Planck to weak lensing effect on the CMB angular power spectrum suggests that the normalized amplitude of physical lensing power AL > 1 at 2σ hints at a potentially important internal inconsistency. Therefore, we also include a study of the constraints on AL. Using the prior on ∑ mν as measured by SDSS-III BOSS and BICEP 2 likelihood, we find that the model with running spectral index (dns/d ln k ≠ 0) leads to a value of AL>1 at 3.1 σ. But, the model with dns/d ln k =0 makes AL consistent with 1, at 2.1σ and also shows that Neff is consistent with its theoretical value of 3.046 at around 2σ. Therefore, the analysis in this paper shows that the model with dns/d ln k =0 gives consistency with other cosmological parameters (Neff and AL ) when the current limits on ∑ mν and r0.05 are considered. However, on reducing the value of r0.05, the model with non-zero dns/d ln k gives consistent result of

  18. DOES RECTUS FEMORIS TRANSFER INCREASE KNEE FLEXION DURING STANCE PHASE IN CEREBRAL PALSY?

    PubMed Central

    de Morais, Mauro César; Blumetti, Francesco Camara; Kawamura, Cátia Miyuki; Lopes, José Augusto Fernandes; Neves, Daniella Lins; Cardoso, Michelle de Oliveira

    2016-01-01

    ABSTRACT Objective: To evaluate whether distal rectus femoris transfer (DRFT) is related to postoperative increase of knee flexion during the stance phase in cerebral palsy (CP). Methods: The inclusion criteria were Gross Motor Function Classification System (GMFCS) levels I-III, kinematic criteria for stiff-knee gait at baseline, and individuals who underwent orthopaedic surgery and had gait analyses performed before and after intervention. The patients included were divided into the following two groups: NO-DRFT (133 patients), which included patients who underwent orthopaedic surgery without DRFT, and DRFT (83 patients), which included patients who underwent orthopaedic surgery that included DRFT. The primary outcome was to evaluate in each group if minimum knee flexion in stance phase (FMJFA) changed after treatment. Results: The mean FMJFA increased from 13.19° to 16.74° (p=0.003) and from 10.60° to 14.80° (p=0.001) in Groups NO-DRFT and DRFT, respectively. The post-operative FMJFA was similar between groups NO-DRFT and DRFT (p=0.534). The increase of FMJFA during the second exam (from 13.01° to 22.51°) was higher among the GMFCS III patients in the DRFT group (p<0.001). Conclusion: In this study, DRFT did not generate additional increase of knee flexion during stance phase when compared to the control group. Level of Evidence III, Retrospective Comparative Study. PMID:26997910

  19. Discharge Characteristics of Biceps Brachii Motor Units at Recruitment When Older Adults Sustained an Isometric Contraction

    PubMed Central

    Holmes, Matthew R.; Enoka, Roger M.

    2011-01-01

    The purpose of this study was to compare the discharge characteristics of motor units recruited during an isometric contraction that was sustained with the elbow flexor muscles by older adults at target forces that were less than the recruitment threshold force of each isolated motor unit. The discharge times of 27 single motor units were recorded from the biceps brachii in 11 old adults (78.8 ± 5.9 yr). The target force was set at either a relatively small (6.6 ± 3.7% maximum) or large (11.4 ± 4.5% maximum) difference below the recruitment threshold force and the contraction was sustained until the motor unit was recruited and discharged action potentials for about 60 s. The time to recruitment was longer for the large target-force difference (P = 0.001). At recruitment, the motor units discharged repetitively for both target-force differences, which contrasts with data from young adults when motor units discharged intermittently at recruitment for the large difference between recruitment threshold force and target force. The coefficient of variation (CV) for the first five interspike intervals (ISIs) increased from the small (18.7 ± 7.9) to large difference (35.0 ± 10.2%, P = 0.008) for the young adults, but did not differ for the two target force differences for the old adults (26.3 ± 14.7 to 24.0 ± 13.1%, P = 0.610). When analyzed across the discharge duration, the average CV for the ISI decreased similarly for the two target-force differences (P = 0.618) in old adults. These findings contrast with those of young adults and indicate that the integration of synaptic input during sustained contractions differs between young and old adults. PMID:21160000

  20. Discharge characteristics of biceps brachii motor units at recruitment when older adults sustained an isometric contraction.

    PubMed

    Pascoe, Michael A; Holmes, Matthew R; Enoka, Roger M

    2011-02-01

    The purpose of this study was to compare the discharge characteristics of motor units recruited during an isometric contraction that was sustained with the elbow flexor muscles by older adults at target forces that were less than the recruitment threshold force of each isolated motor unit. The discharge times of 27 single motor units were recorded from the biceps brachii in 11 old adults (78.8 ± 5.9 yr). The target force was set at either a relatively small (6.6 ± 3.7% maximum) or large (11.4 ± 4.5% maximum) difference below the recruitment threshold force and the contraction was sustained until the motor unit was recruited and discharged action potentials for about 60 s. The time to recruitment was longer for the large target-force difference (P = 0.001). At recruitment, the motor units discharged repetitively for both target-force differences, which contrasts with data from young adults when motor units discharged intermittently at recruitment for the large difference between recruitment threshold force and target force. The coefficient of variation (CV) for the first five interspike intervals (ISIs) increased from the small (18.7 ± 7.9) to large difference (35.0 ± 10.2%, P = 0.008) for the young adults, but did not differ for the two target force differences for the old adults (26.3 ± 14.7 to 24.0 ± 13.1%, P = 0.610). When analyzed across the discharge duration, the average CV for the ISI decreased similarly for the two target-force differences (P = 0.618) in old adults. These findings contrast with those of young adults and indicate that the integration of synaptic input during sustained contractions differs between young and old adults. PMID:21160000

  1. The progression of bone and muscle atrophy in mice hind limb with immobilization.

    PubMed

    Minematsu, Akira; Imagita, Hidetaka; Kanemura, Naohiko; Yoshimura, Osamu

    2006-09-01

    This study investigated the time course of changes of bone and muscle atrophy in mice with immobilization by denervation and fixation. The animals were fifty-two male C57 BL/6J mice, aged 10 weeks old. Eight mice were used as the base line, and the remaining ones were cut at the sciatic nerve of the left hind limb and fixed with a plaster cast. At week 1, 2, 3, and 4 after the operation, a cross-sectional area of the rectus femoris muscles and bone mechanical strength with a three-point bending test of the femur and tibia were measured. The time course of changes of the bone mechanical strength and of the cross-sectional area of the rectus femoris muscles between the intact and experimental limbs in each period compared with the control limbs, was determined. The bone mechanical strength of the femur, tibia, and the cross-sectional area of the rectus femoris muscles of the experimental limbs significantly decreased compared with those of the intact limbs at week 4, 3, 2 and 1 after the operation (p<0.05). Compared with the intact limbs, the bone mechanical strength and the cross-sectional area of the rectus femoris muscles of the experimental limbs declined approximately 10% and 30%, respectively, during the experiment (p<0.05). It was demonstrated that bone and muscle atrophy occurred at an early stage after immobilization by denervation and fixation, and that both types of atrophy progressed simultaneously in the present study. PMID:16995493

  2. Toward an understanding of foreground emission in the BICEP2 region

    SciTech Connect

    Flauger, Raphael; Hill, J. Colin; Spergel, David N. E-mail: jch@astro.princeton.edu

    2014-08-01

    BICEP2 has reported the detection of a degree-scale B-mode polarization pattern in the Cosmic Microwave Background (CMB) and has interpreted the measurement as evidence for primordial gravitational waves. Motivated by the profound importance of the discovery of gravitational waves from the early Universe, we examine to what extent a combination of Galactic foregrounds and lensed E-modes could be responsible for the signal. We reanalyze the BICEP2 results and show that the 100 ×150 GHz and 150 ×150 GHz data are consistent with a cosmology with r=0.2 and negligible foregrounds, but also with a cosmology with r=0 and a significant dust polarization signal. We give independent estimates of the dust polarization signal in the BICEP2 region using a number of different approaches: (1) data-driven models based on Planck 353 GHz intensity, polarization fractions inferred from the same Planck data used by the BICEP2 team but corrected for CMB and CIB contributions, and polarization angles from starlight polarization data or the Planck sky model; (2) the same set of pre-Planck models used by the BICEP2 team but taking into account the higher polarization fractions observed in the CMB- and CIB-corrected map; (3) a measurement of neutral hydrogen gas column density N{sub HI} in the BICEP2 region combined with an extrapolation of a relation between HI column density and dust polarization derived by Planck; and (4) a dust polarization map based on digitized Planck data, which we only use as a final cross-check. While these approaches are consistent with each other, the expected amplitude of the dust polarization power spectrum remains uncertain by about a factor of three. The lower end of the prediction leaves room for a primordial contribution, but at the higher end the dust in combination with the standard CMB lensing signal could account for the BICEP2 observations, without requiring the existence of primordial gravitational waves. By measuring the cross-correlations between

  3. Reconstructing the local potential of inflation with BICEP2 data

    SciTech Connect

    Ma, Yin-Zhe; Wang, Yi E-mail: yw366@cam.ac.uk

    2014-09-01

    We locally reconstruct the inflationary potential by using the current constraints on r and n{sub s} from BICEP2 data. Assuming small and negligible α{sub s}, the inflationary potential is approximately linear in Δφ∼ M{sub pl} range but becomes non-linear in Δφ∼ 10 M{sub pl} range. However if we vary the value of α{sub s} within the range given by constraints from Planck measurement, the local reconstruction is only valid in the range of Δφ∼ 0.4 M{sub pl}, which challenges the inflationary background from the point of view of effective field theory. We show that, within the range of Δ φ ∼ 0.4 M{sub pl}, the inflation potential can be precisely reconstructed. With the current reconstruction, we show that V(φ) ∼ φ{sup 2} and φ{sup 3} are consistent, while φ model is ruled out by 95% confidence level of the reconstructed range of potential. This sets up a strong limit of large-field inflation models.

  4. Reconstructing the local potential of inflation with BICEP2 data

    NASA Astrophysics Data System (ADS)

    Ma, Yin-Zhe; Wang, Yi

    2014-09-01

    We locally reconstruct the inflationary potential by using the current constraints on r and ns from BICEP2 data. Assuming small and negligible αs, the inflationary potential is approximately linear in Δphi~ Mpl range but becomes non-linear in Δphi~ 10 Mpl range. However if we vary the value of αs within the range given by constraints from Planck measurement, the local reconstruction is only valid in the range of Δphi~ 0.4 Mpl, which challenges the inflationary background from the point of view of effective field theory. We show that, within the range of Δ phi ~ 0.4 Mpl, the inflation potential can be precisely reconstructed. With the current reconstruction, we show that V(phi) ~ phi2 and phi3 are consistent, while phi model is ruled out by 95% confidence level of the reconstructed range of potential. This sets up a strong limit of large-field inflation models.

  5. Axion cold dark matter in view of BICEP2 results.

    PubMed

    Gondolo, Paolo; Visinelli, Luca

    2014-07-01

    The properties of axions that constitute 100% of cold dark matter (CDM) depend on the tensor-to-scalar ratio r at the end of inflation. If r=0.20(-0.05)(+0.07) as reported by the BICEP2 Collaboration, then "half" of the CDM axion parameter space is ruled out. Namely, in the context of single-field slow-roll inflation, for axions to be 100% of the CDM, the Peccei-Quinn symmetry must be broken after the end of inflation, so that axion nonadiabatic primordial fluctuations are compatible with observational constraints. The cosmic axion density is then independent of the tensor-to-scalar ratio r, and the axion mass is expected to be in a narrow range that, however, depends on the cosmological model before primordial nucleosynthesis. In the standard Lambda CDM cosmology, the CDM axion mass range is ma=(71±2  μeV)(αdec+1)6/7, where αdec is the fractional contribution to the cosmic axion density from decays of axionic strings and walls. PMID:25032919

  6. Interprofessional analysis of esthetical deformity from long head biceps tenotomy

    PubMed Central

    Almeida, Alexandre; Valin, Márcio Rangel; Lotti, Cleber; de Almeida, Nayvaldo Couto; Agostini, Ana Paula

    2015-01-01

    OBJECTIVE: To evaluate the perception of an esthetical deformity resultant from arthroscopic long head biceps (LHB) tenotomy according to the degree of experience of the assisting professional. METHODS: 120 patients submitted to shoulder surgery were photographed and photos were mounted in a PowerPoint presentation. Three shoulder specialist surgeons, three generalist orthopedic surgeons and three graduated residents analyzed the presentation. RESULTS: On all patients we observed most agreement among the shoulder specialists. When just the patients with LHB tenotomy were analyzed, the specialists agreed moderately, the generalists had small agreement and the residents, a poor one. Analyzing patients with BMI < 30, there was major agreement between the specialists, while the generalists and residents had poor agreement. Analyzing patients with BMI ≥ 30, the generalists had small kappa agreement, while the specialists and residents had no agreement. CONCLUSIONS: The perception of an esthetical deformity regarding a LHB tenotomy did not have significant agreement between different level of professionals, even though the specialists showed similar perception on tenotomy patients. The evaluation of obese patients lowered the agreement on the three groups of professionals. Level of Evidence III. Case Control Study. PMID:26207087

  7. Biceps instability and Slap type II tear in overhead athletes.

    PubMed

    Osti, Leonardo; Soldati, Francesco; Cheli, Andrea; Pari, Carlotta; Massari, Leo; Maffulli, Nicola

    2012-10-01

    Type II lesions are common lesions encountered in overhead athletes with controversies arising in term of timing for treatment, surgical approach, rehabilitation and functional results. The aim of our study was to evaluate the outcomes of arthroscopic repair of type II SLAP tears in overhead athletes, focusing on the time elapsed from diagnosis and treatment, time needed to return to sport, rate of return to sport and to previous level of performance, providing an overview concerning evidence for the effectiveness of different surgical approaches to type II SLAP tears in overhead athletes. A internet search on peer reviewed Journal from 1990, first descriprion of this pathology, to 2012, have been conducted evaluating the outcomes for both isolated Slap II tear overhead athletes and those who presented associated lesions treated. The results have been analyzed according to the scale reported focusing on return to sport and level of activity. Apart from a single study, non prospective level I and II studies were detected. Return to play at the same level ranged form 22% to 94% with different range of technique utilized with the majority of the authors recommending the fixation of these lesions but biceps tenodesis can lead to higher satisfaction racte when directly compated to the anchor fixation. Associated pathologies such as partial or full tickness rotator cuff tear did not clearly affect the outcomes and complications rate. There is no consensus regarding timing and treatment for type II SLAP, especially in overhead athletes who need to regain a high level of performance. PMID:23738307

  8. Signaling Pathways Related to Protein Synthesis and Amino Acid Concentration in Pig Skeletal Muscles Depend on the Dietary Protein Level, Genotype and Developmental Stages

    PubMed Central

    Liu, Yingying; Li, Fengna; Kong, Xiangfeng; Tan, Bie; Li, Yinghui; Duan, Yehui; Blachier, François; Hu, Chien-An A.; Yin, Yulong

    2015-01-01

    Muscle growth is regulated by the homeostatic balance of the biosynthesis and degradation of muscle proteins. To elucidate the molecular interactions among diet, pig genotype, and physiological stage, we examined the effect of dietary protein concentration, pig genotype, and physiological stages on amino acid (AA) pools, protein deposition, and related signaling pathways in different types of skeletal muscles. The study used 48 Landrace pigs and 48 pure-bred Bama mini-pigs assigned to each of 2 dietary treatments: lower/GB (Chinese conventional diet)- or higher/NRC (National Research Council)-protein diet. Diets were fed from 5 weeks of age to respective market weights of each genotype. Samples of biceps femoris muscle (BFM, type I) and longissimus dorsi muscle (LDM, type II) were collected at nursery, growing, and finishing phases according to the physiological stage of each genotype, to determine the AA concentrations, mRNA levels for growth-related genes in muscles, and protein abundances of mechanistic target of rapamycin (mTOR) signaling pathway. Our data showed that the concentrations of most AAs in LDM and BFM of pigs increased (P<0.05) gradually with increasing age. Bama mini-pigs had generally higher (P<0.05) muscle concentrations of flavor-related AA, including Met, Phe, Tyr, Pro, and Ser, compared with Landrace pigs. The mRNA levels for myogenic determining factor, myogenin, myocyte-specific enhancer binding factor 2 A, and myostatin of Bama mini-pigs were higher (P<0.05) than those of Landrace pigs, while total and phosphorylated protein levels for protein kinase B, mTOR, and p70 ribosomal protein S6 kinases (p70S6K), and ratios of p-mTOR/mTOR, p-AKT/AKT, and p-p70S6K/p70S6K were lower (P<0.05). There was a significant pig genotype-dependent effect of dietary protein on the levels for mTOR and p70S6K. When compared with the higher protein-NRC diet, the lower protein-GB diet increased (P<0.05) the levels for mTOR and p70S6K in Bama mini-pigs, but

  9. Signaling Pathways Related to Protein Synthesis and Amino Acid Concentration in Pig Skeletal Muscles Depend on the Dietary Protein Level, Genotype and Developmental Stages.

    PubMed

    Liu, Yingying; Li, Fengna; Kong, Xiangfeng; Tan, Bie; Li, Yinghui; Duan, Yehui; Blachier, François; Hu, Chien-An A; Yin, Yulong

    2015-01-01

    Muscle growth is regulated by the homeostatic balance of the biosynthesis and degradation of muscle proteins. To elucidate the molecular interactions among diet, pig genotype, and physiological stage, we examined the effect of dietary protein concentration, pig genotype, and physiological stages on amino acid (AA) pools, protein deposition, and related signaling pathways in different types of skeletal muscles. The study used 48 Landrace pigs and 48 pure-bred Bama mini-pigs assigned to each of 2 dietary treatments: lower/GB (Chinese conventional diet)- or higher/NRC (National Research Council)-protein diet. Diets were fed from 5 weeks of age to respective market weights of each genotype. Samples of biceps femoris muscle (BFM, type I) and longissimus dorsi muscle (LDM, type II) were collected at nursery, growing, and finishing phases according to the physiological stage of each genotype, to determine the AA concentrations, mRNA levels for growth-related genes in muscles, and protein abundances of mechanistic target of rapamycin (mTOR) signaling pathway. Our data showed that the concentrations of most AAs in LDM and BFM of pigs increased (P<0.05) gradually with increasing age. Bama mini-pigs had generally higher (P<0.05) muscle concentrations of flavor-related AA, including Met, Phe, Tyr, Pro, and Ser, compared with Landrace pigs. The mRNA levels for myogenic determining factor, myogenin, myocyte-specific enhancer binding factor 2 A, and myostatin of Bama mini-pigs were higher (P<0.05) than those of Landrace pigs, while total and phosphorylated protein levels for protein kinase B, mTOR, and p70 ribosomal protein S6 kinases (p70S6K), and ratios of p-mTOR/mTOR, p-AKT/AKT, and p-p70S6K/p70S6K were lower (P<0.05). There was a significant pig genotype-dependent effect of dietary protein on the levels for mTOR and p70S6K. When compared with the higher protein-NRC diet, the lower protein-GB diet increased (P<0.05) the levels for mTOR and p70S6K in Bama mini-pigs, but

  10. Effects of supplementation with branched-chain amino acids to low-protein diets on expression of genes related to lipid metabolism in skeletal muscle of growing pigs.

    PubMed

    Duan, Yehui; Duan, Yangmiao; Li, Fengna; Li, Yinghui; Guo, Qiuping; Ji, Yujiao; Tan, Bie; Li, Tiejun; Yin, Yulong

    2016-09-01

    Branched-chain amino acids (BCAA), including leucine (Leu), isoleucine (Ile), and valine (Val), play critical roles in energy homeostasis and lipid metabolism in addition to their other functions, such as in protein metabolism. This study investigated the effects of different dietary BCAA ratios on the intramuscular fat (IMF) content and fatty acid composition in different location of skeletal muscles, including the longissimus dorsi (LD), biceps femoris (BF), and psoas major (PM) muscles of growing pigs, and also examined the mRNA expression levels of genes involved in lipid metabolism in these muscle tissues. The experiment was performed on 40 growing pigs (Large White × Landrace) with a similar initial weight (9.85 ± 0.35 kg). The pigs were randomly assigned to one of five diets: diet A was a positive control and contained 20 % crude protein (CP) with a Leu:Ile:Val ratio of 1:0.51:0.63 according to the recommendation of the National Research Council (NRC); for diets B to E, the CP level was reduced to 17 %, and the Leu:Ile:Val ratios were 1:1:1, 1:0.75:0.75, 1:0.51:0.63, and 1:0.25:0.25, respectively. No significant difference was observed in the average feed intake and feed efficiency of the pigs fed the low protein diet (17 % CP) with BCAA treatments relative to the positive control. However, there was a tendency for increased feed efficiency of the 1:0.75:0.75 group compared with the 1:1:1 group (P = 0.09). The BCAA ratio of 1:0.75:0.75 (17 % CP) increased the IMF content of BF muscle (P < 0.01). Moreover, varied dietary BCAA supplementation with a reduced protein level had different effects on the fatty acid composition of the LD, BF, and PM muscles. The BCAA ratio of 1:0.51:0.63-1:0.75:0.75 (17 % CP) significantly lowered the ratio of n-6 to n-3 polyunsaturated fatty acid in these muscles compared with the positive control group (20 % CP). This effect was associated with an increase in mRNA expression levels of acetyl-CoA carboxylase

  11. Your Muscles

    MedlinePlus

    ... Homework? Here's Help White House Lunch Recipes Your Muscles KidsHealth > For Kids > Your Muscles Print A A ... and skeletal (say: SKEL-uh-tul) muscle. Smooth Muscles Smooth muscles — sometimes also called involuntary muscles — are ...

  12. The characterization of decellularized human skeletal muscle as a blueprint for mimetic scaffolds.

    PubMed

    Wilson, Klaire; Terlouw, Abby; Roberts, Kevin; Wolchok, Jeffrey C

    2016-08-01

    The use of decellularized skeletal muscle (DSM) as a cell substrate and scaffold for the repair of volumetric muscle loss injuries has shown therapeutic promise. The performance of DSM materials motivated our interest in exploring the chemical and physical properties of this promising material. We suggest that these properties could serve as a blueprint for the development of next generation engineered materials with DSM mimetic properties. In this study, whole human lower limb rectus femoris (n = 10) and upper limb supraspinatus muscle samples (n = 10) were collected from both male and female tissue donors. Skeletal muscle samples were decellularized and nine property values, capturing key compositional, architectural, and mechanical properties, were measured and statistically analyzed. Mean values for each property were determined across muscle types and sexes. Additionally, the influence of muscle type (upper vs lower limb) and donor sex (male vs female) on each of the DSM material properties was examined. The data suggests that DSM materials prepared from lower limb rectus femoris samples have an increased modulus and contain a higher collagen content then upper limb supraspinatus muscles. Specifically, lower limb rectus femoris DSM material modulus and collagen content was approximately twice that of lower limb supraspinatus DSM samples. While muscle type did show some influence on material properties, we did not find significant trends related to sex. The material properties reported herein may be used as a blueprint for the data-driven design of next generation engineered scaffolds with muscle mimetic properties, as well as inputs for computational and physical models of skeletal muscle. PMID:27324779

  13. Agonist and Antagonist Muscle EMG Activity Pattern Changes with Skill Acquisition.

    ERIC Educational Resources Information Center

    Engelhorn, Richard

    1983-01-01

    Using electromyography (EMG), researchers studied changes in the control of biceps and triceps brachii muscles that occurred as women college students learned two elbow flexion tasks. Data on EMG activity, angular kinematics, training, and angular displacement were analyzed. (Author/PP)

  14. BICEP2/Keck Array. VII. Matrix Based E/B Separation Applied to Bicep2 and the Keck Array

    NASA Astrophysics Data System (ADS)

    BICEP2 Collaboration; Keck Array Collaboration; Ade, P. A. R.; Ahmed, Z.; Aikin, R. W.; Alexander, K. D.; Barkats, D.; Benton, S. J.; Bischoff, C. A.; Bock, J. J.; Bowens-Rubin, R.; Brevik, J. A.; Buder, I.; Bullock, E.; Buza, V.; Connors, J.; Crill, B. P.; Duband, L.; Dvorkin, C.; Filippini, J. P.; Fliescher, S.; Grayson, J.; Halpern, M.; Harrison, S.; Hildebrandt, S. R.; Hilton, G. C.; Hui, H.; Irwin, K. D.; Kang, J.; Karkare, K. S.; Karpel, E.; Kaufman, J. P.; Keating, B. G.; Kefeli, S.; Kernasovskiy, S. A.; Kovac, J. M.; Kuo, C. L.; Leitch, E. M.; Lueker, M.; Megerian, K. G.; Namikawa, T.; Netterfield, C. B.; Nguyen, H. T.; O'Brient, R.; Ogburn, R. W., IV; Orlando, A.; Pryke, C.; Richter, S.; Schwarz, R.; Sheehy, C. D.; Staniszewski, Z. K.; Steinbach, B.; Sudiwala, R. V.; Teply, G. P.; Thompson, K. L.; Tolan, J. E.; Tucker, C.; Turner, A. D.; Vieregg, A. G.; Weber, A. C.; Wiebe, D. V.; Willmert, J.; Wong, C. L.; Wu, W. L. K.; Yoon, K. W.

    2016-07-01

    A linear polarization field on the sphere can be uniquely decomposed into an E-mode and a B-mode component. These two components are analytically defined in terms of spin-2 spherical harmonics. Maps that contain filtered modes on a partial sky can also be decomposed into E-mode and B-mode components. However, the lack of full sky information prevents orthogonally separating these components using spherical harmonics. In this paper, we present a technique for decomposing an incomplete map into E and B-mode components using E and B eigenmodes of the pixel covariance in the observed map. This method is found to orthogonally define E and B in the presence of both partial sky coverage and spatial filtering. This method has been applied to the Bicep2 and the Keck Array maps and results in reducing E to B leakage from ΛCDM E-modes to a level corresponding to a tensor-to-scalar ratio of r\\lt 1× {10}-4.

  15. GLENOHUMERAL MUSCLE ACTIVATION DURING PROVOCATIVE TESTS DESIGNED TO DIAGNOSE SUPERIOR LABRUM ANTERIOR-POSTERIOR LESIONS

    PubMed Central

    Wood, Vanessa J.C.; Sabick, Michelle B.; Pfeiffer, Ron P.; Kuhlman, Seth M.; Christensen, Jason H.; Curtin, Michael J.

    2012-01-01

    Background Despite considerable medical advances, arthroscopy remains the only definitive means of Superior Labrum Anterior-Posterior (SLAP) lesion diagnosis. Natural shoulder anatomic variants limit the reliability of radiographic findings and clinical evaluations are not consistent. Accurate clinical diagnostic techniques would be advantageous due to the invasiveness, patient risk, and financial cost associated with arthroscopy. Purpose The purpose was to examine the behavior of the joint stabilizing muscles in provocative tests for SLAP lesions. Electromyography was used to characterize the muscle behavior, with particular interest in the long head biceps brachii (LHBB), as activation of the long head and subsequent tension in the biceps tendon should, based on related research, elicit labral symptoms in SLAP lesion patients. Study Design Controlled Laboratory Study Methods Volunteers (N=21) without a history of shoulder pathology were recruited. The tests analyzed were Active Compression, Speed's, Pronated Load, Biceps I, Biceps II, Resisted Supination External Rotation, and Yergason's. Tests were performed with a dynamometer to improve reproducibility. Muscle activity was recorded for the long and short heads of the biceps brachii, anterior deltoid, pectoralis major, latissimus dorsi, infraspinatus, and supraspinatus. Muscle behavior for each test was characterized by peak activation and proportion of muscle activity. Results Speed's, Active Compression Palm-Up, Bicep I and Bicep II, produced higher long head activations. Resisted Supination External Rotation, Bicep I, Bicep II, and Yergason's, produced a higher LHBB proportion. Conclusion Bicep I, and Bicep II elicited promising long head behavior (high activation and selectivity). Speed's and Active Compression Palm-Up elicited higher activation of the LHBB , and Resisted Supination and Yergason's elicited selective LHBB activity. These top performing tests utilize a unique range of test variables that may

  16. Avulsion of the direct head of rectus femoris following arthroscopic subspine impingement resection: a case report.

    PubMed

    Devitt, Brian M; Smith, Bjorn; Stapf, Robert; O'Donnell, John M

    2016-04-01

    Arthroscopic resection of the anterior inferior iliac spine (AIIS) for subspine impingement has become a relatively common procedure. The AIIS is the origin of the direct head of rectus femoris (dhRF). Previous studies have reported that removal of the contributing portion of the AIIS causing impingement is unlikely to weaken the attachment of the dhRF. The purpose of this article is to report a case of avulsion of the dhRF, following revision hip arthroscopy for the treatment of subspine impingement. A 23-year-old professional footballer underwent revision left hip arthroscopy for the treatment of subspine impingement. 5-mm of bone was resected inferior to the AIIS. Two-weeks post-operatively, he presented with sudden onset, severe left anterior thigh pain following a fall and hyperextension of his left hip. The patient felt a pop over the anterior aspect of his hip. He noticed immediate swelling, severe pain and stiffness. Examination revealed diffuse swelling, 4/5-power on straight-leg-raise, focal tenderness over the AIIS but no palpable gap. MRI confirmed the clinical suspicion of a dhRF avulsion. Given the minimal loss of power and the lack of significant retraction, the patient was treated conservatively. He was instructed to avoid excessive hip extension. He returned to full participation at 3-months. This article highlights a case of avulsion of the dhRF due to a hyperextension injury of the hip following arthroscopic resection of subspinal impingement, a previously unreported complication. Resection of soft and bone from the AIIS may weaken the insertion of the dhRF. Care should be taken during post-operative rehabilitation to avoid trauma and excessive forces on the dhRF tendon, which may lead to rupture. Rehabilitation should be focused on range of motion of the hip. PMID:27026819

  17. Avulsion of the direct head of rectus femoris following arthroscopic subspine impingement resection: a case report

    PubMed Central

    Devitt, Brian M.; Smith, Bjorn; Stapf, Robert; O’Donnell, John M.

    2016-01-01

    Arthroscopic resection of the anterior inferior iliac spine (AIIS) for subspine impingement has become a relatively common procedure. The AIIS is the origin of the direct head of rectus femoris (dhRF). Previous studies have reported that removal of the contributing portion of the AIIS causing impingement is unlikely to weaken the attachment of the dhRF. The purpose of this article is to report a case of avulsion of the dhRF, following revision hip arthroscopy for the treatment of subspine impingement. A 23-year-old professional footballer underwent revision left hip arthroscopy for the treatment of subspine impingement. 5-mm of bone was resected inferior to the AIIS. Two-weeks post-operatively, he presented with sudden onset, severe left anterior thigh pain following a fall and hyperextension of his left hip. The patient felt a pop over the anterior aspect of his hip. He noticed immediate swelling, severe pain and stiffness. Examination revealed diffuse swelling, 4/5-power on straight-leg-raise, focal tenderness over the AIIS but no palpable gap. MRI confirmed the clinical suspicion of a dhRF avulsion. Given the minimal loss of power and the lack of significant retraction, the patient was treated conservatively. He was instructed to avoid excessive hip extension. He returned to full participation at 3-months. This article highlights a case of avulsion of the dhRF due to a hyperextension injury of the hip following arthroscopic resection of subspinal impingement, a previously unreported complication. Resection of soft and bone from the AIIS may weaken the insertion of the dhRF. Care should be taken during post-operative rehabilitation to avoid trauma and excessive forces on the dhRF tendon, which may lead to rupture. Rehabilitation should be focused on range of motion of the hip. PMID:27026819

  18. Muscle imaging in muscle dystrophies produced by mutations in the EMD and LMNA genes.

    PubMed

    Díaz-Manera, Jordi; Alejaldre, Aida; González, Laura; Olivé, Montse; Gómez-Andrés, David; Muelas, Nuria; Vílchez, Juan José; Llauger, Jaume; Carbonell, Pilar; Márquez-Infante, Celedonio; Fernández-Torrón, Roberto; Poza, Juan José; López de Munáin, Adolfo; González-Quereda, Lidia; Mirabet, Sonia; Clarimon, Jordi; Gallano, Pía; Rojas-García, Ricard; Gallardo, Eduard; Illa, Isabel

    2016-01-01

    Identifying the mutated gene that produces a particular muscle dystrophy is difficult because different genotypes may share a phenotype and vice versa. Muscle MRI is a useful tool to recognize patterns of muscle involvement in patients with muscle dystrophies and to guide the diagnosis process. The radiologic pattern of muscle involvement in patients with mutations in the EMD and LMNA genes has not been completely established. Our objective is to describe the pattern of muscle fatty infiltration in patients with mutations in the EMD and in the LMNA genes and to search for differences between the two genotypes that could be helpful to guide the genetic tests. We conducted a national multicenter study in 42 patients, 10 with mutations in the EMD gene and 32 with mutations in the LMNA gene. MRI or CT was used to study the muscles from trunk to legs. Patients had a similar pattern of fatty infiltration regardless of whether they had the mutation in the EMD or LMNA gene. The main muscles involved were the paravertebral, glutei, quadriceps, biceps, semitendinosus, semimembranosus, adductor major, soleus, and gastrocnemius. Involvement of peroneus muscle, which was more frequently affected in patients with mutations in the EMD gene, was useful to differentiate between the two genotypes. Muscle MRI/CT identifies a similar pattern of muscle fatty infiltration in patients with mutations in the EMD or the LMNA genes. The involvement of peroneus muscles could be useful to conduct genetic analysis in patients with an EDMD phenotype. PMID:26573435

  19. Influence of exercise intensity on atrophied quadriceps muscle in the rat.

    PubMed

    Tanaka, Shoji; Obatake, Taishi; Hoshino, Koichi; Nakagawa, Takao

    2015-11-01

    [Purpose] The aim of this study was to determine the effect of resistance training on atrophied skeletal muscle in rats based on evidence derived from physical therapy. [Subjects and Methods] Rats were forced to undergo squats as resistance training for 3 weeks after atrophying the rectus femoris muscle by hindlimb suspension for 2 weeks. The intensity of resistance training was adjusted to 50% and 70% of the maximum lifted weight, i.e., 50% of the one-repetition maximum and 70% of the one-repetition maximum, respectively. [Results] Three weeks of training did not alter the one-repetition maximum, and muscle fibers were injured while measuring the one-repetition maximum and reloading. The decrease in cross-sectional area in the rectus femoris muscle induced by unloading for 2 weeks was significantly recovered after training at 70% of the one-repetition maximum. The levels of muscle RING-finger protein-1 mRNA expression were significantly lower in muscles trained at 70% of the one-repetition maximum than in untrained muscles. [Conclusion] These results suggest that high-intensity resistance training can promote atrophic muscle recovery, which provides a scientific basis for therapeutic exercise methods for treatment of atrophic muscle in physical therapy. PMID:26696716

  20. Influence of exercise intensity on atrophied quadriceps muscle in the rat

    PubMed Central

    Tanaka, Shoji; Obatake, Taishi; Hoshino, Koichi; Nakagawa, Takao

    2015-01-01

    [Purpose] The aim of this study was to determine the effect of resistance training on atrophied skeletal muscle in rats based on evidence derived from physical therapy. [Subjects and Methods] Rats were forced to undergo squats as resistance training for 3 weeks after atrophying the rectus femoris muscle by hindlimb suspension for 2 weeks. The intensity of resistance training was adjusted to 50% and 70% of the maximum lifted weight, i.e., 50% of the one-repetition maximum and 70% of the one-repetition maximum, respectively. [Results] Three weeks of training did not alter the one-repetition maximum, and muscle fibers were injured while measuring the one-repetition maximum and reloading. The decrease in cross-sectional area in the rectus femoris muscle induced by unloading for 2 weeks was significantly recovered after training at 70% of the one-repetition maximum. The levels of muscle RING-finger protein-1 mRNA expression were significantly lower in muscles trained at 70% of the one-repetition maximum than in untrained muscles. [Conclusion] These results suggest that high-intensity resistance training can promote atrophic muscle recovery, which provides a scientific basis for therapeutic exercise methods for treatment of atrophic muscle in physical therapy. PMID:26696716

  1. Expression of Dihydropyridine and Ryanodine Receptors in Type IIA Fibers of Rat Skeletal Muscle

    PubMed Central

    Anttila, Katja; Mänttäri, Satu; Järvilehto, Matti

    2007-01-01

    In this study, the fiber type specificity of dihydropyridine receptors (DHPRs) and ryanodine receptors (RyRs) in different rat limb muscles was investigated. Western blot and histochemical analyses provided for the first time evidence that the expression of both receptors correlates to a specific myosin heavy chain (MHC) composition. We observed a significant (p=0.01) correlation between DHP as well as Ry receptor density and the expression of MHC IIa (correlation factor r=0.674 and r=0.645, respectively) in one slow-twitch, postural muscle (m. soleus), one mixed, fast-twitch muscle (m. gastrocnemius) and two fast-twitch muscles (m. rectus femoris, m. extensor digitorum longus). The highest DHP and Ry receptor density was found in the white part of m. rectus femoris (0.058±0.0060 and 0.057±0.0158 ODu, respectively). As expected, the highest relative percentage of MHC IIa was also found in the white part of m. rectus femoris (70.0±7.77%). Furthermore, histochemical experiments revealed that the IIA fibers stained most strongly for the fluorophore-conjugated receptor blockers. Our data clearly suggest that the expression of DHPRs and RyRs follows a fiber type-specific pattern, indicating an important role for these proteins in the maintenance of an effective Ca2+ cycle in the fast contracting fiber type IIA. PMID:17576431

  2. [Effects of surgery on muscles on clinical and radiographic findings in the hip joint region in cerebral palsy patients].

    PubMed

    Schejbalová, A; Havlas, V

    2008-10-01

    PURPOSE OF THE STUDY Isolated or combined surgical procedures on muscles around the hip joint are currently indicated by many authors. In cerebral palsy patients they are regarded as essential intervention. MATERIAL In the years 2005-2007, surgery in the hip joint region was essential for 150 children between 3 and 18 years of age. At the time of surgery, the patients' locomotion ranged from stage 1 to stage 7 of the Vojta system. METHODS The outcome was evaluated by clinical and radiographic examination at 2 and 6 months post-operatively and hip migration percentage and Wiberg's CE angle were measured. RESULTS The best clinical and radiographic outcomes were achieved in children younger than 6 years of age. On the other hand, isolated transfer of the distal rectus femoris muscle significantly affected pelvis anteflexion in adolescent patients. The most marked decrease in migration percentage was found after adductor tenotomy combined with surgery on the iliopsoas muscle (55.6 %) or when the two procedures were combined with distal rectus femoris transfer. DISCUSSION Combined surigical procedures, i.e., adductor tenotomy, surgery on the iliopsoas muscle or rectus femoris muscle and medial hamstrings, with fixation using an abduction modified Atlanta brace, are effective in patients with marked lateral hip migration who are younger that 6 years. Isolated adductor tenotomy and distal transfer of the rectus femoris muscle markedly improve standing position in walking patients. CONCLUSION An appropriate combination of surgical procedures on muscles in the hip region and on medial hamstrings can significantly improve the patient's locomotion and, if lateral migration is present, help to avoid surgery on bones. PMID:19026189

  3. Revised cosmological parameters after BICEP 2 and BOSS

    SciTech Connect

    Das, Santanu; Mukherjee, Suvodip; Souradeep, Tarun E-mail: suvodip@iucaa.ernet.in

    2015-02-01

    Estimation of parameters of the 'standard' model of cosmology have dramatically improved over past few decades due to increasingly exquisite measurements made by Cosmic Microwave Background (CMB) experiments. Recent data from Planck matches well with the minimal ΛCDM model. A likelihood analysis using Planck, WMAP and a selection of high resolution experiments (highL), tensor to scalar ratio r{sub 0.002} is found to be <0.11 when dn{sub s}/dln k = 0. Planck also imposes an upper bound on neutrino mass ∑ m{sub ν}<0.23 eV using Planck + WMAP + highL + BAO likelihood. However, recently results from BICEP 2 claims the detection of r= 0.2{sup +0.07}{sub −0.05} from polarization spectra. Further, results from SDSS-III BOSS large scale galaxy survey constrains the total neutrino mass to ∑ m{sub ν}=0.36 ± 0.10 eV . It is important to study the consequences of these new measurements on other cosmological parameters. In this paper we assess the revised constraints on cosmological parameters in light of these two measurements that are in some tension with the constraints from Planck. The sensitivity of Planck to weak lensing effect on the CMB angular power spectrum suggests that the normalized amplitude of physical lensing power A{sub L} > 1 at 2σ hints at a potentially important internal inconsistency. Therefore, we also include a study of the constraints on A{sub L}. Using the prior on ∑ m{sub ν} as measured by SDSS-III BOSS and BICEP 2 likelihood, we find that the model with running spectral index (dn{sub s}/dln k ≠ 0) leads to a value of A{sub L}>1 at 3.1 σ. But, the model with dn{sub s}/dln k =0 makes A{sub L} consistent with 1, at 2.1σ and also shows that N{sub eff} is consistent with its theoretical value of 3.046 at around 2σ. Therefore, the analysis in this paper shows that the model with dn{sub s}/dln k =0 gives consistency with other cosmological parameters (N{sub eff} and A{sub L} ) when the current limits on ∑ m{sub

  4. Axion cold dark matter: Status after Planck and BICEP2

    NASA Astrophysics Data System (ADS)

    Di Valentino, Eleonora; Giusarma, Elena; Lattanzi, Massimiliano; Melchiorri, Alessandro; Mena, Olga

    2014-08-01

    We investigate the axion dark matter scenario (ADM), in which axions account for all of the dark matter in the Universe, in light of the most recent cosmological data. In particular, we use the Planck temperature data, complemented by WMAP E-polarization measurements, as well as the recent BICEP2 observations of B-modes. Baryon acoustic oscillation data, including those from the baryon oscillation spectroscopic survey, are also considered in the numerical analyses. We find that, in the minimal ADM scenario and for ΛQCD=200 MeV, the full data set implies that the axion mass ma=82.2±1.1 μeV [corresponding to the Peccei-Quinn symmetry being broken at a scale fa=(7.54±0.10)×1010 GeV], or ma=76.6±2.6 μeV [fa=(8.08±0.27)×1010 GeV] when we allow for a nonstandard effective number of relativistic species Neff. We also find a 2σ preference for Neff>3.046. The limit on the sum of neutrino masses is ∑mν<0.25 eV at 95% C.L. for Neff=3.046, or ∑mν<0.47 eV when Neff is a free parameter. Considering extended scenarios where either the dark energy equation-of-state parameter w, the tensor spectral index nt, or the running of the scalar index dns/dlnk is allowed to vary does not change significantly the axion mass-energy density constraints. However, in the case of the full data set exploited here, there is a preference for a nonzero tensor index or scalar running, driven by the different tensor amplitudes implied by the Planck and BICEP2 observations. We also study the effect on our estimates of theoretical uncertainties, in particular the imprecise knowledge of the QCD scale ΛQCD, in the calculation of the temperature-dependent axion mass. We find that in the simplest ADM scenario the Planck +WP data set implies that the axion mass ma=63.7±1.2 μeV for ΛQCD=400 MeV. We also comment on the possibility that axions do not make up for all the dark matter, or that the contribution of string-produced axions has been grossly underestimated; in that case, the values

  5. Probing nuclear rates with Planck and BICEP2

    NASA Astrophysics Data System (ADS)

    Di Valentino, Eleonora; Gustavino, Carlo; Lesgourgues, Julien; Mangano, Gianpiero; Melchiorri, Alessandro; Miele, Gennaro; Pisanti, Ofelia

    2014-07-01

    Big-bang nucleosynthesis (BBN) relates key cosmological parameters to the primordial abundance of light elements. In this paper, we point out that the recent observations of cosmic microwave background anisotropies by the Planck satellite and by the BICEP2 experiment constrain these parameters with such a high level of accuracy that the primordial deuterium abundance can be inferred with remarkable precision. For a given cosmological model, one can obtain independent information on nuclear processes in the energy range relevant for BBN, which determine the eventual H2/H yield. In particular, assuming the standard cosmological model, we show that a combined analysis of Planck data and of recent deuterium abundance measurements in metal-poor damped Lyman-alpha systems provides independent information on the cross section of the radiative capture reaction d(p ,γ)He3 converting deuterium into helium. Interestingly, the result is higher than the values suggested by a fit of present experimental data in the BBN energy range (10-300 keV), whereas it is in better agreement with ab initio theoretical calculations, based on models for the nuclear electromagnetic current derived from realistic interactions. Due to the correlation between the rate of the above nuclear process and the effective number of neutrinos Neff, the same analysis points out a Neff>3 as well. We show how this observation changes when assuming a nonminimal cosmological scenario. We conclude that further data on the d(p ,γ)He3 cross section in the few hundred keV range, which can be collected by experiments like LUNA, may either confirm the low value of this rate, or rather give some hint in favor of next-to-minimal cosmological scenarios.

  6. Open Versus Arthroscopic Biceps Tenodesis: A Comparison of Functional Outcomes

    PubMed Central

    Duchman, Kyle R; DeMik, David E.; Uribe, Bastian; Wolf, Brian R; Bollier, Matthew

    2016-01-01

    Background The proximal aspect of the long head of the biceps brachii (LHB) is a frequent source of anterior shoulder pain. Multiple techniques for LHB tenodesis have been described. However, comparative outcomes are lacking. The present study aims to compare functional results, patient reported outcomes, complications, and clinical failures for patients undergoing open versus arthroscopic LHB tenodesis. Methods All patients who underwent open or arthroscopic LHB tenodesis from 2009-2012 at a single institution were identified. Patient demographics, comorbidities, and operative variables of interest, including concomitant procedures, were recorded. Minimum 1-year follow-up was required for inclusion. Outcomes, including patient reported outcomes, physical exam findings, and complications were compared between open and arthroscopic LHB tenodesis patients. Results Overall, 45 patients (25 open, 20 arthroscopic) were available for analysis. In total, there was a single clinical failure in a patient who underwent arthroscopic LHB tenodesis. No other complications or failures were noted. Active shoulder forward elevation was increased in the open tenodesis group as compared to the arthroscopic tenodesis group (177.8 ± 9.3° vs. 171.3 ± 11.7°; p = 0.049). Otherwise, there was no difference in range of motion or strength. For both groups, both the SF-36 and ASES scores improved significantly from preoperative values. Conclusion Both open and arthroscopic LHB tenodesis provide good to excellent outcomes with few complications. Given the recent increased utilization of LHB tenodesis, future studies should use randomization and prospective data collection in order to determine if discrete patient populations are better served by either open or arthroscopic LHB tenodesis techniques PMID:27528841

  7. Short-term effects of integrated motor imagery practice on muscle activation and force performance.

    PubMed

    Di Rienzo, F; Blache, Y; Kanthack, T F D; Monteil, K; Collet, C; Guillot, A

    2015-10-01

    The effect of motor imagery (MI) practice on isometric force development is well-documented. However, whether practicing MI during rest periods of physical training improves the forthcoming performance remains unexplored. We involved 18 athletes in a counterbalanced design including three physical training sessions scheduled over five consecutive days. Training involved 10 maximal isometric contractions against a force plate, with the elbow at 90°. During two sessions, we integrated MI practice (focusing on either muscle activation or relaxation) during the inter-trial rest periods. We measured muscle performance from force plate and electromyograms of the biceps brachii and anterior deltoideus. We continuously monitored electrodermal activity (EDA) to control sympathetic nervous system activity. MI of muscle activation resulted in higher isometric force as compared to both MI of muscle relaxation and passive recovery (respectively +2.1% and +3.5%). MI practice of muscle relaxation also outperformed the control condition (+1.9%). Increased activation of the biceps brachii was recorded under both MI practice conditions compared to control. Biceps brachii activation was similar between the two MI practice conditions, but electromyography revealed a marginal trend toward greater activation of the anterior deltoideus during MI practice of muscle activation. EDA and self-reports indicated that these effects were independent from physiological arousal and motivation. These results might account for priming effects of MI practice yielding to higher muscle activation and force performance. Present findings may be of interest for applications in sports training and neurologic rehabilitation. PMID:26241339

  8. Mathematical modeling of the human knee joint

    SciTech Connect

    Ricafort, Juliet

    1996-05-01

    A model was developed to determine the forces exerted by several flexor and extensor muscles of the human knee under static conditions. The following muscles were studied: the gastrocnemius, biceps femoris, semitendinosus, semimembranosus, and the set of quadricep muscles. The tibia and fibula were each modeled as rigid bodies; muscles were modeled by their functional lines of action in space. Assumptions based on previous data were used to resolve the indeterminacy.

  9. Relation between systemic inflammatory markers, peripheral muscle mass, and strength in limb muscles in stable COPD patients

    PubMed Central

    Ferrari, Renata; Caram, Laura MO; Faganello, Marcia M; Sanchez, Fernanda F; Tanni, Suzana E; Godoy, Irma

    2015-01-01

    The aim of this study was to investigate the association between systemic inflammatory mediators and peripheral muscle mass and strength in COPD patients. Fifty-five patients (69% male; age: 64±9 years) with mild/very severe COPD (defined as forced expiratory volume in the first second [FEV1] =54%±23%) were evaluated. We evaluated serum concentrations of IL-8, CRP, and TNF-α. Peripheral muscle mass was evaluated by computerized tomography (CT); midthigh cross-sectional muscle area (MTCSA) and midarm cross-sectional muscle area (MACSA) were obtained. Quadriceps, triceps, and biceps strength were assessed through the determination of the one-repetition maximum. The multiple regression results, adjusted for age, sex, and FEV1%, showed positive significant association between MTCSA and leg extension (0.35 [0.16, 0.55]; P=0.001), between MACSA and triceps pulley (0.45 [0.31, 0.58]; P=0.001), and between MACSA and biceps curl (0.34 [0.22, 0.47]; P=0.001). Plasma TNF-α was negatively associated with leg extension (−3.09 [−5.99, −0.18]; P=0.04) and triceps pulley (−1.31 [−2.35, −0.28]; P=0.01), while plasma CRP presented negative association with biceps curl (−0.06 [−0.11, −0.01]; P=0.02). Our results showed negative association between peripheral muscle mass (evaluated by CT) and muscle strength and that systemic inflammation has a negative influence in the strength of specific groups of muscles in individuals with stable COPD. This is the first study showing association between systemic inflammatory markers and strength in upper limb muscles. PMID:26345641

  10. Progressive Muscle Atrophy and Weakness After Treatment by Mantle Field Radiotherapy in Hodgkin Lymphoma Survivors

    SciTech Connect

    Leeuwen-Segarceanu, Elena M. van; Dorresteijn, Lucille D.A.; Pillen, Sigrid; Biesma, Douwe H.; Vogels, Oscar J.M.; Alfen, Nens van

    2012-02-01

    Purpose: To describe the damage to the muscles and propose a pathophysiologic mechanism for muscle atrophy and weakness after mantle field radiotherapy in Hodgkin lymphoma (HL) survivors. Methods and Materials: We examined 12 patients treated by mantle field radiotherapy between 1969 and 1998. Besides evaluation of their symptoms, the following tests were performed: dynamometry; ultrasound of the sternocleidomastoid, biceps, and antebrachial flexor muscles; and needle electromyography of the neck, deltoid, and ultrasonographically affected arm muscles. Results: Ten patients (83%) experienced neck complaints, mostly pain and muscle weakness. On clinical examination, neck flexors were more often affected than neck extensors. On ultrasound, the sternocleidomastoid was severely atrophic in 8 patients, but abnormal echo intensity was seen in only 3 patients. Electromyography of the neck muscles showed mostly myogenic changes, whereas the deltoid, biceps, and antebrachial flexor muscles seemed to have mostly neurogenic damage. Conclusions: Many patients previously treated by mantle field radiotherapy develop severe atrophy and weakness of the neck muscles. Neck muscles within the radiation field show mostly myogenic damage, and muscles outside the mantle field show mostly neurogenic damage. The discrepancy between echo intensity and atrophy suggests that muscle damage is most likely caused by an extrinsic factor such as progressive microvascular fibrosis. This is also presumed to cause damage to nerves within the radiated field, resulting in neurogenic damage of the deltoid and arm muscles.

  11. LATERAL PAIN IN AN ATHLETE'S KNEE: A RARE CASE OF DISLOCATION OF THE FEMORAL BICEPS TENDON

    PubMed Central

    Duarte, Aires; Severino, Nilson; da Silva, Ana Paula Simões; de Lima, Marcos Vaz; Resende, Vanessa Ribeiro; Kertzman, Paulo F.

    2015-01-01

    Dislocation of the femoral biceps tendon is rare and is described clinically in the literature as a lateral pain in the knee. It was initially reported as an anomalous insertion of the long head of the femoral biceps. Subsequently, it was found to be caused by abnormal mobility of the tendon over the prominence of the fibular head at certain angles of knee flexion. The objective of the present report was to describe and discuss a condition of lateral knee pain in a swimmer who started to present subluxation of the femoral biceps during sports practice, which incapacitated him from taking part in trials and competitions. The case is discussed in the light of the literature surveyed; the likelihood that the etiology for the trauma leading to this condition was repetition; and the surgical treatment instituted, which led to excellent results and the patient's return to his habitual sports practice. PMID:27047902

  12. Nonoperative Treatment of Distal Biceps Brachii Musculotendinous Partial Rupture: A Report of Two Cases

    PubMed Central

    López-Zabala, I.; Fernández-Valencia, J. A.

    2013-01-01

    Musculotendinous ruptures of the distal biceps brachii are extremely rare injuries whose clinical presentation is similar to distal biceps avulsion. We describe two cases of patients who suffered a distal biceps brachii musculotendinous partial rupture. The first patient was playing soccer as goalkeeper and experienced sudden pain while throwing the ball overhead with his left arm. The second patient experienced sudden pain while weightlifting with his right arm. The mechanism of injury was the same in the two cases, as both involved glenohumeral elevation with elbow extension and forearm supination. Neither of these two patients underwent surgical repair or rehabilitation, and both had perfect scores of 100 on the Mayo Clinic Performance Index for the Elbow at one-year followup. PMID:23956903

  13. Can self-ordering scalar fields explain the BICEP2 B-mode signal?

    SciTech Connect

    Durrer, Ruth; Figueroa, Daniel G.; Kunz, Martin E-mail: daniel.figueroa@unige.ch

    2014-08-01

    We show that self-ordering scalar fields (SOSF), i.e. non-topological cosmic defects arising after a global phase transition, cannot explain the B-mode signal recently announced by BICEP2. We compute the full C{sub ℓ}{sup B} angular power spectrum of B-modes due to vector and tensor perturbations of SOSF, modeled in the large N limit of a spontaneously broken global O(N) symmetry. We conclude that the low ℓ multipoles detected by BICEP2 cannot be due mainly to SOSF, since they have the wrong spectrum at low multipoles. As a byproduct we derive the first cosmological constraints on this model, showing that the BICEP2 B-mode polarization data admits at most a 2-3% contribution from SOSF in the temperature anisotropies, similar to (but somewhat tighter than) the recently studied case of cosmic strings.

  14. Surgical management of acute distal biceps tendon rupture associated with contralateral radial palsy

    PubMed Central

    Ennaciri, Badr; Beaudouin, Emmanuel; Mahfoud, Mustapha; Berrada, Mohamed Saleh; Montbarbon, Eric

    2015-01-01

    Acute distal biceps tendon rupture constitute a rare lesion of biceps injuries, typically, easy to diagnosis after lifting a heavy object. Treatment is controversial, nonoperative for sedentary and elderly patients; surgical for young and active individuals. Many operative techniques are described, they all aim to restore an excellent strength of flexion and supination. We opted for one-incision method and fixation using trans-osseous anchoring for our patient, because we are convinced that is a simpler and safer technique. Postoperative rehabilitation, after a period of elbow immobilization, must be operated for returning to full activity. Biceps tendon repair has permitted to our patient who suffer from right upper limb handicap due to radial nerve palsy, recuperating the lost strength and force in his dominant limb and maintaining some quality of life. PMID:26958121

  15. The biomechanics of running in athletes with previous hamstring injury: A case-control study.

    PubMed

    Daly, C; McCarthy Persson, U; Twycross-Lewis, R; Woledge, R C; Morrissey, D

    2016-04-01

    Hamstring injury is prevalent with persistently high reinjury rates. We aim to inform hamstring rehabilitation by exploring the electromyographic and kinematic characteristics of running in athletes with previous hamstring injury. Nine elite male Gaelic games athletes who had returned to sport after hamstring injury and eight closely matched controls sprinted while lower limb kinematics and muscle activity of the previously injured biceps femoris, bilateral gluteus maximus, lumbar erector spinae, rectus femoris, and external oblique were recorded. Intergroup comparisons of muscle activation ratios and kinematics were performed. Previously injured athletes demonstrated significantly reduced biceps femoris muscle activation ratios with respect to ipsilateral gluteus maximus (maximum difference -12.5%, P = 0.03), ipsilateral erector spinae (maximum difference -12.5%, P = 0.01), ipsilateral external oblique (maximum difference -23%, P = 0.01), and contralateral rectus femoris (maximum difference -22%, P = 0.02) in the late swing phase. We also detected sagittal asymmetry in hip flexion (maximum 8°, P = 0.01), pelvic tilt (maximum 4°, P = 0.02), and medial rotation of the knee (maximum 6°, P = 0.03) effectively putting the hamstrings in a lengthened position just before heel strike. Previous hamstring injury is associated with altered biceps femoris associated muscle activity and potentially injurious kinematics. These deficits should be considered and addressed during rehabilitation. PMID:25913546

  16. BICEP2 and SPUD: Searching for Inflation with Degree-Scale Polarimetry from the South Pole

    NASA Astrophysics Data System (ADS)

    Kovac, John; BICEP/SPUD Collaboration

    2006-12-01

    Inflation predicts a cosmic gravitational-wave background (CGB), the amplitude of which measures the Inflationary energy scale. The CGB in turn produces a faint but unique signature in the 'B-mode' polarization of the CMB at angular scales between 4 and 2 degrees. The simplest models of Inflation predict the CGB at levels r 0.01 to 0.1. At these levels, the Inflationary B-mode signal should be within experimental reach, leading the 2005 Task Force on CMB Research to identify this search as the number one priority for the field. BICEP, the first CMB polarimeter specifically designed for this search, began operating at South Pole Station in early 2006. BICEP is mapping 2% of the sky that is uniquely free of Galactic confusion with angular resolution of 0.9 deg (100 GHz) and 0.6 deg (150 GHz), and should reach sensitivity to r < 0.1 during 2008. A coordinated series of upgrades will retain the compact, cryogenic optical design which has been key to BICEP's success and efficiency, while providing the increased sensitivity and more exacting control of instrumental effects and confusion from Galactic foregrounds necessary to search more deeply. A powerful new 150 GHz receiver, BICEP2, is planned to replace BICEP1 in 2009, exploiting newly available antenna-coupled TES detector arrays to achieve 9 times higher mapping speed. In 2010, the first of a series of compact, mechanically-cooled receivers, SPUD1, will be ready for deployment on the DASI mount, providing similar speed at 100 GHz in parallel with BICEP2. In two seasons of operation, these receivers provide the sensitivity to detect r > 0.02 with 95% confidence, characterize the Galactic foregrounds in the cleanest field on the sky, and prepare for a yet more sensitive search for the CGB from South Pole with 6 SPUD-like telescopes deployed simultaneously on the DASI mount.

  17. Natural inflation: consistency with cosmic microwave background observations of Planck and BICEP2

    NASA Astrophysics Data System (ADS)

    Freese, Katherine; Kinney, William H.

    2015-03-01

    Natural inflation is a good fit to all cosmic microwave background (CMB) data and may be the correct description of an early inflationary expansion of the Universe. The large angular scale CMB polarization experiment BICEP2 has announced a major discovery, which can be explained as the gravitational wave signature of inflation, at a level that matches predictions by natural inflation models. The natural inflation (NI) potential is theoretically exceptionally well motivated in that it is naturally flat due to shift symmetries, and in the simplest version takes the form V(phi) = Λ4 [1 ± cos(Nphi/f)]. A tensor-to-scalar ratio r > 0.1 as seen by BICEP2 requires the height of any inflationary potential to be comparable to the scale of grand unification and the width to be comparable to the Planck scale. The Cosine Natural Inflation model agrees with all cosmic microwave background measurements as long as f >= mPl (where mPl = 1.22 × 1019 GeV) and Λ ~ mGUT ~ 1016 GeV. This paper also discusses other variants of the natural inflation scenario: we show that axion monodromy with potential Vpropto phi2/3 is inconsistent with the BICEP2 limits at the 95% confidence level, and low-scale inflation is strongly ruled out. Linear potentials V propto phi are inconsistent with the BICEP2 limit at the 95% confidence level, but are marginally consistent with a joint Planck/BICEP2 limit at 95%. We discuss the pseudo-Nambu Goldstone model proposed by Kinney and Mahanthappa as a concrete realization of low-scale inflation. While the low-scale limit of the model is inconsistent with the data, the large-field limit of the model is marginally consistent with BICEP2. All of the models considered predict negligible running of the scalar spectral index, and would be ruled out by a detection of running.

  18. Arthroscopic tenodesis through positioning portals to treat proximal lesions of the biceps tendon.

    PubMed

    Shen, Ji; Gao, Qing-feng; Zhang, Yao; He, Yao-hua

    2014-12-01

    Arthroscopic biceps tenodesis is a good choice for treating proximal lesions of the biceps tendon. However, there are few descriptions of the surgical approach. We introduce a technique for proximal biceps tenodesis using positioning portals and placing suture anchors. Our patients had a minimum of 12 months of follow-up. Between January 2010 and June 2012, a total of 49 patients (21 men, 28 women) underwent arthroscopic biceps tenodesis. The pathology was mainly associated with proximal lesions of the biceps tendon, with the diagnosis confirmed in all patients. Patients were evaluated preoperatively and then up to and including the final follow-up. Their pain and conditions were assessed using the Constant, American Shoulder and Elbow Surgeons (ASES), and University of California at Los Angeles (UCLA) scores for pain; range of active forward flexion; and active range of motion. All data were analyzed statistically. All patients were operated on successfully. They achieved good healing during the follow-up (mean 14 months; range 12-34 months). Before surgery the ASES, Constant, and UCLA scores were 17.0, 39.4, and 15.4, respectively. After surgery they were 33.6, 89.1, and 31.2, respectively. The scores had significantly improved: ASES scores from 17.0 to 33.6 (P < 0.05); Constant scores from 39.4 to 89.1 (P < 0.05); UCLA scores from 15.4 to 31.2 (P < 0.05). Arthroscopic tenodesis through positioning portals to treat proximal lesions of the biceps tendon produces satisfactory clinical outcomes. This technique is convenient and safe. PMID:25239022

  19. Prospective Randomized Study of Arthroscopic Proximal vs Open Subpectoral Biceps Tenodesis

    PubMed Central

    Gobezie, Reuben; Shishani, Yousef; Flocken, Janice

    2016-01-01

    Objectives: The biceps tendon is recognized as a significant source of pain in the shoulder for many patients. Operative techniques for tenodesis of the biceps tendon vary widely. No studies have been conducted directly comparing arthroscopic proximal vs. open subpectoral biceps tenodesis using a prospective study. We aim to compare the functional outcomes, pain relief, and complications of proximal vs. subpectoral biceps tenodesis. Methods: A prospective randomized study of 129 consecutive patients requiring biceps tenodesis for treatment of biceps tendon tears, biceps instability or superior labral tears was performed. Clinical outcome measures used to conduct the study included active range of motion, VAS pain score, ASES score and SANE scores. Complications and revisions were also documented. Results: Mean follow-up was 13.2 months (12-24 months) with 50 subpectoral tenodesis and 46 proximal tenodesis patients reaching minimum follow-up of 12 months. In the subpectoral group, the VAS improved from 5.7 to 2.0 (p < 0.001), ASES score improved from 49.8 to 77.7 (p< 0.001), and SANE scores improved from 42.1% to 77.7% (p<0.001). In the arthroscopic proximal tenodesis group, the VAS pain score improved from 5.9 to 1.8 (p<0.001), ASES score improved from 52.0 to 82.5 (p<0.001), and SANE scores improved from 42.8% to 78.6% (p<0.001). The revision rate for the subpectoral group was 4% (2/50 patients). The revision rate for the arthroscopic proximal tenodesis group was 8.6% (4/46). Twelve patients had persistent tenderness over the bicipital groove: 7 following proximal tenodesis and 5 following subpectoral tenodesis. No significant difference was found between methods in any outcome measures evaluated. Conclusion: This study found no difference in the functional outcomes or pain relief between proximal vs subpectoral biceps tenodesis. However, revision rates and occurrence of post-operative persistent bicipital groove pain for arthroscopic proximal tenodesis with

  20. Biceps Tenotomy Versus Tenodesis in Active Patients Younger Than 55 Years

    PubMed Central

    Friedman, Jamie L.; FitzPatrick, Jennifer L.; Rylander, Lucas S.; Bennett, Christine; Vidal, Armando F.; McCarty, Eric C.

    2015-01-01

    Background: Proximal biceps pathology is a significant factor in shoulder pain. Surgical treatment options include biceps tenotomy and subpectoral biceps tenodesis. Tenotomy is a simple procedure, but it may produce visible deformity, subjective cramping, or loss of supination strength. Tenodesis is a comparatively technical procedure involving a longer recovery, but it has been hypothesized to achieve better outcomes in younger active patients (<55 years). Hypothesis: This study investigated the outcomes of younger patients who underwent either a biceps tenotomy or tenodesis as part of treatment for shoulder pain. The hypothesis was that, apart from cosmetic deformity, there will be no difference in outcome between the 2 treatment options. Study Design: Cohort study; Level of evidence, 3. Methods: Isometric strength and endurance testing of operative and nonoperative shoulders for forearm supination (FS) and elbow flexion (EF) were tested utilizing an isometric dynamometer. Objective physical assessment was also performed. Subjective outcomes using the modified American Shoulder and Elbow Surgeons score (ASES); Disability of the Arm, Shoulder, and Hand (DASH); visual analog scale (VAS); and perceived biceps symptoms were collected. Results: A total of 42 patients (22 tenotomy, 20 tenodesis) with an average follow-up of 3.3 years were studied. The average age at follow-up was 49.9 years. Thirty-five percent (7/20) of tenotomy patients exhibited a “Popeye” deformity, compared with 18.2% (4/22) of tenodesis patients. Strength prior to fatiguing exercise was similar between tenodesis and tenotomy for FS (6.9 vs 7.3 lbs; P < .05), EF in neutral (35.4 vs 35.4 lbs), and EF in supination (33.8 vs 34.2 lbs). Strength was not significantly different between groups for isometric strength and endurance measures. Subjective functional outcome measured by the DASH, ASES, and VAS scores were similar between groups. Frequency of complaints of cramping was higher in the

  1. Fundamental study of lower limb muscle activity using an angled whole body vibration exercise instrument.

    PubMed

    Yu, Chang Ho; Kang, Seung Rok; Kwon, Tae Kyu

    2014-01-01

    This research was performed to assess the effects of angled whole body vibration on muscle activity of the lower limbs, by examining adults in their twenties during squat exercises, taking into account two variables of exercise intensity (vibration frequency and gradient). Twenty healthy males in their twenties with previous experience of more than 6 month's weight training and no past medical history were included in this study. The experiment was performed by participating in squat exercises which consisted of 3 sets (1 set = 5 seconds x 3 repetitions of exercise), and the muscle activities of the Rectus Femoris, Vastus Lateralis, Vastus Medialis were measured with variation in the gradients of 0°, 10°, and 20°, and vibration frequencies of 20, 30, and 40 Hz. At 30 and 40 Hz, the vastus lateralis showed the highest change in muscle activity, while activity of the vastus medialis also increased significantly. Analysis of muscle activity according to the gradient showed a significant increase of the vastus lateralis at 20°, while the highest muscle activity at 20° was observed for the vastus medialis. In comparison of the change in lower limb muscle activity according to simultaneous stimulation, at a gradient of 10°, high activity was shown in muscle, while at 20°, high muscle activities were produced at 40 Hz in the vastus lateralis, 40 Hz in the rectus femoris, and both 30 and 40 Hz in the vastus medialis. PMID:25226944

  2. “ROCAMBOLE-LIKE” BICEPS TENODESIS: TECHNIQUE AND RESULTS

    PubMed Central

    Godinho, Glaydson Gomes; Mesquita, Fabrício Augusto Silva; França, Flávio de Oliveira; Freitas, José Márcio Alves

    2015-01-01

    Objective: To present a new technique for bicipital tenodesis and its results: accomplished partially via arthroscopy and grounded in concepts of the normal and pathological anatomy of the tendon of the biceps long head. It is based on the predisposition of this tendon towards becoming attached to the intertubercular sulcus after rupture or tenotomy (auto-tenodesis). Methods: Evaluations were conducted on 63 patients (63 shoulders), aged from 32 to 77 years (average 55), consisting of 32 females (51%) and 31 males (49%). Thirty-five of the patients (55.6%) were over 60 years of age and 28 patients (44.4%) were under 60 years of age. Eighteen were sports participants (28.6%). Fourteen had injuries associated with the subscapularis (22.2%). The average follow up was 43 months (ranging from 12 to 74 months). The right shoulder accounted for 48 cases (76.2%), of which one was a left-handed individual and 47 were right-handed. The left shoulder accounted for 15 (23%) of the patients, of whom two were left-handed and 13 were right-handed. There were no bilateral occurrences. The statistical analysis were done using SPSS version 18. Pearson's chi-square test and continuity corrections were used to investigate the statistical significance of associations between variables. Associations were taken to be statistically significant when p was less than 0.05. Results: Residual Popeye deformity was perceived by seven patients (11.1%); it was only observed by the examiner in 15 cases (23.8%); and neither the patient nor the examiner observed it in 41 cases (65%). There were no statistically valid influences from age, participation in contact or throwing sports, subscapularis tendon-associated injury or Popeye deformity. Fifty-eight patients (92.06%) were satisfied, two patients were dissatisfied (3.17%) and three patients were indifferent (4.76%). Conclusion: The technique presented high patient satisfaction rates (92.06%) and residual deformity was perceived by 11.1% of the

  3. Muscle function during takeoff and landing flight in the pigeon (Columba livia).

    PubMed

    Robertson, Angela M Berg; Biewener, Andrew A

    2012-12-01

    This study explored the muscle strain and activation patterns of several key flight muscles of the pigeon (Columba livia) during takeoff and landing flight. Using electromyography (EMG) to measure muscle activation, and sonomicrometry to quantify muscle strain, we evaluated the muscle function patterns of the pectoralis, biceps, humerotriceps and scapulotriceps as pigeons flew between two perches. These recordings were analyzed in the context of three-dimensional wing kinematics. To understand the different requirements of takeoff, midflight and landing, we compared the activity and strain of these muscles among the three flight modes. The pectoralis and biceps exhibited greater fascicle strain rates during takeoff than during midflight or landing. However, the triceps muscles did not exhibit notable differences in strain among flight modes. All observed strain, activation and kinematics were consistent with hypothesized muscle functions. The biceps contracted to stabilize and flex the elbow during the downstroke. The humerotriceps contracted to extend the elbow at the upstroke-downstroke transition, followed by scapulotriceps contraction to maintain elbow extension during the downstroke. The scapulotriceps also appeared to contribute to humeral elevation. Greater muscle activation intensity was observed during takeoff, compared with mid-flight and landing, in all muscles except the scapulotriceps. The timing patterns of muscle activation and length change differed among flight modes, yet demonstrated that pigeons do not change the basic mechanical actions of key flight muscles as they shift from flight activities that demand energy production, such as takeoff and midflight, to maneuvers that require absorption of energy, such as landing. Similarly, joint kinematics were consistent among flight modes. The stereotypy of these neuromuscular and joint kinematic patterns is consistent with previously observed stereotypy of wing kinematics relative to the pigeon's body

  4. Morphological and functional relationships with ultrasound measured muscle thickness of the upper extremity and trunk

    PubMed Central

    Loenneke, Jeremy P.; Thiebaud, Robert S.; Loftin, Mark

    2014-01-01

    Unless a subject’s muscle is relatively small, a single image from a standard ultrasound can only measure muscle thickness (MT). Thus, it is important to know whether MT is related to morphological and functional characteristics of individual muscles of the extremity and trunk. In this review, we summarize previously published articles in the upper extremity and trunk demonstrating the relationships between ultrasound-measured MT and muscle morphology (cross-sectional area, CSA and muscle volume, MV) and muscular or respiratory function. The linear relationship between MT and muscle CSA or MV has been observed in biceps brachii, triceps brachii, pectoralis major, psoas major, and supraspinatus muscles. Previous studies suggest that MT in the upper arm and trunk may reflect muscle CSA and MV for the individual muscles. Unfortunately, few studies exist regarding the functional relationship with ultrasound MT in the upper extremity and trunk. Future research is needed to investigate these findings further.

  5. Clinical utility of the Duncan-Ely test for rectus femoris dysfunction during the swing phase of gait.

    PubMed

    Marks, M C; Alexander, J; Sutherland, D H; Chambers, H G

    2003-11-01

    The Ely Test (or Duncan-Ely test) has been accepted as a clinical tool to assess rectus femoris spasticity by passively flexing the knee rapidly while the patient lies prone in a relaxed state. In this retrospective review, patients' dynamic knee range of motion (ROM) during gait and an electromyogram (EMG) were compared with the results of the Ely test. Data for 70 patients (44 males, 26 females; 104 limbs) were included. Mean age of patients was 13 years, SD 9 years, range 4 years 5 months to 54 years. All patients were diagnosed with cerebral palsy (spastic diplegia, n = 42; spastic quadriplegia, n = 15, and hemiplegia, n = 13). All patients were ambulatory (50 independent, 20 with assistive devices). A standard matrix was used to calculate sensitivity and specificity of the Ely test as well as its positive and negative predictive value. For the gait variables examined (decreased dynamic knee ROM, timing of peak knee flexion, and abnormal EMG in swing) the sensitivity of the Ely test ranged from 56 to 59% and the specificity ranged from 64 to 85%. For the same variables the positive predictive value ranged from 91 to 98% and the negative predictive value ranged from 4 to 19%. The Ely test was shown to have a good positive predictive value (i.e. the certainty about the presence of rectus spasticity in patients with a positive Ely test result) for rectus femoris dysfunction during gait. PMID:14580132

  6. CHARACTERIZATION OF THE BICEP TELESCOPE FOR HIGH-PRECISION COSMIC MICROWAVE BACKGROUND POLARIMETRY

    SciTech Connect

    Takahashi, Y. D.; Holzapfel, W. L.; Ade, P. A. R.; Barkats, D.; Bock, J. J.; Chiang, H. C.; Hristov, V. V.; Jones, W. C.; Kovac, J. M.; Lange, A. E.; Mason, P. V.; Matsumura, T.; Battle, J. O.; Dowell, C. D.; Bierman, E. M.; Keating, B. G.; Duband, L.; Hivon, E. F.; Kuo, C. L.; Leitch, E. M.

    2010-03-10

    The Background Imaging of Cosmic Extragalactic Polarization (BICEP) experiment was designed specifically to search for the signature of inflationary gravitational waves in the polarization of the cosmic microwave background (CMB). Using a novel small-aperture refractor and 49 pairs of polarization-sensitive bolometers, BICEP has completed three years of successful observations at the South Pole beginning in 2006 February. To constrain the amplitude of the inflationary B-mode polarization, which is expected to be at least 7 orders of magnitude fainter than the 3 K CMB intensity, precise control of systematic effects is essential. This paper describes the characterization of potential systematic errors for the BICEP experiment, supplementing a companion paper on the initial cosmological results. Using the analysis pipelines for the experiment, we have simulated the impact of systematic errors on the B-mode polarization measurement. Guided by these simulations, we have established benchmarks for the characterization of critical instrumental properties including bolometer relative gains, beam mismatch, polarization orientation, telescope pointing, sidelobes, thermal stability, and timestream noise model. A comparison of the benchmarks with the measured values shows that we have characterized the instrument adequately to ensure that systematic errors do not limit BICEP's two-year results, and identifies which future refinements are likely necessary to probe inflationary B-mode polarization down to levels below a tensor-to-scalar ratio r = 0.1.

  7. Clinical and Sonographic Evaluation of Bicortical Button for Proximal Biceps Tenodesis.

    PubMed

    Meadows, James R; Diesselhorst, Matthew M; Finnoff, Jonathan T; Swanson, Britta L; Swanson, Kyle E

    2016-01-01

    Use of a cortical button for proximal biceps tenodesis has demonstrated strength comparable to that of other types of fixation in biomechanical models, but few studies have evaluated the clinical outcome of such fixation. In the study reported here, 18 patients who underwent open subpectoral biceps tenodesis with a bicortical button were assessed, at minimum 12-month follow-up, with the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire, a pain scale, physical examination, biceps supination strength testing, and ultrasonographic evaluation (to determine tenodesis integrity and proximity of the button to the axillary nerve). No patient had symptoms of axillary nerve damage, clinical deformity, or tenodesis failure. Mean DASH score was 15.15 (scale range: 0, none to 100, extreme difficulty), and mean pain score was 12.6 (scale range: 0, none to 100, worst pain). Seventy-eight percent of patients had no bicipital groove tenderness, 89% had full elbow range of motion, and 94% had full shoulder range of motion. Mean forearm supination strength of the operated arm (125.04 lb) was significantly (P = .01) less than that of the nonoperated arm (134.39 lb). Mean (SD) distance from button to posterior circumflex humeral artery was 18.17 (9.0) mm. The study results suggest that subpectoral biceps tenodesis with a bicortical button is a safe, stable procedure that results in excellent functional outcomes. PMID:27552466

  8. Clinical Outcomes and Complications of Cortical Button Distal Biceps Repair: A Systematic Review of the Literature

    PubMed Central

    Pantazis, Konstantinos

    2016-01-01

    Objectives. The purpose of the present study was to investigate the clinical outcomes and complications of the cortical button distal biceps fixation method. Material and Methods. All methods followed the PRISMA guidelines. Included studies had to describe clinical outcomes and complications after acute distal biceps repair with cortical button fixation. Eligibility criteria also included English language, more than 5 cases with minimum follow-up of 6 months, and preferably usage of at least one relevant clinical score (MEPS, ASES, and/or DASH) for final outcome. A loss of at least 30° in motion—flexion, extension, pronation, or supination—and a loss of at least 30% of strength were considered an unsatisfactory result. Results. The review identified 7 articles including 105 patients (mean age 43.6 years) with 106 acute distal biceps ruptures. Mean follow-up was 26.3 months. Functional outcome of ROM regarding flexion/extension and pronation/supination was satisfactory in 94 (89.5%) and 86 (82%) patients in respect. Averaged flexion and supination strength had been reported in 6/7 studies (97 patients) and were satisfactory in 82.4% of them. The most common complication was transient nerve palsy (14.2%). The overall reoperation rate was 4.8% (5/105 cases). Conclusion. Cortical button fixation for acute distal biceps repair is a reproducible operation with good clinical results. Most of the complications can be avoided with appropriate surgical technique. PMID:27525303

  9. Interference Screw vs. Suture Anchor Fixation for Open Subpectoral Biceps Tenodesis: Does it Matter?

    PubMed Central

    Millett, Peter J; Sanders, Brett; Gobezie, Reuben; Braun, Sepp; Warner, Jon JP

    2008-01-01

    Background Bioabsorbable interference screw fixation has superior biomechanical properties compared to suture anchor fixation for biceps tenodesis. However, it is unknown whether fixation technique influences clinical results. Hypothesis We hypothesize that subpectoral interference screw fixation offers relevant clinical advantages over suture anchor fixation for biceps tenodesis. Study Design Case Series. Methods We performed a retrospective review of a consecutive series of 88 patients receiving open subpectoral biceps tenodesis with either interference screw fixation (34 patients) or suture anchor fixation (54 patients). Average follow up was 13 months. Outcomes included Visual Analogue Pain Scale (0–10), ASES score, modified Constant score, pain at the tenodesis site, failure of fixation, cosmesis, deformity (popeye) and complications. Results There were no failures of fixation in this study. All patients showed significant improvement between their preoperative and postoperative status with regard to pain, ASES score, and abbreviated modified Constant scores. When comparing IF screw versus anchor outcomes, there was no statistical significance difference for VAS (p = 0.4), ASES score (p = 0.2), and modified Constant score (P = 0.09). One patient (3%) treated with IF screw complained of persistent bicipital groove tenderness, versus four patients (7%) in the SA group (nonsignificant). Conclusion Subpectoral biceps tenodesis reliably relieves pain and improves function. There was no statistically significant difference in the outcomes studied between the two fixation techniques. Residual pain at the site of tenodesis may be an issue when suture anchors are used in the subpectoral location. PMID:18793424

  10. Content Analysis Schedule for Bilingual Education Programs: BICEP Intercambio de la Cultura.

    ERIC Educational Resources Information Center

    Shore, Marietta Saravia; Nafus, Charles

    This content analysis schedule for BICEP Intercambio de la Cultura (San Bernardino, California), presents information on the history, funding, and scope of the project. Included are sociolinguistic process variables such as the native and dominant languages of students and their interaction. Information is provided on staff selection and the…

  11. A joint analysis of Planck and BICEP2 B modes including dust polarization uncertainty

    SciTech Connect

    Mortonson, Michael J.; Seljak, Uroš E-mail: useljak@berkeley.edu

    2014-10-01

    We analyze BICEP2 and Planck data using a model that includes CMB lensing, gravity waves, and polarized dust. Recently published Planck dust polarization maps have highlighted the difficulty of estimating the amount of dust polarization in low intensity regions, suggesting that the polarization fractions have considerable uncertainties and may be significantly higher than previous predictions. In this paper, we start by assuming nothing about the dust polarization except for the power spectrum shape, which we take to be C{sub l}{sup BB,dust} ∝ l{sup -2.42}. The resulting joint BICEP2+Planck analysis favors solutions without gravity waves, and the upper limit on the tensor-to-scalar ratio is r<0.11, a slight improvement relative to the Planck analysis alone which gives r<0.13 (95% c.l.). The estimated amplitude of the dust polarization power spectrum agrees with expectations for this field based on both HI column density and Planck polarization measurements at 353 GHz in the BICEP2 field. Including the latter constraint on the dust spectrum amplitude in our analysis improves the limit further to r < 0.09, placing strong constraints on theories of inflation (e.g., models with r>0.14 are excluded with 99.5% confidence). We address the cross-correlation analysis of BICEP2 at 150 GHz with BICEP1 at 100 GHz as a test of foreground contamination. We find that the null hypothesis of dust and lensing with 0r= gives Δ χ{sup 2} < 2 relative to the hypothesis of no dust, so the frequency analysis does not strongly favor either model over the other. We also discuss how more accurate dust polarization maps may improve our constraints. If the dust polarization is measured perfectly, the limit can reach r < 0.05 (or the corresponding detection significance if the observed dust signal plus the expected lensing signal is below the BICEP2 observations), but this degrades quickly to almost no improvement if the dust calibration error is 20% or larger or if the dust maps

  12. A joint analysis of Planck and BICEP2 B modes including dust polarization uncertainty

    NASA Astrophysics Data System (ADS)

    Mortonson, Michael J.; Seljak, Uroš

    2014-10-01

    We analyze BICEP2 and Planck data using a model that includes CMB lensing, gravity waves, and polarized dust. Recently published Planck dust polarization maps have highlighted the difficulty of estimating the amount of dust polarization in low intensity regions, suggesting that the polarization fractions have considerable uncertainties and may be significantly higher than previous predictions. In this paper, we start by assuming nothing about the dust polarization except for the power spectrum shape, which we take to be ClBB,dust propto l-2.42. The resulting joint BICEP2+Planck analysis favors solutions without gravity waves, and the upper limit on the tensor-to-scalar ratio is r<0.11, a slight improvement relative to the Planck analysis alone which gives r<0.13 (95% c.l.). The estimated amplitude of the dust polarization power spectrum agrees with expectations for this field based on both HI column density and Planck polarization measurements at 353 GHz in the BICEP2 field. Including the latter constraint on the dust spectrum amplitude in our analysis improves the limit further to r < 0.09, placing strong constraints on theories of inflation (e.g., models with r>0.14 are excluded with 99.5% confidence). We address the cross-correlation analysis of BICEP2 at 150 GHz with BICEP1 at 100 GHz as a test of foreground contamination. We find that the null hypothesis of dust and lensing with 0r= gives Δ χ2 < 2 relative to the hypothesis of no dust, so the frequency analysis does not strongly favor either model over the other. We also discuss how more accurate dust polarization maps may improve our constraints. If the dust polarization is measured perfectly, the limit can reach r < 0.05 (or the corresponding detection significance if the observed dust signal plus the expected lensing signal is below the BICEP2 observations), but this degrades quickly to almost no improvement if the dust calibration error is 20% or larger or if the dust maps are not processed through the

  13. Clinical and Biomechanical Evaluation of an All-Arthroscopic Suprapectoral Biceps Tenodesis

    PubMed Central

    Kahlenberg, Cynthia A.; Patel, Ronak M.; Nair, Rueben; Deshmane, Prashant P.; Harnden, Galen; Terry, Michael A.

    2014-01-01

    Background: Pathology of the long head of the biceps (LHB) is a well-recognized cause of shoulder pain in the adult population and can be managed surgically with tenotomy or tenodesis. Purpose: To compare the biomechanical strength of an all-arthroscopic biceps tenodesis technique that places the LHB distal to the bicipital groove in the suprapectoral region with a more traditional mini-open subpectoral tenodesis. This study also evaluates the clinical outcomes of patients who underwent biceps tenodesis using the all-arthroscopic technique. Study Design: Controlled laboratory study and case series; Level of evidence, 4. Methods: For the biomechanical evaluation of the all-arthroscopic biceps tenodesis technique, in which the biceps tendon is secured to the suprapectoral region distal to the bicipital groove with an interference screw, 14 fresh-frozen human cadaveric shoulders (7 matched pairs) were used to compare load to failure and displacement at peak load with a traditional open subpectoral location. For the clinical evaluation, 49 consecutive patients (51 shoulders) with a mean follow-up of 2.4 years who underwent an all-arthroscopic biceps tenodesis were evaluated using the American Shoulder and Elbow Surgeons (ASES) score preoperatively and at last follow-up, as well as the University of California, Los Angeles (UCLA) Shoulder Score at last follow-up. Results: On biomechanical evaluation, there was no significant difference in peak failure load, displacement at peak load, or displacement after cyclic testing between the arthroscopic suprapectoral and mini-open subpectoral groups. In the clinical evaluation, the mean preoperative ASES score was 65.4, compared with 87.1 at last follow-up. The mean UCLA score at last follow-up was 30.2. Forty-eight (94.1%) patients reported satisfaction with the surgery. In subgroup analysis comparing patients who had a rotator cuff repair or labral repair at time of tenodesis with patients who did not have either of these

  14. Arthroscopic Changes of the Biceps Pulley in Rotator Cuff Tear and Its Clinical Significance in Relation to Treatment

    PubMed Central

    Choi, Chang Hyuk; Kim, Se Sik; Lee, Ju Hwan

    2015-01-01

    Background In the case of rotator cuff tears, the biceps pulley can be stressed by the unstable biceps tendon, and this can subsequently affect the stability of the subscapularis tendon. Therefore, it is important to distinguish between normal variations and lesions of the biceps pulley that affect anterosuperior lesions in cases of rotator cuff tears. Methods From January 2002 through November 2010, we observed biceps pulley and associated anterosuperior lesions in 589 of 634 cases (93%) of arthroscopic rotator cuff repair, including 72 cases (12.2%) of small tears, 219 cases (37.2%) of medium tears, 134 cases (22.8%) of large tears, and 164 cases (27.8%) of massive tears. We classified normal stretched biceps pulleys as type I, stretched biceps pulleys with mild changes as type II, those with a partial tear as type III, and torn pulleys as type IV. Results We were able to classify 589 cases of biceps pulleys as type I, II, III, or IV associated lesions in rotator cuff tears. Type I was seen in 91 cases (15.4%), type II in 216 cases (36.7%), type III in 157 cases (26.7%), and type IV in 101 cases (17.1%); unidentified cases numbered 24 (4.1%). Nearly three-quarters, 73.3%, of the cases (432/589) had associated anterosuperior lesions, and combined treatment for the associated lesions was administered in 29.2% (172/589) of cases. Conclusions Biceps pulley lesions with more than partial tears were identified in 48% of rotator cuff tear cases. The incidence and severity of pulley lesions were related to the rotator cuff tear size, the status of the long head of the biceps tendon and subscapularis tendon lesion, and the treatment methods. PMID:26330960

  15. Prediction of Muscle Fatigue during Minimally Invasive Surgery Using Recurrence Quantification Analysis

    PubMed Central

    Keshavarz Panahi, Ali; Cho, Sohyung

    2016-01-01

    Due to its inherent complexity such as limited work volume and degree of freedom, minimally invasive surgery (MIS) is ergonomically challenging to surgeons compared to traditional open surgery. Specifically, MIS can expose performing surgeons to excessive ergonomic risks including muscle fatigue that may lead to critical errors in surgical procedures. Therefore, detecting the vulnerable muscles and time-to-fatigue during MIS is of great importance in order to prevent these errors. The main goal of this study is to propose and test a novel measure that can be efficiently used to detect muscle fatigue. In this study, surface electromyography was used to record muscle activations of five subjects while they performed fifteen various laparoscopic operations. The muscle activation data was then reconstructed using recurrence quantification analysis (RQA) to detect possible signs of muscle fatigue on eight muscle groups (bicep, triceps, deltoid, and trapezius). The results showed that RQA detects the fatigue sign on bilateral trapezius at 47.5 minutes (average) and bilateral deltoid at 57.5 minutes after the start of operations. No sign of fatigue was detected for bicep and triceps muscles of any subject. According to the results, the proposed novel measure can be efficiently used to detect muscle fatigue and eventually improve the quality of MIS procedures with reducing errors that may result from overlooked muscle fatigue. PMID:27313884

  16. Comparing clinical data and muscle imaging of DYSF and ANO5 related muscular dystrophies.

    PubMed

    Ten Dam, Leroy; van der Kooi, Anneke J; Rövekamp, Fleur; Linssen, Wim H J P; de Visser, Marianne

    2014-12-01

    In this retrospective cross-sectional study clinical and muscle imaging data of patients with Miyoshi distal myopathy phenotype (MMD1 and MMD3) and limb girdle muscular dystrophy 2L (LGMD2L) were described. MMD1 and MMD3 are genetically heterogenous diseases based on DYSF and ANO5 gene defects. MMD3 and LGMD2L are clinically different diseases caused by an ANO5 gene defect. All groups showed predominant fatty degeneration of the gluteus minimus muscle and of the posterior segments of the thigh and calf muscles with sparing of the gracilis muscle. Muscle atrophy, hypertrophy and asymmetric muscle involvement on muscle imaging did not differ between groups. The pattern of fatty degeneration of muscles and of muscle weakness shows only minor differences between MMD1 (n=6) and MMD3 (n=8) patients with more frequently fatty degeneration of the rectus femoris, anterior tibial, and extensor digitorum muscles and more frequently muscle weakness in the anterior tibial, peroneal and calf muscle in MMD1. In the ANO5 related phenotypes the lateral head of the gastrocnemius muscle was less frequently involved in LGMD2L (n=13) and no differences in the incidence of muscle weakness was found. Therefore, MMD3 and LGMD2L should be considered as part of one spectrum of ANO5 related muscle disease. PMID:25176504

  17. Muscle atrophy

    MedlinePlus

    Muscle wasting; Wasting; Atrophy of the muscles ... There are two types of muscle atrophy. Disuse atrophy occurs from a lack of physical activity. In most people, muscle atrophy is caused by not using the ...

  18. Muscle Disorders

    MedlinePlus

    Your muscles help you move and help your body work. Different types of muscles have different jobs. There are many problems that can affect muscles. Muscle disorders can cause weakness, pain or even ...

  19. Muscle atrophy

    MedlinePlus

    Muscle wasting; Wasting; Atrophy of the muscles ... There are two types of muscle atrophy: disuse and neurogenic. Disuse atrophy is caused by not using the muscles enough . This type of atrophy can often be ...

  20. Muscle Cramps

    MedlinePlus

    Muscle cramps are sudden, involuntary contractions or spasms in one or more of your muscles. They often occur after exercise or at night, ... to several minutes. It is a very common muscle problem. Muscle cramps can be caused by nerves ...

  1. Discriminating neurogenic from myopathic disease via measurement of muscle anisotropy.

    PubMed

    Garmirian, Lindsay P; Chin, Anne B; Rutkove, Seward B

    2009-01-01

    Skeletal muscle is electrically anisotropic, with a tendency for applied electrical current to flow more readily along muscle fibers than across them. In this study, we assessed a method for non-invasive measurement of anisotropy to determine its potential to serve as a new technique for distinguishing neurogenic from myopathic disease. Measurements were made on the biceps brachii and tibialis anterior muscles in 15 normal subjects and 12 patients with neuromuscular disease (6 with amyotrophic lateral sclerosis and 6 with various myopathies) using 50 kHZ applied current. Consistent multi-angle anisotropic patterns were found for reactance and phase in both muscles in normal subjects. Normalized anisotropy differences for each subject were defined, and group average values identified. The amyotrophic lateral sclerosis (ALS) patients demonstrated increased and distorted anisotropy patterns, whereas myopathic patients demonstrated normal or reduced anisotropy. These results suggest that non-invasive measurement of muscle anisotropy has potential for diagnosis of neuromuscular diseases. PMID:19058193

  2. 3D False Color Computed Tomography for Diagnosis and Follow-Up of Permanent Denervated Human Muscles Submitted to Home-Based Functional Electrical Stimulation

    PubMed Central

    Carraro, Ugo; Edmunds, Kyle J.

    2015-01-01

    This report outlines the use of a customized false-color 3D computed tomography (CT) protocol for the imaging of the rectus femoris of spinal cord injury (SCI) patients suffering from complete and permanent denervation, as characterized by complete Conus and Cauda Equina syndrome. This muscle imaging method elicits the progression of the syndrome from initial atrophy to eventual degeneration, as well as the extent to which patients' quadriceps could be recovered during four years of home-based functional electrical stimulation (h-b FES). Patients were pre-selected from several European hospitals and functionally tested by, and enrolled in the EU Commission Shared Cost Project RISE (Contract n. QLG5-CT-2001-02191) at the Department of Physical Medicine, Wilhelminenspital, Vienna, Austria. Denervated muscles were electrically stimulated using a custom-designed stimulator, large surface electrodes, and customized progressive stimulation settings. Spiral CT images and specialized computational tools were used to isolate the rectus femoris muscle and produce 3D and 2D reconstructions of the denervated muscles. The cross sections of the muscles were determined by 2D Color CT, while muscle volumes were reconstructed by 3D Color CT. Shape, volume, and density changes were measured over the entirety of each rectus femoris muscle. Changes in tissue composition within the muscle were visualized by associating different colors to specified Hounsfield unit (HU) values for fat, (yellow: [-200; -10]), loose connective tissue or atrophic muscle, (cyan: [-9; 40]), and normal muscle, fascia and tendons included, (red: [41; 200]). The results from this analysis are presented as the average HU values within the rectus femoris muscle reconstruction, as well as the percentage of these tissues with respect to the total muscle volume. Results from this study demonstrate that h-b FES induces a compliance-dependent recovery of muscle volume and size of muscle fibers, as evidenced by the

  3. Renal vascular responses to static handgrip: role of muscle mechanoreflex

    NASA Technical Reports Server (NTRS)

    Momen, Afsana; Leuenberger, Urs A.; Ray, Chester A.; Cha, Susan; Handly, Brian; Sinoway, Lawrence I.

    2003-01-01

    During exercise, the sympathetic nervous system is activated, which causes vasoconstriction. The autonomic mechanisms responsible for this vasoconstriction vary based on the particular tissue being studied. Attempts to examine reflex control of the human renal circulation have been difficult because of technical limitations. In this report, the Doppler technique was used to examine renal flow velocity during four muscle contraction paradigms in conscious humans. Flow velocity was divided by mean arterial blood pressure to yield an index of renal vascular resistance (RVR). Fatiguing static handgrip (40% of maximal voluntary contraction) increased RVR by 76%. During posthandgrip circulatory arrest, RVR remained above baseline (2.1 +/- 0.2 vs. 2.8 +/- 0.2 arbitrary units; P < 0.017) but was only 40% of the end-grip RVR value. Voluntary biceps contraction increased RVR within 10 s of initiation of contraction. This effect was not associated with an increase in blood pressure. Finally, involuntary biceps contraction also raised RVR. We conclude that muscle contraction evokes renal vasoconstriction in conscious humans. The characteristic of this response is consistent with a primary role for mechanically sensitive afferents. This statement is based on the small posthandgrip circulatory arrest response and the vasoconstriction that was observed with involuntary biceps contraction.

  4. A new approach to assess the spasticity in hamstrings muscles using mechanomyography antagonist muscular group.

    PubMed

    Krueger, Eddy; Scheeren, Eduardo M; Nogueira-Neto, Guilherme N; Button, Vera Lúcia da S N; Nohama, Percy

    2012-01-01

    Several pathologies can cause muscle spasticity. Modified Ashworth scale (MAS) can rank spasticity, however its results depend on the physician subjective evaluation. This study aims to show a new approach to spasticity assessment by means of MMG analysis of hamstrings antagonist muscle group (quadriceps muscle). Four subjects participated in the study, divided into two groups regarding MAS (MAS0 and MAS1). MMG sensors were positioned over the muscle belly of rectus femoris (RF), vastus lateralis (VL) and vastus medialis (VM) muscles. The range of movement was acquired with an electrogoniometer placed laterally to the knee. The system was based on a LabVIEW acquisition program and the MMG sensors were built with triaxial accelerometers. The subjects were submitted to stretching reflexes and the integral of the MMG (MMG(INT)) signal was calculated to analysis. The results showed that the MMG(INT) was greater to MAS1 than to MAS0 [muscle RF (p = 0.004), VL (p = 0.001) and VM (p = 0.007)]. The results showed that MMG was viable to detect a muscular tonus increase in antagonist muscular group (quadriceps femoris) of spinal cord injured volunteers. PMID:23366325

  5. Tendon of the long head of the biceps originating from the rotator cuff – An uncommon anatomical variation: case report☆

    PubMed Central

    Andreoli, Carlos Vicente; Esteves, Leonardo Roure; Figueiredo, Eduardo; Belangero, Paulo Santoro; de Castro Pochini, Alberto; Ejnisman, Benno

    2015-01-01

    Anatomical variations at the origin of the biceps tendon have been described by several authors, but occurrences of an origin in the supraspinatus are rare. It is unclear whether this variation might contribute toward pathological conditions of the shoulder. Our objective here was to describe a case of an anatomical variation in the origin of the tendon of the long head of the biceps. The clinical information, preoperative images and arthroscopic images relating to a patient with an aberrant origin of the long head of the biceps, which was observed during shoulder arthroscopy, were reviewed. In this case study, the origin of the biceps was found in the rotator cuff, without any origin from the supraglenoid tubercle or upper labrum. This variant did not seem to contribute toward the pathological condition of the shoulder, and standard treatment for the concomitant condition was sufficient for treating it. PMID:26962493

  6. The effect of increase in baggage weight on elderly women's lower extremity muscle activation during gait.

    PubMed

    Kim, Seong-Gil; Nam, Chan-Woo; Yong, Min-Sik

    2014-01-01

    The aim of the present study was to examine the effect of increased baggage weight on the muscle activation of elderly women's lower extremities during gait. A total of 24 elderly women who were residing in communities in Daegu, South Korea aged 79.6±6.2, 149.7±7.0cm in height, and 53.5±7.2kg in weight participated in this study. The muscle activation of each muscle was measured three times at 2kg, 3kg, and 4kg of baggage weight while the subjects were conducting treadmill walking wearing backpacks. Electrodes were placed on four muscles: the quadriceps muscle (rectus femoris), the hamstring muscle (semitendinosus), the tibialis anterior muscle, and the soleus muscle. The results show that the rates of increase in muscle activation in the tibialis anterior and soleus muscles according to baggage weight increase were higher than those in the quadriceps and hamstring muscles (<0.05). These results indicate that the heavier weight loads increase the activation of muscles that control the ankle joints causing muscle fatigue. Moreover, a decrease in balance ability through muscle fatigue can be a risk factor for falls. Thus, elderly people should be instructed not to carry heavy objects. PMID:25179442

  7. Progress toward a detection of inflationary B-modes with the BICEP2 and Keck Array polarimeters

    NASA Astrophysics Data System (ADS)

    Sheehy, Christopher D.

    Recent measurements of the temperature anisotropies of the Cosmic Microwave Background (CMB) have provided growing support for an inflationary epoch in the early Universe. The theory of Inflation, first proposed by Alan Guth in 1981, posits that shortly after the Big Bang, the Universe underwent a brief period of faster-than-light expansion, during which quantum vacuum fluctuations were imprinted as real density fluctuations. After inflation, these density fluctuations evolved in accordance with simple physics to create all the struc- ture in the Universe we see today. In the same way that inflation produces density fluctu- ations (scalar perturbations in the spacetime metric) it also produces gravity waves (tensor perturbations in the metric.) The effect of these primordial gravity waves at the time of recombination would be evident as a slight curl component, or B-mode component, of the CMB polarization. Detecting inflationary B-modes would constitute compelling, direct evi- dence for an inflationary paradigm, as well as offer a way to study the (currently unknown) physical mechanism responsible for inflation. BICEP, BICEP2 and the Keck Array are polarimeters aiming to make a first detection of the degree scale B-mode polarization of the CMB. BICEP's 2-year results, released in 2010, are currently the most sensitive B-mode upper limits; the 3-year analysis is currently in preparation. BICEP2 and the Keck Array will make far deeper measurements. In this thesis, I describe the BICEP, BICEP2 and Keck experimental campaign, and discuss the BICEP2 instrument characteristics most relevant for a power spectrum analysis. I also outline a new and powerful technique for cleaning polarization data of systematics resulting from beam non-idealities. Lastly, I apply this method and present preliminary BICEP2 maps and simulated power spectra that demonstrate the experiment's unprecedented sensitivity.

  8. Arthroscopic biceps tenodesis compared with repair of isolated type II SLAP lesions in patients older than 35 years.

    PubMed

    Denard, Patrick J; Lädermann, Alexandre; Parsley, B K; Burkhart, Stephen S

    2014-03-01

    This study compared arthroscopic biceps tenodesis with biceps repair for isolated type II superior labrum anterior and posterior (SLAP) lesions in patients older than 35 years. The authors identified isolated type II SLAP lesions that were surgically managed over a 5-year period. Minimum 2-year follow-up data were available for 22 patients who underwent biceps repair (repair group) and for 15 patients who underwent a primary biceps tenodesis (tenodesis group). Mean age at surgery was 45.2±5.5 years in the repair group and 52.0±8.0 years in the tenodesis group. In the repair group, functional outcome improved from baseline to final follow-up using the American Shoulder and Elbow Surgeons (ASES) (47.5 to 87.4, respectively; P<.0001) and University of California, Los Angeles (UCLA) scores (18.5 to 31.2, respectively; P<.0001). In the tenodesis group, similar findings were observed for the ASES (43.4 to 89.9, respectively; P<.0001) and UCLA scores (19.0 to 32.7, respectively; P<.0001). No difference was found in functional outcome between the groups. Full range of motion recovery was delayed by approximately 3 months in the repair group compared with the tenodesis group (P=.0631). Two patients in the repair group required a secondary capsular release. Seventy-seven percent of patients in the repair group and 100% of patients in the tenodesis group were satisfied and returned to normal activity (P=.0673). In the current study, individuals older than 35 years with an isolated type II SLAP lesion had a shorter postoperative recovery, a more predictable functional outcome, and a higher rate of satisfaction and return to activity with a biceps tenodesis compared with a biceps repair. Based on these observations, biceps tenodesis is preferable to biceps repair for isolated type II SLAP lesions in nonoverhead athletes older than 35 years. PMID:24762158

  9. Differences in Supraspinal and Spinal Excitability during Various Force Outputs of the Biceps Brachii in Chronic- and Non-Resistance Trained Individuals

    PubMed Central

    Pearcey, Gregory E. P.; Power, Kevin E.; Button, Duane C.

    2014-01-01

    Motor evoked potentials (MEP) and cervicomedullary evoked potentials (CMEP) may help determine the corticospinal adaptations underlying chronic resistance training-induced increases in voluntary force production. The purpose of the study was to determine the effect of chronic resistance training on corticospinal excitability (CE) of the biceps brachii during elbow flexion contractions at various intensities and the CNS site (i.e. supraspinal or spinal) predominantly responsible for any training-induced differences in CE. Fifteen male subjects were divided into two groups: 1) chronic resistance-trained (RT), (n = 8) and 2) non-RT, (n = 7). Each group performed four sets of ∼5 s elbow flexion contractions of the dominant arm at 10 target forces (from 10%–100% MVC). During each contraction, subjects received 1) transcranial magnetic stimulation, 2) transmastoid electrical stimulation and 3) brachial plexus electrical stimulation, to determine MEP, CMEP and compound muscle action potential (Mmax) amplitudes, respectively, of the biceps brachii. All MEP and CMEP amplitudes were normalized to Mmax. MEP amplitudes were similar in both groups up to 50% MVC, however, beyond 50% MVC, MEP amplitudes were lower in the chronic RT group (p<0.05). CMEP amplitudes recorded from 10–100% MVC were similar for both groups. The ratio of MEP amplitude/absolute force and CMEP amplitude/absolute force were reduced (p<0.012) at all contraction intensities from 10–100% MVC in the chronic-RT compared to the non-RT group. In conclusion, chronic resistance training alters supraspinal and spinal excitability. However, adaptations in the spinal cord (i.e. motoneurone) seem to have a greater influence on the altered CE. PMID:24875495

  10. BICEP2/Keck - Planck joint analysis and prospects for Galactic foreground removal from CMB observations

    NASA Astrophysics Data System (ADS)

    Crill, Brendan

    2015-08-01

    The joint analysis of 150 GHz polarized maps from BICEP2 and Keck Array at 150 GHz with Planck data at 353 GHzallowed the removal of Galactic dust contamination from the measurement of lensed B-modes in the deep (57 nK deg)BICEP2/Keck maps as well as setting an upper limit on the primordial gravitational wave background from inflation. We present this analysis, describe prospects for polarized foreground cleaning of future suborbitalmeasurements of CMB, and additionally describe Planck's measurements of the spatial correlation of polarizedemission from synchrotron and dust at high galactic latitude, which complicates the removal of Galactic foregrounds at the foregroundminimum of 70-100 GHz.

  11. "Relaxed" biceps proximal tenodesis: an arthroscopic technique with decreased residual tendon tension.

    PubMed

    Valenti, Philippe; Benedetto, Ivan; Maqdes, Ali; Lima, Sara; Moraiti, Constantina

    2014-10-01

    Tenodesis of the long head of the biceps tendon (LHB) at the upper part of the bicipital groove has been related to persistent postoperative bicipital pain. This is possibly due to the inflammation of the remaining tendon within the groove. This, in turn, could be attributed to the continual mechanical stress placed on the tendon in the narrow bicipital groove. Theoretically, should the LHB be more "relaxed," the mechanical stress applied on it would be diminished. On the basis of this rationale, we present an arthroscopic biceps tenodesis technique, according to which the tendon is fixed at the entrance of the bicipital groove, using a bioabsorbable screw, relaxed by 5 mm. In this lax position, the residual LHB tension is expected to be decreased compared with the initial tension, whereas no cosmetic deformity (Popeye sign) or impaired muscular performance is anticipated. PMID:25473621

  12. Comparisons of muscle oxygenation changes between arm and leg muscles during incremental rowing exercise with near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Zhang, Zhongxing; Wang, Bangde; Gong, Hui; Xu, Guodong; Nioka, Shoko; Chance, Britton

    2010-01-01

    Our purpose is to compare the changes in muscle oxygenation in the vastus lateralis (VL) and biceps brachii (BB) muscles simultaneously using near-infrared spectroscopy (NIRS) during incremental rowing exercise in eight rowers. Based on the BB and VL muscle oxygenation patterns, two points are used to characterize the muscle oxygenation kinetics in both the arm and the leg muscles. The first point is the breaking point (Bp), which refers to an accelerated fall in muscle oxygenation that correlates with the gas exchange threshold (GET). The second point is the leveling-off point (Lo), which suggests the upper limit of O2 extraction. The GET occurred at 63.3+/-2.4% of maximal oxygen uptake (V˙O2 max). The Bp appeared at 45.0+/-3.8% and 55.6+/-2.4% V˙O2 max in the BB and VL, respectively. The Lo appeared at 63.6+/-4.1% and 86.6+/-1.0% V˙O2 max in these two muscles, respectively. Both the Bp and the Lo occurred earlier in BB compared with VL. These results suggest that arm muscles have lower oxidative capacity than leg muscles during rowing exercise. The rowers with higher exercise performances showed heavier workloads, as evaluated by Bp and Lo. The monitoring of muscle oxygenation by NIRS in arm and leg muscles during rowing could be a useful guide for evaluation and training.

  13. Long Head of the Biceps Pathology Combined with Rotator Cuff Tears

    PubMed Central

    Ditsios, Konstantinos; Agathangelidis, Filon; Boutsiadis, Achilleas; Karataglis, Dimitrios; Papadopoulos, Pericles

    2012-01-01

    The long head of the biceps tendon (LHBT) is an anatomic structure commonly involved in painful shoulder conditions as a result of trauma, degeneration, or overuse. Recent studies have pointed out the close correlation between LHBT lesions and rotator cuff (RCT) tears. Clinicians need to take into account the importance of the LHBT in the presence of other shoulder pathologies. This paper provides an up-to-date overview of recent publications on anatomy, pathophysiology, diagnosis, classification, and current treatment strategies. PMID:23209915

  14. Editorial Commentary: To Screw or to Sew--Which Is Better for Arthroscopic Biceps Tenodesis?

    PubMed

    Feldman, Michael D

    2016-04-01

    As the popularity of arthroscopic biceps tenodesis continues to grow, surgeons must choose between performing a soft-tissue tenodesis and performing a bony tenodesis. Although there is no difference in visual analog scale, Constant, or American Shoulder and Elbow Surgeons scores at greater than 2 years' follow-up, elbow flexion strength index and fixation failure rates favor bony tenodesis, important factors to consider when deciding which procedure to perform. PMID:27039679

  15. USDA yield grades and various carcass traits as predictors of carcass composition.

    PubMed

    Lunt, D K; Smith, G C; Savell, J W; Murphey, C E; Carpenter, Z L; McKeith, F K; Johnson, D D

    1985-01-01

    Twenty-five carcasses from each of three breedtypes (Brahman, Angus and Brahman × Angus) were physically separated into fat, lean and bone. Several muscles from the round and the femur were used to derive equations to predict carcass composition and muscle-to-bone ratio. The femur (as a percentage of the carcass) was shown to predict percentage carcass bone with 90% accuracy. All of the muscles studied were highly related to total carcass lean but the percentage of carcass as M. biceps femoris was the best single muscle indicator of carcass lean of the muscles studied. More variation in carcass lean could be accounted for by a multiple regression equation, involving all four muscles studied, than by any single muscle. M. biceps femoris-to-femur ratio was found to predict carcass muscle-to-bone ratio with a high degree of accuracy. The USDA yield grades were found to be reliable indicators of carcass composition. A two-variable equation involving adjusted fat thickness and biceps femoris accounted for 88·6% of the variation (RSD = 1/·64) in percentage of carcass as separable lean. PMID:22055934

  16. The Knotted Sky II: does BICEP2 require a nontrivial primordial power spectrum?

    SciTech Connect

    Abazajian, Kevork N.; Aslanyan, Grigor; Easther, Richard; Price, Layne C. E-mail: g.aslanyan@auckland.ac.nz E-mail: lpri691@aucklanduni.ac.nz

    2014-08-01

    An inflationary gravitational wave background consistent with BICEP2 is difficult to reconcile with a simple power-law spectrum of primordial scalar perturbations. Tensor modes contribute to the temperature anisotropies at multipoles with l∼< 100, and this effect — together with a prior on the form of the scalar perturbations — was the source of previous bounds on the tensor-to-scalar ratio. We compute Bayesian evidence for combined fits to BICEP2 and Planck for three nontrivial primordial spectra: a) a running spectral index, b) a cutoff at fixed wavenumber, and c) a spectrum described by a linear spline with a single internal knot. We find no evidence for a cutoff, weak evidence for a running index, and significant evidence for a ''broken'' spectrum. Taken at face-value, the BICEP2 results require two new inflationary parameters in order to describe both the broken scale invariance in the perturbation spectrum and the observed tensor-to-scalar ratio. Alternatively, this tension may be resolved by additional data and more detailed analyses.

  17. Rare case of upper arm compartment syndrome following biceps tendon rupture.

    PubMed

    Fung, Daniel A; Frey, Steven; Grossman, Robert B

    2008-05-01

    We present a case of upper arm compartment syndrome following a biceps tendon rupture in a 77-year old man on warfarin sodium. Compartment syndrome is common in the forearm and leg, but rare in the upper arm with only a handful of cases reported in the literature. Our patient's anticoagulated state predisposed him to the development of compartment syndrome. To the best of our knowledge there has been only one other case reported in the literature of upper arm compartment syndrome following biceps tendon rupture in a patient on warfarin sodium. Compartment syndrome of the upper arm is a rare occurrence. Previous cases have occurred due to malposition of blood pressure cuffs, injections, venepuncture, trauma, tourniquets, shoulder dislocation, surgical complication, subatmospheric pressure induced, biceps rupture, and triceps rupture. The fascia of the upper arm is relatively thinner and more distensible than the fascia of the leg or forearm. This creates more room for the compartment to swell before pressures builds up to a significant level. Thus, a significantly increased amount of pressure needs to build up before compartment syndrome will occur in the upper arm. Once the diagnosis was formed, the patient was treated with emergent fasciotomy and evacuation of hematoma. After a prolonged hospital stay, the patient was released with minor neurological deficits. At final follow-up, the patient was neurovascularly intact with no complaints of numbness or tingling, and he had regained full motor function throughout. PMID:19292309

  18. Viability of the matter bounce scenario in Loop Quantum Cosmology from BICEP2 last data

    NASA Astrophysics Data System (ADS)

    de Haro, Jaume; Amorós, Jaume

    2014-08-01

    The CMB map provided by the Planck project constrains the value of the ratio of tensor-to-scalar perturbations, namely r, to be smaller than 0.11 (95 % CL). This bound rules out the simplest models of inflation. However, recent data from BICEP2 is in strong tension with this constrain, as it finds a value r=0.20+0.07-0.05 with 0r= disfavored at 7.0 σ, which allows these simplest inflationary models to survive. The remarkable fact is that, even though the BICEP2 experiment was conceived to search for evidence of inflation, its experimental data matches correctly theoretical results coming from the matter bounce scenario (the alternative model to the inflationary paradigm). More precisely, most bouncing cosmologies do not pass Planck's constrains due to the smallness of the value of the tensor/scalar ratio r<= 0.11, but with new BICEP2 data some of them fit well with experimental data. This is the case with the matter bounce scenario in the teleparallel version of Loop Quantum Cosmology.

  19. Ultrasound-guided platelet-rich plasma injection for distal biceps tendinopathy

    PubMed Central

    Bell, Simon N; Connell, David; Coghlan, Jennifer A

    2015-01-01

    Background Distal biceps tendinopathy is an uncommon cause of elbow pain. The optimum treatment for cases refractory to conservative treatment is unclear. Platelet-rich plasma has been used successfully for other tendinopathies around the elbow. Methods Six patients with clinical and radiological evidence of distal biceps tendinopathy underwent ultrasound-guided platelet-rich plasma (PRP) injection. Clinical examination findings, visual analogue score (VAS) for pain and Mayo Elbow Performance scores were recorded. Results The Mayo Elbow Performance Score improved from 68.3 (range 65 to 85) (fair function) to 95 (range 85 to 100) (excellent function). The VAS at rest improved from a mean of 2.25 (range 2 to 5) pre-injection to 0. The VAS with movement improved from a mean of 7.25 (range 5 to 8) pre-injection to 1.3 (range 0 to 2). No complications were noted. Discussion Ultrasound-guided PRP injection appears to be a safe and effective treatment for recalcitrant cases of distal biceps tendinopathy. Further investigation with a randomized controlled trial is needed to fully assess its efficacy.

  20. Viability of the matter bounce scenario in Loop Quantum Cosmology from BICEP2 last data

    SciTech Connect

    De Haro, Jaume; Amorós, Jaume E-mail: jaume.amoros@upc.edu

    2014-08-01

    The CMB map provided by the Planck project constrains the value of the ratio of tensor-to-scalar perturbations, namely r, to be smaller than 0.11 (95 % CL). This bound rules out the simplest models of inflation. However, recent data from BICEP2 is in strong tension with this constrain, as it finds a value r=0.20{sup +0.07}{sub -0.05} with 0r= disfavored at 7.0 σ, which allows these simplest inflationary models to survive. The remarkable fact is that, even though the BICEP2 experiment was conceived to search for evidence of inflation, its experimental data matches correctly theoretical results coming from the matter bounce scenario (the alternative model to the inflationary paradigm). More precisely, most bouncing cosmologies do not pass Planck's constrains due to the smallness of the value of the tensor/scalar ratio r≤ 0.11, but with new BICEP2 data some of them fit well with experimental data. This is the case with the matter bounce scenario in the teleparallel version of Loop Quantum Cosmology.

  1. Skeletal muscle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There are approximately 650-850 muscles in the human body these include skeletal (striated), smooth and cardiac muscle. The approximation is based on what some anatomists consider separate muscle or muscle systems. Muscles are classified based on their anatomy (striated vs. smooth) and if they are v...

  2. Botulinum toxin type A injections for the management of muscle tightness following total hip arthroplasty: a case series

    PubMed Central

    Bhave, Anil; Zywiel, Michael G; Ulrich, Slif D; McGrath, Mike S; Seyler, Thorsten M; Marker, David R; Delanois, Ronald E; Mont, Michael A

    2009-01-01

    Background Development of hip adductor, tensor fascia lata, and rectus femoris muscle contractures following total hip arthroplasties are quite common, with some patients failing to improve despite treatment with a variety of non-operative modalities. The purpose of the present study was to describe the use of and patient outcomes of botulinum toxin injections as an adjunctive treatment for muscle tightness following total hip arthroplasty. Methods Ten patients (14 hips) who had hip adductor, abductor, and/or flexor muscle contractures following total arthroplasty and had been refractory to physical therapeutic efforts were treated with injection of botulinum toxin A. Eight limbs received injections into the adductor muscle, 8 limbs received injections into the tensor fascia lata muscle, and 2 limbs received injection into the rectus femoris muscle, followed by intensive physical therapy for 6 weeks. Results At a mean final follow-up of 20 months, all 14 hips had increased range in the affected arc of motion, with a mean improvement of 23 degrees (range, 10 to 45 degrees). Additionally all hips had an improvement in hip scores, with a significant increase in mean score from 74 points (range, 57 to 91 points) prior to injection to a mean of 96 points (range, 93 to 98) at final follow-up. There were no serious treatment-related adverse events. Conclusion Botulinum toxin A injections combined with intensive physical therapy may be considered as a potential treatment modality, especially in difficult cases of muscle tightness that are refractory to standard therapy. PMID:19709429

  3. Skeletal muscle blood flow and flow heterogeneity during dynamic and isometric exercise in humans.

    PubMed

    Laaksonen, Marko S; Kalliokoski, Kari K; Kyröläinen, Heikki; Kemppainen, Jukka; Teräs, Mika; Sipilä, Hannu; Nuutila, Pirjo; Knuuti, Juhani

    2003-03-01

    The effects of dynamic and intermittent isometric knee extension exercises on skeletal muscle blood flow and flow heterogeneity were studied in seven healthy endurance-trained men. Regional muscle blood flow was measured using positron emission tomography (PET) and an [(15)O]H(2)O tracer, and electromyographic (EMG) activity was recorded in the quadriceps femoris (QF) muscle during submaximal intermittent isometric and dynamic exercises. QF blood flow was 61% (P = 0.002) higher during dynamic exercise. Interestingly, flow heterogeneity was 13% (P = 0.024) lower during dynamic compared with intermittent isometric exercise. EMG activity was significantly higher (P < 0.001) during dynamic exercise, and the change in EMG activity from isometric to dynamic exercise was tightly related to the change in blood flow in the vastus lateralis muscle (r = 0.98, P < 0.001) but not in the rectus femoris muscle (r = -0.09, P = 0.942). In conclusion, dynamic exercise causes higher and less heterogeneous blood flow than intermittent isometric exercise at the same exercise intensity. These responses are, at least partly, related to the increased EMG activity. PMID:12446282

  4. Muscle Deoxygenation Causes Muscle Fatigue

    NASA Technical Reports Server (NTRS)

    Murthy, G.; Hargens, A. R.; Lehman, S.; Rempel, D.

    1999-01-01

    Muscle fatigue is a common musculoskeletal disorder in the work place, and may be a harbinger for more disabling cumulative trauma disorders. Although the cause of fatigue is multifactorial, reduced blood flow and muscle oxygenation may be the primary factor in causing muscle fatigue during low intensity muscle exertion. Muscle fatigue is defined as a reduction in muscle force production, and also occurs among astronauts who are subjected to postural constraints while performing lengthy, repetitive tasks. The objectives of this research are to: 1) develop an objective tool to study the role of decreased muscle oxygenation on muscle force production, and 2) to evaluate muscle fatigue during prolonged glovebox work.

  5. Muscle disorder

    MedlinePlus

    Blood tests sometimes show abnormally high muscle enzymes. If a muscle disorder might also affect other family members, genetic testing may be done. When someone has symptoms and signs of a muscle disorder, tests such as an electromyogram , ...

  6. Muscle aches

    MedlinePlus

    ... common cause of muscle aches and pain is fibromyalgia , a condition that causes tenderness in your muscles ... imbalance, such as too little potassium or calcium Fibromyalgia Infections, including the flu, Lyme disease , malaria , muscle ...

  7. Muscle disorder

    MedlinePlus

    Myopathic changes; Myopathy; Muscle problem ... Blood tests sometimes show abnormally high muscle enzymes. If a muscle disorder might also affect other family members, genetic testing may be done. When someone has symptoms and signs ...

  8. Optimizing the Distribution of Leg Muscles for Vertical Jumping.

    PubMed

    Wong, Jeremy D; Bobbert, Maarten F; van Soest, Arthur J; Gribble, Paul L; Kistemaker, Dinant A

    2016-01-01

    A goal of biomechanics and motor control is to understand the design of the human musculoskeletal system. Here we investigated human functional morphology by making predictions about the muscle volume distribution that is optimal for a specific motor task. We examined a well-studied and relatively simple human movement, vertical jumping. We investigated how high a human could jump if muscle volume were optimized for jumping, and determined how the optimal parameters improve performance. We used a four-link inverted pendulum model of human vertical jumping actuated by Hill-type muscles, that well-approximates skilled human performance. We optimized muscle volume by allowing the cross-sectional area and muscle fiber optimum length to be changed for each muscle, while maintaining constant total muscle volume. We observed, perhaps surprisingly, that the reference model, based on human anthropometric data, is relatively good for vertical jumping; it achieves 90% of the jump height predicted by a model with muscles designed specifically for jumping. Alteration of cross-sectional areas-which determine the maximum force deliverable by the muscles-constitutes the majority of improvement to jump height. The optimal distribution results in large vastus, gastrocnemius and hamstrings muscles that deliver more work, while producing a kinematic pattern essentially identical to the reference model. Work output is increased by removing muscle from rectus femoris, which cannot do work on the skeleton given its moment arm at the hip and the joint excursions during push-off. The gluteus composes a disproportionate amount of muscle volume and jump height is improved by moving it to other muscles. This approach represents a way to test hypotheses about optimal human functional morphology. Future studies may extend this approach to address other morphological questions in ethological tasks such as locomotion, and feature other sets of parameters such as properties of the skeletal

  9. Effects of Below-knee Assembly Work at Different Reach Distances on Upper-extremity Muscle Activity.

    PubMed

    Shin, Seung-Je; Yoo, Won-Gyu

    2014-08-01

    [Purpose] We investigated upper-extremity muscle activity during below-knee assembly work performed by healthy adults at three different reach distances evaluate the physical risk factors associated with neck and shoulder disorders of reach distances. [Subjects] Sixteen young male workers were recruited. [Methods] Activities of the right upper trapezius, anterior deltoid, and biceps brachii muscles were measured during below-knee assembly work at the three different reach distances. [Results] The normalized EMG data of the upper trapezius, anterior deltoid, and biceps brachii muscles generally increased significantly as the reach distance at which the assembly work was performed increased. [Conclusion] Below-knee workers should engage in work that involves shorter (nearer) reach distances. PMID:25202196

  10. ECCENTRIC TRAINING FOR THE REHABILITATION OF A HIGH LEVEL WRESTLER WITH DISTAL BICEPS TENDINOSIS: A CASE REPORT

    PubMed Central

    Magrum, Eric M.

    2012-01-01

    Background and Purpose: Distal biceps brachii tendinosis is a relatively uncommon clinical diagnosis seen by physical therapists. As a result, there is little evidence guiding clinical decisions regarding best practice or effective treatment options to restore individuals to their previous level of function. The purpose of this case report is to describe the use of eccentric training as the primary intervention in the rehabilitation of a patient with distal biceps tendinosis. Case Description: A 41-year-old male electrician and collegiate wrestling coach presented to a university outpatient physical therapy clinic with a two month duration of pain in the right antecubital space which occurred when the patient was performing close-grip body weight curl ups for the first time. Sharp pain was noted in the right arm during the lowering phase of the exercise. Following the examination, distal biceps tendinosis appeared to be the likely diagnosis. The patient was educated in eccentric exercise principles and was prescribed eccentric loading exercises for the distal biceps brachii tendon in two different positions of elbow flexion. Outcomes: The patient was seen in physical therapy for three visits over the course of four weeks. Following eccentric training, the patient reported decreased pain, demonstrated increased right elbow flexion and forearm supination strength, was no longer tender to palpation of the distal biceps tendon and showed clinically significant improvement in QuickDASH scores. Discussion: Given the lack of available research on the rehabilitation of distal biceps tendinosis, eccentric training showing benefits with other upper quarter tendinoses and the positive outcomes in this case, it may be appropriate for physical therapists to employ eccentric training for patients with distal biceps tendinosis. Level of Evidence: 5 (Single case report) PMID:22893861

  11. Bifurcated Bicipital Aponeurosis Giving Origin to Flexor and Extensor Muscles of the Forearm - A Case Report.

    PubMed

    Nayak, Satheesha B; Swamy, Ravindra S; Shetty, Prakashchandra; Maloor, Prasad A; Dsouza, Melanie R

    2016-02-01

    Bicipital aponeurosis is usually attached to the antebrachial fascia on the medial side of forearm and to posterior border of ulna assisting in the supination of the forearm along with biceps brachii muscle. Variations in the bicipital aponeurosis may lead to neurovascular compression as reported earlier. In the present case, the bicipital aponeurosis had two slips i.e. medial and lateral. Medial slip gave origin to some fibers of pronator teres and flexor carpi radialis and the lateral slip gave origin to some fibers of brachioradialis. Such unusual slips of bicipital aponeurosis may distribute the stress concentration and may work in different directions affecting the supination of forearm by biceps brachii muscle and bicipital aponeurosis. PMID:27042440

  12. A new approach for the validation of skeletal muscle modelling using MRI data

    NASA Astrophysics Data System (ADS)

    Böl, Markus; Sturmat, Maike; Weichert, Christine; Kober, Cornelia

    2011-05-01

    Active and passive experiments on skeletal muscles are in general arranged on isolated muscles or by consideration of the whole muscle packages, such as the arm or the leg. Both methods exhibit advantages and disadvantages. By applying experiments on isolated muscles it turns out that no information about the surrounding tissues are considered what leads to insufficient specifications of the isolated muscle. Especially, the muscle shape and the fibre directions of an embedded muscle are completely different to that of the same isolated muscle. An explicit advantage, in contrast, is the possibility to study the mechanical characteristics in an unique, isolated way. On the other hand, by applying experiments on muscle packages the aforementioned pros and cons reverse. In such situation, the whole surrounding tissue is considered in the mechanical characteristics of the muscle which are much more difficult to identify. However, an embedded muscle reflects a much more realistic situation as in isolated condition. Thus, in the proposed work to our knowledge, we, for the first time, suggest a technique that allows to study characteristics of single skeletal muscles inside a muscle package without any computation of the tissue around the muscle of interest. In doing so, we use magnetic resonance imaging data of an upper arm during contraction. By applying a three-dimensional continuum constitutive muscle model we are able to study the biceps brachii inside the upper arm and validate the modelling approach by optical experiments.

  13. Acute effects of anterior thigh foam rolling on hip angle, knee angle, and rectus femoris length in the modified Thomas test.

    PubMed

    Vigotsky, Andrew D; Lehman, Gregory J; Contreras, Bret; Beardsley, Chris; Chung, Bryan; Feser, Erin H

    2015-01-01

    Background. Foam rolling has been shown to acutely increase range of motion (ROM) during knee flexion and hip flexion with the experimenter applying an external force, yet no study to date has measured hip extensibility as a result of foam rolling with controlled knee flexion and hip extension moments. The purpose of this study was to investigate the acute effects of foam rolling on hip extension, knee flexion, and rectus femoris length during the modified Thomas test. Methods. Twenty-three healthy participants (male = 7; female = 16; age = 22 ± 3.3 years; height = 170 ± 9.18 cm; mass = 67.7 ± 14.9 kg) performed two, one-minute bouts of foam rolling applied to the anterior thigh. Hip extension and knee flexion were measured via motion capture before and after the foam rolling intervention, from which rectus femoris length was calculated. Results. Although the increase in hip extension (change = +1.86° (+0.11, +3.61); z(22) = 2.08; p = 0.0372; Pearson's r = 0.43 (0.02, 0.72)) was not due to chance alone, it cannot be said that the observed changes in knee flexion (change = -1.39° (-5.53, +2.75); t(22) = -0.70; p = 0.4933; Cohen's d = - 0.15 (-0.58, 0.29)) or rectus femoris length (change = -0.005 (-0.013, +0.003); t(22) = -1.30; p = 0.2070; Cohen's d = - 0.27 (-0.70, 0.16)) were not due to chance alone. Conclusions. Although a small change in hip extension was observed, no changes in knee flexion or rectus femoris length were observed. From these data, it appears unlikely that foam rolling applied to the anterior thigh will improve passive hip extension and knee flexion ROM, especially if performed in combination with a dynamic stretching protocol. PMID:26421244

  14. Skeletal muscle responses to unloading in humans

    NASA Technical Reports Server (NTRS)

    Dudley, G.; Tesch, P.; Hather, B.; Adams, G.; Buchanan, P.

    1992-01-01

    This study examined the effects of unloading on skeletal muscle structure. Method: Eight subjects walked on crutches for six weeks with a 110 cm elevated sole on the right shoe. This removed weight bearing by the left lower limb. Magnetic resonance imaging of both lower limbs and biopsies of the left m. vastus laterallis (VL) were used to study muscle structure. Results: Unloading decreased (P less than 0.05) muscle cross-sectional areas (CSA) of the knee extensors 16 percent. The knee flexors showed about 1/2 of this response (-7 percent, P less than 0.05). The three vasti muscles each showed decreases (P less than 0.05) of about 15 percent. M. rectus femoris did not change. Mean fiber CSA in VL decreased (P less than 0.05) 14 percent with type 2 and type 1 fibers showing reductions of 15 and 11 percent respectively. The ankle extensors showed a 20 percent decrease (P less than 0.05) in CSA. The reduction for the 'fast' m. gastrocnemius was 27 percent compared to the 18 percent decrease for the 'slow' soleus. Summary: The results suggest that decreases in muscle CSA are determined by the relative change in impact loading history because atrophy was (1) greater in extensor than flexor muscles, (2) at least as great in fast as compared to slow muscles or fibers, and (3) not dependent on single or multi-joint function. They also suggest that the atrophic responses to unloading reported for lower mammals are quantitatively but not qualitatively similar to those of humans.

  15. Electrophysiologic and clinico-pathologic characteristics of statin-induced muscle injury

    PubMed Central

    Abdulrazaq, Mohammed; Hamdan, Farqad; Al-Tameemi, Waseem

    2015-01-01

    Objective(s): In this study, we aimed at evaluation of electrophysiological and histopathalogical characteristics of statin-induced muscle injury as well as clinical features of patients who develop this condition in terms of frequency and pattern of evolution. Materials and Methods: Forty patients (age 39-74 years) including 25 subjects with type 2 diabetes mellitus, 9 with cardiovascular diseases and 6 with hyperlipidemia, who were receiving atrovastatin 40 mg/day for variable period, were studied. Thirty three healthy subjects (age 31-74 years) served as control group. Creatine phosphokinease level, thyroid function, motor unit potential parameters and muscle fiber conduction velocity of biceps brachii and tibialis anterior muscles were measured. Results: Creatine phosphokinase level was elevated in statin users, particularly in those with diabetes mellitus. Less than 50% of statin users experienced symptoms related to muscle injury. Muscle fiber conduction velocity of the biceps brachii muscle was significantly reduced. Statin users with diabetes mellitus showed significant changes in electrophysiological parameters as compared to those with cardiovascular diseases and hyperlipidemia. Muscle biopsies showed muscle fiber variation in size, fibrosis and mild inflammatory cell infiltration. Immunohistochemical evaluation of muscle biopsies showed positive expression of Bcl-2 and one patient showed positive P53 immunohistochemical expression with elevated level of creatine phosphokinase. Conclusion: Atorvastatin increased average creatine kinase, statins produce mild muscle injury even in asymptomatic subjects. Diabetic statin users were more prone to develop muscle injury than others. Muscle fiber conduction velocity evaluation is recommended as a simple and reliable test to diagnose statin-induced myopathy instead of invasive muscle biopsy. PMID:26557961

  16. Muscle Activation during Gait in Children with Duchenne Muscular Dystrophy.

    PubMed

    Ropars, Juliette; Lempereur, Mathieu; Vuillerot, Carole; Tiffreau, Vincent; Peudenier, Sylviane; Cuisset, Jean-Marie; Pereon, Yann; Leboeuf, Fabien; Delporte, Ludovic; Delpierre, Yannick; Gross, Raphaël; Brochard, Sylvain

    2016-01-01

    The aim of this prospective study was to investigate changes in muscle activity during gait in children with Duchenne muscular Dystrophy (DMD). Dynamic surface electromyography recordings (EMGs) of 16 children with DMD and pathological gait were compared with those of 15 control children. The activity of the rectus femoris (RF), vastus lateralis (VL), medial hamstrings (HS), tibialis anterior (TA) and gastrocnemius soleus (GAS) muscles was recorded and analysed quantitatively and qualitatively. The overall muscle activity in the children with DMD was significantly different from that of the control group. Percentage activation amplitudes of RF, HS and TA were greater throughout the gait cycle in the children with DMD and the timing of GAS activity differed from the control children. Significantly greater muscle coactivation was found in the children with DMD. There were no significant differences between sides. Since the motor command is normal in DMD, the hyper-activity and co-contractions likely compensate for gait instability and muscle weakness, however may have negative consequences on the muscles and may increase the energy cost of gait. Simple rehabilitative strategies such as targeted physical therapies may improve stability and thus the pattern of muscle activity. PMID:27622734

  17. Optimizing the Distribution of Leg Muscles for Vertical Jumping

    PubMed Central

    Wong, Jeremy D.; Bobbert, Maarten F.; van Soest, Arthur J.; Gribble, Paul L.; Kistemaker, Dinant A.

    2016-01-01

    A goal of biomechanics and motor control is to understand the design of the human musculoskeletal system. Here we investigated human functional morphology by making predictions about the muscle volume distribution that is optimal for a specific motor task. We examined a well-studied and relatively simple human movement, vertical jumping. We investigated how high a human could jump if muscle volume were optimized for jumping, and determined how the optimal parameters improve performance. We used a four-link inverted pendulum model of human vertical jumping actuated by Hill-type muscles, that well-approximates skilled human performance. We optimized muscle volume by allowing the cross-sectional area and muscle fiber optimum length to be changed for each muscle, while maintaining constant total muscle volume. We observed, perhaps surprisingly, that the reference model, based on human anthropometric data, is relatively good for vertical jumping; it achieves 90% of the jump height predicted by a model with muscles designed specifically for jumping. Alteration of cross-sectional areas—which determine the maximum force deliverable by the muscles—constitutes the majority of improvement to jump height. The optimal distribution results in large vastus, gastrocnemius and hamstrings muscles that deliver more work, while producing a kinematic pattern essentially identical to the reference model. Work output is increased by removing muscle from rectus femoris, which cannot do work on the skeleton given its moment arm at the hip and the joint excursions during push-off. The gluteus composes a disproportionate amount of muscle volume and jump height is improved by moving it to other muscles. This approach represents a way to test hypotheses about optimal human functional morphology. Future studies may extend this approach to address other morphological questions in ethological tasks such as locomotion, and feature other sets of parameters such as properties of the skeletal

  18. Complex left profunda femoris vein to renal vein bypass for the management of progressive chronic iliofemoral occlusion.

    PubMed

    Anaya-Ayala, Javier E; Adams, Matthew K; Telich-Tarriba, Jose E; Dresser, Kelly L; Ismail, Nyla; Peden, Eric K

    2013-01-01

    Chronic occlusions of the inferior vena cava (IVC) and iliofemoral veins are long-term sequelae of deep venous thrombosis (DVT) that can lead to postthrombotic syndrome (PTS). Patients may present with a wide spectrum of signs and symptoms, ranging from mild discomfort and swelling to severe venous hypertension and ulcerations. We report a 68-year-old man who had a history of left lower extremity DVT after a laminectomy and who developed PTS with nonhealing ulcers. The patient underwent a cross-pubic femorofemoral venous bypass that failed to improve his clinical status. After unsuccessful endovascular attempts for recanalization of the iliofemoral segment, a profunda femoris to IVC bypass was performed. The symptoms recurred 2 years later. Venography revealed restenosis at the caval anastomosis that did not resolve by endovascular means. A surgical revision was performed, and given the quality of the IVC, a jump bypass was created to the left renal vein. The swelling improved and the ulcers healed completely. Twenty-eight months after the complex reconstructions, he remains ulcer-free with mild edema controlled with stockings. Venous reconstructions remain a viable option for patients with symptomatic and recalcitrant nonmalignant obstruction of the large veins. PMID:23122979

  19. The Contribution of "Resting" Body Muscles to the Slow Component of Pulmonary Oxygen Uptake During High-Intensity Cycling

    PubMed Central

    Ozyener, Fadil; Whipp, Brian J.; Ward, Susan A.

    2012-01-01

    Oxygen uptake (VO2) kinetics during moderate constant-workrate (WR) exercise (>lactate-threshold (θL)) are well described as exponential. AboveθL, these kinetics are more complex, consequent to the development of a delayed slow component (VO2sc), whose aetiology remains controversial. To assess the extent of the contribution to the VO2sc from arm muscles involved in postural stability during cycling, six healthy subjects completed an incremental cycle-ergometer test to the tolerable limit for estimation of θL and determination of peak VO2. They then completed two constant-WR tests at 90% of θL and two at 80% of ∆ (difference between θL and VO2peak). Gas exchange variables were derived breath-by-breath. Local oxygenation profiles of the vastus lateralis and biceps brachii muscles were assessed by near-infrared spectroscopy, with maximal voluntary contractions (MVC) of the relevant muscles being performed post-exercise to provide a frame of reference for normalising the exercise-related oxygenation responses across subjects. Above supra-θL, VO2 rose in an exponential-like fashion ("phase 2), with a delayed VO2sc subsequently developing. This was accompanied by an increase in [reduced haemoglobin] relative to baseline (∆[Hb]), which attained 79 ± 13 % (mean, SD) of MVC maximum in vastus lateralis at end-exercise and 52 ± 27 % in biceps brachii. Biceps brachii ∆[Hb] was significantly correlated with VO2 throughout the slow phase. In contrast, for sub- L exercise, VO2 rose exponentially to reach a steady state with a more modest increase in vastus lateralis ∆[Hb] (30 ± 11 %); biceps brachii ∆[Hb] was minimally affected (8 ± 2 %). That the intramuscular O2 desaturation profile in biceps brachii was proportional to that for VO2sc during supra-θL cycle ergometry is consistent with additional stabilizing arm work contributing to the VO2sc. Key points The source(s) of the "slow component" component of pulmonary oxygen uptake kinetics (VO2sc) associated

  20. Dimensions of forelimb muscles in orangutans and chimpanzees

    PubMed Central

    Oishi, Motoharu; Ogihara, Naomichi; Endo, Hideki; Ichihara, Nobutsune; Asari, Masao

    2009-01-01

    Eight forelimbs of three orangutans and four chimpanzees were dissected and the muscle mass, fascicle length and physiological cross-sectional area (PCSA) of all forelimb muscles were systematically recorded to explore possible interspecies variation in muscle dimensions. Muscle mass and PCSA were divided by the total mass and total PCSA of the entire forelimb muscles for normalization. The results indicate that the mass and PCSA ratios of the monoarticular elbow flexors (M. brachialisand M. brachioradialis) are significantly larger in orangutans. In contrast, the mass ratios of the biarticular muscles in the upper arm (the short head of M. biceps brachiiand the long head of M. triceps brachii) are significantly larger in chimpanzees. For the rotator cuff muscles, the force-generating capacity of M. subscapularisis significantly larger in orangutans, whereas the opposite rotator cuff muscle, M. infraspinatus, is larger in chimpanzees. These differences in forelimb muscle dimensions of the two species may reflect functional specialization for their different positional and locomotor behaviors. PMID:19619166

  1. Multiple Muscular Variations in the Neck, Upper Extremity, and Lower Extremity Biased toward the Left Side of a Single Cadaver

    PubMed Central

    2015-01-01

    Although numerous reports have found accessory or supernumerary muscles throughout the human body, multiple appearances of these variations biased toward one side of body are rare. We report a 76-yr-old male cadaver with an accessory head of the biceps brachii and palmaris profundus, and a muscular slip between the biceps femoris and semitendinosus on the left side in addition to a bilateral accessory belly of the digastric muscle. No remarkable nervous, vascular, or visceral variation accompanied these variations. An interruption of normal somitogenesis or myogenesis may be a cause of these variations. PMID:25829821

  2. Myotonometry as a Surrogate Measure of Muscle Strength

    NASA Technical Reports Server (NTRS)

    Ang, B. S.; Feeback, D. L.; Leonard, C. T.; Sykes, J.; Kruger, E.; Clarke, M. S. F.

    2007-01-01

    Space flight-induced muscle atrophy/neuromuscular degradation and the consequent decrements in crew-member performance are of increasing concern as mission duration lengthens, and planetary exploration after extended space flight is planned. Pre- to post-flight strength measures have demonstrated that specific countermeasures, such as resistive exercise, are effective at countering microgravity-induced muscle atrophy and preventing decrements in muscle strength. However, in-flight assessment/monitoring of exercise countermeasure effectiveness will be essential during exploration class missions due to their duration. The ability to modify an exercise countermeasure prescription based on such real-time information will allow each individual crew member to perform the optimal amount and type of exercise countermeasure to maintain performance. In addition, such measures can be used to determine if a crew member is physically capable of performing a particular mission-related task during exploration class missions. The challenges faced in acquiring such data are those common to all space operations, namely the requirement for light-weight, low power, mechanically reliable technologies that make valid measurements in microgravity, in this case of muscle strength/neuromuscular function. Here we describe a simple, light-weight, low power, non-invasive device, known as the Myotonometer, that measures tissue stiffness as an indirect measure of muscle contractile state and muscle force production. Repeat myotonometer measurements made at the same location on the surface of the rectis femoris muscle (as determined using a 3D locator device, SEM plus or minus 0.34 mm) were shown to be reproducible over time at both maximal voluntary contraction (MVC) and at rest in a total of 17 sedentary subjects assessed three times over a period of seven days. In addition, graded voluntary isometric force production (i.e. 20%, 40%, 60%, 80% & 100% of MVC) during knee extension was shown to

  3. Discomfort and muscle activation during car egress in drivers with hemiplegia following stroke

    PubMed Central

    Jung, Nam-hae; Kim, Hwanhee; Chang, Moonyoung

    2015-01-01

    [Purpose] This study investigated and compared the discomfort experienced during car egress with the car door opened at different angles and muscle activation in drivers with hemiplegia following stroke and non-disabled drivers. [Subjects and Methods] The participants were five drivers with hemiplegia and five non-disabled drivers. The discomfort experienced during car egress was measured using the nine-point Likert scale when the door was opened wide and when it was opened 45°. Muscle activation was measured using the TeleMyo 2400T G2 electromyography system. Electromyograph electrodes were placed on the erector spinae, rectus abdominis, and rectus femoris muscles. [Results] In the non-disabled drivers, there was no significant difference in the discomforts they experienced during car egress when the door was opened wide and when it was opened 45°. However, the discomfort experienced by drivers with hemiplegia when the door was opened 45° was significantly higher than that experienced when it was opened wide. There was a significant difference in the activation of the erector spinae, but no difference in the activation of the rectus abdominis or rectus femoris muscles. [Conclusion] This study will help to understand the difficulties experienced by drivers with hemiplegia following stroke during car ingress and egress. PMID:26834350

  4. Detection of B-mode polarization at degree angular scales by BICEP2.

    PubMed

    Ade, P A R; Aikin, R W; Barkats, D; Benton, S J; Bischoff, C A; Bock, J J; Brevik, J A; Buder, I; Bullock, E; Dowell, C D; Duband, L; Filippini, J P; Fliescher, S; Golwala, S R; Halpern, M; Hasselfield, M; Hildebrandt, S R; Hilton, G C; Hristov, V V; Irwin, K D; Karkare, K S; Kaufman, J P; Keating, B G; Kernasovskiy, S A; Kovac, J M; Kuo, C L; Leitch, E M; Lueker, M; Mason, P; Netterfield, C B; Nguyen, H T; O'Brient, R; Ogburn, R W; Orlando, A; Pryke, C; Reintsema, C D; Richter, S; Schwarz, R; Sheehy, C D; Staniszewski, Z K; Sudiwala, R V; Teply, G P; Tolan, J E; Turner, A D; Vieregg, A G; Wong, C L; Yoon, K W

    2014-06-20

    We report results from the BICEP2 experiment, a cosmic microwave background (CMB) polarimeter specifically designed to search for the signal of inflationary gravitational waves in the B-mode power spectrum around ℓ∼80. The telescope comprised a 26 cm aperture all-cold refracting optical system equipped with a focal plane of 512 antenna coupled transition edge sensor 150 GHz bolometers each with temperature sensitivity of ≈300  μK(CMB)√s. BICEP2 observed from the South Pole for three seasons from 2010 to 2012. A low-foreground region of sky with an effective area of 380 square deg was observed to a depth of 87 nK deg in Stokes Q and U. In this paper we describe the observations, data reduction, maps, simulations, and results. We find an excess of B-mode power over the base lensed-ΛCDM expectation in the range 30 < ℓ < 150, inconsistent with the null hypothesis at a significance of >5σ. Through jackknife tests and simulations based on detailed calibration measurements we show that systematic contamination is much smaller than the observed excess. Cross correlating against WMAP 23 GHz maps we find that Galactic synchrotron makes a negligible contribution to the observed signal. We also examine a number of available models of polarized dust emission and find that at their default parameter values they predict power ∼(5-10)× smaller than the observed excess signal (with no significant cross-correlation with our maps). However, these models are not sufficiently constrained by external public data to exclude the possibility of dust emission bright enough to explain the entire excess signal. Cross correlating BICEP2 against 100 GHz maps from the BICEP1 experiment, the excess signal is confirmed with 3σ significance and its spectral index is found to be consistent with that of the CMB, disfavoring dust at 1.7σ. The observed B-mode power spectrum is well fit by a lensed-ΛCDM+tensor theoretical model with tensor-to-scalar ratio r = 0

  5. Distinguishing between extra natural inflation and natural inflation after BICEP2

    SciTech Connect

    Kohri, Kazunori; Lim, C.S.; Lin, Chia-Min E-mail: lim@lab.twcu.ac.jp

    2014-08-01

    In this paper, we carefully calculated the tensor-to-scalar ratio, the running spectral index, and the running of running spectrum for (extra) natural inflation in order to compare with recent BICEP2 data, PLANCK satellite data and future 21 cm data. We discovered that the prediction for running spectral index and the running of running spectrum in natural inflation is different from that in the case of extra natural inflation. Near future observation for the running spectral index can only provide marginal accuracy which may not allow us distinguishing between extra natural inflation from natural inflation clearly unless the experimental accuracy can be further improved.

  6. Imaging of Posterior Interosseous Neuropathy following Distal Biceps Repair: A Report of 3 Cases

    PubMed Central

    Fitzpatrick, Darren; Petchprapa, Catherine; Rybak, Leon

    2015-01-01

    Three cases of PIN palsy following biceps repair are presented with clinical and imaging correlation. The imaging findings in these cases will be discussed and the orthopedic literature, as regards possible surgical approaches and technical factors believed to predispose to or prevent this complication, will be reviewed. It is important for radiologists to serve as consultants in these uncommon but sometimes devastating complications, helping to quickly and accurately recognize the imaging findings corresponding to the clinical symptoms and aiding the surgeon in diagnosis and treatment by identifying the possible causes and sites of nerve compression. PMID:26770861

  7. Medial Biceps Sling Takedown May Be Necessary to Expose an Occult Subscapularis Tendon Tear

    PubMed Central

    Hartzler, Robert U.; Burkhart, Stephen S.

    2014-01-01

    With a systematic approach to diagnosis, including a thorough history, physical examination, advanced imaging, and arthroscopic evaluation, most subscapularis tendon tears may be readily discovered. Occult tears, on the other hand, may escape arthroscopic detection if a high index of suspicion and certain intraoperative examination steps are lacking. We describe an occult tear pattern in which a subscapularis tendon tear was completely hidden by an intact medial biceps tendon sling. Takedown of the sling, which was expendable because a tenodesis was planned, was required to expose this occult tear. Awareness of occult subscapularis tear patterns makes diagnosis and repair possible. PMID:25685681

  8. Attrition tendinitis of long head of biceps brachii in relation to humeral head osteonecrosis: case report.

    PubMed

    Wiesler, Ethan R; Sarlikiotis, Thomas; Mavrogenis, Andreas F; Kokkalis, Zinon T

    2013-01-01

    This case report identifies a 41-year-old male patient who developed anterior shoulder pain in the setting of humeral head osteonecrosis. As a consequence of the cartilage degeneration, multiple loose bodies formed and migrated into the bicipital tendon sheath, causing attrition tendinitis, which was a feature of the clinical presentation. The patient was treated by a combination of arthroscopic glenohumeral joint debridement and open tenodesis of the biceps using a suture anchor. Follow-up revealed asymptomatic shoulder function by 18 months. This is the first report in the literature of bicipital tendinitis in the context of avascular necrosis of the shoulder. PMID:24063803

  9. Medial biceps sling takedown may be necessary to expose an occult subscapularis tendon tear.

    PubMed

    Hartzler, Robert U; Burkhart, Stephen S

    2014-12-01

    With a systematic approach to diagnosis, including a thorough history, physical examination, advanced imaging, and arthroscopic evaluation, most subscapularis tendon tears may be readily discovered. Occult tears, on the other hand, may escape arthroscopic detection if a high index of suspicion and certain intraoperative examination steps are lacking. We describe an occult tear pattern in which a subscapularis tendon tear was completely hidden by an intact medial biceps tendon sling. Takedown of the sling, which was expendable because a tenodesis was planned, was required to expose this occult tear. Awareness of occult subscapularis tear patterns makes diagnosis and repair possible. PMID:25685681

  10. Monitoring the ripening process of Iberian ham by computer vision on magnetic resonance imaging.

    PubMed

    Antequera, Teresa; Caro, Andrés; Rodríguez, Pablo G; Pérez, Trinidad

    2007-07-01

    This paper explores the use of MRI (Magnetic Resonance Imaging) in combination with a fully automated Image Analysis method for the recognition of Biceps Femoris and Semimembranosus muscles in Iberian ham. A quantitative description of volume and a study of moisture and weight relationships during the product's ripening process are included. Three Active Contour methods (Variational Calculus, Dynamic Programming, and Greedy Algorithms) are used to recognize the Biceps Femoris and Semimembranosus muscles by means of Computer Vision techniques. The recognition of both muscles via MRI entails a low error rate (3-10%). A loss of weight in hams during the ripening process is related to a decrease in size (r(2)=0.992). The high correlation implies that the information obtained by means of Computer Vision techniques can be used as a non-invasive complement to the traditional processes of ham weighing and moisture estimation. PMID:22061001

  11. Whole-body vibration increases upper and lower body muscle activity in older adults: potential use of vibration accessories.

    PubMed

    Marín, Pedro J; Santos-Lozano, Alejandro; Santin-Medeiros, Fernanda; Vicente-Rodriguez, German; Casajús, Jose A; Hazell, Tom J; Garatachea, Nuria

    2012-06-01

    The current study examined the effects of whole-body vibration (WBV) on upper and lower body muscle activity during static muscle contractions (squat and bicep curls). The use of WBV accessories such as hand straps attached to the platform and a soft surface mat were also evaluated. Surface electromyography (sEMG) was measured for the medial gastrocnemius (MG), vastus lateralis (VL), and biceps brachii (BB) muscles in fourteen healthy older adults (74.8±4.5 years; mean±SD) with a WBV stimulus at an acceleration of 40 m s(-2) (30 Hz High, 2.5 mm or 46 Hz Low, 1.1 mm). WBV increased lower body (VL and MG) sEMG vs baseline (no WBV) though this was decreased with the use of the soft mat. The addition of the bicep curl with hand straps had no effect on lower body sEMG. WBV also increased BB sEMG vs baseline which was further increased when using the hand straps. There was no upper body effect of the soft mat. This study demonstrates WBV increases both lower and upper body muscle activity in healthy older adults. Moreover, WBV accessories such as hand straps attached to the platform or a soft surface mat may be used to alter exercise intensity. PMID:22406015

  12. Muscle Activation during Push-Ups with Different Suspension Training Systems

    PubMed Central

    Calatayud, Joaquin; Borreani, Sebastien; Colado, Juan C.; Martín, Fernando F; Rogers, Michael E.; Behm, David G.; Andersen, Lars L.

    2014-01-01

    The purpose of this study was to analyze upper extremity and core muscle activation when performing push-ups with different suspension devices. Young fit male university students (n = 29) performed 3 push-ups each with 4 different suspension systems. Push-up speed was controlled using a metronome and testing order was randomized. Average amplitude of the electromyographic root mean square of Triceps Brachii, Upper Trapezius, Anterior Deltoid, Clavicular Pectoralis, Rectus Abdominis, Rectus Femoris, and Lumbar Erector Spinae was recorded. Electromyographic signals were normalized to the maximum voluntary isometric contraction (MVIC). Electromyographic data were analyzed with repeated-measures analysis of variance with a Bonferroni post hoc. Based upon global arithmetic mean of all muscles analyzed, the suspended push-up with a pulley system provided the greatest activity (37.76% of MVIC; p < 0.001). Individually, the suspended push-up with a pulley system also provided the greatest triceps brachii, upper trapezius, rectus femoris and erector lumbar spinae muscle activation. In contrast, more stable conditions seem more appropriate for pectoralis major and anterior deltoid muscles. Independent of the type of design, all suspension systems were especially effective training tools for reaching high levels of rectus abdominis activation. Key Points Compared with standard push-ups on the floor, suspended push-ups increase core muscle activation. A one-anchor system with a pulley is the best option to increase TRICEP, TRAPS, LUMB and FEM muscle activity. More stable conditions such as the standard push-up or a parallel band system provide greater increases in DELT and PEC muscle activation. A suspended push-up is an effective method to achieve high muscle activity levels in the ABS. PMID:25177174

  13. Effects of walking speed and age on the muscle forces of unimpaired gait subjects

    NASA Astrophysics Data System (ADS)

    Fliger, Carlos G.; Crespo, Marcos J.; Braidot, Ariel A.; Ravera, Emiliano P.

    2016-04-01

    Clinical gait analysis provides great contributions to the understanding of gait disorders and also provides a mean for a more comprehensive treatment plan. However, direct measures of muscle forces are difficult to obtain in clinical settings because it generally requires invasive techniques. Techniques of musculoskeletal modeling have been used for several decades to improve the benefits of clinical gait analysis, but many of the previous studies were focused on analyzing separately the muscle forces distribution of children or adult subjects with only one condition of walking speed. For these reason, the present study aims to enhance the current literature by describing the age and speed gait effects on muscle forces during walking. We used a musculoskeletal model with 23 degrees of freedom and 92 musculotendon actuators to represent 76 muscles in the lower extremities and torso. The computed muscle control algorithm was used to estimate the muscle forces from the kinematics and to adjust the model obtained in the residual reduction algorithm. We find that hamstrings has an important peak in the mid-stance phase in the adult group but this peak disappears in the children group with the same walking speed condition. Furthermore, the rectus femoris presents an increase in the muscle force during the pre- and mid-swing in concordance with the increment in the walking speed of subjects. This behavior could be associated with the role that the rectus femoris has in the acceleration of the knee joint. Finally, we show that the soleus is the muscle that perform the major force throughout the gait cycle regardless of age and walking speed.

  14. Tendinopathies Around the Elbow Part 2: Medial Elbow, Distal Biceps and Triceps Tendinopathies

    PubMed Central

    Donaldson, Oliver; Vannet, Nicola; Gosens, Taco; Kulkarni, Rohit

    2013-01-01

    In the second part of this review article the management of medial elbow tendinopathy, distal biceps and distal triceps tendinopathy will be discussed. There is a scarcity of publications concerning any of these tendinopathies. This review will summarise the current best available evidence in their management. Medial elbow tendinopathy, also known as Golfer's elbow, is up to 6 times less common than lateral elbow tendinopathy. The tendinopathy occurs in the insertion of pronator teres and flexor carpi radialis. Diagnosis is usually apparent through a detailed history and examination but care must be made to exclude other conditions affecting the ulnar nerve or less commonly the ulnar collateral ligament complex. If doubt exists then MRI/US and electrophysiology can be used. Treatment follows a similar pattern to that of lateral elbow tendinopathy. Acute management is with activity modification and topical NSAIDs. Injection therapy and surgical excision are utilised for recalcitrant cases. Distal biceps and triceps tendinopathies are very rare and there is limited evidence published. Sequelae of tendinopathy include tendon rupture and so it is vital to manage these tendinopathies appropriately in order to minimise this significant complication. Their management and that of partial tears will be considered. PMID:27582910

  15. MEASUREMENT OF COSMIC MICROWAVE BACKGROUND POLARIZATION POWER SPECTRA FROM TWO YEARS OF BICEP DATA

    SciTech Connect

    Chiang, H. C.; Barkats, D.; Bock, J. J.; Hristov, V. V.; Jones, W. C.; Kovac, J. M.; Lange, A. E.; Mason, P. V.; Matsumura, T.; Ade, P. A. R.; Battle, J. O.; Dowell, C. D.; Nguyen, H. T.; Bierman, E. M.; Keating, B. G.; Duband, L.; Hivon, E. F.; Holzapfel, W. L.; Kuo, C. L.; Leitch, E. M.

    2010-03-10

    Background Imaging of Cosmic Extragalactic Polarization (BICEP) is a bolometric polarimeter designed to measure the inflationary B-mode polarization of the cosmic microwave background (CMB) at degree angular scales. During three seasons of observing at the South Pole (2006 through 2008), BICEP mapped {approx}2% of the sky chosen to be uniquely clean of polarized foreground emission. Here, we present initial results derived from a subset of the data acquired during the first two years. We present maps of temperature, Stokes Q and U, E and B modes, and associated angular power spectra. We demonstrate that the polarization data are self-consistent by performing a series of jackknife tests. We study potential systematic errors in detail and show that they are sub-dominant to the statistical errors. We measure the E-mode angular power spectrum with high precision at 21 <= l <= 335, detecting for the first time the peak expected at l {approx} 140. The measured E-mode spectrum is consistent with expectations from a LAMBDACDM model, and the B-mode spectrum is consistent with zero. The tensor-to-scalar ratio derived from the B-mode spectrum is r = 0.02{sup +0.31}{sub -0.26}, or r < 0.72 at 95% confidence, the first meaningful constraint on the inflationary gravitational wave background to come directly from CMB B-mode polarization.

  16. Single field inflation with modulated potential in light of Planck and BICEP2

    NASA Astrophysics Data System (ADS)

    Wan, Youping; Li, Siyu; Li, Mingzhe; Qiu, Taotao; Cai, Yifu; Zhang, Xinmin

    2014-07-01

    The recently released BICEP2 data detected the primordial B-mode polarization in the cosmic microwave background (CMB) map which strongly supports for a large tensor-to-scalar ratio, and, thus, is found to be in tension with the Planck experiment with no evidence of primordial gravitational waves. Such an observational tension, if confirmed by forthcoming measurements, would bring a theoretical challenge for the very early Universe models. To address this issue, we revisit a single field inflation model proposed by Wang et al. [Int. J. Mod. Phys. D 14, 1347 (2005)] and Feng et al. [Phys. Rev. D 68, 103511 (2003)] which includes a modulated potential. We show that this inflation model can give rise to a sizable negative running behavior for the spectral index of primordial curvature perturbation and a large tensor-to-scalar ratio. Applying these properties, our model can nicely explain the combined Planck and BICEP2 observations. To examine the validity of analytic calculations, we numerically confront the predicted temperature and B-mode power spectra with the latest CMB observations and explicitly show that our model is consistent with the current data.

  17. ISOKINETIC AND FUNCTIONAL EVALUATION OF DISTAL BICEPS RECONSTRUCTION USING THE MAYO MINI-DOUBLE ROUTE TECHNIQUE

    PubMed Central

    Júnior, José Carlos Garcia; de Castro Filho, Carlos Daniel Candido; de Castro Mello, Tadeu Fujita; de Vasconcelos, Rodrigo Antunes; Zabeu, José Luís Amim; Garcia, Jesely Pereira Myrrha

    2015-01-01

    Objective: To evaluate the functional outcome among patients with distal biceps injuries who were operated using the Mayo mini-double route technique, with a minimum follow-up of six months after surgery, through digital isokinetic dynamometry, goniometry and subjective scores in order to establish objective and subjective improvement patterns and discuss the effectiveness of the procedure. Methods: Nine patients who underwent surgery to treat distal biceps injury were evaluated by means of Cybex digital dynamometry using an angular velocity of 30°/s with five repetitions and 120°/s with 15 repetitions, in comparison with the uninjured side. DASH (Disabilities of the arm, shoulder and hand), Mayo elbow score and conventional goniometry were also used. Results: Digital dynamometer showed that using the angular velocity of 30°/s with five repetitions, there was an average flexion deficit of 9.6% and an average supination deficit of -28.97%. Using an angular velocity of 120°/s with fifteen repetitions, the average flexion deficit was 4.43% and the average supination deficit was -24.1%. Conclusions: The loss of flexion followed the pattern already shown in the literature. However, in our series, there were supination strength gains, possibly due to the strict rehabilitation protocol. The technique used in this study was safe and low-cost, with few complications and good functional results. PMID:27047869

  18. Self-unitarization of New Higgs Inflation and compatibility with Planck and BICEP2 data

    SciTech Connect

    Germani, Cristiano; Wintergerst, Nico; Watanabe, Yuki E-mail: watanabe@resceu.s.u-tokyo.ac.jp

    2014-12-01

    In this paper we show that the Germani-Kehagias model of Higgs inflation (or New Higgs Inflation), where the Higgs boson is kinetically non-minimally coupled to the Einstein tensor is in perfect compatibility with the latest Planck and BICEP2 data. Moreover, we show that the tension between the Planck and BICEP2 data can be relieved within the New Higgs inflation scenario by a negative running of the spectral index. Regarding the unitarity of the model, we argue that it is unitary throughout the evolution of the Universe. Weak couplings in the Higgs-Higgs and Higgs-graviton sectors are provided by a large background dependent cut-off scale during inflation. In the same regime, the W and Z gauge bosons acquire a very large mass, thus decouple. On the other hand, if they are also non-minimally coupled to the Higgs boson, their effective masses can be enormously reduced. In this case, the W and Z bosons are no longer decoupled. After inflation, the New Higgs model is well approximated by a quartic Galileon with a renormalizable potential. We argue that this can unitarily create the right conditions for inflation to eventually start.

  19. Neutrinos and dark energy after Planck and BICEP2: data consistency tests and cosmological parameter constraints

    NASA Astrophysics Data System (ADS)

    Zhang, Jing-Fei; Geng, Jia-Jia; Zhang, Xin

    2014-10-01

    The detection of the B-mode polarization of the cosmic microwave background (CMB) by the BICEP2 experiment implies that the tensor-to-scalar ratio r should be involved in the base standard cosmology. In this paper, we extend the ΛCDM r+neutrino/dark radiation models by replacing the cosmological constant with the dynamical dark energy with constant w. Four neutrino plus dark energy models are considered, i.e., the wCDM r ∑ mν, wCDM r Neff, wCDM r ∑ mν Neff, and wCDM r Neff mν,sterileeff models. The current observational data considered in this paper include the Planck temperature data, the WMAP 9-year polarization data, the baryon acoustic oscillation data, the Hubble constant direct measurement data, the Planck Sunyaev-Zeldovich cluster counts data, the Planck CMB lensing data, the cosmic shear data, and the BICEP2 polarization data. We test the data consistency in the four cosmological models, and then combine the consistent data sets to perform joint constraints on the models. We focus on the constraints on the parameters w, ∑ mν, Neff, and mν,sterileeff.

  20. The structure and vascularization of the biceps brachii long head tendon.

    PubMed

    Kolts, I; Tillmann, B; Lüllmann-Rauch, R

    1994-01-01

    In the present study we examined the structure and the blood supply of the long biceps tendon as well as the surface of the intertubercular sulcus, using tissue samples from children and adults. The applied methods were light and electron microscopy, immunohistochemistry, and arterial injection techniques. The tendon represents a sliding tendon with the intertubercular sulcus and humeral head as hypomochlion. The parts facing the humerus show some ultrastructural features of fibrous cartilage, the ovoid chondrocyte-like cells of the tendon lying within felt-like matrix. In the opposite part adjacent to the capsule, the tendon resembles a traction tendon. The intertubercular sulcus is covered by fibrous cartilage. The tendon is supplied with arteries from three different sources. The density of intratendinous vessels in the traction zone is comparable to that of other tendons, while in the sliding zone it is markably decreased. The immediate vicinity of the sliding surface is avascular. Our findings show that the long biceps tendon is structurally adapted to both its functions as sliding and traction tendon. The blood supply seems to be related to the metabolic requirements of the different parts of the tendon. PMID:8304595

  1. Neutrinos and dark energy after Planck and BICEP2: data consistency tests and cosmological parameter constraints

    SciTech Connect

    Zhang, Jing-Fei; Geng, Jia-Jia; Zhang, Xin E-mail: gengjiajia163@163.com

    2014-10-01

    The detection of the B-mode polarization of the cosmic microwave background (CMB) by the BICEP2 experiment implies that the tensor-to-scalar ratio r should be involved in the base standard cosmology. In this paper, we extend the ΛCDM r+neutrino/dark radiation models by replacing the cosmological constant with the dynamical dark energy with constant w. Four neutrino plus dark energy models are considered, i.e., the wCDM r ∑ m{sub ν}, wCDM r N{sub eff}, wCDM r ∑ m{sub ν} N{sub eff}, and wCDM r N{sub eff} m{sub ν,sterile}{sup eff} models. The current observational data considered in this paper include the Planck temperature data, the WMAP 9-year polarization data, the baryon acoustic oscillation data, the Hubble constant direct measurement data, the Planck Sunyaev-Zeldovich cluster counts data, the Planck CMB lensing data, the cosmic shear data, and the BICEP2 polarization data. We test the data consistency in the four cosmological models, and then combine the consistent data sets to perform joint constraints on the models. We focus on the constraints on the parameters w, ∑ m{sub ν}, N{sub eff}, and m{sub ν,sterile}{sup eff}.

  2. One- Versus Two-Incision Technique for Distal Biceps Tendon Repair

    PubMed Central

    Johnson, Timothy S.; Johnson, David C.; Allen, Answorth A.; Weiland, Andrew J.; Cavanaugh, John; Noonan, Dennis; Lyman, Stephen

    2008-01-01

    There are several techniques that have been described for distal biceps tendon repair but there is still controversy regarding the optimal technique. Our hypothesis is that the single-incision technique will have a similar complication rate and functionally equivalent restoration of function compared with the two-incision approach. A retrospective review of consecutive biceps tendon repairs was performed at one institution over a 5-year period. Thirty-six patients met the inclusion criteria and 26 were available for follow-up including subjective assessment, physical examination, and strength testing. Patients were divided into two groups based on the surgical approach utilized: 12 patients underwent single-incision repair and 14 had a two-incision repair. The average follow-up was 33 months (minimum 13; maximum 75). There were no statistically significant differences in regards to flexion strength or endur