Yeh, Peter C; Shin, Steven S
Mallet injuries are the most common closed tendon injury in the athlete. Flexor digitorum profundus ruptures are rare in baseball, but are common injuries in contact sports. The diagnosis for each condition is based on clinical examination, although radiographs should be evaluated for a possible bony component. Treatment for mallet injury depends on the athlete's goals of competition and understanding of the consequences of any treatment chosen. Gripping, throwing, and catching would be restricted or impossible with the injured finger immobilized. Treatment of FDP ruptures is almost always surgical and requires reattachment of the torn tendon to the distal phalanx.
Wei, David H; Terrono, Andrew L
Swan neck deformity, or hyperextension of the proximal interphalangeal joint, may occur secondary to trauma, rheumatoid arthritis, cerebral palsy, or Ehlers-Danlos syndrome, and can be treated with tenodesis of one slip of the flexor digitorum sublimis tendon. This technique has several variations, differing primarily in the specific location and method that a single slip of the flexor digitorum sublimis tendon is secured, but they all serve to create a static volar restraint against hyperextension. Options include tunneling the tendon through the bone of the proximal phalanx, attaching the tendon to the A1 or A2 pulley, or securing the tendon with bone anchors in the proximal phalanx.
Senda, Hiroya; Mizutani, Jun; Okamoto, Hideki
Abstract An intratendinous ganglion of the hand is a rare entity, and only one case report of flexor tendon has been published in the English literature. We herein report two cases of an intratendinous ganglion occurring in the extensor digitorum communis and flexor digitorum superficialis tendon, respectively. PMID:28164147
Wittmayer, Brian C; Freed, Lewis
The flexor digitorum accessorius longus is a rare muscular occurrence in the lower extremity. It has been reported as an etiology of tarsal tunnel syndrome through prior case reports. By means of individual case study, we revisit flexor digitorum accessorius longus as a cause of tarsal tunnel syndrome. This case study discusses diagnosis along with surgical treatment of tarsal tunnel syndrome induced by the presence of flexor digitorum accessorius longus.
Batista, Jorge Pablo; del Vecchio, Jorge Javier; Golanó, Pau; Vega, Jordi
Endoscopy for the posterior region of the ankle through two portals is becoming more widespread for the treatment of a large number of conditions which used to be treated with open surgery years ago. The tendon of the flexor hallucis longus (FHL) travels along an osteofibrous tunnel between the posterolateral and posteromedial tubercles of the talus. Chronic inflammation of this tendon may lead to painful stenosing tenosynovitis. The aim of this report is to describe two cases depicting an accessory tendon which is an anatomical variation of the flexor hallucis longus in patients with posterior friction syndrome due to posterior ankle impingement and associated with a posteromedial osteochondral lesion of the talus. The anatomical variation (FDAL) described was a finding during an endoscopy of the posterior region of the ankle, and we have spared it by sectioning the superior flexor retinaculum only. The accessory flexor digitorum longus is an anatomical variation and should be taken into account when performing an arthroscopy of the posterior region of the ankle. We recommend this treatment on this type of injury although we admit this does not make a definite conclusion. PMID:26060592
Hamman, J; Ali, A; Phillips, C; Cunningham, B; Mass, D P
Many reports have been devoted to characterizing the significance of the pulleys for the flexor digitorum profundus (FDP). However, no comparable work has been published on the flexor digitorum superficialis (FDS). This study characterized the FDS in a human cadaver model. Eleven fresh-frozen cadaver hands were used. By using a tensiometer, data were gathered for tendon excursion, tendon load, and work of flexion. Changes in efficiency were caused by excision of annular pulleys A1, A2, A3, and the palmar aponeurotic pulley. We also measured the effect of FDP excision on FDS efficiency. Sectioning of the A2 and A3 pulleys together caused statistically significant losses of efficiency in all three parameters (work, load, and excursion). When the FDP was removed from a finger with an intact pulley system, losses in both work and excursion efficiencies were significant. Removing the FDP while cutting different pulleys caused significant decrease in FDS excursion efficiency. We conclude that A2 and A3 are the most important pulleys for maintaining normal FDS function, and that the presence of the FDP in the digital sheath is essential for optimal FDS excursion efficiency.
JONES, M.; ABRAHAMS, P. H.; SAÑUDO, J. R.; CAMPILLO, M.
In 1813 Gantzer described 2 accessory muscles in the human forearm which bear his name (Wood, 1868; Macalister, 1875; Testut, 1884; Le Double, 1897). The more frequent of the 2 accessory muscles or ‘accessorius ad pollicem’ was found to arise from the coronoid process of the ulna, coursing distally to attach into the flexor pollicis longus muscle (flexor pollicis longus accessory head, FPLah). The less frequently observed or ‘accessorius ad flexorem profundum digitorum’ was again found to arise from the coronoid process and course to join into the flexor digitorum profundus (flexor digitorum profundus accessory head, FDPah). Since their initial description, they have been examined in further detail by a number of authors (Wood, 1868; Macalister, 1875; Le Double, 1897; Dykes & Anson, 1944; Mangini, 1960; Malhotra et al. 1982; Dellon & McKinnon, 1987; Kida, 1988). These studies, most of them focusing on the FPLah, all show different results of prevalence, origin, insertion, relations and nerve supply. We undertook this study with the aim of providing a more accurate account of the detailed morphology of both accessory muscles because of the above-mentioned inconsistent anatomical descriptions and the lack of information as to important aspects such as vascular supply, morphology (shape and length) and the coexistence of both accessory heads. PMID:9419002
Herrin, Sean O.
Muscle variants are routinely encountered in the dissection laboratory and in clinical practice and therefore anatomists and clinicians need to be aware of their existence. Here we describe two different accessory muscles identified while performing educational dissection of a 51-year-old male cadaver. Tensor fasciae suralis, a rare muscle variant, was identified bilaterally and accessory flexor digitorum longus, a more common muscle variant, was present unilaterally. Tensor fasciae suralis and accessory flexor digitorum longus are clinically relevant muscle variants. To our knowledge, the coexistence of tensor fasciae suralis and accessory flexor digitorum longus in the same individual has not been reported in either cadaveric or imaging studies. PMID:28210274
Bale, Logan S W; Herrin, Sean O
Muscle variants are routinely encountered in the dissection laboratory and in clinical practice and therefore anatomists and clinicians need to be aware of their existence. Here we describe two different accessory muscles identified while performing educational dissection of a 51-year-old male cadaver. Tensor fasciae suralis, a rare muscle variant, was identified bilaterally and accessory flexor digitorum longus, a more common muscle variant, was present unilaterally. Tensor fasciae suralis and accessory flexor digitorum longus are clinically relevant muscle variants. To our knowledge, the coexistence of tensor fasciae suralis and accessory flexor digitorum longus in the same individual has not been reported in either cadaveric or imaging studies.
Felder, Jerrod J; Guseila, Loredana M; Saranathan, Archana; Shary, Timothy J; Lippitt, Steven B; Elias, John J
The current study was performed to determine the strength and rigidity of the intact flexor digitorum profundus (FDP) tendon attachment and compare the rigidity at the attachment site to the rigidity within a more proximal part of the tendon. Eight cadaveric index fingers were tested to failure of the FDP tendon. Lines were drawn on each tendon with India ink stain at the position of the attachment to bone and 5 mm and 10 mm proximally. Each test was recorded using a high resolution video camera. A minimum of six images per test were used for analysis of tissue deformation. The centroid of each line was computationally identified to characterize the deformation of the tendon between the lines. Force vs. deformation curves were generated for the 5 mm region representing the tendon attachment and the 5 mm region adjacent to the attachment. Stiffness measurements were generated for each curve, and normalized by the initial length to determine the rigidity. The failure strength ranged from 263 N to 548 N, with rigidity values ranging from 2201 N/(mm/mm) to 8714 N/(mm/mm) and from 3459 N/(mm/mm) to 6414 N/(mm/mm) for the attachment and the tendon proximal to the attachment, respectively. The rigidity did not vary significantly between the attachment and proximal tendon based on a Wilcoxon signed rank test (p = 0.2). The measured strength and rigidity establish biomechanical properties for the FDP tendon attachment to bone.
Kaufmann, Robert A; Kozin, Scott H; Mirarchi, Adam; Holland, Burt; Porter, Scott
Grip strength is generated through extrinsic flexor tendon and intrinsic muscle actuation. In the study reported here, we analyzed the grip-generating properties of the flexor digitorum profundus (FDP) and flexor digitorum superficialis (FDS) tendons during grip-strength generation. In vivo gripping was reproduced in 11 cadaveric forearms through pneumatic tensioning of flexor tendons. A Jamar dynamometer (TEC, Clifton, NJ) was positioned in the hand at varying degrees of angulation measured between the Jamar compression axis and the second metacarpal. Maximum gripping strength during isolated FDP and FDS tensioning generated maximum compressive forces at different angles (P < .0001). The isolated FDP showed continued increased grip strength with larger angles and was most effective when the dynamometer handle was in contact with the distal phalanx. The isolated FDS was most effective at smaller angles when the handle made contact with the middle phalanx. The isolated FDS shows an initial increase in grip strength as the contact point moves toward the middle phalanx (P < .01) and then a tendency for grip strength to decline as the contact point moves over the distal phalanx (P < .01). The FDP and FDS tendons demonstrate unique abilities to generate compression on a dynamometer. This knowledge is important to consider when evaluating grip strength in patients who have injured the extrinsic finger flexors.
Kim, Hong Geum; Chung, Myung Eun; Song, Dae Heon; Kim, Ju Yong; Sul, Bo Mi; Oh, Chang Hoon
Objective To determine the optimal injection site in the flexor digitorum longus (FDL) muscle for effective botulinum toxin injection. Methods Fourteen specimens from eight adult Korean cadavers were used in this study. The most proximal medial point of the tibia plateau was defined as the proximal reference point; the most distal tip of the medial malleolus was defined as the distal reference point. The distance of a line connecting the proximal and distal reference points was defined as the reference length. The X-coordinate was the distance from the proximal reference point to the intramuscular motor endpoint (IME), or motor entry point (MEP) on the reference line, and the Y-coordinate was the distance from the nearest point from MEP on the medial border of the tibia to the MEP. IME and MEP distances from the proximal reference point were evaluated using the raw value and the X-coordinate to reference length ratio was determined as a percentage. Results The majority of IMEs were located within 30%-60% of the reference length from the proximal reference point. The majority of the MEPs were located within 40%-60% of the reference length from the proximal reference point. Conclusion We recommend the anatomical site for a botulinum toxin injection in the FDL to be within a region 30%-60% of the reference length from the proximal reference point. PMID:25750869
Sasi, P. Kiran; Mahapatra, Swagath; Raj Pallapati, Samuel C.; Thomas, Binu P.
Traumatic musculotendinous junction avulsions are rare injuries except in avulsion amputations. They pose a significant challenge to the treating surgeon. We present a 24-year-old male who sustained an open musculotendinous avulsion of the flexor pollicis longus tendon. He was treated with primary tendon transfer using the flexor digitorum superficialis of ring finger, in flexor zone 3. The functional result at 10 months following surgery was excellent. PMID:27019757
Cassell, M D; Bergman, R A
An unusual and unrecorded variation in palmaris longus muscle is described. The muscle had a normal appearance and origin from the common tendon arising from the medial epicondyle of the humerus and from the surrounding intermuscular septa. The distal tendon however entered the hand via the carpal tunnel medial and deep to the median nerve, split and inserted into the lateral and medial sides of the middle phalanx of the ring finger. It therefore substituted completely for the slip to the ring finger from flexor digitorum superficials, which was absent.
CARBERRY, STEVEN; BRINKMEIER, HEINRICH; ZHANG, YAXIN; WINKLER, CLAUDIA K.; OHLENDIECK, KAY
Duchenne muscular dystrophy is due to genetic abnormalities in the dystrophin gene and represents one of the most frequent genetic childhood diseases. In the X-linked muscular dystrophy (mdx) mouse model of dystrophinopathy, different subtypes of skeletal muscles are affected to a varying degree albeit the same single base substitution within exon 23 of the dystrophin gene. Thus, to determine potential muscle subtype-specific differences in secondary alterations due to a deficiency in dystrophin, in this study, we carried out a comparative histological and proteomic survey of mdx muscles. We intentionally included the skeletal muscles that are often used for studying the pathomechanism of muscular dystrophy. Histological examinations revealed a significantly higher degree of central nucleation in the soleus and extensor digitorum longus muscles compared with the flexor digitorum brevis and interosseus muscles. Muscular hypertrophy of 20–25% was likewise only observed in the soleus and extensor digitorum longus muscles from mdx mice, but not in the flexor digitorum brevis and interosseus muscles. For proteomic analysis, muscle protein extracts were separated by fluorescence two-dimensional (2D) gel electrophoresis. Proteins with a significant change in their expression were identified by mass spectrometry. Proteomic profiling established an altered abundance of 24, 17, 19 and 5 protein species in the dystrophin-deficient soleus, extensor digitorum longus, flexor digitorum brevis and interosseus muscle, respectively. The key proteomic findings were verified by immunoblot analysis. The identified proteins are involved in the contraction-relaxation cycle, metabolite transport, muscle metabolism and the cellular stress response. Thus, histological and proteomic profiling of muscle subtypes from mdx mice indicated that distinct skeletal muscles are differentially affected by the loss of the membrane cytoskeletal protein, dystrophin. Varying degrees of perturbed protein
Carberry, Steven; Brinkmeier, Heinrich; Zhang, Yaxin; Winkler, Claudia K; Ohlendieck, Kay
Duchenne muscular dystrophy is due to genetic abnormalities in the dystrophin gene and represents one of the most frequent genetic childhood diseases. In the X-linked muscular dystrophy (mdx) mouse model of dystrophinopathy, different subtypes of skeletal muscles are affected to a varying degree albeit the same single base substitution within exon 23 of the dystrophin gene. Thus, to determine potential muscle subtype-specific differences in secondary alterations due to a deficiency in dystrophin, in this study, we carried out a comparative histological and proteomic survey of mdx muscles. We intentionally included the skeletal muscles that are often used for studying the pathomechanism of muscular dystrophy. Histological examinations revealed a significantly higher degree of central nucleation in the soleus and extensor digitorum longus muscles compared with the flexor digitorum brevis and interosseus muscles. Muscular hypertrophy of 20-25% was likewise only observed in the soleus and extensor digitorum longus muscles from mdx mice, but not in the flexor digitorum brevis and interosseus muscles. For proteomic analysis, muscle protein extracts were separated by fluorescence two-dimensional (2D) gel electrophoresis. Proteins with a significant change in their expression were identified by mass spectrometry. Proteomic profiling established an altered abundance of 24, 17, 19 and 5 protein species in the dystrophin-deficient soleus, extensor digitorum longus, flexor digitorum brevis and interosseus muscle, respectively. The key proteomic findings were verified by immunoblot analysis. The identified proteins are involved in the contraction-relaxation cycle, metabolite transport, muscle metabolism and the cellular stress response. Thus, histological and proteomic profiling of muscle subtypes from mdx mice indicated that distinct skeletal muscles are differentially affected by the loss of the membrane cytoskeletal protein, dystrophin. Varying degrees of perturbed protein
Godwin, Y; Wheble, G A C; Feig, C
This study estimated the prevalence of independent flexor digitorum superficialis function in the small fingers of 90 violin and viola players. The hypothesis tested was that the independent digital movements required in this population would select out those with absent flexor digitorum superficialis function. Professional string players were tested clinically, using standard and modified tests, for flexor digitorum superficialis function. Two additional physical tests were applied: the gap and stretch tests. These tests assess ring finger movement once the small finger is placed and the instrument is held in the chin-hold position. A statistically significant reduction in the prevalence of absent flexor digitorum superficialis function was confirmed in the musicians compared with a control group and published meta-analysis. This suggests that independent flexor digitorum superficialis function is important for professional musicians playing at an elite level.
Duran-Stanton, Amelia M; Bui-Mansfield, Liem T
Anomalous muscles of the ankle are common. Although they are often asymptomatic, they can sometimes cause tarsal tunnel syndrome. We report a case of tarsal tunnel syndrome due to flexor digitorum accessorius longus and peroneocalcaneus internus muscles diagnosed on magnetic resonance imaging. Recognition of the most common accessory muscles of the ankle on magnetic resonance imaging and tarsal tunnel syndrome are also reviewed.
Jain, D K; Kakarala, G; Compson, J; Singh, R
This study was done to identify whether the dimensions of the distal phalanges allow suture anchor fixation of the flexor digitorum profundus tendon. Forty pairs of hands were dissected to measure the anteroposterior and lateral dimensions of distal phalanges of all digits. The mean anteroposterior depth of the distal phalanx at the insertion of the tendon was found to be 4.7 mm for the little finger, 5.4 mm for the ring finger, 5.9 mm for the middle finger, 5.4 mm for the index finger and 6.9 mm for the thumb respectively. The commonly available anchors and drill bits for fingers were found to be suboptimal for anchoring the flexor digitorum profundus tendon to the distal phalanx of the little finger. The drill bits used for these anchors were found to be too long for the little fingers and some ring and index fingers.
Kilbreath, S L; Gorman, R B; Raymond, J; Gandevia, S C
In humans, the flexor digitorum profundus (FDP), which is a multi-tendoned muscle, produces forces that flex the four distal interphalangeal joints of the fingers. We determined whether the force associated with activity in a single motor unit in the FDP was confined to a single finger or distributed to more than one finger during a natural grasp. The discharge of single low-threshold motor units (n = 69) was recorded at sites across the muscle during weak voluntary grasping involving all fingers and spike-triggered averaging of the forces under each of the finger pads was used to assess the distribution pattern. Spike-triggered averaging revealed that time-locked changes in force occurred under the ‘test’ finger (that finger on which the unit principally acted) as well as under the ‘non-test’ fingers. However, for the index-, middle- and ring-finger units, the changes in force under non-test fingers were typically small (< 20 % of those under the test finger). For little-finger units, the mean changes in force under the adjacent ring finger were large (>50 % of those under the test finger). The distribution of forces by little-finger units differed significantly from that for each of the other three fingers. Apart from increases in force under non-test fingers, there was occasional unloading of adjacent fingers (22/267 combinations), usually affecting the index finger. The increases in force under the test finger correlated significantly with the background force for units acting on the middle, ring and little fingers. During a functional grasp, the activity of single units in the FDP allows for a relatively selective control of forces at the tips of the index, middle and ring fingers, but this is limited for little-finger units. PMID:12181299
El Domiaty, M A; Zoair, M M; Sheta, A A
Entrapment neuropathy in the forearm is not uncommon. Surgical interference for nerve decompression should be preceded by accurate diagnosis of the exact cause and site of the nerve entrapment. The aim of the present study was to investigate the prevalence of accessory heads of the flexor pollicis longus and flexor digitorum profundus muscles (FPLah) and (FDPah) in Egyptians and their topographical relationship with both the median nerve and its anterior interosseous branch. A total of 42 upper limbs of embalmed cadavers, 36 from males and 6 from females, were examined to elucidate the prevalence of both the FPLah and the FDPah muscles, their origin, insertion, nerve supply and morphology. The distribution of these two muscles in the right and left male and female upper limbs and their relationship to the anterior interosseous and median nerves were recorded. The total lengths of both accessory muscles and the lengths of their fleshy bellies and tendons were also measured. The FPLah was found to be present more frequently (61.9%) than it was absent, whereas the FDPah was observed in only 14.24% of the specimens examined. The combination of the accessory muscles in the same forearm was noticed in 9.52% of cases. As regards side, the FPLah appeared in 77.7% of the right forearms and in 50% of the left, while the FDPah was found in only 25% of the left forearms. The accessory muscles showed no single morphology, as the FPLah appeared fusiform in 53.8%, slender in 30.8% and voluminous fusiform in 15.4%, while the FDPah was slender in 66.6% and triangular in 33.3% of specimens. The FPLah arose mainly from the under surface of flexor digitorum superficialis, while the FDPah took its origin from the under surface of flexor digitorum superficialis or from the medial epicondyle. The insertion of the FPLah was mainly into the upper third of the FPL tendon, while the FDPah tendon joined the tendons of the flexor digitorum profundus muscle to the index or middle and ring
Momose, T; Amadio, P C; Zhao, C; Zobitz, M E; Couvreur, P J; An, K N
We studied the breaking strength and gliding resistance between the pulley and flexor tendon for various suture techniques. Canine flexor digitorum profundus tendons were transected and sutured using one of eight repair techniques: modified Kessler (MK); Tsuge (Tsuge); two variations of a double modified Kessler (DK1, DK2); combined modified Kessler-modified Tsuge (MKT); augmented Becker (Becker); Cruciate (Cruciate); and modified double Tsuge (DT). The force to produce a 1.5 mm gap, ultimate failure load, resistance to gap formation, and gliding resistance were measured. The force to produce a 1.5 mm gap and the ultimate breaking force were higher with the DK1, DK2, MKT, Becker, Cruciate, and DT repairs than they were with the MK and Tsuge repair, while the gliding resistance of the Becker was higher than that of the MK, DK1, DK2, MKT. Cruciate, and UT repairs. In addition to confirming that repair strength increases as the number of strands crossing the repair increases, we also found that these stronger repairs need not produce higher gliding resistance than less robust repairs.
Calderón, Juan C; Bolaños, Pura; Torres, Sonia H; Rodríguez-Arroyo, Greta; Caputo, Carlo
Enzymatically dissociated flexor digitorum brevis (FDB) and soleus fibres from mouse were used to compare the kinetics of electrically elicited Ca2+ transients of slow and fast skeletal muscle fibres, using the fast Ca2+ dye MagFluo4-AM, at 20-22 degrees C. For FDB two Ca2+ transient morphologies, types I (MT-I, 11 fibres, 19%) and II (MT-II, 47 fibres, 81%), were found, the kinetic parameters (amplitude, rise time, half width, decay time, and time constants of decay) being statistically different. For soleus (n = 20) only MT-I was found, with characteristics similar to MT-I from FDB. Correlations with histochemically determined mATPase, reduced nicotinamide adenine dinucleotide diaphorase and alpha-glycerophosphate dehydrogenase activities, as well as immunostaining and myosin heavy chain electrophoretic analysis of both muscles suggest that signals classified as MT-I may correspond to slow type I and fast IIA fibres while those classified as MT-II may correspond to fast IIX/D fibres. The results point to the importance of Ca2+ signaling for characterization of muscle fibres, but also to its possible role in determining fibre function.
Fedorczyk, Jane M; Barr, Ann E; Rani, Shobha; Gao, Helen G; Amin, Mamta; Amin, Shreya; Litvin, Judith; Barbe, Mary F
Upper extremity tendinopathies are associated with performance of forceful repetitive tasks. We used our rat model of repetitive strain injury to study changes induced in forelimb flexor digitorum tendons. Rats were trained to perform a high repetition high force (HRHF) handle-pulling task (12 reaches/min at 60 +/- 5% maximum pulling force [MPF]), or a low repetition negligible force (LRNF) reaching and food retrieval task (three reaches/min at 5 +/- 5% MPF), for 2 h/day in 30 min sessions, 3 days/week for 3-12 weeks. Forelimb grip strength was tested. Flexor digitorum tendons were examined at midtendon at the level of the carpal tunnel for interleukin (IL)-1beta, neutrophil, and macrophage influx, Substance P, connective tissue growth factor (CTGF), and periostin-like factor (PLF) immunoexpression, and histopathological changes. In HRHF rats, grip strength progressively decreased, while IL-1beta levels progressively increased in the flexor digitorum peritendon (para- and epitendon combined) and endotendon with task performance. Macrophage invasion was evident in week 6 and 12 HRHF peritendon but not endotendon. Also in HRHF rats, Substance P immunoexpression increased in week 12 peritendon as did CTGF- and PLF-immunopositive fibroblasts, the increased fibroblasts contributing greatly to peritendon thickening. Endotendon collagen disorganization was evident in week 12 HRHF tendons. LRNF tendons did not differ from controls, even at 12 weeks. Thus, we observed exposure-dependent changes in flexor digitorum tendons within the carpal tunnel, including increased inflammation, nociceptor-related neuropeptide immunoexpression, and fibrotic histopathology, changes associated with grip strength decline.
Aimola, Ettore; Valle, Maria Stella; Casabona, Antonino
Muscle reflexes, evoked by opposing a sudden joint displacement, may be modulated by several factors associated with the features of the mechanical perturbation. We investigated the variations of muscle reflex response in relation to the predictability of load magnitude during a reactive grasping task. Subjects were instructed to flex the fingers 2–5 very quickly after a stretching was exerted by a handle pulled by loads of 750 or 1250 g. Two blocks of trials, one for each load (predictable condition), and one block of trials with a randomized distribution of the loads (unpredictable condition) were performed. Kinematic data were collected by an electrogoniometer attached to the middle phalanx of the digit III while the electromyography of the Flexor Digitorum Superficialis muscle was recorded by surface electrodes. For each trial we measured the kinematics of the finger angular rotation, the latency of muscle response and the level of muscle activation recorded below 50 ms (short-latency reflex), between 50 and 100 ms (long-latency reflex) and between 100 and 140 ms (initial portion of voluntary response) from the movement onset. We found that the latency of the muscle response lengthened from predictable (35.5±1.3 ms for 750 g and 35.5±2.5 ms for 1250 g) to unpredictable condition (43.6±1.3 ms for 750 g and 40.9±2.1 ms for 1250 g) and the level of muscle activation increased with load magnitude. The parallel increasing of muscle activation and load magnitude occurred within the window of the long-latency reflex during the predictable condition, and later, at the earliest portion of the voluntary response, in the unpredictable condition. Therefore, these results indicate that when the amount of an upcoming perturbation is known in advance, the muscle response improves, shortening the latency and modulating the muscle activity in relation to the mechanical demand. PMID:25271638
Dum, R P; O'Donovan, M J; Toop, J; Burke, R E
The properties of flexor digitorum longus (FDL) muscles and of individual motor units were studied in cats 30-50 wk after self-reinnervation by FDL motoneurons (FDL----FDL) or cross-reinnervation by soleus (SOL) motoneurons (SOL----FDL). Individual motor units were functionally isolated by intracellular recording and stimulation of identified SOL alpha-motoneurons. Glycogen-depletion methods permitted histochemical study of muscle fibers belonging to physiologically characterized muscle units. The observations were compared with data from normal cat FDL muscles and motor units (27). Intentionally self-reinnervated FDL muscles (FDL----FDL; n = 5) were normal in size and wet weight. FDL----FDL motor units could be classified into the same physiological categories found in normal FDL [types: fast contracting, fatigable (FF), fast contracting, fatigue resistant (FR), and slow (S); n = 24], with approximately the same proportions as normal. The histochemical muscle fiber types associated with these categories were also qualitatively normal although there was evidence of marked distortion of the normal histochemical mosaic. These data confirm other studies of self-reinnervation and suggest that self-reinnervation can produce complete interconversion of muscle fiber types. Cross-reinnervation of FDL muscle by SOL motoneurons (SOL----FDL; n = 12) produced muscles that were smaller (about half the normal wet weight) and more red than normal. SOL----FDL muscle contracted more slowly than normal or FDL----FDL muscles and had much higher proportions of histochemical type I muscle fibers. In those SOL----FDL muscles, in which little or no unwanted self-reinnervation could be demonstrated, greater than 95% of the muscle fibers were type I. Forty-one individual motor units in SOL----FDL muscles were isolated by intracellular penetration in functionally identified SOL alpha-motoneurons. Their muscle units were all type S by physiological criteria (absence of "sag" in unfused
Dum, R P; O'Donovan, M J; Toop, J; Tsairis, P; Pinter, M J; Burke, R E
The properties of whole soleus (SOL) muscles and of individual motor units were studied in cats 30-50 wk after self-reinnervation by soleus (SOL) motoneurons (SOL----SOL) or cross-reinnervation by flexor digitorum longus (FDL) motoneurons (FDL----SOL). As in the preceding paper (22), intracellular and glycogen-depletion methods were used to examine the physiological and histochemical properties of individual motor units. The results were compared with data from normal SOL motor units (8, 12). Intentionally self-reinnervated SOL muscles (SOL----SOL; n = 6) were normal in size and wet weight, and all of the five SOL----SOL motor units studied had physiological and histochemical characteristics that matched those of normal SOL units. Cross-reinnervation of SOL by FDL alpha-motoneurons (FDL----SOL; n = 7) produced muscles with wet weights and appearance essentially identical to normal SOL. However, whole-muscle twitch contraction times were much shorter (mean 60.4 ms) than those of normal (mean 136.9 ms, n = 18) or SOL----SOL muscles (mean 115.3 ms; n = 6). Despite this difference, none of the FDL----SOL muscles contained more than 7% histochemical type II muscle fibers, all of which were type IIA. Normal cat SOL muscles can contain up to 5% type IIA fibers, but none of our SOL----SOL muscles showed any type II fibers. Two FDL----SOL muscles had significant amounts of unintended self-reinnervation, permitting side-by-side comparison of FDL----SOL and SOL----SOL muscle fibers. The twitch contraction times of the two populations differed markedly, but they were histochemically indistinguishable except for the fact that SOL----SOL fibers had high neutral fat content (as do normal SOL fibers), whereas FDL----SOL showed much lower fat content. The 23 FDL----SOL muscle units studied were classified as physiological type S by criteria ("sag" test and fatigue resistance) used to identify motor-unit types in normal cat muscles. All five of the FDL----SOL units studied
Molloy, A P; Lyons, R; Bergin, D; Kearns, S R
The flexor digitorium accessorius muscle is an unusual anatomical variant found in the posteromedial aspect of the hindfoot and ankle. As previously described, its location predisposes patients to developing tarsal tunnel syndrome. This case illustrates the diagnosis, treatment and resolution of tarsal tunnel syndrome in a paediatric patient, secondary to the presence of flexor digitorium accessorius muscle.
Rigó, István Zoltán; Røkkum, Magne
We compared the results of two methods for reinsertion of flexor digitorum profundus tendons retrospectively. In 35 fingers of 29 patients pull-out suture and in 13 fingers of 11 patients transverse intraosseous loop technique was performed with a mean follow-up of 8 and 6 months, respectively. Eleven and nine fingers achieved "excellent" or "good" function according to Strickland and Glogovac at 8 weeks; 20 and ten at the last control in the pull-out and transverse intraosseous loop groups, respectively. The difference at 8 weeks was statistically significant in favour of the transverse intraosseous loop group. Ten patients underwent 12 complications in the pull-out group (four superficial infections; one rerupture, one PIP and one DIP joint contracture, one adhesion, two granulomas, one nail deformity and one carpal tunnel syndrome) and four of them were reoperated (one carpal tunnel release, one teno-arthrolysis and two resections of granuloma). There was no complication and no reoperation in the transverse intraosseous loop group, the difference being statistically significant for the former. In our study the transverse intraosseous loop technique seemed to be a safe alternative with possibly better functional results compared to the pull-out suture.
Richter, Martinus; Zech, Stefan
Lengthening osteotomy of the calcaneus (LO) and flexor digitorum longus tendon (FDL) transfer to the navicular is one option for the treatment of flexible flatfoot deformity (FD). The aim of the study was to analyse the amount of correction and clinical outcome including pedographic assessment. In a prospective consecutive non-controlled clinical followup study, all patients with FD that were treated with LO and FDL from September 1st 2006 to August 31st, 2009 were included. Assessment was performed before surgery and at 2-year-followup including clinical examination (with staging of posterior tibialis insufficiency) weight bearing radiographs (Talo-1st metatarsal angles (TMT)), pedography (increased midfoot contact area and force) and Visual Analogue Scale Foot and Ankle (VAS FA). 112 feet in 102 patients were analysed (age, 57.6 (13-82), 42% male). In 12 feet (9%) wound healing delay without further surgical measures was registered. All patients achieved full weight bearing during the 7th postoperative week. Until followup, revision surgery was done in 3 patients (fusion calcaneocuboid joint (n=2), correction triple arthrodesis (n=1)). 101 feet (90%) completed 2-year-followup. TMT dorsoplantar/lateral/Index and VAS FA scores were increased, and posterior tibialis insufficiency stage, pedographic midfoot contact area and force percentage were decreased (each p<.05). All relevant parameters (stage of posterior tibialis insufficiency, TMT angles and Index, pedographic midfoot contact area and force percentage, VAS FA) were improved 2 years after LO and FDL transfer to the navicular in FD. The complication rate was low. This method allows safe and predictable correction.
Ostric, Srdjan Andrei; Russell, Robert C; Petrungaro, Jason
Zone III flexor tendon injuries are relatively rare in comparison to other flexor tendon injuries in zones I, II, IV, and V. Often, these are open injuries resulting from an electrical device like a saw; however, closed injures are even rarer, and those mid-substance ruptures resulting from bowling with no evidence of underlying tendinopathy from diseases like gout are highly unusual. The principles underlying tendon repair remain the same regardless of the etiology. In this case, we delineate some of the options and stress the guiding principles of the various methods available in this interesting and unusual case.
Cabaj, Anna M.; Sławińska, Urszula
The effects of sciatic nerve crush (SNC) and treatment with Riluzole on muscle activity during unrestrained locomotion were identified in an animal model by analysis of the EMG activity recorded from soleus (Sol) and extensor digitorum longus (EDL) muscles of both hindlimbs; in intact rats (IN) and in groups of rats treated for 14 days with saline (S) or Riluzole (R) after right limb nerve crush at the 1st (1S and 1R) or 2nd (2S and 2R) day after birth. Changes in the locomotor pattern of EMG activity were correlated with the numbers of survived motor units (MUs) identified in investigated muscles. S rats with 2–8 and 10–28 MUs that survived in Sol and EDL muscles respectively showed increases in the duration and duty factor of muscle EMG activity and a loss of correlation between the duty factors of muscle activity, and abnormal flexor-extensor co-activation 3 months after SNC. R rats with 5, 6 (Sol) and 15–29 MUs (EDL) developed almost normal EMG activity of both Sol and control EDL muscles, whereas EDL muscles with SNC showed a lack of recovery. R rats with 8 (Sol) and 23–33 (EDL) MUs developed almost normal EMG activities of all four muscles. A subgroup of S rats with a lack of recovery and R rats with almost complete recovery that had similar number of MUs (8 and 24–28 vs 8 and 23–26), showed that the number of MUs was not the only determinant of treatment effectiveness. The results demonstrated that rats with SNC failed to develop normal muscle activity due to malfunction of neuronal circuits attenuating EDL muscle activity during the stance phase, whereas treatment with Riluzole enabled almost normal EMG activity of Sol and EDL muscles during locomotor movement. PMID:28095499
Graves, A E; Kornatz, K W; Enoka, R M
The purpose of this study was to determine the effect of age on the ability to exert steady forces and to perform steady flexion movements with the muscles that cross the elbow joint. An isometric task required subjects to exert a steady force to match a target force that was displayed on a monitor. An anisometric task required subjects to raise and lower inertial loads so that the angular displacement around the elbow joint matched a template displayed on a monitor. Steadiness was measured as the coefficient of variation of force and as the normalized standard deviation of wrist acceleration. For the isometric task, steadiness as a function of target force decreased similarly for old adults and young adults. For the anisometric task, steadiness increased as a function of the inertial load and there were significant differences caused by age. Old adults were less steady than young adults during both shortening and lengthening contractions with the lightest loads. Furthermore, old adults were least steady when performing lengthening contractions. These behaviors appear to be associated with the patterns of muscle activation. These results suggest that different neural strategies are used to control isometric and anisometric contractions performed with the elbow flexor muscles and that these strategies do not change in parallel with advancing age.
Abe, Takashi; Tayashiki, Kota; Nakatani, Miyuki; Watanabe, Hironori
[Purpose] To investigate the relationships between toe flexor muscle strength with (TFS-5-toes) and without (TFS-4-toes) the contribution of the great toe, anatomical and physiological muscle cross-sectional areas (CSA) of intrinsic toe flexor muscle and physical performance were measured. [Subjects] Seventeen men (82% sports-active) and 17 women (47% sports-active), aged 20 to 35 years, volunteered. [Methods] Anatomical CSA was measured in two intrinsic toe flexor muscles (flexor digitorum brevis [FDB] and abductor hallucis) by ultrasound. Muscle volume and muscle length of the FDB were also estimated, and physiological CSA was calculated. [Results] Both TFS-5-toes and TFS-4-toes correlated positively with walking speed in men (r=0.584 and r=0.553, respectively) and women (r=0.748 and r=0.533, respectively). Physiological CSA of the FDB was significantly correlated with TFS-5-toes (r=0.748) and TFS-4-toes (r=0.573) in women. In men, physiological CSA of the FDB correlated positively with TFS-4-toes (r=0.536), but not with TFS-5-toes (r=0.333). [Conclusion] Our results indicate that physiological CSA of the FDB is moderately associated with TFS-4-toes while toe flexor strength correlates with walking performance. PMID:26957721
Oshita, Kazushige; Yano, Sumio
This study was conducted to assess the relations of force fluctuations during isometric plantar-flexion and postural sway during quiet standing. Twelve healthy men (M age = 21 yr., SD = 1) performed unilateral plantar flexion measured by a strain gauge force transducer. Participants performed force-matching tasks; sustained plantar flexion for 20 sec. at levels corresponding to 10% and 20% of maximum voluntary contraction with the visual feedback. Also, participants were asked to stand quietly with their eyes open, and then the center of mass displacement and velocity in the anteroposterior were measured. In analysis, postural sway was associated with force fluctuation at only 10% of maximum voluntary contraction. The statistically significant correlation between variables was found only at corresponding contraction intensities for plantar-flexor muscles. From this one may infer neural strategies in plantar-flexor muscles during quiet standing may be characteristics similar to those controlling the plantar-flexion force in young adults.
Shamsian, Negin; Exton, Rebecca; Shibu, MM
Congenital absence of the flexor pollicis longus (FPL) is an unusual finding that is frequently associated with thumb hypoplasia. Isolated FPL absence is the rarest of the congenital thumb anomalies. The present article describes a patient with a congenitally absent FPL, and discusses the chosen method of reconstruction. PMID:22131842
Jun, Ilsub; Lee, Jaehong; Kim, Hansoo; Yang, KyungHan
[Purpose] The purpose of this study was to identify changes in the thickness of the deep cervical flexors (DCFs) according to the degree of mouth opening (MO) in normal adults. [Subjects] The study's subjects were 50 normal adults (30 men, 20 women). [Methods] Ultrasound was used to obtain images of muscles, and the NIH ImageJ software was used to measure the thickness of each muscle. [Results] An increase in MO resulted in a corresponding increase in the thickness of the DCFs, and in isometric exercises (IEs), the thickness of the DCFs further increased during MO. [Conclusion] During MO, the thickness of the DCFs increased. This may be due to correlations between mandibular movements and DCFs. Therefore, the results are likely to be utilized as new clinical research data.
Background OnabotulinumtoxinA has demonstrated significant benefit in adult focal spasticity. This study reviews the injection patterns (i.e., muscle distribution, dosing) of onabotulinumtoxinA for treatment of adult spasticity, as reported in published studies. Methods A systematic review of clinical trials and observational studies published between 1990 and 2011 reporting data on muscles injected with onabotulinumtoxinA in adult patients treated for any cause of spasticity. Results 28 randomized, 5 nonrandomized, and 37 single-arm studies evaluating 2,163 adult patients were included. The most frequently injected upper-limb muscles were flexor carpi radialis (64.0% of patients), flexor carpi ulnaris (59.1%), flexor digitorum superficialis (57.2%), flexor digitorum profundus (52.5%), and biceps brachii (38.8%). The most frequently injected lower-limb muscles were the gastrocnemius (66.1% of patients), soleus (54.7%), and tibialis posterior (50.5%). The overall dose range reported was 5–200 U for upper-limb muscles and 10–400 U for lower-limb muscles. Conclusions The reviewed evidence indicates that the muscles most frequently injected with onabotulinumtoxinA in adults with spasticity were the wrist, elbow, and finger flexors and the ankle plantar flexors. OnabotulinumtoxinA was injected over a broad range of doses per muscle among the studies included in this review, but individual practitioners should be mindful of local regulatory approvals and regulations. PMID:24011236
Ferreira, Aline M; Tanaka, Denise M; Barbosa, Rafael I; Marcolino, Alexandre M; Elui, Valeria MC; Mazzer, Nilton
Objective: To evaluate the activity of wrist extensor muscle, correlating with wrist motion during gripping after flexor tendon repair. Design: Cross-sectional clinical measurement study. Setting: Laboratory for biomechanics and rehabilitation. Subjects: A total of 11 patients submitted to rehabilitation by early passive motion of the fingers with wrist flexion position were evaluated after 8 weeks of fingers flexor tendon repair and 11 healthy volunteers, all ranging from 20 to 37 years of age. Intervention: Volunteers performed an isometric standardized gripping task. Main measures: We used electrogoniometry to analyze wrist range of motion and surface electromyography, considering 100% maximum voluntary contraction to represent the amplitude of electromyographic activity of the extensor carpi radialis and flexor digitorum superficialis. Results: Patients with flexor tendon repair showed co-activation deficit between wrist extensor (extensor carpi radialis) and flexor finger muscles (flexor digitorum superficialis) during gripping in the intermediate phase of rehabilitation, despite some recovering mobility for wrist extension (p ≤ 0.05). A moderate correlation between range of motion and extensor carpi radialis was present only for injured group (r = 0.32). Total active motion score, which represents finger active excursion, was regular or poor in 65% of cases, all with nerve repair associated. Conclusion: Wrist extensors have an important synergist role at handgrip, although some imbalance can be present after flexor tendon repair. These preliminary findings suggest that emphasis could be directed to add synergistic wrist motion in rehabilitation protocols after flexor tendon repair. Future studies with early active rehabilitation are necessary. PMID:26770674
Maratta, Robert; Fenrich, Keith K; Zhao, Ethan; Neuber-Hess, Monica S; Rose, P Ken
Serotonergic (5-HT) and noradrenergic (NA) input to spinal motoneurons is essential for generating plateau potentials and self-sustained discharges. Extensor motoneurons are densely innervated by 5-HT and NA synapses and have robust plateau potentials and self-sustained discharges. Conversely, plateau potentials and self-sustained discharges are very rare in flexor motoneurons. The most likely reasons for this difference are that flexor motoneurons have few 5-HT and NA synapses and/or they are distributed distant to the channels responsible for plateau potentials and self-sustained discharges. However, the distribution of 5-HT and NA synapses on flexor motoneurons is unknown. Here we describe the distribution and density of 5-HT and NA synapses on motoneurons that innervate the flexor neck muscle, rectus capitis anterior (RCA), in the adult cat. Using a combination of intracellular staining, fluorescent immunohistochemistry, and 3D reconstruction techniques, we found that 5-HT and NA synapses are widely distributed throughout the dendritic trees of RCA motoneurons, albeit with a strong bias to small-diameter dendrites and to medial dendrites in the case of NA contacts. The number of 5-HT and NA contacts per motoneuron ranged, respectively, from 381 to 1,430 and from 642 to 1,382, which is 2.3- and 1.4-fold less than neck extensor motoneurons (Montague et al., J Comp Neurol 2013;521:638-656). These results suggest that 5-HT and NA synapses on flexor motoneurons may provide a powerful means of amplifying synaptic currents without incurring plateau potentials or self-sustained discharges. This feature is well suited to meet the biomechanical demands imposed on flexor muscles during different motor tasks.
Hwang, Kun; Huan, Fan; Kim, Dae Joong
The aim of this study was to determine the fibre types of the muscles moving the index fingers in humans. Fifteen forearms of eight adult cadavers were used. The sampled muscles were the first lumbrical (LM), first volar interosseous (VI), first dorsal interosseus (DI), second flexor digitorum profundus (FDP), second flexor digitorum superficialis (FDS), and extensor digitorum (ED). Six micrometer thick sections were stained for fast muscle fibres. The procedure was performed by applying mouse monoclonal anti-skeletal myosin antibody (fast) and avidin-biotin peroxidase complex staining. Rectangular areas (0.38 mm × 0.38 mm) were photographed and the boundaries of the muscle areas were marked on the translucent film. The numbers and sizes of the muscle fibres in each part were evaluated by the image analyser program and calculated per unit area (1 mm(2)). The proportion of the fast fibres was significantly (p = 0.012) greater in the intrinsic muscles (55.7 ± 17.1%) than in the extrinsic muscles (45.9 ± 17.1%). Among the six muscles, the VI had a significantly higher portion (59.3%) of fast fibres than the FDS (40.6%) (p = 0.005) or the FDP (45.1%) (p = 0.023). The density of the non-fast fibres was significantly (p = 0.015) greater in the extrinsic muscles (539.2 ± 336.8/mm(2)) than in the intrinsic muscles (383.4 ± 230.4/mm2). Since the non-fast fibres represent less fatigable fibres, it is thought that the extrinsic muscles have higher durability against fatigue, and the intrinsic muscles, including the LM, should move faster than the FDS or FDP because the MP joint should be flexed before the IP joint to grip an object.
Kafri, Michal; Zaltsberg, Nir; Dickstein, Ruth
Somatosensory stimulation modulates cortical and corticospinal excitability and consequently affects motor output. Therefore, low-amplitude transcutaneous electrical nerve stimulation (TENS) has the potential to elicit favorable motor responses. The purpose of the two presented pilot studies was to shed light on TENS parameters that are relevant for the enhancement of two desirable motor outcomes, namely, electromyographic (EMG) activity and contraction strength of the finger flexors and wrist muscles. In 5 and 10 healthy young adults (in Study I and Study II, respectively) TENS was delivered to the volar aspect of the forearm. We manipulated TENS frequency (150 Hz vs. 5 Hz), length of application (10, 20, and 60 min), and side of application (unilateral, right forearm vs. bilateral forearms). EMG amplitude and grip force were measured before (Pre), immediately after (Post), and following 15 min of no stimulation (Study I only). The results indicated that low-frequency bursts of TENS applied to the skin overlying the finger flexor muscles enhance the EMG activity of the finger flexors and grip force. The increase in EMG activity of the flexor muscles was observed after 20 min of stimulation, while grip force was increased only after 1 h. The effects of uni- and bilateral TENS were comparable. These observations allude to a modulatory effect of TENS on the tested motor responses; however, unequivocal conclusions of the findings are hampered by individual differences that affect motor outcomes, such as in level of attention.
Miranda, B. H.; Cerovac, S.
Background Spontaneous flexor tendon rupture is considered to be invariably associated with previous hand/wrist injury or systemic disease such as rheumatoid arthritis. Case Description A 54-year-old man presented with a 4-month history of mild ulnar wrist pain and spontaneous left little finger flexion loss in the absence of distant/recent trauma and systemic arthropathy. Surgical exploration confirmed a zone IV left little finger flexor digitorum profundus (FDP5) attritional rupture (100%), ring finger flexor digitorum profundus (FDP4) attenuation (40%) and a disrupted lunotriquetral ligament and volar-ulnar wrist capsule. Volar subluxation of the narrowed carpal tunnel resulted in flexor tendon attrition against the hamate hook. A side-to-side tendon transfer was performed along with a lunotriquetral ligament repair and temporary Kirschner wire fixation. At 6 months the patient had full active, synchronous flexion of the ring and little fingers and reduced wrist pain. Literature Review Traumatic flexor tendon ruptures have been reported following distal radius/hamate hook fractures, from carpal bone osteophytes, accessory carpal bones and intraosseous ganglia. Attritional ruptures caused by chronic, degenerative carpal pathology are less common. Clinical Relevance This case highlights an unusual cause of flexor tendon rupture due to chronic carpal instability. PMID:25032080
Suwa, Yuichi; Suzuki, Naoki; Soga, Temma; Harada, Ryuhei; Shibui, Aya; Kuroda, Hiroshi; Izumi, Rumiko; Tateyama, Maki; Nakashima, Ichiro; Sonoo, Masahiro; Aoki, Masashi
Sporadic inclusion body myositis (sIBM) is a chronic progressive myopathy characterized by muscle weakness of both the quadriceps femoris and finger flexors. We herein present the case of a typical male patient with sIBM, which manifested as the isolated weakness of the finger flexors three years after the disease onset. We have identified several patients with sIBM in our cohort with muscle weakness of the flexors but not the quadriceps femoris. Examination of the flexor digitorum profundus muscle is important for the early and proper diagnosis of sIBM, even if a patient only presents with isolated finger flexor muscle weakness. PMID:27904121
Cha, Hyun-Gyu; Kim, Myoung-Kwon; Shin, Young-Jun
[Purpose] The purpose of this study was to examine the effects of forearm elastic taping on grip and wrist flexor muscle strength. [Subjects and Methods] This was a single-blind, crossover study. This study selected 40 healthy subjects with no history of orthopedic disorders and was conducted after consent to participate was obtained. Grip and wrist flexor muscle strength of subjects were assessed by a handheld dynamometer and a Commander Muscle Tester, respectively, with forearm elastic taping or nonelastic taping. [Results] After application of forearm elastic taping, grip strength and wrist flexor muscle strength significantly increased compared with the nonelastic taping group. [Conclusion] Application of forearm elastic taping is considered to have positive effects on improving wrist and grip strength. PMID:27821932
Sun, L-Q; Zhao, G; Gao, S-H; Chen, C
We report a new method of flexor tendon repair in zone II using a standard modified Kessler technique combined with a vascularized dorsal fascial flap from the finger pedicled on a dorsal cutaneous branch of the proper digital artery, which is placed as a mechanical barrier between the flexor digitorum superficialis and profundus tendons. The functional outcomes of 14 patients (Group A) with flexor tendon repairs in zone II by this new technique were compared with those of 32 patients (Group B) with flexor tendon repairs in zone II using a standard modified Kessler technique only. Patients in Group A had a higher proportion of excellent results (on the modified Strickland system) and more movement in the distal interphalangeal joint than the patients in Group B.
Duci, Shkelzen B; Arifi, Hysni M; Ahmeti, Hasan R; Manxhuka-Kerliu, Suzana; Neziri, Burim; Mekaj, Agon Y; Lajqi, Shpetim; Shahini, Labinot
Background: The main goals of flexor tendon surgery are to restore digital motion by providing tendon healing and to preserve tendon gliding. Our purpose was to investigate the effects of 5-fluorouracil (5-FU) on tendon adhesions in partially divided profundus flexor tendons (flexor digitorum profundus [FDPs]) following surgical repair and in partially divided FDPs without surgical repair, and to compare the results of the repair versus the nonrepair of zone two injuries via macroscopic and biomechanical evaluations of tendon adhesions. Methods: We used 32 adult male European rabbits (Oryctolagus cunniculus) weighing from 2.5 to 3.5 kg. The study was performed on the deep flexor tendons of the second and third digits of the right hind paws of the rabbits; thus, a total of 64 tendons were examined in this study. Results: Based on the results achieved in our experimental study, the load (N) significantly increased in subgroup 1a in which the tendons were surgically repaired and were not treated with 5-FU compared with subgroup 2a in which tendons were surgically repaired and treated with 5-FU. Conclusions: The load (N) significantly increased in subgroup 1a in which the tendons were surgically repaired and were not treated with 5-FU compared to subgroup 2a in which the tendons were surgically repaired and treated with 5-FU. Therefore, these results revealed a decrease in adhesion formation in the subgroup that was treated with 5-FU due to increased resistance to tendon adhesions during their excursion through the tendon sheath, which in this case required greater traction force. PMID:26063369
Al-Qattan, Mohammad M
There is a paucity of the literature on the outcome of zone III flexor tendon injuries. In this paper, we report on the results of zone III flexor tendon repair in 35 consecutive adult patients with clean cut lacerations of both flexor tendons in 42 fingers. There were 25 men and 10 women with an average age of 32 years. Repair of both flexor tendons was performed using 'figure of eight' core sutures and a continuous epitendinous suture. Postoperatively, an immediate active range of motion protocol was applied to ensure full active extension of the interphalangeal joints. The results were assessed using the Strickland-Glogovac grading system. There were no ruptures. One patient with two injured fingers developed complex regional pain syndrome and the final outcome was fair in both fingers. In the remaining 34 patients (40 fingers), 33 patients (38 fingers) had an excellent outcome and the remaining patient (two fingers) had a good outcome.
Shim, Je-Myung; Jung, Ju-Hyeon; Kim, Hwan-Hee
[Purpose] The aim of this study was to examine whether plantar flexor static stretching and dynamic stretching using an Aero-Step results in changes in foot pressure during gait in healthy adults. [Subjects] Eighteen normal adults were randomly allocated to either a dynamic stretching using an Aero-Step group (DSUAS) group (n = 8) or a static stretching (SS) group (n = 10). [Methods] The DSUAS and SS participants took part in an exercise program for 15 minutes. Outcome measures were foot plantar pressure, which was measured during the subject's gait stance phase; the asymmetric ratio of foot pressure for both feet; and the visual analogue scale (VAS) measured during the interventions. [Results] There were significant differences in the asymmetric ratio of foot pressure for both feet and VAS between the two groups after intervention. However, there were no significant differences in foot plantar pressure during the gait stance phase within both groups. [Conclusion] DSUSAS is an effective stretching method, as pain during it is lower than that with SS, which can minimize the asymmetric ratio of foot pressure for both feet during gait due to asymmetric postural alignment.
Gabra, Joseph N; Gordon, Joshua L; Marquardt, Tamara L; Li, Zong-Ming
The transverse carpal ligament (TCL) is a component of the flexor pulley system of the wrist, keeping the flexor tendons in place by resisting their volar displacement. The purpose of this study was to investigate the in vivo biomechanical interaction between the TCL and flexor tendons in response to tendon tensioning with the wrist at various postures. In eight healthy subjects, the flexor digitorum superficialis and profundus tendons were tensioned by isometrically applying loads (5, 10, and 15N) to the index finger while the wrist posture was at 20° extension, neutral, 20° flexion, and 40° flexion. The TCL and flexor tendons were imaged at the distal carpal tunnel cross section using ultrasound. The volar-dorsal positions of the tendons, TCL arch height, and TCL-tendon distances were calculated. With increasing wrist flexion, the flexor tendons moved volarly, the TCL arch height increased, and the TCL-tendon distances decreased, indicating that the flexor tendons contacted the TCL and pushed it volarly. The TCL-tendon interaction was amplified by the combination of finger loading and wrist flexion. This study provides in vivo evidence of the biomechanical interaction between the TCL and flexor tendons. Repetitive TCL-tendon interactions may implicate the interacting tissues and the median nerve resulting in tissue maladaptation and nerve compression.
Jaiser, Stephan R.; Baker, Mark R.; Baker, Stuart N.
We investigated beta-band intermuscular coherence (IMC) in 92 healthy adults stratified by decade of age, and analysed variability between and within subjects. In the dominant upper limb, IMC was estimated between extensor digitorum communis and first dorsal interosseous as well as between flexor digitorum superficialis and first dorsal interosseous. In the ipsilateral lower limb, IMC was measured between medial gastrocnemius and extensor digitorum brevis as well as between tibialis anterior and extensor digitorum brevis. Age-related changes in IMC were analysed with age as a continuous variable or binned by decade. Intrasession variance of IMC was examined by dividing sessions into pairs of epochs and comparing coherence estimates between these pairs. Eight volunteers returned for a further session after one year, allowing us to compare intrasession and intersession variance. We found no age-related changes in IMC amplitude across almost six decades of age, allowing us to collate data from all ages into an aggregate normative dataset. Interindividual variability ranged over two orders of magnitude. Intrasession variance was significantly greater than expected from statistical variability alone, and intersession variance was even larger. Potential contributors include fluctuations in task performance, differences in electrode montage and short-term random variation in central coupling. These factors require further exploration and, where possible, minimisation. This study provides evidence that coherence is remarkably robust to senescent changes in the nervous system and provides a large normative dataset for future applications of IMC as a biomarker in disease states. PMID:26901129
André, Helô-Isa; Carnide, Filomena; Borja, Edgar; Ramalho, Fátima; Santos-Rocha, Rita; Veloso, António P
Purpose This study aimed to develop a new field test protocol with a standardized measurement of strength and power in plantar flexor muscles targeted to functionally independent older adults, the calf-raise senior (CRS) test, and also evaluate its reliability and validity. Patients and methods Forty-one subjects aged 65 years and older of both sexes participated in five different cross-sectional studies: 1) pilot (n=12); 2) inter- and intrarater agreement (n=12); 3) construct (n=41); 4) criterion validity (n=33); and 5) test–retest reliability (n=41). Different motion parameters were compared in order to define a specifically designed protocol for seniors. Two raters evaluated each participant twice, and the results of the same individual were compared between raters and participants to assess the interrater and intrarater agreement. The validity and reliability studies involved three testing sessions that lasted 2 weeks, including a battery of functional fitness tests, CRS test in two occasions, accelerometry, and strength assessments in an isokinetic dynamometer. Results The CRS test presented an excellent test–retest reliability (intraclass correlation coefficient [ICC] =0.90, standard error of measurement =2.0) and interrater reliability (ICC =0.93–0.96), as well as a good intrarater agreement (ICC =0.79–0.84). Participants with better results in the CRS test were younger and presented higher levels of physical activity and functional fitness. A significant association between test results and all strength parameters (isometric, r=0.87, r2=0.75; isokinetic, r=0.86, r2=0.74; and rate of force development, r=0.77, r2=0.59) was shown. Conclusion This study was successful in demonstrating that the CRS test can meet the scientific criteria of validity and reliability. The test can be a good indicator of ankle strength in older adults and proved to discriminate significantly between individuals with improved functionality and levels of physical activity
Moon, Hyun-Ju; Goo, Bong-Oh; Kwon, Hae-Yeon; Jang, Jun-Hyeok
[Purpose] The purpose of this study was to identify changes in the thicknesses of the cervical flexors according to eye coordination during deep cervical flexor training. [Subjects and Methods] Twenty normal adults were randomly selected, and during their deep cervical flexor training and eye tracking, the thicknesses of the longus colli and the sternocleidomastoid were measured using ultrasonic waves. [Results] The thickness of the longus colli statistically significantly increased when deep cervical flexor training and eye coordination were performed simultaneously. However, the thickness of the sternocleidomastoid did not show statistically significant differences according to eye coordination. [Conclusion] Eye coordination during deep cervical flexor training is likely to increase the thickness of the longus colli selectively. PMID:26834355
Ferlic, D C
Rheumatoid flexor tenosynovitis at the wrist can cause locking, limitation of motion, nerve compression, and rupture of tendons. To prevent and treat these conditions, a flexor tenosynovectomy, combined with nerve decompression and tendon reconstruction as indicated, is necessary. If tendons are ruptured, the flexor pollicis longus and profundus to the index finger are most commonly affected. On the fingers flexor tenosynovitis can also cause locking, decrease in range of motion and rupture tendons. Flexor tenosynovitis of the fingers should be treated with decompression of the tendons health with preservation of the pulley system.
Cavadas, P C; Pérez-García, A; Thione, A; Lorca-García, C
The reconstruction of finger flexor tendons with vascularized flexor digitorum superficialis (FDS) tendon grafts (flaps) based on the ulnar vessels as a single stage is not a popular technique. We reviewed 40 flexor tendon reconstructions (four flexor pollicis longus and 36 finger flexors) with vascularized FDS tendon grafts in 38 consecutive patients. The donor tendons were transferred based on the ulnar vessels as a single-stage procedure (37 pedicled flaps, three free flaps). Four patients required composite tendon and skin island transfer. Minimum follow-up was 12 months, and functional results were evaluated using a total active range of motion score. Multiple linear regression analysis was performed to evaluate the factors that could be associated with the postoperative total active range of motion. The average postoperative total active range of motion (excluding the thumbs) was 178.05° (SD 50°). The total active range of motion was significantly lower for patients who were reconstructed with free flaps and for those who required composite tendon and skin island flap. Age, right or left hand, donor/motor tendon and pulley reconstruction had no linear effect on total active range of motion. Overall results were comparable with a published series on staged tendon grafting but with a lower complication rate. Vascularized pedicled tendon grafts/flaps are useful in the reconstruction of defects of finger flexor tendons in a single stage, although its role in the reconstructive armamentarium remains to be clearly established.
Background Measuring the strength of individual foot muscles is very challenging; however, measuring muscle morphology has been shown to be associated with strength. A reliable method of assessing foot muscle atrophy and hypertrophy would therefore be beneficial to researchers and clinicians. Thus, the aim of this study was to evaluate the test-retest intra-observer reliability of ultrasound to measure the morphology of the primary toe flexor muscles. Method The abductor hallucis, flexor hallucis brevis, flexor digitorum brevis, quadratus plantae and abductor digiti minimi muscles in the foot, and the flexor digitorum longus and flexor hallucis longus muscles in the shank were assessed in five males and five females (mean age = 32.1 ± 10.1 years). Muscles were imaged using a GE Venue 40 ultrasound (6-9 or 7.6-10.7 MHz transducer) in a random order, and on two occasions 1-6 days apart. Muscle thickness and cross-sectional area were measured using Image J software with the assessor blinded to muscle and day of scan. Intraclass correlation coefficients (ICC) and limits of agreement were calculated to assess day-to-day repeatability of the measurements. Results The method was found to have good reliability (ICC = 0.89-0.99) with limits of agreement between 8-28% of the relative muscle size. Conclusion The protocol described in this paper showed that ultrasound is a reliable method to measure morphology of the toe flexor muscles. The portability and advantages of ultrasound make it a useful tool for clinical and research settings. PMID:23557252
Strickland, J W
In this five-part series, we have attempted to review our current understanding of flexor tendon anatomy, physiology, biomechanics, healing and adhesion formation around a repaired tendon. The methods of acute flexor tendon repair, conventional free tendon grafting, staged flexor tendon reconstruction and pulley restoration have been discussed as well as flexor tenolysis, rehabilitation and results. From these articles it may be seen that flexor tendon surgery is a complex and difficult art which requires a thorough appreciation of the normal flexor tendon system, the exact status of that system following injury and a strong understanding of the techniques which may be best utilized to restore flexor tendon function. The procedures described require both technical skill and experience and postoperative therapy programs must be carefully instituted based on the unique status of each patient. With the important advances occurring in many areas of flexor tendon surgery, it is realistic to believe that in the near future the techniques described in these articles may be substantially altered and modified. Results will continue to improve until the patient and surgeon can realistically expect to return most digits to nearly full function after flexor tendon interruption.
Baltusnikas, Juozas; Kilikevicius, Audrius; Venckunas, Tomas; Fokin, Andrej; Bünger, Lutz; Lionikas, Arimantas; Ratkevicius, Aivaras
Myostatin dysfunction promotes muscle hypertrophy, which can complicate assessment of muscle properties. We examined force generating capacity and creatine kinase (CK) efflux from skeletal muscles of young mice before they reach adult body and muscle size. Isolated soleus (SOL) and extensor digitorum longus (EDL) muscles of Berlin high (BEH) mice with dysfunctional myostatin, i.e., homozygous for inactivating myostatin mutation, and with a wild-type myostatin (BEH+/+) were studied. The muscles of BEH mice showed faster (P < 0.01) twitch and tetanus contraction times compared with BEH+/+ mice, but only EDL displayed lower (P < 0.05) specific force. SOL and EDL of age-matched but not younger BEH mice showed greater exercise-induced CK efflux compared with BEH+/+ mice. In summary, myostatin dysfunction leads to impairment in muscle force generating capacity in EDL and increases susceptibility of SOL and EDL to protein loss after exercise.
A brief literature review is made of the morphological changes in the bones of the lower limbs of man, which are the result of his upright walk. The author's task has been to study the morphological changes of Mm. extensores digitorum pedis from the viewpoint of evolutionary myology. The following material has been studied: Lower limbs of adults, 151 less than or equal to N less than or equal to 358. Pelvic limbs of Marsupialia, Insectivora, and non-hominide primates; N = 122. Lower limbs of human embryos and fetuses; N = 71. The following acknowledgements are the author's own studies. They begin with an evolutionary-myological study of m. extensor hallucis longus and of m. extensor digitorum longus, together with m. peroneus tertius.
Hiebert, G W; Whelan, P J; Prochazka, A; Pearson, K G
1. In this investigation, we tested the hypothesis that muscle spindle afferents signaling the length of hind-leg flexor muscles are involved in terminating extensor activity and initiating flexion during walking. The hip flexor muscle iliopsoas (IP) and the ankle flexors tibialis anterior (TA) and extensor digitorum longus (EDL) were stretched or vibrated at various phases of the step cycle in spontaneously walking decerebrate cats. Changes in electromyogram amplitude, duration, and timing were then examined. The effects of electrically stimulating group I and II afferents in the nerves to TA and EDL also were examined. 2. Stretch of the individual flexor muscles (IP, TA, or EDL) during the stance phase reduced the duration of extensor activity and promoted the onset of flexor burst activity. The contralateral step cycle also was affected by the stretch, the duration of flexor activity being shortened and extensor activity occurring earlier. Therefore, stretch of the flexor muscles during the stance phase reset the locomotor rhythm to flexion ipsilaterally and extension contralaterally. 3. Results of electrically stimulating the afferents from the TA and EDL muscles suggested that different groups of afferents were responsible for the resetting of the step cycle. Stimulation of the TA nerve reset the locomotor step cycle when the stimulus intensity was in the group II range (2-5 xT). By contrast, stimulation of the EDL nerve generated strong resetting of the step cycle in the range of 1.2-1.4 xT, where primarily the group Ia afferents from the muscle spindles would be activated. 4. Vibration of IP or EDL during stance reduced the duration of the extensor activity by similar amounts to that produced by muscle stretch or by electrical stimulation of EDL at group Ia strengths. This suggests that the group Ia afferents from IP and EDL are capable of resetting the locomotor pattern generator. Vibration of TA did not affect the locomotor rhythm. 5. Stretch of IP or
Winges, Sara A.; Johnston, Jamie A.; Santello, Marco
To gain insight into the synergistic control of hand muscles, we have recently quantified the strength of correlated neural activity across motor units from extrinsic digit flexors during a five-digit object-hold task. We found stronger synchrony and coherence across motor units from thumb and index finger flexor muscle compartment than between the thumb flexor and other finger flexor muscle compartments. The present study of two-digit object hold was designed to determine the extent to which such distribution of common input among thumb-finger flexor muscle compartments, revealed by holding an object with five digits, is preserved when varying the functional role of a given digit pair. We recorded normal force exerted by the digits and electrical activity of single motor units from muscle flexor pollicis longus (FPL) and two compartments of the m. flexor digitorum profundus (FDP2 and FDP3; index and middle finger, respectively). Consistent with our previous results from five-digit grasping, synchrony and coherence across motor units from FPL-FDP2 was significantly stronger than in FPL-FDP3 during object hold with two digits [common input strength: 0.49 ± 0.02 and 0.35 ± 0.02 (means ± SE), respectively; peak coherence: 0.0054 and 0.0038, respectively]. This suggests that the distribution of common neural input is muscle-pair specific regardless of grip type. However, the strength of coherence, but not synchrony, was significantly stronger in two- versus five-digit object hold for both muscle combinations, suggesting the periodicity of common input is sensitive to grip type. PMID:16723414
Stecina, Katinka; Quevedo, Jorge; McCrea, David A
Reflex actions of muscle afferents in hindlimb flexor nerves were examined on ipsilateral motoneurone activity recorded in peripheral nerves during midbrain stimulation-evoked fictive locomotion and during fictive scratch in decerebrate cats. Trains of stimuli (15-30 shocks at 200 Hz) were delivered during the flexion phase at intensities sufficient to activate both group I and II afferents (5 times threshold, T). In many preparations tibialis anterior (TA) nerve stimulation terminated ongoing flexion and reset the locomotor cycle to extension (19/31 experiments) while extensor digitorum longus (EDL) stimulation increased and prolonged the ongoing flexor phase activity (20/33 preparations). The effects of sartorius, iliopsoas and peroneus longus muscle afferent stimulation were qualitatively similar to those of EDL nerve. Resetting to extension was seen only with higher intensity stimulation (5T) while ongoing flexor activity was often enhanced at group I intensity (2T) stimulation. The effects of flexor nerve stimulation were qualitatively similar during fictive scratch. Reflex reversals were consistently observed in some fictive locomotor preparations. In those cases, EDL stimulation produced a resetting to extension and TA stimulation prolonged the ongoing flexion phase. Occasionally reflex reversals occurred spontaneously during only one of several stimulus presentations. The variable and opposite actions of flexor afferents on the locomotor step cycle indicate the existence of parallel spinal reflex pathways. A hypothetical organization of reflex pathways from flexor muscle afferents to the spinal pattern generator networks with competing actions of group I and group II afferents on the flexor and extensor portions of this central circuitry is proposed.
Luria, Shai; Haze, Amir
Pyogenic flexor tenosynovitis is an uncommon, emergent hand infection. The literature lacks any description of the disease and the variability of its manifestations in young children. We describe 3 cases. Two cases were diagnosed and treated promptly, and the third presented late, with atypical clinical signs, causing a delay in his diagnosis and treatment and stressing the caution to be taken with the evaluation of these children with signs of hand infection.
Zhao, Chunfeng; Ettema, Anke M; Berglund, Lawrence J; An, Kai-Nan; Amadio, Peter C
The purpose of this study was to investigate the effect of carpal tunnel pressure on the gliding characteristics of flexor tendons within the carpal tunnel. Eight fresh human cadaver wrists and hands were used. A balloon was inserted into the carpal tunnel to elevate the pressure. The mean gliding resistance of the middle finger flexor digitorum superficialis tendon was measured with the following six conditions: (1) as a baseline, before balloon insertion; (2) balloon with 0 mmHg pressure; (3) 30 mmHg; (4) 60 mmHg; (5) 90 mmHg; (6) 120 mmHg. The gliding resistance of flexor tendon gradually increased as the carpal tunnel pressure was elevated. At pressures above 60 mmHg, the increase in gliding resistance became significant compared to the baseline condition. This study helps us to understand the relationship between carpal tunnel pressure, which is elevated in the patient with carpal tunnel syndrome (CTS) and tendon gliding resistance, which is a component of the work of flexion. These findings suggest that patients with CTS may have to expend more energy to accomplish specific motions, which may in turn affect symptoms of hand pain, weakness and fatigue, seen commonly in such patients.
Lui, Tun Hing
Flexor hallucis longus (FHL) tendon transfer is indicated for reconstruction of the Achilles tendon with a gap larger than 5 cm. The tendon can be harvested at zone 2 or zone 3 by minimally invasive techniques with the advantage of minimal soft-tissue dissection. The tendon can be harvested under the sustentaculum tali by zone 2 FHL tendoscopy. It is adequate for FHL transfer to the posterior calcaneal tubercle. If a double-thickness reconstruction of a huge gap of the Achilles tendon is indicated, the tendon can be harvested at the level of the hallux by means of a tendon stripper. However, the interconnection tendon of the master knot of Henry can be split together with the FHL or flexor digitorum longus tendon instead of being cut. Zone 2 FHL tendoscopy can be used to release the split tendon to complete the FHL harvest.
Evgeniou, Evgenios; Iyer, Srinivasan
Flexor tenosynovitis is an aggressive closed-space infection of the digital flexor tendon sheaths of the hand. We present a case of pyogenic flexor tenosynovitis in an immunocompromised patient and discuss the importance of early diagnosis and referral to a specialist hand surgery unit. A 61-year-old man visited his general practitioner because of swelling and tenderness of his left index finger. The patient was discharged on oral antibiotics but returned 4 days after because of deterioration of his symptoms and was referred to a plastic surgery unit. A diagnosis of flexor tenosynovitis was made and the patient required multiple debridements in theatre, resulting in the amputation of the infected finger. Pyogenic flexor tenosynovitis is a relatively common but often misdiagnosed hand infection. Patients with suspected flexor tenosynovitis should be referred and treated early to avoid significant morbidity, especially when risk factors for poor prognosis are present.
Hamilton, C D; Glousman, R E; Jobe, F W; Brault, J; Pink, M; Perry, J
The medical collateral ligament is a common site of injury in baseball pitchers, causing substantial morbidity and loss of pitching time. Twenty-six skilled baseball pitchers with medial collateral ligament insufficiency were studied before surgery with high-speed cinematography and fine-wire electromyography of eight muscles around the elbow. Data from the pitchers with injured elbows were compared with data obtained from uninjured pitchers. The flexor carpi radialis muscle in the pitchers with medial collateral ligament deficiencies revealed significantly decreased firing during the acceleration and deceleration phase of the fastball when compared with that of the pitchers with normal elbows, and the flexor carpi radialis muscle was significantly depressed during the early cocking and deceleration phases. The extensor muscles revealed slightly increased activity in the injured elbows; however, this was not statistically significant. Although the muscles of the flexor pronator group (especially the flexor carpi ulnaris muscle and the flexor digitorum superficialis muscles) are anatomically positioned to provide dynamic stability of the elbow, they did not demonstrate increased electrical activity in pitchers with medial collateral ligament deficiencies. This finding suggests that the muscles on the medial side of the elbow do not supplant the role of the medial collateral ligament during the fastball pitch.
Nicchia, Grazia P; Mola, Maria G; Pisoni, Michela; Frigeri, Antonio; Svelto, Maria
Aquaporin-4 (AQP4) is the neuromuscular water channel expressed at the sarcolemma of mammalian fast-twitch fibers that mediates a high water transport rate, which is important during muscle activity. Clinical interest in the neuromuscular expression of AQP4 has increased as it is associated with the protein complex formed by dystrophin, the product of the gene affected in Duchenne muscular dystrophy. The expression of AQP4 during development has not been characterized. In this study, we analyzed the expression of AQP4 in extensor digitorum longus (EDL) and soleus, a fast- and slow-twitch muscle, respectively, during the first weeks after birth. The results show that AQP4 expression in both types of skeletal muscle occurs postnatally. The time course of expression of AQP4 in the two types of muscles was also different. Whereas the expression of AQP4 protein levels in the EDL showed a progressive increase during the first month after birth, reaching levels found in adults by day 24, the levels of the protein in the soleus showed a transient peak between day 12 and day 24 and declined thereafter, an effect that may be related to the transient high number of fast motor units innervating the soleus muscle during this time. The results suggest that AQP4 expression in skeletal muscle is under neuronal influence and contribute to the understanding of the molecular events of fiber differentiation during development.
Green, D. G.; Kellerth, J.-O.
1. Intracellular records have been taken from cat motoneurones innervating flexor muscles of the hind limb. Contractions of the ankle flexors tibialis anterior and extensor digitorum longus were elicited by stimulation of the peripheral end of the cut L 7 ventral root and the reflex effects of these contractions were recorded in silent and repetitively firing motoneurones. 2. Contraction usually produces a hyperpolarizing response inside flexor motoneurones. This hyperpolarization is tension-sensitive in the sense that when, at constant muscle extension, the strength of the contraction is increased, the magnitude of the inhibitory response is augmented. 3. Increasing the resting length of the muscles, while using a stimulus of constant strength to the ventral root, causes this inhibitory response to increase in some cells. More often, however, the hyperpolarization caused by contraction is gradually reduced in duration and/or amplitude as the muscles are extended. 4. Even with the muscles slackened, so that they develop no tension at their ends, contraction usually produces prominent hyperpolarization of the motoneurones. 5. By passing polarizing currents or injecting chloride ions through the intracellular micro-electrode, the hyperpolarizing potentials produced by contraction of the slack and extended muscles are shown to be, at least in part, genuinely post-synaptic inhibitory events. 6. When the neurone is fired repetitively by injected current, the `silent period' in contraction corresponds to the hyperpolarization of the post-synaptic membrane. 7. Monosynaptic testing of the flexor motoneurone pool has been used to confirm the essential features of the intracellularly recorded activity. 8. Acutely spinalizing the animal increases the magnitude of the inhibitory responses caused by contraction. 9. Recordings from dorsal root fibres show that Golgi tendon organs of the ankle flexors are very sensitive to contraction and are indeed often activated by the
Mickle, Karen J; Angin, Salih; Crofts, Gillian; Nester, Christopher J
Study Design Descriptive, cross-sectional. Background Age-related muscle atrophy is common in lower-limb muscles. We therefore speculated that foot muscles may also diminish with age. However, there is a paucity of literature characterizing foot muscle strength and morphology, and any relationship between these 2, in older people. Objective To compare the strength and size of the toe flexor muscles of older adults relative to their younger counterparts. Methods Seventeen young adults with a normal foot type were matched by sex and body mass index to 17 older adults with a normal foot type, from an available sample of 41 younger (18 to 50 years of age) and 44 older (60 or more years of age) adults. Among the matched groups (n = 34), muscle thickness and cross-sectional area for 5 intrinsic and 2 extrinsic toe flexor muscles were obtained using ultrasound. Toe strength was assessed using a pressure platform. Differences in toe flexor strength and muscle size between the young and older matched groups were determined using analysis of covariance (controlling for height). Correlations between strength and size of the toe flexor muscles of the pooled group (n = 34) were also calculated. Results Toe strength and the thickness and cross-sectional area of most foot muscles were significantly reduced in the older adults (P<.05). Hallux and toe flexor strength values were strongly correlated with the size of the intrinsic toe flexor muscles. Conclusion The smaller foot muscles appear to be affected by sarcopenia in older adults. This could contribute to reduced toe flexion force production and may affect the ability of older people to walk safely. Interventions aimed at reversing foot muscle atrophy in older people require further investigation. J Orthop Sports Phys Ther 2016;46(12):1065-1070. Epub 29 Oct 2016. doi:10.2519/jospt.2016.6597.
Yang, Tai-Hua; Lu, Szu-Ching; Lin, Wei-Jr; Zhao, Kristin; Zhao, Chunfeng; An, Kai-Nan; Jou, I-Ming; Lee, Pei-Yuan
Background The flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) are critical for finger flexion. Although research has recently focused on these tendons’ coactivity, their contributions in different tasks remain unclear. This study created a novel simultaneous approach to investigate the coactivity between the tendons and to clarify their contributions in different tasks. Methods Ten human cadaveric hands were mounted on our custom frame with the FDS and FDP of the third finger looped through a mechanical pulley connected to a force transducer. Joint range of motion, tendon excursion and loading force were recorded during individual joint motion and free joint movement from rest to maximal flexion. Each flexor tendon’s moment arm was then calculated. Results In individual motions, we found that the FDP contributed more than the FDS in proximal interphalangeal (PIP) joint motion, with an overall slope of 1.34 and all FDP-to-FDS excursion (P/S) ratios greater than 1.0 with force increase. However, the FDP contributed less than the FDS in metacarpophalangeal (MCP) joint motion, with an overall slope of 0.95 and P/S ratios smaller than 1.0 throughout the whole motion except between 1.9% and 13.1% force. In free joint movement, the FDP played a greater role than the FDS, with an overall ratio of 1.37 and all P/S ratios greater than 1.0. Conclusions The new findings include differences in finger performance and excursion amounts between the FDS and FDP throughout flexion. Such findings may provide the basis for new hand models and treatments. PMID:27513744
DiGiovanni, Daria L; Rademacher, Nathalie; Riggs, Laura M; Baumruck, Rebecca A; Gaschen, Lorrie
Palmar/plantar annular desmitis is a common disease that may be associated with adhesions and structures affecting the flexor tendons, which requires tenoscopy to diagnose. The purpose of this descriptive study was to develop a dynamic sonographic technique for evaluating the motion of normal equine flexor tendons in relation to the palmar/plantar annular ligament and to compare findings with horses previously diagnosed with palmar/plantar annular desmitis. Ten healthy adult horses were examined prospectively and the images of four horses diagnosed with palmar/plantar annular desmitis were retrospectively evaluated. Dynamic sonography was performed at the level of the metacarpo/metatarsophalangeal joint by maximally extending and flexing the interphalangeal joints. Palmar/plantar annular ligament thickness (mm), size of any gap between the flexor tendons, and subjectively increased angulation of the long linear echoes of the superficial digital flexor tendon were measured. The presence of gliding motion between the palmar/plantar annular ligament and superficial digital flexor tendon was determined by consensus. Twenty-eight healthy control limbs (16 hind/12 fore) and four with palmar/plantar annular desmitis (3 hind/1 fore) were evaluated. Controls had unrestricted gliding motion between the palmar/plantar annular ligament and flexor tendons and zero to 13° of angulation of the long linear echoes. The four affected horses had restricted gliding motion and between 20-35° angulation of the long linear echoes. Dynamic ultrasound is a feasible technique for detecting restricted flexor tendon and palmar/plantar annular ligament gliding motion, as well as subjectively increased angulation of the long linear echoes of the flexor tendon in affected horses compared with controls and warrants further investigation.
Hahn, P; Lanz, U
Primary or secondary flexor tendon surgery occasionally leads to damaged flexor pulleys. Insufficient pulley reconstruction causes loss of finger function by bow stringing of the flexor tendon. This paper reviews the anatomy and biomechanics of the flexor pulley system. Different techniques of reconstruction are discussed.
Zhao, Chunfeng; Ettema, Anke M; Osamura, Naoki; Berglund, Lawrence J; An, Kai-Nan; Amadio, Peter C
The purpose of this study was to investigate the gliding characteristics of flexor tendons within the carpal tunnel with varied wrist positions and tendon motion styles, which may help us to understand the relationship between carpal tunnel syndrome (CTS) and repetitive hand motion. Eight fresh human cadaveric wrists and hands were used. The peak (PGR) and mean (MGR) gliding resistance of the middle finger flexor digitorum superficialis tendon were measured with the wrist in 0, 30, and 60 degrees of flexion and extension. While moving all three fingers together, the PGR at 60 degrees flexion was significantly higher than that at 0, 30, or 60 degrees extension. While moving the middle finger alone, the PGR at 60 and 30 degrees flexion was significantly higher than the PGR at 60 degrees extension. The PGR moving the middle finger FDS alone was significantly greater than that for all three digits moving together in 0, 30, and 60 degrees flexion. Differential finger motion with wrist flexion elevated the tendon gliding resistance in the carpal tunnel, which may be relevant in considering the possible role of wrist position and activity in the etiology of CTS.
Tat, Jimmy; Kociolek, Aaron M; Keir, Peter J
Non-inflammatory fibrosis and thickening of the subsynovial connective tissue (SSCT) are characteristic in carpal tunnel syndrome (CTS) patients. These pathological changes have been linked to repetitive hand tasks that create shear forces between the flexor tendons and SSCT. We measured the relative motion of the flexor digitorum superficialis tendon and SSCT during two repetitive finger tasks using color Doppler ultrasound. Twelve participants performed flexion-extension cycles for 30 min with the long finger alone (differential movement) and with all four fingers together (concurrent movement). Shear strain index (SSI, a relative measure of excursion in flexion and extension) and maximum velocity ratio (MVR, the ratio of SSCT versus tendon during flexion and extension) were used to represent shear. A linear effect of exertion time was significant and corresponded with larger tendon shear in differential motion. The flexion SSI increased 20.4% from the first to the 30th minute, while MVR decreased 8.9% in flexion and 8.7% in extension. No significant changes were found during concurrent motion. These results suggest that exposure to repetitive differential finger tasks may increase the risk of shear injury in the carpal tunnel.
Giant cell tumour of tendon sheath with simultaneous two tendon involvement of the foot treated with excision of the tumour and reconstruction of the flexor retinaculum using tibialis posterior tendon in a paediatric patient: A rare case report.
Tiwari, Vivek; Ansari, Tahir; Mittal, Samarth; Sharma, Pankaj; Nalwa, Aasma
Giant cell tumour of tendon sheath is a benign soft tissue tumour arising from the tendon sheath. The involvement of foot and ankle by such tumours is relatively rare. Children are not commonly afflicted by this condition. All such tumours are reported to arise either from a single tendon sheath or one joint. We report a case of giant cell tumour of tendon sheath in a 12-year-old child, arising simultaneously from the tendon sheaths of tibialis posterior and flexor digitorum longus tendons, as well as extending into the ankle joint. It was treated by complete excision of the mass along with the tendon sheaths with reconstruction of the flexor retinaculum. The location of the tumour, age of the patient, diffuse nature of the tumour and novel technique of reconstruction of the flexor retinaculum make this case extremely rare and the first to be reported in literature.
Fluke, Erin C; Carayannopoulos, Nikoletta L; Lindsey, Ronald W
Pyogenic flexor tenosynovitis is an orthopedic emergency most commonly caused by Staphylococcus aureus and streptococci and occasionally, when associated with water exposure, Mycobacterium marinum. Shewanella algae, a gram-negative bacillus found in warm saltwater environments, has infrequently been reported to cause serious soft tissue infections and necrosis. In this case, S. algae caused complicated flexor tenosynovitis requiring open surgical irrigation and debridement. Flexor tenosynovitis caused by S. algae rapidly presented with all 4 Kanavel cardinal signs as well as subcutaneous purulence, ischemia, and necrosis, thus meeting the requirements for Pang et al group III classification of worst prognosis. Because of its rarity and virulence, S. algae should always be considered in cases of flexor tenosynovitis associated with traumatic water exposure to treat and minimize morbidity appropriately.
Yu, JaeHo; Lee, SoYeon; Kim, HyongJo; Seo, DongKwon; Hong, JiHeon; Lee, DongYeop
The application of transcutaneous electrical nerve stimulation (TENS) enhances muscle weakness and static balance by muscle fatigue. It was said that TENS affects decrease of the postural sway. On the other hand, the applications of TENS to separate dorsi-plantar flexor and the comparison with and without visual input have not been studied. Thus, the aim of this study was to compare the effects of TENS on fatigued dorsi-plantar flexor with and without visual input. 13 healthy adult males and 12 females were recruited and agreed to participate as the subject (mean age 20.5 ± 1.4, total 25) in this study after a preliminary research. This experiment was a single group repeated measurements design in three days. The first day, after exercise-induced fatigue, the standing position was maintained for 30 minutes and then the postural sway was measured on eyes open(EO) and eyes closed(EC). The second, TENS was applied to dorsi flexor in standing position for 30 minutes after conducting exercise-induced fatigue. On the last day, plantar flexor applied by TENS was measured to the postural sway on EO and EC after same exercise-induced fatigue. The visual input was not statistically difference between the groups. However, when compared of dorsi-plantar flexor after applied to TENS without visual input, the postural sway of plantar flexor was lower than the dorsi flexor (p< 0.05). As the result, the application of TENS in GCM clinically decreases the postural sway with visual input it helps to stable posture control and prevent to falling down.
Zhao, Chunfeng; Wei, Zhuang; Kirk, Ramona L.; Thoreson, Andrew R.; Jay, Gregory D.; Moran, Steven L.; An, Kai-Nan; Amadio, Peter C.
Background Using allograft is an attractive alternative for flexor tendon reconstruction because of the lack of donor morbidity, and better matching to the intrasynovial environment. The purpose of this study was to use biolubricant molecules to modify the graft surface to decrease adhesions and improve digit function. Methods 28 flexor digitorum profundus (FDP) tendons from the 2nd and 5th digits of 14 dogs were first lacerated and repaired to create a model with repair failure and scar digit for tendon reconstruction. Six weeks after the initial surgery, the tendons were reconstructed with FDP allograft tendons obtained from canine cadavers. One graft tendon in each dog was treated with saline as a control and the other was treated with gelatin, carbodiimide derivatized, hyaluronic acid and lubricin (cd-HA-Lubricin). Six weeks postoperatively, digit function, graft mechanics, and biology were analyzed. Results Allograft tendons treated with cd-HA-Lubricin had decreased adhesions at the proximal tendon/graft repair and within flexor sheath, improved digit function, and increased graft gliding ability. The treatment also reduced the strength at the distal tendon to bone repair, but the distal attachment rupture rate was similar for both graft types. Histology showed that viable cells migrated to the allograft, but these were limited to the tendon surface. Conclusion cd-HA-Lubricin treatment of tendon allograft improves digit functional outcomes after flexor tendon reconstruction. However, delayed bone-tendon healing should be a caution. Furthermore, the cell infiltration into the allograft tendons substance should be a target for future studies, to shorten the allograft self-regeneration period. PMID:24445876
Yucesoy, Can A; Baan, Guus; Huijing, Peter A
The goal of the present study was to test the hypothesis that epimuscular myofascial force transmission occurs between deep flexor muscles of the rat and their antagonists: previously unstudied mechanical effects of length changes of deep flexors on the anterior crural muscles (i.e., extensor digitorum longus (EDL), as well as tibialis anterior and extensor hallucis longus muscle complex (TA+EHL) and peroneal (PER) muscles were assessed experimentally. These muscles or muscle groups were kept at constant length, whereas, distal length changes were imposed on deep flexor (DF) muscles before performing isometric contractions. Distal forces of all muscle-tendon complexes were measured simultaneously, in addition to EDL proximal force. Distal lengthening of DF caused substantial significant effects on its antagonistic muscles: (1) increase in proximal EDL total force (maximally 19.2%), (2) decrease in distal EDL total (maximally 8.4%) and passive (maximally 49%) forces, (3) variable proximo-distal total force differences indicating net proximally directed epimuscular myofascial loads acting on EDL at lower DF lengths and net distally directed loads at higher DF lengths, (4) decrease in TA+EHL total (maximally 50%) and passive (maximally 66.5%) forces and (5) decrease in PER total force (maximally 51.3%). It is concluded that substantial inter-antagonistic epimuscular myofascial force transmission occurs between deep flexor, anterior crural and peroneal muscles. In the light of our present results and recently reported evidence on inter-antagonistic interaction between anterior crural, peroneal and triceps surae muscles, we concluded that epimuscular myofascial force transmission is capable of causing major effects within the entire lower leg of the rat. Implications of such large scale myofascial force transmission are discussed and expected to be crucial to muscle function in healthy, as well as pathological conditions.
Coats, Robert W; Echevarría-Oré, Julio C; Mass, Daniel P
Flexor tendon repair in zone II is still a technically demanding procedure, but the outcomes have become more predictable and satisfying. Of keystone importance for obtaining the goals of normal strength and gliding of repaired flexor tendons are an atraumatic surgical technique, an appropriate suture material, a competent pulley system, and the use of early motion rehabilitation protocols. The overall goal of hand and finger function also implies timely addressing of neurovascular injuries. New devices such as the TenoFix (Ortheon Medical; Winter Park, Florida) have shown adequate strength in the laboratory but are bulky and untested for work of flexion. Insufficient clinical data and high cost may prevent widespread use.
King, Elizabeth A; Lien, John R
Closed pulley ruptures are rare in the general population but occur more frequently in rock climbers due to biomechanical demands on the hand. Injuries present with pain and swelling over the affected pulley, and patients may feel or hear a pop at the time of injury. Sequential pulley ruptures are required for clinical bowstringing of the flexor tendons. Ultrasound confirms diagnosis of pulley rupture and evaluates degree of displacement of the flexor tendons. Isolated pulley ruptures frequently are treated conservatively with early functional rehabilitation. Sequential pulley ruptures require surgical reconstruction. Most climbers are able to return to their previous activity level.
Flexor tendon pulley has been very early noticed and described. Terminology usually accepted recognizes 6 arcifom pulleys (A0 to A5) and 3 cruciform pulleys (C1 to C3). Anatomy and physiology of this flexor tendon gliding and reflection system at the level of the digital sheet are exposed. The integrity necessity of this system became obvious regarding the flexor tendons repair. Four main pathologies may be concerned: the trigger finger congenital or progressive, due to a chondroid metaplasia of the A1 pulley; tenosynovial ganglions arising at the weak point between A1 and A2 pulley; lesions of the flexor tendon sheet during traumatic lacerations or surgical repairs; quite experimental lesions creating isolated ruptures of one or several pulleys which occur during sport practice, especially high level rock climbing. The repair techniques are exposed to allow to graduate and hierarchy the reparation technique regarding the pathology. A2 and A4 repair is always indicated. The best reconstruction material is an extensor retinaculum graft. But its poor surface available often draws to use conventional palmaris longus free graft.
Kociolek, Aaron M; Tat, Jimmy; Keir, Peter J
Pathological changes in carpal tunnel syndrome patients include fibrosis and thickening of the subsynovial connective tissue (SSCT) adjacent to the flexor tendons in the carpal tunnel. These clinical findings suggest an etiology of excessive shear-strain force between the tendon and SSCT, underscoring the need to assess tendon gliding characteristics representative of repetitive and forceful work. A mechanical actuator moved the middle finger flexor digitorum superficialis tendon proximally and distally in eight fresh frozen cadaver arms. Eighteen experimental conditions tested the effects of three well-established biomechanical predictors of injury, including a combination of two wrist postures (0° and 30° flexion), three tendon velocities (50, 100, 150mm/sec), and three forces (10, 20, 40N). Tendon gliding resistance was determined with two light-weight load cells, and integrated over tendon displacement to represent tendon frictional work. During proximal tendon displacement, frictional work increased with tendon velocity (58.0% from 50-150mm/sec). There was a significant interaction between wrist posture and tendon force. In wrist flexion, frictional work increased 93.0% between tendon forces of 10 and 40N. In the neutral wrist posture, frictional work only increased 33.5% (from 10-40N). During distal tendon displacement, there was a similar multiplicative interaction on tendon frictional work. Concurrent exposure to multiple biomechanical work factors markedly increased tendon frictional work, thus providing a plausible link to the pathogenesis of work-related carpal tunnel syndrome. Additionally, our study provides the conceptual basis to evaluate injury risk, including the multiplicative repercussions of combined physical exposures.
Hu, Xiaogang; Suresh, Nina L.; Xue, Cindy; Rymer, William Z.
The extensor digitorum communis muscle plays an important role in hand dexterity during object manipulations. This multi-tendinous muscle is believed to be controlled through separate motoneuron pools, thereby forming different compartments that control individual digits. However, due to the complex anatomical variations across individuals and the flexibility of neural control strategies, the spatial activation patterns of the extensor digitorum communis compartments during individual finger extension have not been fully tracked under different task conditions. The objective of this study was to quantify the global spatial activation patterns of the extensor digitorum communis using high-density (7 × 9) surface electromyogram (EMG) recordings. The muscle activation map (based on the root mean square of the EMG) was constructed when subjects performed individual four finger extensions at the metacarpophalangeal joint, at different effort levels and under different finger constraints (static and dynamic). Our results revealed distinct activation patterns during individual finger extensions, especially between index and middle finger extensions, although the activation between ring and little finger extensions showed strong covariance. The activation map was relatively consistent at different muscle contraction levels and for different finger constraint conditions. We also found that distinct activation patterns were more discernible in the proximal–distal direction than in the radial–ulnar direction. The global spatial activation map utilizing surface grid EMG of the extensor digitorum communis muscle provides information for localizing individual compartments of the extensor muscle during finger extensions. This is of potential value for identifying more selective control input for assistive devices. Such information can also provide a basis for understanding hand impairment in individuals with neural disorders. PMID:26500558
Massicotte, Vicky S; Frara, Nagat; Harris, Michele Y; Amin, Mamta; Wade, Christine K; Popoff, Steven N; Barbe, Mary F
We have shown that prolonged repetitive reaching and grasping tasks lead to exposure-dependent changes in bone microarchitecture and inflammatory cytokines in young adult rats. Since aging mammals show increased tissue inflammatory cytokines, we sought here to determine if aging, combined with prolonged performance of a repetitive upper extremity task, enhances bone loss. We examined the radius, forearm flexor muscles, and serum from 16 mature (14–18 mo of age) and 14 young adult (2.5–6.5 mo of age) female rats after performance of a high repetition low force (HRLF) reaching and grasping task for 12 weeks. Young adult HRLF rats showed enhanced radial bone growth (e.g., increased trabecular bone volume, osteoblast numbers, bone formation rate, and mid-diaphyseal periosteal perimeter), compared to age-matched controls. Mature HRLF rats showed several indices of radial bone loss (e.g., decreased trabecular bone volume, and increased cortical bone thinning, porosity, resorptive spaces and woven bone formation), increased osteoclast numbers and inflammatory cytokines, compared to age-matched controls and young adult HRLF rats. Mature rats weighed more yet had lower maximum reflexive grip strength, than young adult rats, although each age group was able to pull at the required reach rate (4 reaches/min) and required submaximal pulling force (30 force-grams) for a food reward. Serum estrogen levels and flexor digitorum muscle size were similar in each age group. Thus, mature rats had increased bone degradative changes than in young adult rats performing the same repetitive task for 12 weeks, with increased inflammatory cytokine responses and osteoclast activity as possible causes. PMID:26517953
Novais Van Petten, Adriana Maria Valladão; Ávila, Antônio Ferreira
Objective: To investigate the effect of using wrist immobilization orthoses made from different materials, on activation of the flexor and extensor musculature of the forearm while performing specific tasks. Methods: Twenty-six adults, with an average age of 26.2 years, underwent the Jebsen-Taylor functional hand test and the grip strength test (Jamar® dynamometer) under three conditions: free hand, wearing a composite orthosis and wearing a thermoplastic orthosis. The tests were carried out using the dominant hand only. During the tests, surface electrodes were attached to the flexor and extensor muscles of the forearm to record the muscle electrical activity. The results obtained under the three conditions were compared and analyzed using the Wilcoxon statistical test. Results: Significant differences in muscle activation were found between using the free hand and using any of the orthoses. There was no significant difference in muscle activation between the two types of orthosis. A decrease in activity of the extensor muscles of the forearm was observed during all the tasks, as well as an increase in activation of the flexor muscles with the use of the orthoses. Conclusion: These results are important for defining whether an orthosis should be prescribed during the rehabilitation process for a wide range of disorders, such as tendinitis of the flexors and extensors of the wrist and fingers, as well as for predicting the length of time for which these devices should be used. PMID:27022523
As tendon transfer of the flexor hallucis longus (FHL) and the flexor digitorum longus (FDL) is an established procedure, exact knowledge of the formation of the chiasma plantare is of great interest. Although the quadratus plantae (QP) appears to play a major role, it has been rarely addressed in previous studies. The aim of the present study was to reinvestigate the formation of the chiasma plantare and the composition of the long flexor tendons in order to clarify the inexact and partly contradictory descriptions published from 1865 onward. The chiasma plantare and the long flexor tendons in both feet of 50 formalin-fixed specimens of body donors (25 men and women) were analyzed by gross anatomical dissection. It was composed of one (3%), two (69%) or three layers (28%) which were variably established by the tendinous and muscular fibers of the FHL, the FDL and the QP. In 61% the FHL gave one or more slips to the FDL, and in 39% there was a bidirectional interconnection between the two tendons. The slip from the FHL to the FDL largely reinforces the second (45%), or the second and third tendon (46%). Thus, the FHL is involved in the first tendon in all cases, in the second one in 97% of cases, and in the third tendon in about one half of cases (53%). In all instances, the FDL contributes to the third to fourth, in 98% the second, and in at least 39% to the first tendon. The QP reinforces the second to fourth tendon in nearly all cases, the fifth in about one half of cases, and even the first tendon in 14% of cases. In addition, the individual composition of the five long flexor tendons arising from the chiasma plantare was analyzed in detail. Special emphasis was placed on the evaluation of side and sex differences as well as individual symmetry. Furthermore, biomechanical, developmental and phylogenetic aspects were outlined. In terms of the outcome of this study, the FHL appears to be the better donor for tendon transfer to restore lost function, but
Lee, Daniel J; Southgate, Richard D; Farhat, Youssef M; Loiselle, Alayna E; Hammert, Warren C; Awad, Hani A; O'Keefe, Regis J
Parathyroid hormone (PTH) 1-34 is known to enhance fracture healing. Tendon repair is analogous to bone healing in its dependence on the proliferation and differentiation of mesenchymal stem cells, matrix formation, and tissue remodeling.(1,2,3) We hypothesized that PTH 1-34 enhances tendon healing in a flexor digitorum longus (FDL) tendon repair model. C57Bl/6J mice were treated with either intraperitoneal PTH 1-34 or vehicle-control (PBS). Tendons were harvested at 3-28 days for histology, gene expression, and biomechanical testing. The metatarsophalangeal joint range of motion was reduced 1.5-2-fold in PTH 1-34 mice compared to control mice. The gliding coefficient, a measure of adhesion formation, was 2-3.5-fold higher in PTH 1-34 mice. At 14 days post-repair, the tensile strength was twofold higher in PTH 1-34 specimens, but at 28 days there were no differences. PTH 1-34 mice had increased fibrous tissue deposition that correlated with elevated expression of collagens and fibronectin as seen on quantitative PCR. PTH 1-34 accelerated the deposition of reparative tissue but increased adhesion formation.
Iyer, Srinivasan; Basu, Indraneil; Kaba, Rahim; Pabari, Amit
Flexor tendon rupture following a Colles' fracture is a rare complication with only a handful of cases reported since the initial report in 1932. We present a case in which all digital flexor tendons ruptured within 6 months of a Colles' fracture. Previous reported cases have demonstrated rupture of either the radial or ulnar digital flexors but this case is the first in which all the digital flexors have been involved. This case report highlights the clinical implications of this rare occurrence and stresses the importance of accurate reduction and thorough clinical examination following bony injuries to the wrist.
Damkat-Thomas, L; Black, CE; Herbert, K
An unusual case of fibromatosis of the dominant left flexor pollicus longus (FPL) in a thirteen year old schoolboy. Initially presenting with pain in the thenar eminence and difficulty flexing the metacarpal phalangeal joint (MPJ), other symptoms include locking, triggering and difficulty writing. MRI showed a 4cm segment of thickened abnormal tendon. Intra-operatively three 1cm nodules were excised from the FPL while preserving the tendon. Histopathology reported the nodules as fibromatosis. A literature search revealed that this has not previously been reported although symptomatic tendon sheath fibromas have. Our patient achieved a good result following surgical intervention and the two year review has shown no complications. PMID:24946359
Elsheikh, Bakri; Arnold, W. David; Gharibshahi, Shahram; Reynolds, Jerold; Freimer, Miriam; Kissel, John T.
Introduction Although formal spirometry is the gold standard for monitoring respiratory function in patients with myasthenia gravis (MG), such testing is often delayed or unavailable. There is a need for a simple bedside test that can accurately measure respiratory function. Method We conducted a prospective, cross-sectional, single-blind study in adults with acetylcholine receptor antibody positive MG. Participants performed the single breath count test (SBCT) and underwent manual muscle strength testing, while a respiratory therapist performed spirometry blinded to SBCT and strength results. Results Thirty-one patients, aged 57 ±19 years participated. SBCT showed significant correlations with forced vital capacity (FVC), negative inspiratory force (NIF), and neck flexor strength (P<0.01). FVC showed significant correlation with neck flexor strength (P=0.02) but no correlation with shoulder abductor strength. Discussion These data suggest that the SBCT and neck flexor strength testing are valuable tools for bedside assessment of respiratory function in MG patients. PMID:26437790
Cooper, Maureen A; Laverty, Peter H; Soiderer, Emily E
Two cats presented with bilateral flexor tendon contracture following onychectomy. This previously unreported complication proved to be painful and debilitating. Deep digital flexor tenectomy successfully resolved the problem. Twelve months after surgery, the first cat remains free of complications. The second cat recovered full limb function, but died of unrelated causes.
Abstract Two cats presented with bilateral flexor tendon contracture following onychectomy. This previously unreported complication proved to be painful and debilitating. Deep digital flexor tenectomy successfully resolved the problem. Twelve months after surgery, the first cat remains free of complications. The second cat recovered full limb function, but died of unrelated causes. PMID:15884646
Griffin, M; Hindocha, S; Jordan, D; Saleh, M; Khan, W
Flexor tendon injuries still remain a challenging condition to manage to ensure optimal outcome for the patient. Since the first flexor tendon repair was described by Kirchmayr in 1917, several approaches to flexor tendon injury have enabled successful repairs rates of 70-90%. Primary surgical repair results in better functional outcome compared to secondary repair or tendon graft surgery. Flexor tendon injury repair has been extensively researched and the literature demonstrates successful repair requires minimal gapping at the repair site or interference with tendon vascularity, secure suture knots, smooth junction of tendon end and having sufficient strength for healing. However, the exact surgical approach to achieve success being currently used among surgeons is still controversial. Therefore, this review aims to discuss the results of studies demonstrating the current knowledge regarding the optimal approach for flexor tendon repair. Post-operative rehabilitation for flexor tendon surgery is another area, which has caused extensive debate in hand surgery. The trend to more active mobilisation protocols seems to be favoured but further study in this area is needed to find the protocol, which achieves function and gliding but avoids rupture of the tendons. Lastly despite success following surgery complications commonly still occur post surgery, including adhesion formation, tendon rupture and stiffness of the joints. Therefore, this review aims to discuss the appropriate management of these difficulties post surgery. New techniques in management of flexor tendon will also be discussed including external laser devices, addition of growth factors and cytokines. PMID:22431948
Waterman, Brian R; Dunn, John C; Kusnezov, Nicholas; Romano, David; Pirela-Cruz, Miguel A
First described in 1734, the extensor digitorum brevis manus (EDBM) is an anomalous extensor muscle found in the dorsum of the wrist and hand. Extensor muscle variants of the hand are not uncommon, and EDBM has an estimated reported incidence of approximately 2%. Although few extensor muscle variants become clinically significant, there is a paucity of literature discussing these anatomic variants, with most reports arising from cadaveric studies or isolated case series. Similarly, there are few established indications for surgical treatment of EDBM. In this case report, we describe the successful treatment of a young patient with persistently symptomatic anomalous extensor tendon with surgical excision and propose an algorithm for management after failure of conservative measures.
Riley, Danny A.; Bain, James L. W.; Ellis, Stanley
The size, distribution, and content of catalase-reactive microperoxisomes were investigated cytochemically in three types of muscle fibers from the soleus and the extensor digitorum longus (EDL) of male rats. Muscle fibers were classified on the basis of the mitochondrial content and distribution, the Z-band widths, and the size and shape of myofibrils as the slow-twitch oxidative (SO), the fast-twitch oxidative glycolytic (FOG), and the fast-twitch glycolytic (FG) fibers. It was found that both the EDL and soleus SO fibers possessed the largest microperoxisomes. A comparison of microperoxisome number per muscle fiber area or the microperoxisome area per fiber area revealed following ranking, starting from the largest number and the area-ratio values: soleus SO, EDL SO, EDL FOG, and EDL FG.
Riley, D. A.; Ellis, S.; Slocum, G. R.; Satyanarayana, T.; Bain, J. L.; Sedlak, F. R.
Prolonged exposure of humans to hypogravity causes weakening of their skeletal muscles. This problem was studied in rats exposed to hypogravity for 7 days aboard Spacelab 3. Hindlimb muscles were harvested 12-16 hours postflight for histochemical, biochemical, and ultrastructural analyses. The majority of the soleus and extensor digitorum longus fibers exhibited simple cell shrinkage. However, approximately 1% of the fibers in flight soleus muscles appeared necrotic. Flight muscle fibers showed increased glycogen, lower subsarcolemmal staining for mitochondrial enzymes, and fewer subsarcolemmal mitochondria. During atrophy, myofibrils were eroded by multiple focal losses of myofilaments; lysosomal autophagy was not evident. Tripeptidylaminopeptidase and calcium-activated protease activities of flight soleus fibers were significantly increased, implying a role in myofibril breakdown. Simple fiber atrophy appears to account for muscle weakening during spaceflight, but fiber necrosis is also a contributing factor.
Liu, Mingju; Yue, Yongping; Li, Dejia; Duan, Dongsheng
Catalase is a major antioxidant enzyme. Increasing catalase expression represents a promising avenue to improve muscle function in certain physiological conditions and in some muscle diseases. We hypothesized that catalase overexpression should not impair normal muscle contraction. We delivered a hemagglutinin (HA)-tagged human catalase gene to normal mouse muscle by an adeno-associated viral vector (AAV). Western blot and immunostaining revealed efficient expression of HA-tagged catalase. Enzymatic assay demonstrated an approximately threefold increase in catalase activity in AAV-infected muscles. Catalase overexpression impaired neither twitch nor tetanic tension in the extensor digitorum longus (EDL) muscle. Furthermore, EDL fatigue response was not altered. Taken together, we have developed a novel AAV vector to enhance catalase expression. Lack of apparent toxicity in normal muscle strongly supports further exploration of this vector to reduce oxidative stress-induced muscle damage.
Zhao, Chunfeng; Zobitz, Mark E.; Sun, Yu-Long; Predmore, Kelly S.; Amadio, Peter C.; An, Kai-Nan; Moran, Steven L.
Background: Topical 5-fluorouracil has been reported to reduce adhesions in animal models of tenolysis. The purpose of this study was to investigate the effects of topical 5-fluorouracil on adhesion formation after tendon repairs were subjected to immediate postoperative rehabilitation in a canine model in vivo. Methods: Sixty dogs were randomly assigned to either a 5-fluorouracil treatment (thirty dogs) or a control group (thirty dogs). Each treatment group was then divided into three survival time points: ten days, twenty-one days, and forty-two days. The second and fifth flexor digitorum profundus tendons from each dog were fully lacerated at the zone-II area and then were repaired. Passive motion therapy started at day 5 postoperatively and continued until the dogs were killed. The repaired tendons were evaluated for normalized work of flexion, gliding resistance, repair strength, gene expression for type-I and type-III collagen and transforming growth factor-β1, and histological appearance. Results: The normalized work of flexion of the repaired tendons treated with 5-fluorouracil was significantly lower than that of the repaired tendons without 5-fluorouracil treatment at ten days. However, there was no significant difference between treated and untreated tendons at twenty-one and forty-two days. There was also no significant difference in gliding resistance, repair failure strength, or stiffness between treated and untreated tendons at any time point, or in the gross or histological appearance of adhesions at the time of killing. The expression of types-I and III collagen and transforming growth factor-β1 of the repaired tendon with 5-fluorouracil treatment was significantly lower than that of the tendons without treatment at ten days postoperatively, but not at twenty-one or forty-two days. Conclusions: Although 5-fluorouracil treatment can reduce adhesions in in vivo models of tenolysis, this treatment had only a transient effect in an in vivo model of
Chinchalkar, Shrikant J; Pipicelli, Joey G; Agur, Anne; Athwal, George S
In this manuscript, these authors have utilized years of clinical experience to suggest rehabilitation modifications for Zone III flexor tendon injuries. - VictoriaPriganc, PhD, OTR, CHT, CLT, Practice Forum Editor.
Spoor, C F; Badoux, D M
A hitherto-unknown atavistic muscle in the dog initiated a review of the literature on the homologies and nomenclature of the forelimb flexors in carnivores and man. A consequence is that we recommend a revision of the nomenclature in the Nomina Anatomica Veterinaria (Ithaca, New York, 1983) so that it is in agreement with the Nomina Anatomica (Wilkins, Baltimore, 1983). This revision mainly consists of the incorporation of the terms M. palmaris longus and Mm. flexores breves manus.
Crowley, Timothy P
Rock climbing has increased in popularity over the past two decades. Closed traumatic rupture of the finger flexor tendon pulleys is rare among the general population but is seen much more commonly in rock climbers. This article reviews the anatomy and biomechanics of the finger flexor tendon pulleys, how they may be injured in rock climbing and how these injuries are best diagnosed and managed.
Lui, Tun Hing
Tenosynovitis of the flexor hallucis longus tendon is a condition typically found in ballet dancers and sometimes in soccer players and is related to chronic overuse. It mostly involves the portion of the tendon behind the ankle joint. However, the portion of the tendon under the sustentaculum tali can also be involved. Open synovectomy requires extensive dissection. We report the technique of arthroscopic synovectomy of the deep portion of the flexor hallucis longus.
Kheterpal, Arvin; Zoga, Adam; McClure, Kristen
Calcific tendinitis is a common source of musculoskeletal pain in adults; however, it is rarely encountered in children. Calcific tendinitis is the most commonly encountered manifestation of hydroxyapatite deposition disease, in which calcium hydroxyapatite crystal deposition occurs in tendons. It may cause acute or chronic pain, or may be entirely asymptomatic. We describe a case of acute calcific tendinitis of the flexor pollicis longus tendon in an 8-year-old boy, who initially presented to our department for workup of a mass felt along the volar aspect of the right wrist.
Yip, R.K.; Riley, D.A.
The histochemical study examined the effects of chronic methylmercury (MeHg) intoxication on the motor and sensory innervation of extensor digitorum longus muscles. Light microscopic examination of silver-stained axons in the intramuscular nerve bundles of MeHg-treated rats showed Wallerian-like degeneration and a reduction in the number of nerve fibers. Disrupted axons were predominantly sensory because 22.2% of spindle afferents (I/sub a/) and 90.0% of Golgi tendon organ (I/sub b/) sensory fibers were completely degenerated whereas less than 1% of motor ending were totally destroyed. Partial disruption occurred in the cholinesterase and motor terminals of 13.7% of endplates. Their results demonstrated greater vulnerability of sensory nerves than of motor nerves to MeHg-induced degeneration. Thus, the abnormal reflexes, ataxia, and muscle weakness following MeHg poisoning appear related to reduction of proprioceptive feedback from muscles and tendons irradiation to the documented lesions in the central nervous system.
Hakim, Chady H.
Muscle stiffness is a major clinical feature in Duchenne muscular dystrophy (DMD). DMD is the most common lethal inherited muscle-wasting disease in boys, and it is caused by the lack of the dystrophin protein. We recently showed that the extensor digitorum longus (EDL) muscle of mdx mice (a DMD mouse model) exhibits disease-associated muscle stiffness. Truncated micro- and mini-dystrophins are the leading candidates for DMD gene therapy. Unfortunately, it has never been clear whether these truncated genes can mitigate muscle stiffness. To address this question, we examined the passive properties of the EDL muscle in transgenic mdx mice that expressed a representative mini- or micro-gene (ΔH2-R15, ΔR2-15/ΔR18-23/ΔC, or ΔR4-23/ΔC). The passive properties were measured at the ages of 6 and 20 mo and compared with those of age-matched wild-type and mdx mice. Despite significant truncation of the gene, surprisingly, the elastic and viscous properties were completely restored to the wild-type level in every transgenic strain we examined. Our results demonstrated for the first time that truncated dystrophin genes may effectively treat muscle stiffness in DMD. PMID:23221959
Wong, Jason K.F.; Lui, Yin H.; Kapacee, Zoher; Kadler, Karl E.; Ferguson, Mark W. J.; McGrouther, Duncan A.
Intrasynovial flexor tendon injuries of the hand can frequently be complicated by tendon adhesions to the surrounding sheath, limiting finger function. We have developed a new tendon injury model in the mouse to investigate the three-dimensional cellular biology of intrasynovial flexor tendon healing and adhesion formation. We investigated the cell biology using markers for inflammation, proliferation, collagen synthesis, apoptosis, and vascularization/myofibroblasts. Quantitative immunohistochemical image analysis and three-dimensional reconstruction with cell mapping was performed on labeled serial sections. Flexor tendon adhesions were also assessed 21 days after wounding using transmission electron microscopy to examine the cell phenotypes in the wound. When the tendon has been immobilized, the mouse can form tendon adhesions in the flexor tendon sheath. The cell biology of tendon healing follows the classic wound healing response of inflammation, proliferation, synthesis, and apoptosis, but the greater activity occurs in the surrounding tissue. Cells that have multiple “fibripositors” and cells with cytoplasmic protrusions that contain multiple large and small diameter fibrils can be found in the wound during collagen synthesis. In conclusion, adhesion formation occurs due to scarring between two damaged surfaces. The mouse model for flexor tendon injury represents a new platform to study adhesion formation that is genetically tractable. PMID:19834058
Hlavackova, Petra; Vuillerme, Nicolas
The present study investigated the effects of somatosensory conditions at the foot and ankle on postural responses to plantar-flexor muscle fatigue during bipedal quiet stance. Twenty-two young healthy adults were asked to stand upright as still as possible with their eyes closed in three somatosensory conditions (normal, altered and improved) both prior to and after exercises inducing plantar-flexor muscle fatigue. In the normal condition, the postural task was executed on a firm support surface constituted by the force platform. In the altered condition, a 2-cm thick foam support surface was placed under the subjects' feet. In the improved condition, increased cutaneous feedback at the foot and ankle was provided by strips of athletic tape applied across both their ankle joints. Muscle fatigue was induced in the plantar-flexor muscles of both legs through the execution of a repeated standing heel raise exercise. Centre of foot pressure displacements were recorded using a force platform. Results showed that plantar-flexor muscle fatigue yielded increased centre of foot pressure displacements under normal foot and ankle sensory conditions. Furthermore, this effect was exacerbated under altered foot and ankle sensory conditions and mitigated under improved foot and ankle sensory conditions. Altogether, the present findings suggested an increased reliance on somatosensory information from the foot and ankle for controlling upright posture in the presence of plantar-flexor muscle fatigue.
Pasut, Alessandra; Jones, Andrew E.; Rudnicki, Michael A.
Muscle regeneration in the adult is performed by resident stem cells called satellite cells. Satellite cells are defined by their position between the basal lamina and the sarcolemma of each myofiber. Current knowledge of their behavior heavily relies on the use of the single myofiber isolation protocol. In 1985, Bischoff described a protocol to isolate single live fibers from the Flexor Digitorum Brevis (FDB) of adult rats with the goal to create an in vitro system in which the physical association between the myofiber and its stem cells is preserved 1. In 1995, Rosenblattmodified the Bischoff protocol such that myofibers are singly picked and handled separately after collagenase digestion instead of being isolated by gravity sedimentation 2, 3. The Rosenblatt or Bischoff protocol has since been adapted to different muscles, age or conditions 3-6. The single myofiber isolation technique is an indispensable tool due its unique advantages. First, in the single myofiber protocol, satellite cells are maintained beneath the basal lamina. This is a unique feature of the protocol as other techniques such as Fluorescence Activated Cell Sorting require chemical and mechanical tissue dissociation 7. Although the myofiber culture system cannot substitute for in vivo studies, it does offer an excellent platform to address relevant biological properties of muscle stem cells. Single myofibers can be cultured in standard plating conditions or in floating conditions. Satellite cells on floating myofibers are subjected to virtually no other influence than the myofiber environment. Substrate stiffness and coating have been shown to influence satellite cells' ability to regenerate muscles 8, 9 so being able to control each of these factors independently allows discrimination between niche-dependent and -independent responses. Different concentrations of serum have also been shown to have an effect on the transition from quiescence to activation. To preserve the quiescence state of
Newmeyer, William L; Manske, Paul R
New surgical procedures, novel concepts, and/or the presentation of very good results with an apparently discredited technique meet varying degrees of resistance among the establishment of any profession. In hand surgery this phenomenon was exemplified in a striking fashion with the presentation of a controversial report entitled, "Primary repair of flexor tendons in no man's land" by Kleinert, Kutz, Ashbell, and Martinez of Louisville, KY, at the 1967 American Society for Surgery of the Hand (ASSH) annual meeting. The discussant, Joseph Boyes, expressed such skepticism that a special ASSH committee was appointed to go to Louisville and review the results to determine if they were as good as claimed. They were, and today primary flexor tendon repair is the procedure of choice for most flexor tendon lacerations.
Leijnse, J N A L; Carter, S; Gupta, A; McCabe, S
The extensor digitorum communis (ED) is generally regarded as a fairly undiversified muscle that gives extensor tendons to all fingers. Some fine wire electromyographic (EMG) investigations have been carried out to study individuation of the muscle parts to the different fingers. However, individuated surface EMG of the ED has not been investigated. This study analyses the anatomy of the ED muscle parts to the different fingers in detail and proposes optimal locations for surface or indwelling electrodes for individuated EMG and for electrostimulation with neuroprostheses. The dissections show that the ED arises from extensive origin tendons (OT), which originate at the lateral epicondyle and reach far in the forearm. The ED OT is V-shaped with shorter central tendon fibers but with a long radial and an even longer ulnar slip. The ED parts to the individual fingers consistently arise from distinct OT locations: the ED3 (medius) arises proximally, the ED2 (index) from the radial slip distal to ED3, the ED4 (ring finger) from the ulnar slip distal to ED3, and the ED5 (to ring/little finger) from the ulnar slip distal to ED4. This lengthwise widely spaced arrangement of ED parts compensates to some degree for the narrow ED width and suggests that ED parts should be individually assessable by indwelling and even by surface EMG electrodes, albeit in the latter case with variable mutual cross-talk. Conversely, the anatomic spacing of ED parts warrants that electromyographic stimulation with neuroprostheses by a single implanted electrode cannot likely homogeneously activate all ED parts.
Granito, Renata Neves; Aveiro, Mariana Chaves; Rennó, Ana Claudia Muniz; Oishi, Jorge; Driusso, Patricia
Objective The aim of this study was to analyze the effects of aging on the degree of thoracic kyphosis and peak torque of the trunk flexor and extensor muscles among women without a densitometric diagnosis of osteoporosis. Methods Thirty women were selected to make up three groups: young women (n = 10; 24.60 ± 2.27 years of age); adults (n = 10; 43.50 ± 2.88); and elderly women (n = 10; 62.40 ± 2.67). Bone mineral density (BMD), degree of thoracic kyphosis and peak torque of the trunk flexors and extensors were evaluated. Differences between the groups were evaluated using the Kruskal–Wallis ANOVA and Mann–Whitney U tests. Pearson's correlation coefficient was used to assess correlations between the variables. The significance level was taken to be 5% (p ≤ 0.05). Results The elderly group presented a greater degree of thoracic kyphosis (p = 0.009) and lower peak torque of the trunk flexors and extensors than the young group. The adult group presented lower peak torque of the trunk than the young group. A negative correlation was observed between age and peak torque of the trunk flexors and extensors (p ≤ 0.001), and a positive correlation between age and the degree of thoracic kyphosis (r = 0.58; p ≤ 0.001). The elderly group presented higher values for the eccentric/concentric ratio of the peak torque for flexors (p = 0.03) and extensors (p = 0.02). Conclusion This study suggests that physiological aging may be associated with a greater degree of thoracic kyphosis and lower muscle strength of the trunk flexors and extensors. Moreover, the elderly women showed a relative capacity for preservation of eccentric strength. PMID:26229814
Elliot, David; Giesen, Thomas
Repair of the divided flexor tendon to achieve normal, or near normal, function is an unsolved problem, with each result still uncertain. The authors believe the way forward in primary flexor tendon surgery clinically is by use of strengthened but simpler sutures, appropriate venting of the pulley system, and maintaining early rehabilitation. However, there needs also be consideration of patient factors and other aspects. Research needs to continue more widely, in both the laboratory and the clinical environment, to find ways of better modifying adhesions after surgical repair of the tendon.
al-Qattan, M M; Duerksen, F
Anatomical variations of the muscles and nerves around the wrist are common. Knowledge of such variations is derived from 2 sources: anatomical dissections and clinically reported cases. We present a case of duplication of the tendon of flexor carpi ulnaris with splitting of the ulnar nerve. The ulnar slip of the tendon was inserted into the pisiform bone and the radial slip into the proximal phalanx of the ring finger. The anatomical literature and the clinically reported cases of variations of the flexor carpi ulnaris are reviewed. Images Fig. 1 PMID:1452475
Yu, W S; Kilbreath, S L; Fitzpatrick, R C; Gandevia, S C
The uncommonly good proprioceptive performance of the long flexor of the thumb, flexor pollicis longus (FPL), may add significantly to human manual dexterity. We investigated the forces produced by FPL single motor units during a weak static grip involving all digits by spike-triggered averaging from single motor units, and by averaging from twitches produced by intramuscular stimulation. Nine adult subjects were studied. The forces produced at each digit were used to assess how forces produced in FPL are distributed to the fingers. Most FPL motor units produced very low forces on the thumb and were positively correlated with the muscle force at recruitment. Activity in FPL motor units commonly loaded the index finger (42/55 units), but less commonly the other fingers (P < 0.001). On average, these motor units produced small but significant loading forces on the index finger (∼5.3% of their force on the thumb) with the same time-to-peak force as the thumb (∼50 ms), but had no significant effect on other fingers. However, intramuscular stimulation within FPL did not produce significant forces in any finger. Coherence at 2–10 Hz between the thumb and index finger force was twice that for the other finger forces and the coherence to the non-index fingers was not altered when the index finger did not participate in the grasp. These results indicate that, within the long-term coordinated forces of all digits during grasping, FPL motor units generate forces highly focused on the thumb with minimal peripheral transfer to the fingers and that there is a small but inflexible neural coupling to the flexors of the index finger. PMID:17656436
Arrabal-Campos, Francisco M.
Abstract The purpose of the present study was to evaluate the influence of acute fatigue of the hip flexor muscles on scores attained in tests frequently used in literature to measure hamstring muscle extensibility, namely the passive straight leg raise (PSLR), active straight leg raise (ASLR), passive knee extension (PKE), active knee extension (AKE), sit-and-reach (SR) and toe-touch (TT) tests. A total of seventy-five healthy and recreationally active adults voluntarily participated in this study. To reach fatigue, the participants actively lifted their legs alternately as many times as possible. In the passive tests, the results were 7.10 ± 5.21° and 5.68 ± 4.54° higher (p < 0.01) for PSLR and PKE tests, respectively, after acute fatigue. However, in the ASLR test, the results were lower post-fatigue than pre-fatigue (mean difference = -5.30° ± 9.51°; p < 0.01). The AKE, SR and TT tests did not show significant differences between pre- and post-fatigue (p > 0.05). Moderate (r = 0.40) to high (r = 0.97) correlation coefficients were found, which were statistically significant among all the measured flexibility tests both pre- and post-fatigue. In conclusion, the active implication of the hip flexor muscles until reaching fatigue had acute influences on the results of the PSLR, PKE and ASLR tests, but not on the results of the AKE, SR and TT tests. It is recommended to use the AKE test to assess hamstring muscle extensibility in situations where athletes show fatigue in their hip flexor muscles. PMID:28149407
Casas, Mariana; Figueroa, Reinaldo; Jorquera, Gonzalo; Escobar, Matías; Molgó, Jordi
Tetanic electrical stimulation induces two separate calcium signals in rat skeletal myotubes, a fast one, dependent on Cav 1.1 or dihydropyridine receptors (DHPRs) and ryanodine receptors and related to contraction, and a slow signal, dependent on DHPR and inositol trisphosphate receptors (IP3Rs) and related to transcriptional events. We searched for slow calcium signals in adult muscle fibers using isolated adult flexor digitorum brevis fibers from 5–7-wk-old mice, loaded with fluo-3. When stimulated with trains of 0.3-ms pulses at various frequencies, cells responded with a fast calcium signal associated with muscle contraction, followed by a slower signal similar to one previously described in cultured myotubes. Nifedipine inhibited the slow signal more effectively than the fast one, suggesting a role for DHPR in its onset. The IP3R inhibitors Xestospongin B or C (5 µM) also inhibited it. The amplitude of post-tetanic calcium transients depends on both tetanus frequency and duration, having a maximum at 10–20 Hz. At this stimulation frequency, an increase of the slow isoform of troponin I mRNA was detected, while the fast isoform of this gene was inhibited. All three IP3R isoforms were present in adult muscle. IP3R-1 was differentially expressed in different types of muscle fibers, being higher in a subset of fast-type fibers. Interestingly, isolated fibers from the slow soleus muscle did not reveal the slow calcium signal induced by electrical stimulus. These results support the idea that IP3R-dependent slow calcium signals may be characteristic of distinct types of muscle fibers and may participate in the activation of specific transcriptional programs of slow and fast phenotype. PMID:20837675
Wang, Zhong-Min; Tang, Shen; Messi, María Laura; Yang, Jenny J; Delbono, Osvaldo
Contrasting information suggests either almost complete depletion of sarcoplasmic reticulum (SR) Ca(2+) or significant residual Ca(2+) concentration after prolonged depolarization of the skeletal muscle fiber. The primary obstacle to resolving this controversy is the lack of genetically encoded Ca(2+) indicators targeted to the SR that exhibit low-Ca(2+) affinity, a fast biosensor: Ca(2+) off-rate reaction, and can be expressed in myofibers from adult and older adult mammalian species. This work used the recently designed low-affinity Ca(2+) sensor (Kd = 1.66 mM in the myofiber) CatchER (calcium sensor for detecting high concentrations in the ER) targeted to the SR, to investigate whether prolonged skeletal muscle fiber depolarization significantly alters residual SR Ca(2+) with aging. We found CatchER a proper tool to investigate SR Ca(2+) depletion in young adult and older adult mice, consistently tracking SR luminal Ca(2+) release in response to brief and repetitive stimulation. We evoked SR Ca(2+) release in whole-cell voltage-clamped flexor digitorum brevis muscle fibers from young and old FVB mice and tested the maximal SR Ca(2+) release by directly activating the ryanodine receptor (RyR1) with 4-chloro-m-cresol in the same myofibers. Here, we report for the first time that the Ca(2+) remaining in the SR after prolonged depolarization (2 s) in myofibers from aging (~220 μM) was larger than young (~132 μM) mice. These experiments indicate that SR Ca(2+) is far from fully depleted under physiological conditions throughout life, and support the concept of excitation-contraction uncoupling in functional senescent myofibers.
Summary: The Saint John Protocol describes a rehabilitation program of up to half a fist of protected true active finger flexion beginning 3 to 5 days after flexor tendon repair. We no longer use full fist place and hold. We illustrate with film and text the reasons for these changes. PMID:27975032
Savage, Robert; Tang, Jin Bo
Multistrand core suture repairs have become the mainstay of digital flexor tendon repair in recent decades. Here we briefly describe the history of the development of these multistrand repair methods and their correct nomenclature. A historical account, their evolution, the correct use of nomenclature, and some technical points are reviewed.
Debarge, Romain; Philippot, Rémy; Viola, Jérémy; Besse, Jean Luc
The aim of this study was to evaluate the outcome of the percutaneous flexor tenotomy. We compared the results of two groups. The first group included 23 patients who underwent forefoot surgery without percutaneous flexor tenotomy, and the second group included 50 patients who underwent the same procedure combined with percutaneous flexor tenotomy for claw toe deformities, secondary to shortening metatarsal Scarf osteotomy. The average follow-up was 11.6 months. Three algoneurodystrophies were noted. No delayed wound healing was observed. Functional dissatisfaction rate (18% vs.17.4%) and toe pulp contact defect (12% vs. 8.7%) were not significantly different in the two groups. Toe grasping defect rate (10% vs. 4.3%) was superior in the tenotomy group. Five recurring claw toe deformities of the second toe were noted in the tenotomy group. Percutaneous flexor tenotomy is a simple, rapid, and efficient method to correct reducible secondary claw toe deformities. However, despite a significant postoperative loss of toe grasping function, no patient reported major dissatisfaction.
Leahy, J C; Durkovic, R G
1. We previously demonstrated in the spinal cat that superficial peroneal cutaneous nerve stimulation produced strong reflex contraction in tibialis anterior (TA) and semitendinosus (St) muscles but unexpectedly produced mixed effects in another physiological flexor muscle, extensor digitorum longus (EDL). The goal of the present study was to further characterize the organization of ipsilateral cutaneous reflexes by examining the postsynaptic potentials (PSPs) produced in St, TA, and EDL motoneurons by superficial peroneal and saphenous nerve stimulation in decerebrate, spinal cats. 2. In TA and St motoneurons, low-intensity cutaneous nerve stimulation that activated only large (A alpha) fibers [i.e., approximately 2-3 times threshold (T)], typically produced biphasic PSPs consisting of an initial excitatory phase and subsequent inhibitory phase (EPSP, IPSP). Increasing the stimulus intensity to activate both large (A alpha) and small (A delta) myelinated cutaneous fibers supramaximally (15-45 T) tended to enhance later excitatory components in TA and St motoneurons. 3. In EDL motoneurons, 2-3 T stimulation of the superficial peroneal nerve evoked initial inhibition (of variable magnitude) in 7/10 EDL motoneurons tested, with either excitation (n = 2) or mixed effects (n = 1) observed in the remaining EDL motoneurons. Saphenous nerve stimuli produced excitation either alone, or preceded by an inhibitory phase in EDL. Increasing the stimulus intensity enhanced later inhibitory influences from superficial peroneal and excitatory influences both from superficial peroneal and saphenous nerve inputs in EDL motoneurons. 4. Short-latency (less than 1.8 ms) EPSPs were observed in a few motoneurons in all reflex pathways examined, except for EPSPs in EDL motoneurons evoked by saphenous stimulation. IPSPs with central latencies less than 1.8 ms were also produced by both saphenous (TA, n = 1; EDL, n = 2) and superficial peroneal (EDL, n = 4) nerve stimulation. 5. The results
Marina, M; Porta, J; Vallejo, L; Angulo, R
Motorcycle riders must endure high levels of muscle tension for long periods of time, especially in their arms and forearms, when steering and using handlebar controls. Because the right hand operates the gas handle and front brakes, the present research focuses on fatigue in the right hand flexors. Ten adult riders, aged 32.5±5.5years, volunteered to participate in this study. During the 24h race each rider, on completion of a relay stage, visited the assessment box to do the following handgrip test sequence: (1) 10s of EMG recording at rest, (2) one 3-s maximal voluntary contraction (MVC), (3) 1min rest interval and (4) 50% MVC maintained during 10s. EMG amplitude (MP: μV) and median and mean frequency (MF and MPF: Hz) over the superficial finger flexors were recorded during the whole handgrip test sequence with adhesive surface electrodes. MVC values were maintained during the first two relays (50-60min duration in total) and dropped gradually thereafter (p<0.01). During the monitoring of the 50% MVC, mean amplitude increased (p=0.024) while median and mean frequency tended to decrease. These results suggest fatigue is produced in motorcycle riders in a 24h race. However, the expected reduction of EMG frequency was not confirmed given to a potentially large variability.
Peterson, W W; Manske, P R; Lesker, P A; Kain, C C; Schaefer, R K
A method was developed to reconstruct the fibro-osseous pulleys with Nitex, a synthetic material. Nitex is a closely woven fabric constructed from monofilament nylon fibers. Six adult monkeys (24 digits) had excision of the A1 and A2 pulleys; this was followed by reconstruction of the A2 pulley with the Nitex synthetic material. The animals were killed, two at a time, at 4, 8, and 12 weeks to evaluate the effectiveness of the Nitex pulleys. Flexor tendon function was assessed by biomechanical methods with a tensile testing machine to measure the tendon excursion and the work of flexion (the area under the force-excursion curve) necessary to fully flex each digit; these parameters revealed that the Nitex pulleys were capable of preventing tendon bow-stringing and did not significantly impair tendon gliding. The breaking strength of the Nitex pulleys was comparable to that of normal A2 pulleys (for monkeys weighing less than 10 kg) and it was sufficient to allow immediate mobilization of the digits postoperatively without fear of pulley rupture. Histologic examination showed minimal foreign body reaction around the Nitex, and the gliding surface of a Nitex pulley was found to be covered with a smooth layer of fibrous tissue with minimal adhesions to the underlying flexor tendon. The synthetic Nitex pulley appears to have the potential to function as an effective fibro-osseous pulley replacement.
Al-Qattan, Mohammad M
Previous authors have used either a grasping or a locking technique for flexor tendon repair in zone II. A combined (grasping and locking) 10-strand repair was used by the author in 22 adults (n = 28 fingers) with lacerations of both flexor tendons in zone II. The combined repair is known to be strong (mean tensile strength of 164 N), and the technique was used in selected cases who were thought to be at higher risk of rupture either because of excessive digital oedema (in early tendon repairs) or because of tendon retraction (in late primary tendon repairs). The 10-strand repair was bulky and, hence, only the profundus tendon was repaired; and "venting" of the pulley system was done proximal to the repair site as recommended by other authors. Supervised early active mobilisation was done immediately after the operation. At final follow-up, the outcome was calculated using the original Strickland-Glogovac grading system. There were no ruptures and the final outcome was considered excellent in 19 patients (n = 25 fingers), good in two patients (n = 2 fingers), and fair in the remaining patient (n = 1 finger). It was concluded that the bulky 10-strand repair may be used for zone II finger flexor tendon lacerations as long as a profundus-(?) only repair and "venting" of the pulley system are performed.
Muff, Guillaume; Dufour, Stéphane; Meyer, Alain; Severac, François; Favret, Fabrice; Geny, Bernard; Lecocq, Jehan; Isner-Horobeti, Marie-Eve
[Purpose] To compare measurements of knee extensor and flexor muscle strength performed using a hand-held dynamometer and an isokinetic dynamometer in apparently healthy subjects. [Subjects and Methods] Thirty adult volunteers underwent knee muscle strength evaluation using an isokinetic or a hand-held dynamometer. [Results] Strong positive correlations were found between the 2 methods, with correlation coefficients r ranging from 0.72 (95% confidence interval [CI], 0.48−0.86) to 0.87 (95% CI, 0.75−0.94), depending on the muscle group and the isokinetic evaluation mode. The reproducibility of the hand-held dynamometer findings was good, judged by a coefficient of variation of 3.2–4.2%. However, the correlation between the 2 methods for the assessment of flexor/extensor ratios ranged from −0.04 to 0.46. [Conclusion] Knee extensor and flexor muscle strength recorded with a hand-held dynamometer is reproducible and significantly correlated with the isokinetic values, indicating that this method may in some cases be a useful replacement for isokinetic strength measurement. However, for strength ratio assessment, and when judged against the isokinetic standard, a hand-held dynamometer is not a valid option. PMID:27799667
Muff, Guillaume; Dufour, Stéphane; Meyer, Alain; Severac, François; Favret, Fabrice; Geny, Bernard; Lecocq, Jehan; Isner-Horobeti, Marie-Eve
[Purpose] To compare measurements of knee extensor and flexor muscle strength performed using a hand-held dynamometer and an isokinetic dynamometer in apparently healthy subjects. [Subjects and Methods] Thirty adult volunteers underwent knee muscle strength evaluation using an isokinetic or a hand-held dynamometer. [Results] Strong positive correlations were found between the 2 methods, with correlation coefficients r ranging from 0.72 (95% confidence interval [CI], 0.48-0.86) to 0.87 (95% CI, 0.75-0.94), depending on the muscle group and the isokinetic evaluation mode. The reproducibility of the hand-held dynamometer findings was good, judged by a coefficient of variation of 3.2-4.2%. However, the correlation between the 2 methods for the assessment of flexor/extensor ratios ranged from -0.04 to 0.46. [Conclusion] Knee extensor and flexor muscle strength recorded with a hand-held dynamometer is reproducible and significantly correlated with the isokinetic values, indicating that this method may in some cases be a useful replacement for isokinetic strength measurement. However, for strength ratio assessment, and when judged against the isokinetic standard, a hand-held dynamometer is not a valid option.
Jorquera, Gonzalo; Altamirano, Francisco; Contreras-Ferrat, Ariel; Almarza, Gonzalo; Buvinic, Sonja; Jacquemond, Vincent; Jaimovich, Enrique; Casas, Mariana
An important pending question in neuromuscular biology is how skeletal muscle cells decipher the stimulation pattern coming from motoneurons to define their phenotype as slow or fast twitch muscle fibers. We have previously shown that voltage-gated L-type calcium channel (Cav1.1) acts as a voltage sensor for activation of inositol (1,4,5)-trisphosphate [Ins(1,4,5)P₃]-dependent Ca(2+) signals that regulates gene expression. ATP released by muscle cells after electrical stimulation through pannexin-1 channels plays a key role in this process. We show now that stimulation frequency determines both ATP release and Ins(1,4,5)P₃ production in adult skeletal muscle and that Cav1.1 and pannexin-1 colocalize in the transverse tubules. Both ATP release and increased Ins(1,4,5)P₃ was seen in flexor digitorum brevis fibers stimulated with 270 pulses at 20 Hz, but not at 90 Hz. 20 Hz stimulation induced transcriptional changes related to fast-to-slow muscle fiber phenotype transition that required ATP release. Addition of 30 µM ATP to fibers induced the same transcriptional changes observed after 20 Hz stimulation. Myotubes lacking the Cav1.1-α1 subunit released almost no ATP after electrical stimulation, showing that Cav1.1 has a central role in this process. In adult muscle fibers, ATP release and the transcriptional changes produced by 20 Hz stimulation were blocked by both the Cav1.1 antagonist nifedipine (25 µM) and by the Cav1.1 agonist (-)S-BayK 8644 (10 µM). We propose a new role for Cav1.1, independent of its calcium channel activity, in the activation of signaling pathways allowing muscle fibers to decipher the frequency of electrical stimulation and to activate specific transcriptional programs that define their phenotype.
Thorfinn, J; Angelidis, I K; Gigliello, L; Pham, H M; Lindsey, D; Chang, J
Tissue-engineered rabbit flexor tendons reseeded with cells are stronger in vitro after culture in a bioreactor. It is not known whether this effect persists in vivo. Tenocytes from New Zealand white rabbits were seeded onto rabbit rear paw flexor tendons that were deprived of cells and exposed to cyclic strain in a bioreactor. Reseeded constructs that were kept unloaded in a medium for 5 days were used as controls. The tendons were implanted to bridge a zone II defect in the rabbit. After explantation 4 weeks later, the ultimate tensile strength (UTS) and elastic modulus (EM) were determined. Tendon constructs that were exposed to cyclic strain had significantly improved UTS and EM. Histology showed that cellularity was increased in the bioreactor tendons.
JONES, M.; ABRAHAMS, P. H.; SAÑUDO, J. R.
In 1813 Gantzer described 2 accessory muscles in the human forearm which bear his name (Wood, 1868; Macalister, 1875) and these have subsequently been reported with variable attachments (Wood, 1868; Macalister, 1875; Turner, 1879; Schäfer & Thane, 1894; Le Double, 1897; Dykes & Anson, 1944; Mangini, 1960; Malhotra et al. 1982; Kida, 1988; Tountas & Bergman, 1993). The accessory heads of the deep flexors of the forearm (Gantzer's muscles) have been described as 2 different small bellies which insert either into FPL or FDP. There are no previous reports which have mentioned the existence of an accessory muscle which inserts into both of the 2 deep flexors of the forearm as in the case presented here. PMID:9306208
Bianchi, S.; Martinoli, C.; de Gautard, R.; Gaignot, C.
Recent improvements in ultrasound (US) software and hardware have markedly increased the role of this imaging modality in the evaluation of the musculoskeletal system. US is currently one of the main imaging tools used to diagnose and assess most tendon, muscle, and ligament disorders. Compared with magnetic resonance imaging, US is much less expensive; it has no contraindications and is also widely available. Diseases affecting the digital flexor system (DFS) require early diagnosis if treatment is expected to limit functional impairment of the hand. US scans performed with high-resolution, broad-band transducers allows superb visualization of the flexor tendons of the hand and the annular digital pulleys. In addition, dynamic US can be used to assess movement of the tendon within the pulleys during passive or active joint movements. This article examines the anatomy and US appearance of the normal DFS and reviews the US findings associated with the most common disorders affecting it. PMID:23396583
Guy, Robert; Thomases, Becca
In both theoretical and experimental studies of the effect of fluid elasticity on micro-organism swimming, very different behavior has been observed for small and large amplitude strokes. We present simulations of an undulatory swimmer in an Oldroyd-B fluid and show that the resulting viscoelastic stresses are a nonlinear function of the amplitude. Specifically, there appears to be an amplitude dependent transition that is key to obtaining a speed-up over the Newtonian swimming speed. To understand the physical mechanism of the transition, we examine the stresses in a time-symmetric oscillatory bending beam, or flexor. We compare the flow in a neighborhood of the flexor tips with a large-amplitude oscillatory extensional flow, and we see similar amplitude dependent transitions. We relate these transitions to observed speed-ups in viscoelastic swimmers.
Al-Thunayan, Turki A.; Al-Zahrani, Mohammed T.; Hakeem, Ahmad A.; Al-Zahrani, Fahad M.; Al-Qattan, Mohammad M.
Objectives: To investigate the tensile strength of repaired flexor profundus tendons in young lambs, which would be equivalent to repairs in children older than 2 years of age. Methods: A comparative in-vitro experimental study conducted at King Saud University, Riyadh, Kingdom of Saudi Arabia from October 2014 to December 2015. We utilized 30 flexor profundus tendons of young lambs with a width of 4 mm. All tendons were repaired with a 4-strand repair technique using 4/0 polypropylene core sutures. In group I (n=10 tendons), 2 separate figure-of-eight sutures were applied. In group II (n=10 tendons), simple locking sutures were added to the corners of 2 separate figure-of-eight sutures. In group III (n=10 tendons), the locked cruciate repair was used. All tendon repairs were tested to single-cycle tensile failure. Results: There was no significant difference between groups II and III with regards to gap and breaking forces; and all forces of these 2 groups were significantly higher than the forces in group I. Conclusion: It was concluded that 4 mm-wide pediatric flexor tendons allow a 4-strand repair and the use of 4/0 sutures. The use of locking sutures increases the tensile strength to values that may allow protective mobilization in children. PMID:27570850
Wakefield, C Brent; Cottrell, G Trevor
To date, there is limited research investigating stretching of antagonist muscles and its effects on agonist muscle function. The purpose of this research was to investigate the effects of pre-static stretching (pre-SS) of the hip flexor musculature on passive hip extension range of motion (ROM) and vertical jump height. Fifteen subjects reported to the laboratory on 4 separate days (D1, D2, D3, and D4). D1 was for familiarization, while on D2 to D4, subjects randomly completed 1 of 3 intervention conditions; no stretch (CON), hip flexor stretch (HFS), or hip extensor stretch (HES). Subject's pre- and post-intervention hip extension ROM were measured before performing 3 sets of pre- and post-maximal counter-movement vertical jumps. Vertical jump height was normalized to baseline for data analysis. A repeated-measures ANOVA with post hoc paired sample t-tests revealed a significant increase in vertical jump height in the HFS condition (1.74% ± 0.73; p ≤ 0.05) when compared with CON (-1.34% ± 0.96) or HES (-1.74% ± 0.65) conditions. There was also a significant increase in hip extension ROM after the HFS stretching protocol (6.5 ± 2.75%; p ≤ 0.05) when compared with the CON protocol (-1.73 ± 3.26); however, no significant difference when compared with the HES protocol (1.84 ± 2.79). A correlation analysis showed that the relative hip laxity of each subject had no effect on response to either condition nor did the magnitude of hip ROM change predict improvement in vertical jump. These results suggest that performing SS of the hip flexors may enhance vertical jump performance independent of changes in passive compliance of the hip flexor muscular tendon unit.
Riley, D. A.; Slocum, T.; Bain, J. L. W.; Sedlak, F. R.; Elis, S.; Satyanarayana, T.
Muscle atrophy in rats exposed to hypogravity for seven days aboard Spacelab 3 is examined. Hindlimb muscles were harvested 12-16 days postflight, and prepared for enzyme studies and electron microscopy. Simple cell shrinkage was found, with a mean fiber area decrease of 35.8 percent for soleus and 24.9 percent for extensor digitorum longus (EDL) flight muscle fibers, as compared with control muscle fibers. EDL and soleus muscles showed increases in alkaline myofibrillar ATPase, alpha glycerophosphate dehydrogenase, and glycogen, and a decrease in NADH dehydrogenase staining. The 26 percent increase in calcium activated protease suggests that the focal degradation of myofibrils is the key process of myofibril breakdown. The presence in the flight soleus muscles of one percent necrotic fibers is unexplained. The observed shift towards histochemical fast-muscle type properties is consistent with previous findings.
Suwa, Masataka; Imoto, Takayuki; Kida, Akira; Yokochi, Takashi
[Purpose] To compare the toe flexor, hand grip and knee extensor strengths of young and elderly men, and to examine the association between toe flexor strength and physical activity or inactivity levels. [Subjects and Methods] Young (n=155, 18–23 years) and elderly (n=60, 65–88 years) men participated in this study. Toe flexor, hand grip, and knee extensor strength were measured. Physical activity (time spent standing/walking per day) and inactivity (time spent sitting per day) were assessed using a self-administered questionnaire. [Results] Toe flexor, hand grip, and knee extensor strength of the elderly men were significantly lower than those of the young men. Standing/walking and sitting times of the elderly men were lower than those of the young men. Toe flexor strength correlated with hand grip and knee extensor strength in both groups. In elderly men, toe flexor strength correlated with standing/walking time. In comparison to the young men’s mean values, toe flexor strength was significantly lower than knee extensor and hand grip strength in the elderly group. [Conclusion] The results suggest that age-related reduction in toe flexor strength is greater than those of hand grip and knee extensor strengths. An early loss of toe flexor strength is likely associated with reduced physical activity in elderly men. PMID:27313353
Lin, G T; Amadio, P C; An, K N; Cooney, W P
The anatomy of 55 cadaver digits was studied, both statistically and with simulated active motion using weights attached to the flexor tendons. The modified description of Doyle and Blythe accurately described the anatomy observed. Serial pulley sectioning showed two types of bowstringing, both of which affected the relationship of tendon excursion to joint motion. The most constant, resulting in 15% loss of motion for a fixed tendon excursion, occurred over the concave surfaces of the proximal and middle phalanges. Bowstringing at the proximal interphalangeal joint was present only after 30 degrees of flexion had occurred, because of the convexity of the phalangeal condyles.
Rodriguez, D; Devos Bevernage, B; Maldague, P; Deleu, P-A; Leemrijse, T
Tarsal tunnel syndrome (TTS) defines an entrapment neuropathy of the posterior tibial nerve or one of its branches, within the tarsal tunnel. Numerous etiologies have been described explaining this entrapment, including trauma, space-occupying lesions, foot deformities, etc. We present an unreported cause of a space-occupying lesion in the etiology of TTS, namely the combination of a hypertrophic long distally extended muscle belly of the flexor hallucis longus and repetitive ankle motion. Surgical debulking of the muscle belly in the posterior ankle compartment resolved all symptoms.
Koyama, H; Murakami, K; Suzuki, T; Suzaki, K
Hip flexor spasticity, which is often associated with central nervous system (CNS) diseases, is a major impediment in rehabilitation. In order to cope with this problem, lumbar nerve blocking techniques developed by Meelhuysen and major and minor psoas muscle blocking techniques developed by Awad have been used in combination with physical therapies. Based on these techniques, we conducted major and minor psoas muscle phenol block (motor point block or intramuscular nerve block) under ultrasonic monitoring. Phenol block was conducted in nine patients with cerebral infarction (13 blocking procedures) and three with spinal cord injuries (six blocking procedures) while keeping them in a lateral position with the operation side upside. The beginning of the femoral nerves and part of the lumbar artery were visualized by ultrasound in some patients. As a result of the improvement of hip flexor spasticity, the range of hip joint motion (determined by the Mundale technique, prone hip extension and Thomas test) improved shortly after blocking. When physical therapy was conducted after blocking, improvement of skin care management was observed in eight cases, ability to keep in a stable sitting position in nine, improvement of a standing posture in three, increases in the ability to walk in two and alleviation of pain in three. Although nerve block is reported to result in hematoma, decreases in muscle force, pain, cystic/rectal disorders and hypogonadism, we have observed no such complication in our patients.
GREEN, W T; BANKS, H H
In our experience, transplantation of the flexor carpi ulnaris is the single best procedure to improve function of the wrist and hand in cerebral palsy. It aids dorsiflexion and supination and, at the same time, preserves active motion of the wrist. This is highly desirable since finger control may be seriously impaired in cerebral palsy and the additional motion provided at the wrist may be most helpful. In fact, since using this procedure we have found that fusion of the wrist is rarely indicated. A good result from a flexor carpi ulnaris transplant depends first upon the careful choice of the patient for the procedure.Requirements for the best function from the transplant include reasonable finger control preoperatively with passive flexibility of the hand, wrist, and forearm; stereognosis of the involved hand; reasonable intelligence; high motivation of the patient and family; and a thorough postoperative regimen.The difference between a good result and a poor result was often the thoroughness of the postoperative care. The value of both exercise and support for the part cannot be overemphasized nor can one underestimate the importance of the interest and ambitions of the patient and his family. The procedure should be postponed until the age when the individual may be expected to cooperate in the training of the transplant.
Smith, Andrew C; Mummidisetty, Chaithanya K; Rymer, William Zev; Knikou, Maria
In humans, a chronic spinal cord injury (SCI) impairs the excitability of pathways mediating early flexor reflexes and increases the excitability of late, long-lasting flexor reflexes. We hypothesized that in individuals with SCI, locomotor training will alter the behavior of these spinally mediated reflexes. Nine individuals who had either chronic clinically motor complete or incomplete SCI received an average of 44 locomotor training sessions. Flexor reflexes, elicited via sural nerve stimulation of the right or left leg, were recorded from the ipsilateral tibialis anterior (TA) muscle before and after body weight support (BWS)-assisted treadmill training. The modulation pattern of the ipsilateral TA responses following innocuous stimulation of the right foot was also recorded in 10 healthy subjects while they stepped at 25% BWS to investigate whether body unloading during walking affects the behavior of these responses. Healthy subjects did not receive treadmill training. We observed a phase-dependent modulation of early TA flexor reflexes in healthy subjects with reduced body weight during walking. The early TA flexor reflexes were increased at heel contact, progressively decreased during the stance phase, and then increased throughout the swing phase. In individuals with SCI, locomotor training induced the reappearance of early TA flexor reflexes and changed the amplitude of late TA flexor reflexes during walking. Both early and late TA flexor reflexes were modulated in a phase-dependent pattern after training. These new findings support the adaptive capability of the injured nervous system to return to a prelesion excitability and integration state.
Gillis, Gary B
Most work examining muscle function during anuran locomotion has focused largely on the roles of major hind limb extensors during jumping and swimming. Nevertheless, the recovery phase of anuran locomotion likely plays a critical role in locomotor performance, especially in the aquatic environment, where flexing limbs can increase drag on the swimming animal. In this study, I use kinematic and electromyographic analyses to explore the roles of four anatomical flexor muscles in the hind limb of Bufo marinus during swimming: m. iliacus externus, a hip flexor; mm. iliofibularis and semitendinosus, knee flexors; and m. tibialis anticus longus, an ankle flexor. Two general questions are addressed: (1) What role, if any, do these flexors play during limb extension? and (2) How do limb flexors control limb flexion? Musculus iliacus externus exhibits a large burst of EMG activity early in limb extension and shows low levels of activity during recovery. Both m. iliofibularis and m. semitendinosus are biphasically active, with relatively short but intense bursts during limb extension followed by longer and typically weaker secondary bursts during recovery. Musculus tibialis anticus longus becomes active mid way through recovery and remains active through the start of extension in the next stroke. In conclusion, flexors at all three joints exhibit some activity during limb extension, indicating that they play a role in mediating limb movements during propulsion. Further, recovery is controlled by a complex pattern of flexor activation timing, but muscle intensities are generally lower, suggesting relatively low force requirements during this phase of swimming.
Yun, Sung Joon; Kim, Moon-Hwan; Weon, Jong-Hyuck; Kim, Young; Jung, Sung-Hoon; Kwon, Oh-Yun
[Purpose] This study assessed the relationships between peak toe flexor muscle strength, ankle dorsiflexion range of motion, and countermovement jump height. [Subjects and Methods] Eighteen healthy volunteers participated in the study. Each participant completed tests for peak toe flexor muscle strength, ankle dorsiflexion range of motion, and countermovement jump height. [Results] The results showed (1) a moderate correlation between ankle dorsiflexion range of motion and countermovement jump height and (2) a high correlation between peak first toe flexor muscle strength and countermovement jump height. Peak first toe flexor muscle strength and ankle dorsiflexion range of motion are the main contributors to countermovement jump performance. [Conclusion] These findings indicate that the measurement of peak first toe flexor muscle strength and ankle dorsiflexion range of motion may be useful in clinical practice for improving jump performance in athletes training for sports such as volleyball and basketball. PMID:27630405
Shen, Tiansheng; Cseresnyés, Zoltán; Liu, Yewei; Randall, William R; Schneider, Martin F
The transcription factor nuclear factor of activated T cells (NFAT)c1 has been shown to be involved in turning on slow skeletal muscle fibre gene expression. Previous studies from our laboratory have characterized the stimulation pattern-dependent nuclear import and resting shuttling of NFATc1-green fluorescent protein (GFP) in flexor digitorum brevis (FDB) muscle fibres from adult mouse. In this study, we use viral expression of the transcription factor NFATc1-GFP fusion protein to investigate the mechanisms underlying the nuclear export of the NFATc1-GFP that accumulated in the nuclei of cultured dissociated adult mouse FDB muscle fibres during slow-twitch fibre type electrical stimulation. In these studies, we found that inhibition of either glycogen synthase kinase 3beta (GSK3beta) or casein kinase 1 or 2 (CK1/2) markedly slowed the decay of nuclear NFATc1-GFP after cessation of muscle fibre electrical stimulation, whereas inhibition of casein kinase 1delta, p38 mitogen-activated protein kinase, c-Jun N-terminal kinase and protein kinase A had little effect. Simultaneous inhibition of GSK3beta and CK1/2 completely blocked the nuclear export of NFATc1-GFP after muscle activity. We also developed a simplified model of NFATc1 phosphorylation/dephosphorylation and nuclear fluxes, and used this model to simulate the observed time courses of nuclear NFATc1-GFP with and without NFATc1 kinase inhibition. Our results suggest that GSK3beta and CK1/2 are the major protein kinases that contribute to the removal of NFATc1 that accumulates in muscle fibre nuclei during muscle activity, and that GSK3beta and CK1/2 are responsible for phosphorylating NFATc1 in muscle nuclei in a complementary or synergistic fashion.
Bamman, M. M.; Hunter, G. R.; Stevens, B. R.; Guilliams, M. E.; Greenisen, M. C.
Because resistance exercise (REX) and unloading induce opposing neuromuscular adaptations, we tested the efficacy of REX against the effects of 14 d of bed rest unloading (BRU) on the plantar flexor muscle group. Sixteen men were randomly assigned to no exercise (NOE, N = 8) or REX (N = 8). REX performed 5 sets x 6-10 repetitions to failure of constant resistance concentric/eccentric plantar flexion every other day during BRU. One-repetition maximum (1RM) strength was tested on the training device. The angle-specific torque-velocity relationship across 5 velocities (0, 0.52, 1.05, 1.75, and 2.97 rad.s-1) and the full range-of-motion power-velocity relationship were assessed on a dynamometer. Torque-position analyses identified strength changes at shortened, neutral, and stretched muscle lengths. Concentric and eccentric contractile work were measured across ten repetitions at 1.05 rad.s-1. Maximal neural activation was measured by surface electromyography (EMG). 1RM decreased 9% in NOE and improved 11% in REX (P < 0.05). Concentric (0.52 and 1.05 rad.s-1), eccentric (0.52 and 2.97 rad.s-1), and isometric angle-specific torques decreased (P < 0.05) in NOE, averaging 18%, 17%, and 13%, respectively. Power dropped (P < 0.05) in NOE at three eccentric (21%) and two concentric (14%) velocities. REX protected angle-specific torque and average power at all velocities. Concentric and eccentric strength decreased at stretched (16%) and neutral (17%) muscle lengths (P < 0.05) in NOE while REX maintained or improved strength at all joint positions. Concentric (15%) and eccentric (11%) contractile work fell in NOE (P < 0.05) but not in REX. Maximal plantar flexor EMG did not change in either group. In summary, constant resistance concentric/eccentric REX completely prevented plantar flexor performance deconditioning induced by BRU. The reported benefits of REX should prove useful in prescribing exercise for astronauts in microgravity and for patients susceptible to functional
Lai, Ting-Yu; Chen, Hsiao-I; Shih, Cho-Chiang; Kuo, Li-Chieh; Hsu, Hsiu-Yun; Huang, Chih-Chung
This study aims to determine if the relative displacement between the extensor digitorum communis (EDC) tendon and its surrounding tissues can be used as an adhesion index (AI) for assessing adhesion in metacarpal fractures by comparing two clinical measures, namely single-digit-force and extensor lag (i.e., the difference between passive extension and full active extension). The Fisher–Tippett block-matching method and a Kalman-filter algorithm were used to determine the relative displacements in 39 healthy subjects and 8 patients with metacarpal fractures. A goniometer was used to measure the extensor lag, and a force sensor was used to measure the single-digit-force. Measurements were obtained twice for each patient to evaluate the performance of the AI in assessing the progress of rehabilitation. The Pearson correlation coefficient was calculated to quantify the various correlations between the AI, extensor lag, and single-digit-force. The results showed strong correlations between the AI and the extensor lag, the AI and the single-digit-force, and the extensor lag and the single-digit-force (r = 0.718, −0.849, and −0.741; P = 0.002, P < 0.001, and P = 0.001, respectively). The AI in the patients gradually decreased after continuous rehabilitation, but remained higher than that of healthy participants. PMID:27492808
Johnson, M.; Firoozbakhsh, K.; Moniem, M.; Jamshidi, M.
An SC-based multi-objective decision-making method for determining the optimal flexor-tendon repair technique from experimental and clinical survey data, and with variable circumstances, was presented. Results were compared with those from the Taguchi method. Using the Taguchi method results in the need to perform ad-hoc decisions when the outcomes for individual objectives are contradictory to a particular preference or circumstance, whereas the SC-based multi-objective technique provides a rigorous straightforward computational process in which changing preferences and importance of differing objectives are easily accommodated. Also, adding more objectives is straightforward and easily accomplished. The use of fuzzy-set representations of information categories provides insight into their performance throughout the range of their universe of discourse. The ability of the technique to provide a "best" medical decision given a particular physician, hospital, patient, situation, and other criteria was also demonstrated.
Paradiso, Guillermo; Khan, Farooq; Chen, Robert
It has been suggested that periodic leg movements (PLM) and spinal flexor reflex (FR) share common mechanisms. Although dopaminergic agents improve PLM in humans and strongly influence spinal FR circuitry in animal studies, its effects on FR have not been documented in humans. We describe a 65-year-old man with PLM after overnight withdrawal of dopaminergic agents. The electromyographic pattern of spontaneous PLM closely resembled that of the FR elicited by medial plantar nerve stimulation. Thirty minutes after subcutaneous injection of apomorphine, both PLM and FR were completely abolished. These findings demonstrate that dopaminergic agents can suppress exaggerated FR in humans, and support the hypothesis of common mechanisms for PLM and FR.
The effect of baclofen on the hind limb flexor reflex of the spinal rat was studied. Baclofen inhibited the flexor reflex, this effect not being antagonized by picrotoxin and bicuculline. Baclofen reduced the stimulating action of quipazine and LSD, had no effect on the clonidine-induced reflex stimulation, but inhibited the flexor reflex stimulation induced by amphetamine and fenfluramine. The results obtained bring forth some doubts as to the GABA-mimetic action of baclofen. The action of baclofen on the spinal cord seems to be directed mainly to the presynaptic part of the noradrenergic and serotonergic systems.
Vinnakota, Kalyan C; Rusk, Joshua; Palmer, Lauren; Shankland, Eric; Kushmerick, Martin J
Rates of ATPase and glycolysis are several times faster in actively contracting mouse extensor digitorum longus muscle (EDL) than soleus (SOL), but we find these rates are not distinguishable at rest. We used a transient anoxic perturbation of steady state energy balance to decrease phosphocreatine (PCr) reversibly and to measure the rates of ATPase and of lactate production without muscle activation or contraction. The rate of glycolytic ATP synthesis is less than the ATPase rate, accounting for the continual PCr decrease during anoxia in both muscles. We fitted a mathematical model validated with properties of enzymes and solutes measured in vitro and appropriate for the transient perturbation of these muscles to experimental data to test whether the model accounts for the results. Simulations showed equal rates of ATPase and lactate production in both muscles. ATPase controls glycolytic flux by feedback from its products. Adenylate kinase function is critical because a rise in [AMP] is necessary to activate glycogen phosphorylase. ATPase is the primary source of H+ production. The sum of contributions of the 13 reactions of the glycogenolytic and glycolytic network to total proton load is negligible. The stoichiometry of lactate and H+ production is near unity. These results identify a default state of energy metabolism for resting muscle in which there is no difference in the metabolic phenotype of EDL and SOL. Therefore, additional control mechanisms, involving higher ATPase flux and [Ca2+], must exist to explain the well-known difference in glycolytic rates in fast-twitch and slow-twitch muscles in actively contracting muscle.
The tendons of the Extensor Digitorum Communis (EDC) are frequently injured in hand trauma. Dislocation and spontaneous rupture can also occur during the course of wrist osteoarthritis and rheumatoid arthritis. The EDC exhibits many variations including splitting of its individual slips to the medial four fingers or their absence. The aim of this systematic review is to assemble evidence about the prevalence of the EDC and its variants on the dorsum of the hand. Twenty-four cadaveric studies met the inclusion criteria, providing data from a total of 2,005 hands. Meta-analysis yielded the following results: (a) for EDC-II (Index), the pooled prevalence estimates (PPEs) were 99.8, 98, 1.8, and 0.2% for the total, single, double, and triple slips, respectively; (b) for EDC-III (Middle), the PPEs were 100, 67.7, 24.2, 6, and 0.42% for the total, single, double, triple, and quadruple slips, respectively; (c) for EDC-IV (Ring), the PPEs were 100, 58.6, 29.1, 7.1, and 1.3% for the total, single, double, triple, and quadruple slips, respectively; (d) for EDC-V (Little), the PPEs were 63.2, 58.5, 10.4, 0.94, and 25% for the total, single, double, triple, and common 4th-5th slips, respectively. There were no significant differences in relation to hand side. Many EDC slip variants demonstrated some interaction with ancestry. A sound knowledge of EDC variants and their prevalences is paramount for assessing and treating hand injuries and disorders.
Ahn, Ki Young
Background and Purpose It is recommended that Botox be used within 5 hours of reconstitution, which results in substantial quantities being discarded. This is not only uneconomic, but also inconvenient for treating patients. The aim of this study was to determine the potencies of Botox used within 2 hours of reconstitution with unpreserved saline, the same Botox refrigerated (at +4℃) 72 hours after reconstitution, and during the next 4 consecutive weeks (weeks 1, 2, 3, and 4). This comparison was used to determine the length of refrigeration time during which reconstituted Botox will maintain the same efficacy as freshly reconstituted toxin. Methods Individual paralysis rates in the extensor digitorum brevis (EDB) compound muscle action potential (CMAP) amplitude and area were measured 1 week after injecting fresh reconstituted 2.5 MU of Botox on one side of the foot, and when the same quantity of Botox that had been refrigerated for a designated time (i.e., 72 h, or 1, 2, 3, or 4 weeks) into the other side of the foot. The EDB CMAP amplitude and area at 12 and 16 weeks postinjection were also measured to compare the efficacy durations in all five comparative groups. Results Ninety-four volunteers were divided into five groups according to the refrigerator storage time of the second Botox injection. The paralysis of the EDBs was significant for each injection of Botox, both fresh and refrigerated, with no statistically significant differences between them, regardless of the refrigeration time. There was a tendency toward increased CMAP amplitude and area at 12 or 16 weeks postinjection (p<0.0001). The duration of effective muscle paralysis did not differ significantly throughout the 16-week follow-up period between all five groups. Conclusions The potency of reconstituted Botox is not degraded by subsequent refrigeration for 4 weeks. However, there are definite concerns regarding its sterility, and hence its safety, since multiple withdrawals from the same vial
Yamazaki, H; Kato, H; Hata, Y; Nakatsuchi, Y; Tsuchikane, A
We analysed 21 patients with closed rupture of the flexor tendons caused by carpal bone and joint disorders. The tendon that ruptured depended on the location of the bone perforation into the carpal tunnel. Radiocarpal arthrography was performed in 13 patients and capsular perforation was demonstrated by contrast medium leakage into the carpal canal in 11 patients. This proved a useful diagnostic test. The flexor tendon(s) were reconstructed with free tendon graft in 17 patients, cross-over transfer of flexor tendons from adjacent digits in two and buddying to an adjacent flexor tendon in one patient. Postoperative total active range of motion in the fingers after 13 free tendon graft reconstructions averaged 213 degrees (range 170-265 degrees ). The active range of motion of the thumb-interphalangeal joint after free tendon graft reconstruction in three cases improved from 0 degrees to 33 degrees on average (range 10 degrees -40 degrees ).
Rymer, Ben; Theobald, Peter; Thomas, Peter B.M.
Historically, the surgical treatment of flexor tendon injuries has always been associated with controversy. It was not until 1967, when the paper entitled Primary repair of flexor tendons in no man’s land was presented at the American Society of Hand Surgery, which reported excellent results and catalyzed the implementation of this technique into worldwide practice. We present an up to date literature review using PubMed and Google Scholar where the terms flexor tendon, repair and rehabilitation were used. Topics covered included functional anatomy, nutrition, biome-chanics, suture repair, repair site gapping, and rehabilitation. This article aims to provide a comprehensive and complete overview of flexor tendon repairs. PMID:26793293
Ishida, Hiroshi; Suehiro, Tadanobu; Kurozumi, Chiharu; Ono, Koji; Ando, Suguru; Watanabe, Susumu
The purpose of this study was to clarify the correlation between neck slope angle and deep cervical flexor muscle thickness in healthy subjects. Forty-two healthy male (20.7 ± 2.6 years old) participated in this study. Neck slope angle was measured in a relaxed sitting posture. The deep cervical flexor muscle thickness was measured in a relaxed supine posture. The correlations between neck slope angle and normalized muscle thickness relative to body mass index were determined using Pearson's correlation coefficient. There was a moderate positive correlation between neck slope angle and normalized muscle thickness (r = 0.414, P = 0.006). The result demonstrated that participants with lower neck slope angles had smaller muscle thicknesses of the deep cervical flexor muscles. It appears that the deep cervical flexor muscle thickness might be associated with neck slope angle in a relaxed sitting posture.
Lui, Tun Hing
Tendosynovial chondromatosis of the foot and ankle is a rare disease entity. We reported 3 patients with tenosynovial osteochondromatosis of flexor hallucis longus. They were successfully treated by arthroscopic synovectomy and removal of the loose bodies.
Fischer, Lauren H; Abzug, Joshua M; Osterman, A Lee; Stern, Peter J; Chang, James
Orthopaedic and hand surgeons frequently treat disorders of the flexor and extensor tendon systems. Common conditions, such as trigger finger, de Quervain tenosynovitis, extensor tendon injury, and zone II flexor tendon injury, can be challenging to treat. Complications that limit normal hand function still occur despite advances in surgical techniques and therapy protocols. It is helpful to be aware of the complications related to the treatment of these hand disorders and understand surgical techniques to minimize their frequency.
Lui, Tun Hing
Tenosynovial chondromatosis can occur in the flexor hallucis longus tendon sheath. Complete synovectomy and removal of the loose bodies comprise the treatment of choice. An open procedure requires extensive soft-tissue dissection because the flexor hallucis longus tendon is a deep structure except at the hallux. A tendoscopy approach to synovectomy and removal of loose bodies has the advantage of minimally invasive surgery. This technical note outlines pearls and pitfalls and provides a step-by-step guide to performing this procedure.
Suzuki, Takahito; Shioda, Kohei; Kinugasa, Ryuta; Fukashiro, Senshi
Suzuki, T, Shioda, K, Kinugasa, R, and Fukashiro, S. Simultaneous knee extensor muscle action induces an increase in voluntary force generation of plantar flexor muscles. J Strength Cond Res 31(2): 365-371, 2017-Maximum activation of the plantar flexor muscles is required for various sporting activities that involve simultaneous plantar flexion and knee extension. During a multi-joint movement, activation of the plantar flexor muscles is affected by the activity of the knee extensor muscles. We hypothesized that coactivation of the plantar flexor muscles and knee extensor muscles would result in a higher plantar flexion torque. To test this hypothesis, 8 male volunteers performed maximum voluntary isometric action of the plantar flexor muscles with and without isometric action of the knee extensor muscles. Surface electromyographic data were collected from 8 muscles of the right lower limb. Voluntary activation of the triceps surae muscles, evaluated using the interpolated twitch technique, significantly increased by 6.4 percentage points with intentional knee extensor action (p = 0.0491). This finding is in line with a significant increase in the average rectified value of the electromyographic activity of the vastus lateralis, fibularis longus, and soleus muscles (p = 0.013, 0.010, and 0.045, respectively). The resultant plantar flexion torque also significantly increased by 11.5% of the predetermined maximum (p = 0.031). These results suggest that higher plantar flexor activation coupled with knee extensor activation facilitates force generation during a multi-joint task.
Llanos, Paola; Contreras-Ferrat, Ariel; Georgiev, Tihomir; Osorio-Fuentealba, Cesar; Espinosa, Alejandra; Hidalgo, Jorge; Hidalgo, Cecilia; Jaimovich, Enrique
Insulin stimulates glucose uptake in adult skeletal muscle by promoting the translocation of GLUT4 glucose transporters to the transverse tubule (T-tubule) membranes, which have particularly high cholesterol levels. We investigated whether T-tubule cholesterol content affects insulin-induced glucose transport. Feeding mice a high-fat diet (HFD) for 8 wk increased by 30% the T-tubule cholesterol content of triad-enriched vesicular fractions from muscle tissue compared with triads from control mice. Additionally, isolated muscle fibers (flexor digitorum brevis) from HFD-fed mice showed a 40% decrease in insulin-stimulated glucose uptake rates compared with fibers from control mice. In HFD-fed mice, four subcutaneous injections of MβCD, an agent reported to extract membrane cholesterol, improved their defective glucose tolerance test and normalized their high fasting glucose levels. The preincubation of isolated muscle fibers with relatively low concentrations of MβCD increased both basal and insulin-induced glucose uptake in fibers from controls or HFD-fed mice and decreased Akt phosphorylation without altering AMPK-mediated signaling. In fibers from HFD-fed mice, MβCD improved insulin sensitivity even after Akt or CaMK II inhibition and increased membrane GLUT4 content. Indinavir, a GLUT4 antagonist, prevented the stimulatory effects of MβCD on glucose uptake. Addition of MβCD elicited ryanodine receptor-mediated calcium signals in isolated fibers, which were essential for glucose uptake. Our findings suggest that T-tubule cholesterol content exerts a critical regulatory role on insulin-stimulated GLUT4 translocation and glucose transport and that partial cholesterol removal from muscle fibers may represent a useful strategy to counteract insulin resistance.
Andersson, E A; Nilsson, J; Thorstensson, A
The purpose was to investigate the activation pattern of five major hip flexor muscles and its adaptation to changing speed and mode of progression. A total of 11 healthy subjects performed walking and running on a motor-driven treadmill at speeds ranging from 1.0 to 6.0 m s-1. Intramuscular fine-wire electrodes were used to record myoelectric signals from the iliacus, psoas, sartorius, rectus femoris and tensor fascia latae muscles. The basic pattern, with respect to number of activation periods, remained the same irrespective of speed and mode of progression. However, differences in the relative duration and timing of onset of activation occurred between individual muscles. Over the speed range in walking, a progressively earlier onset was generally seen for the activation period related to hip flexion. Changes in EMG amplitude were measured in the iliacus and psoas muscles and showed a marked increase and difference between walking and running at speeds above 2.0 m s-1. Thus, the alternating flexion-extension movements at the hip during locomotion appear to be governed by a rather fixed 'neural program' which normally only needs minor modulations to accomplish the adjustments accompanying an increase in speed of progression as well as a change from walking to running.
Baxter, Josh R; Piazza, Stephen J
Muscle volume is known to correlate with maximal joint torque in humans, but the role of muscle moment arm in determining maximal torque is less clear. Moderate correlations have been reported between maximal isometric knee extensor torque and knee extensor moment arm, but no such observations have been made for the ankle joint. It has been suggested that smaller muscle moment arms may enhance force generation at high rates of joint rotation, but this has not yet been observed for ankle muscles in vivo. The purpose of the present study was to correlate plantar flexor moment arm and plantar flexor muscle volume with maximal plantar flexor torque measured at different rates of plantar flexion. Magnetic resonance imaging was used to quantify the plantar flexor moment arm and muscle volume of the posterior compartment in 20 healthy young men. Maximal plantar flexor torque was measured isometrically and at three plantar flexion speeds using an isokinetic dynamometer. Plantar flexor torque was significantly correlated with muscle volume (0.222 < R(2) < 0.322) and with muscle moment arm at each speed (0.323 < R(2) < 0.494). While muscle volume was strongly correlated with body mass and stature, moment arm was not. The slope of the torque-moment arm regression line decreased as the rate of joint rotation increased, indicating that subjects with small moment arms experienced smaller reductions in torque at high speeds. The findings of this study suggest that plantar flexor moment arm is a determinant of joint strength that is at least as important as muscle size.
McCall, G. E.; Goulet, C.; Boorman, G. I.; Roy, R. R.; Edgerton, V. R.
The ability to estimate ankle and elbow joint position was tested before, during, and after a 17-day spaceflight. Subjects estimated targeted joint angles during isovelocity (IsoV) joint movements with agonist muscle groups either active or relaxed. These movements included elbow extension (EE) and elbow flexion (EF), and plantarflexion (PF) and dorsiflexion (DF) of the ankle. Subjects also estimated these joint positions while moving the dynamometer at their chosen (variable) velocity (VarV) during EE and PF. For IsoV tests, no differences were observed between active and passive movements for either the ankle or elbow. Compared with those of pre-flight test days, estimates of targeted elbow joint angles were approximately 5 degrees to 15 degrees more flexed in-flight, and returned toward the pre-flight values during recovery. The spaceflight effects for the ankle were inconsistent and less prevalent than those for the elbow. The VarV PF test condition for the 120 degrees target angle at the ankle exhibited approximately 5 degrees to 7 degrees more DF target angle estimates in-flight compared with those pre- or post-flight. In contrast, during IsoV PF there was a tendency for ankle estimates to be approximately 2 degrees to 3 degrees more PF after 2-3 days exposure to spaceflight. These data indicate that during spaceflight the perception of elbow extension is greater than actuality, and are consistent with the interpretation that microgravity induced a flexor bias in the estimation of the actual elbow joint position. Moreover, these effects in joint proprioception during spaceflight were observed in individual isolated single-joint movements during tasks in which vestibular function in maintaining posture were minimal.
Rennie, William R.J.; Muller, Hellmuth
Objective To review the causes and demographics of Linburg syndrome. Design An illustrative case report and a demographic study. Setting Adult and pediatric orthopedic clinics at the Health Sciences Centre in Winnipeg. Patients One patient with Linburg syndrome and 200 patients and relatives presenting to adult and pediatric orthopedic clinics with conditions not involving their hands, wrists or forearms. Outcome measures The presence of the intertendinous anomaly and of carpal tunnel syndrome. Results Tendinous connection(s) between flexor pollicis longus and flexor digitorum profundus muscles were found in 20% of the study population. The anomaly was found in all age groups. No association was found between Linburg syndrome and the presence of carpal tunnel syndrome or previous injury to the hand or forearm. Conclusion Tendinous connection between flexor pollicis longus and flexor digitorum profundus muscles is a common anomaly that rarely causes clinical symptoms. PMID:9711164
Jose, Gomez-Tames; Shuto, Nakamura; Jose, Gonzalez; Wenwei, Yu
Activating flexor reflexes by electrical stimulation has been used as a mechanism to initiate the swing phase or to enhance it for spinal cord injured patients. However, it is necessary to know their contraction dynamics in order to artificially induce them at the right moment of a walking cycle. This requires understanding the temporal activation pattern of both surface and deep muscles simultaneously. This study aimed at developing a system to measure and analyze the temporal activation of both surface and deep muscles during voluntary contraction and flexor reflexes (also called withdrawal reflexes) using ultrasound imaging. A set of experiments were done to verify the validity of the system, while exploring the temporal pattern of muscle activation during flexor reflexes. As a result, we were able to quantify the surface and deep muscle activity by measuring the muscle thickness, pennation angle and long-axis displacement, from the ultrasound images.
Lee, S K; Bae, K W; Choy, W S
It has been suggested that the increased frequency of trigger finger (TF) after carpal tunnel release (CTR) may be caused by the volar migration of the flexor tendons at the wrist altering the tendon biomechanics at the A1 pulley. This hypothesis has not been validated. We performed pre- and post-operative ultrasonography (USG) on the affected wrists of 92 patients who underwent CTR. Pre-operative USG was performed in neutral with no tendon loading; post-operative USG was performed in neutral unloaded and in various positions of wrist flexion whilst loading the flexor tendons with gripping. The mean volar migration of the flexor tendons after CTR was 2.2 (SD 0.4) mm in the unloaded neutral position. It was 1.8 (SD 0.4) mm in patients who did not develop TF and 2.5 (SD 0.5) mm in those who did (p = 0.0067). In loaded wrist flexion, the mean volar migration of flexor tendons after CTR in patients who did not develop TF and those who did was 2.1 and 3.0 mm in 0° flexion; 3.2 and 3.9 mm in 15° flexion; 4.3 and 5.1 mm in 30° flexion; and 4.9 and 5.8 mm in 45° flexion, respectively. There were significant differences between patients with and without TF at each flexion angle. Our data indicate that patients with greater volar migration of the flexor tendons after CTR are more likely to develop TF. This conclusion supports the hypothesis that the occurrence of TF after CTR may be caused by the bowstringing effects of the flexor tendons.
Halperin, Israel; Aboodarda, Saied J; Behm, David G
Non-local muscle fatigue has been demonstrated with unilateral activities, where fatiguing one limb alters opposite limb forces. Fewer studies have examined if non-local fatigue occurs with unrelated muscles. The purpose of this study was to investigate if knee extensors fatigue alters elbow flexors force and electromyography (EMG) activity. Eighteen males completed a control and fatiguing session (randomised). Blood lactate was initially sampled followed by three maximal voluntary contractions (MVC) with the elbow flexors and two with the knee extensors. Thereafter, subjects either sat (control) or performed five sets of bilateral dynamic knee extensions to exhaustion using a load equal to the dominant limb MVC (1-min rest between sets). Immediately afterwards, subjects were assessed for blood lactate and unilateral knee extensors MVC, and after 1 min performed a single unilateral elbow flexor MVC. Two minutes later, subjects performed 12 unilateral elbow flexor MVCs (5 s contraction/10 s rest) followed by a third blood lactate test. Compared to control, knee extensor force dropped by 35% (p < 0.001; ES = 1.6) and blood lactate increased by 18% (p < 0.001; ES = 2.8). Elbow flexor forces were lower after the fatiguing protocol only during the last five MVCs (p < 0.05; ES = ∼ 0.58; ∼ 5%). No changes occurred between conditions in EMG. Elbow flexor forces significantly decreased after knee extensors fatigue. The effect was revealed during the later stages of the repeated MVCs protocol, demonstrating that non-local fatigue may have a stronger effect on repeated rather than on single attempts of maximal force production.
Dovelle, S; Heeter, P K
This article describes the use of the "Washington Regimen" of early controlled motion in the rehabilitation of flexor tendon injuries of the hand. This regimen is derived from a combination of Kleinert's controlled active extension with rubber-hand passive flexion, Duran's controlled passive techniques, and the modification of the Kleinert orthosis that uses a palmar pulley system. Based on results of clinical investigations, this regimen of early controlled motion appears effective in inhibiting peritendinous scarring, joint contractures, and other complications that commonly occur secondary to flexor tendon repairs. A six-week staged regimen of postoperative rehabilitation is presented. Splint design, exercise regimen, and rationale for treatment are reviewed.
Kotwal, Prakash P; Ansari, Mohammed Tahir
Flexor tendon injuries are seen commonly yet the management protocols are still widely debated. The advances in suture techniques, better understanding of the tendon morphology and its biomechanics have resulted in better outcomes. There has been a trend toward the active mobilization protocols with development of multistrand core suture techniques. Zone 2 injuries remain an enigma for the hand surgeons even today but the outcome results have definitely improved. Biomolecular modulation of tendon repair and tissue engineering are now the upcoming fields for future research. This review article focuses on the current concepts in the management of flexor tendon injuries in zone 2. PMID:23325961
Lee, Kang; Moon, Jeong Seok; Seo, Jeong Gook; Lee, Woo Chun
We present one-stage treatment of deep infection following repair of Achilles tendon rupture using flexor hallucis longus transfer. Flexor hallucis longus was used not only to connect the defect in Achillles tendon, but also to control the soft tissue infection with its abundant blood supply, simultaneously. The clinical results for the two patients in this report were excellent without major complication.
Lee, G J; Kwak, S; Kim, H K; Ha, S H; Lee, H J; Baek, G H
Spontaneous flexor tendon rupture is a rare condition and the aetiology is not clear. We report 12 elderly Korean farmers with spontaneous flexor tendon ruptures. We found the rupture in the dominant hand in ten patients. A rupture in the little finger was found in all 12 patients (seven with both flexor tendons ruptured and five with only the profundus ruptured), in the ring finger in four patients (the profundus ruptured in all and both flexor tendons in two patients), and in the middle finger a partial rupture of the profundus in one patient. The tendons were ruptured close to the hook of the hamate. Repetitive friction between the flexor tendons and the hamate hook may cause the ruptures. The hamate hook was excised and the ruptured profundus tendons were reconstructed with tendon transfers with quite favourable functional recovery at follow-up of 1 to 2 years. The ruptured superficialis tendons were not reconstructed. Level of Evidence IV.
Kurtzer, Isaac; Meriggi, Jenna; Parikh, Nidhi; Saad, Kenneth
Postural corrections of the upper limb are required in tasks ranging from handling an umbrella in the changing wind to securing a wriggling baby. One complication in this process is the mechanical interaction between the different segments of the arm where torque applied at one joint induces motion at multiple joints. Previous studies have shown the long-latency reflexes of shoulder muscles (50-100 ms after a limb perturbation) account for these mechanical interactions by integrating information about motion of both the shoulder and elbow. It is less clear whether long-latency reflexes of elbow muscles exhibit a similar capability and what is the relation between the responses of shoulder and elbow muscles. The present study utilized joint-based loads tailored to the subjects' arm dynamics to induce well-controlled displacements of their shoulder and elbow. Our results demonstrate that the long-latency reflexes of shoulder and elbow muscles integrate motion from both joints: the shoulder and elbow flexors respond to extension at both joints, whereas the shoulder and elbow extensors respond to flexion at both joints. This general pattern accounts for the inherent flexion-extension coupling of the two joints arising from the arm's intersegmental dynamics and is consistent with spindle-based reciprocal excitation of shoulder and elbow flexors, reciprocal excitation of shoulder and elbow extensors, and across-joint inhibition between the flexors and extensors.
Mon, Daniel; Zakynthinaki, María S; Cordente, Carlos A; Antón, Antonio J Monroy; Rodríguez, Bárbara Rodríguez; Jiménez, David López
The ability to stabilize the gun is crucial for performance in Olympic pistol shooting and is thought to be related to the shooters muscular strength. The present study examines the relation between performance and finger flexor force as well as shoulder abduction isometric force in senior male air pistol shooting. 46 Spanish national level shooters served as test subjects of the study. Two maximal force tests were carried out recording handgrip and deltoid force data under competition conditions, during the official training time at national Spanish championships. Performance was measured as the total score of 60 shots at competition. Linear regressions were calculated to examine the relations between performance and peak and average finger flexor forces, peak and average finger flexor forces relative to the BMI, peak and average shoulder abduction isometric forces, peak shoulder abduction isometric force relative to the BMI. The connection between performance and other variables such as age, weight, height, BMI, experience in years and training hours per week was also analyzed. Significant correlations were found between performance at competition and average and peak finger flexor forces. For the rest of the force variables no significant correlations were found. Significant correlations were also found between performance at competition and experience as well as training hours. No significant correlations were found between performance and age, weight, height or BMI. The study concludes that hand grip strength training programs are necessary for performance in air pistol shooting.
Berglund, M E; Hart, D A; Reno, C; Wiig, M
The purpose of the study was to contribute to the mapping of molecular events during flexor tendon healing, in particular the growth factors insulin-like growth factor-1 (IGF-1), vascular endothelial growth factor (VEGF) and nerve growth factor (NGF), matrix metalloproteinases (MMP-3 and MMP-13) and their inhibitors (tissue inhibitors of metalloproteinases, TIMP-1 and TIMP-3, and the protease cathepsin K. In a rabbit model of flexor tendon injury, the mRNA expression for the growth factors, MMPs and TIMPs were measured in tendon and tendon sheath tissue at several time points (3, 6, 21, and 42 days) representing different phases of the healing process. We found that MMP-13 remained increased during the study period, whereas MMP-3 returned to normal levels within the first week after injury. TIMP-3 was down-regulated in the tendon sheaths. Cathepsin K was up-regulated in tendons and sheaths after injury. NGF was present in both tendons and sheaths, but unaltered. IGF-1 exhibited a late increase in the tendons, while VEGF was down-regulated at the later time points. In conclusion, we have demonstrated the presence of NGF in flexor tendons. MMP-13 expression appears to play a more protracted role in flexor tendon healing than MMP-3. The relatively low levels of endogenous IGF-1 and VEGF mRNA following injury support their potential beneficial role as exogenous modulators to optimize tendon healing and strength without increasing adhesion formation.
Endo, Jun; Yamaguchi, Satoshi; Sasho, Takahisa
Intratendinous ganglion cysts are rare lesions of unknown etiology that originate within a tendon. We report the case of a 34-year-old female with an intratendinous ganglion in the plantar portion of the flexor hallucis longus tendon. The intratendinous ganglion recurred after ultrasound-guided needle aspiration. Tendoscopic excision of the intratendinous ganglion cyst achieved a satisfactorily result without recurrence.
Timmins, R G; Opar, D A; Williams, M D; Schache, A G; Dear, N M; Shield, A J
The aim of this study was to determine whether declines in knee flexor strength following overground repeat sprints were related to changes in hamstrings myoelectrical activity. Seventeen recreationally active men completed maximal isokinetic concentric and eccentric knee flexor strength assessments at 180°/s before and after repeat sprint running. Myoelectrical activity of the biceps femoris (BF) and medial hamstrings (MHs) was measured during all isokinetic contractions. Repeated measures mixed model [fixed factors = time (pre- and post-repeat sprint) and leg (dominant and nondominant), random factor = participants] design was fitted with the restricted maximal likelihood method. Repeat sprint running resulted in significant declines in eccentric, and concentric, knee flexor strength (eccentric = 26 ± 4 Nm, 15% P < 0.001; concentric 11 ± 2 Nm, 10% P < 0.001). Eccentric BF myoelectrical activity was significantly reduced (10%; P = 0.035). Concentric BF and all MH myoelectrical activity were not altered. The declines in maximal eccentric torque were associated with the change in eccentric BF myoelectrical activity (P = 0.013). Following repeat sprint running, there were preferential declines in the myoelectrical activity of the BF, which explained declines in eccentric knee flexor strength.
Mon, Daniel; Zakynthinaki, María S.; Cordente, Carlos A.; Antón, Antonio J. Monroy; Rodríguez, Bárbara Rodríguez; Jiménez, David López
The ability to stabilize the gun is crucial for performance in Olympic pistol shooting and is thought to be related to the shooters muscular strength. The present study examines the relation between performance and finger flexor force as well as shoulder abduction isometric force in senior male air pistol shooting. 46 Spanish national level shooters served as test subjects of the study. Two maximal force tests were carried out recording handgrip and deltoid force data under competition conditions, during the official training time at national Spanish championships. Performance was measured as the total score of 60 shots at competition. Linear regressions were calculated to examine the relations between performance and peak and average finger flexor forces, peak and average finger flexor forces relative to the BMI, peak and average shoulder abduction isometric forces, peak shoulder abduction isometric force relative to the BMI. The connection between performance and other variables such as age, weight, height, BMI, experience in years and training hours per week was also analyzed. Significant correlations were found between performance at competition and average and peak finger flexor forces. For the rest of the force variables no significant correlations were found. Significant correlations were also found between performance at competition and experience as well as training hours. No significant correlations were found between performance and age, weight, height or BMI. The study concludes that hand grip strength training programs are necessary for performance in air pistol shooting. PMID:26121145
Draganidis, Dimitrios; Chatzinikolaou, Athanasios; Avloniti, Alexandra; Barbero-Álvarez, José C.; Mohr, Magni; Malliou, Paraskevi; Gourgoulis, Vassilios; Deli, Chariklia K.; Douroudos, Ioannis I.; Margonis, Konstantinos; Gioftsidou, Asimenia; Fouris, Andreas D.; Jamurtas, Athanasios Z.; Koutedakis, Yiannis; Fatouros, Ioannis G.
We examined the temporal changes of isokinetic strength performance of knee flexor (KF) and extensor (KE) strength after a football match. Players were randomly assigned to a control (N = 14, participated only in measurements and practices) or an experimental group (N = 20, participated also in a football match). Participants trained daily during the two days after the match. Match and training overload was monitored with GPS devices. Venous blood was sampled and muscle damage was assessed pre-match, post-match and at 12h, 36h and 60h post-match. Isometric strength as well as eccentric and concentric peak torque of knee flexors and extensors in both limbs (dominant and non-dominant) were measured on an isokinetic dynamometer at baseline and at 12h, 36h and 60h after the match. Functional (KFecc/KEcon) and conventional (KFcon/KEcon) ratios were then calculated. Only eccentric peak torque of knee flexors declined at 60h after the match in the control group. In the experimental group: a) isometric strength of knee extensors and knee flexors declined (P<0.05) at 12h (both limbs) and 36h (dominant limb only), b) eccentric and concentric peak torque of knee extensors and flexors declined (P<0.05) in both limbs for 36h at 60°/s and for 60h at 180°/s with eccentric peak torque of knee flexors demonstrating a greater (P<0.05) reduction than concentric peak torque, c) strength deterioration was greater (P<0.05) at 180°/s and in dominant limb, d) the functional ratio was more sensitive to match-induced fatigue demonstrating a more prolonged decline. Discriminant and regression analysis revealed that strength deterioration and recovery may be related to the amount of eccentric actions performed during the match and athletes' football-specific conditioning. Our data suggest that recovery kinetics of knee flexor and extensor strength after a football match demonstrate strength, limb and velocity specificity and may depend on match physical overload and players' physical
Chen, Qiang; Lu, Hui; Yang, Hu
Chitosan has been demonstrated to exert potent anti-adhesive activity during tendon repair; however, the underlying molecular mechanisms remain unclear. The present study aimed to investigate the preventive effects of chitosan on adhesion in rabbit tendon repair, and to investigate the role of the sirtuin (SIRT)1 signaling pathway in this process. A total of 30 rabbits were divided randomly into three equal groups: Group 1, saline treatment; group 2, chitosan treatment; and group 3, chitosan + nicotinamide treatment. The flexor tendon of each of the rabbits was injured, and subsequently each rabbit was injected with the one of the reagents. Six weeks post‑surgery, all of the rabbits were sacrificed and their flexor tendons were harvested for subsequent evaluation of adhesion. Western blotting was used to determine the protein expression levels of specific signaling molecules. An MTT assay was conducted to evaluate the viability of human tenocytes and flow cytometry was used to analyze the apoptotic rate of the cells. The present study demonstrated that treatment with chitosan relieved adhesion in the rabbits with flexor tendon injuries. In addition, chitosan treatment increased SIRT1 expression, and reduced acetylated p65 and p53 expression in the tendons. The effects of chitosan on the tendons were attenuated by treatment with nicotinamide (a SIRT1 inhibitor). In the human tenocytes, pretreatment with chitosan resulted in an inhibition of interleukin (IL)‑1β‑induced apoptosis. Furthermore, chitosan reversed the IL‑1β‑induced downregulation of SIRT1 and upregulation of acetylated p65 and p53. Furthermore, downregulation of Sirt1 by RNA interference abrogated the effects of chitosan on the levels of p65 and p53 acetylation, and the rate of tenocyte apoptosis. In conclusion, chitosan treatment prevented adhesion via the SIRT1 signaling pathway during rabbit flexor tendon repair. These results indicate that SIRT1 may be targeted for therapeutic
Park, Jung Sub; Choi, Jean; Kim, Jung Woon; Jeon, Sang Yun; Kang, Sunghwun
[Purpose] The aim of this study was to examine the flexor/extensor ratio of the knee joints and compare it with the results of Korean Air Force students in G-tolerance test. [Subjects and Methods] The body composition of Korea Air Force students (n=77) was measured by an impedance method. A muscular function test was performed using a Humac Norm (USA) at angular speeds of 60°/sec and 240°/sec and an isokinetic muscular function test was also conducted. [Results] In the failed C and passing groups, muscle mass and fat percentages were significantly higher than those of students in the failed A group. The BMI of the failed C and passing groups were significantly higher than that of the failed A group. The group that passed had a significantly higher value of left knee 60°/sec flexion peak torque than the failed B group. Moreover, the total work of left knee extension of the failed C group and the passing group was significantly higher than that of the failed A group. The C group and the passing group had significantly higher values of the trunk 60°/sec flexor/extensor ratio than the failed A group, and the total work flexor/extensor ratio of the passing group was significantly higher than that of the failed A group. [Conclusions] Based on these results, balance the right and left knee flexor/extensor ratio, and a high flexor/extensor ratio of the trunk are required to endure a high G-tolerance test (+6G/30 sec). Moreover, an improvement in the maximum muscular strength is necessary to endure a situation of rapidly increasing acceleration in the early stage. PMID:27799715
Hernández-Cortés, P; Caba, M; Gómez-Sánchez, R; Gómez-Morales, M
The authors report an unusual case of flexor tenosynovitis, severe carpal tunnel syndrome, and triggering at the carpal tunnel as the first manifestation of gout. A 69-year-old man presented with digital flexion contracture and severe carpal tunnel syndrome of his right hand and was treated surgically. A flexor tenosynovectomy and a median nerve neurolysis were performed through an extended carpal tunnel approach. The sublimis and the profundus tendons were involved. Partial ruptures and multiple whitish lesions suggestive of tophacceous infiltration of the flexor tendons were seen. Macroscopically, the removed synovial tissue was involved by multiple whitish nodules that were milimetric in size and was suggestive of monosodium urate crystals deposits. By light microscopy examination, numerous nonnecrotizing granulomas of different sizes were observed that were compounded by large aggregations of acellular nonpolarized material, surrounded by epithelioid histiocytes, mononuclear cells, and foreign body multinucleated giant cells. Postoperatively, the patient recovered with resolution of the median nerve symptoms and a near-to-full range of motion of the affected digits.To the authors' knowledge, this patient is the first case report with flexor tendons tophacceous infiltration as the first clinical sign of gout. Gouty flexor tenosynovitis can occur in the absence of a long history of gout. A high index of suspicion is paramount to the initiation of proper management. Operative treatment of gouty flexor tenosynovitis is mandatory to debulk tophaceous deposits, improve tendon gliding, and decompress nerves. Routine uric acid determination could be helpful in the preoperative evaluation of patients with flexor tenosynovitis.
Chin, Brian; Cheung, Kevin; Farhangkhoee, Hana; Thoma, Achilleas
Proliferative flexor tenosynovitis of the hand is an inflammatory process involving the synovial sheaths surrounding the tendons. It is most commonly caused by infection, but may also be caused by overuse, diabetes and rheumatic conditions such as rheumatoid arthritis and crystal arthropathies. The present report describes two patients with severe proliferative tenosynovitis, who developed a fistula between the tendon sheath and skin after instrumentation, resulting in persistent synovial drainage. After failing conservative management, both patients were managed with extensive flexor tenosynovectomy to prevent inoculation of bacteria into the flexor sheath. The presentation, management and outcome of each case is described in addition to a discussion of the literature on tenosynovial fistulas.
Farhat, Youssef M.; Al-Maliki, Alaa A.; Easa, Anas; O’Keefe, Regis J.; Schwarz, Edward M.; Awad, Hani A.
Flexor tendon injuries caused by deep lacerations to the hands are a challenging problem as they often result in debilitating adhesions that prevent the movement of the afflicted fingers. Evidence exists that tendon adhesions as well as scarring throughout the body are largely precipitated by the pleiotropic growth factor, TGF-β1, but the effects of TGF-β1 are poorly understood in tendon healing. Using an in vitro model of tendon healing, we previously found that TGF-β1 causes gene expression changes in tenocytes that are consistent with scar tissue and adhesion formation, including upregulation of the anti-fibrinolytic protein, PAI-1. Therefore, we hypothesized that TGF-β1 contributes to scarring and adhesions by reducing the activity of proteases responsible for ECM degradation and remodeling, such as plasmin and MMPs, via upregulation of PAI-1. To test our hypothesis, we examined the effects of TGF-β1 on the protease activity of tendon cells. We found that flexor tendon tenocytes treated with TGF-β1 had significantly reduced levels of active MMP-2 and plasmin. Interestingly, the effects of TGF-β1 on protease activity were completely abolished in tendon cells from homozygous PAI-1 KO mice, which are unable to express PAI-1. Our findings support the hypothesis that TGF-β1 induces PAI-1, which suppresses plasmin and plasmin-mediated MMP activity, and provide evidence that PAI-1 may be a novel therapeutic target for preventing adhesions and promoting a scarless, regenerative repair of flexor tendon injuries. PMID:24962629
An original method for A1 retinaculum reconstruction of flexor pollicis longus sheath with extensor pollicis brevis tendon is presented. Reconstructed retinaculum is very strong. Loss of extensor pollicis brevis did not impaired thumb function.
In the reconstruction of hand flexor tendon injuries it is fundamental to select the best suture technique, which makes possible early, active postoperative mobilization and achievement of the best results. The author reviews the development of suture techniques of the flexor tendon injuries during the last fifteen years, and discusses experimental tendon reconstruction results as well as clinical outcomes. The author describes the importance of different tendon suture materials, the significance of the pulley system of the fingers, the stretching between the sutured tendon ends by tendon sutures and, finally, the importance of the moving course in the reconstructed tendon. He states, that the wide-range adoption of the discussed modern tendon sutures would be necessary for better postoperative results.
Al-Qattan, M M
Over an eight-year period, the author has treated five males (mean age of 31 years) with clean-cut zone 2 lacerations of both flexor tendons of all fingers using the same surgical technique (profundus only repair using three 'figure of eight' core sutures and proximal venting of the pulley system) and the same postoperative mobilization programme (a dorsal blocking splint with immediate active motion that allowed full extension at the interphalangeal joints). There were no ruptures of the repaired 20 fingers. At final follow-up (mean of 22 months after surgery), the outcome was considered excellent in 12 fingers, good in four fingers and fair in the remaining four fingers by the Strickland-Glogovac criteria. The outcome was similar in all four fingers for every patient supporting the hypothesis of previous studies that the outcome of repair of clean-cut flexor tendon lacerations in zone 2 is related to the psychological and biologic characteristics of the patient.
Gayle, J M; Burrell, G A; Anderson, K L; Redding, W R; Blikslager, A T
A first-calf Guernsey cow was referred for evaluation of severe udder edema, mastitis, metritis, and ketosis. During the course of treatment, the cow became recumbent and was unable to rise. Intensive treatment resulted in the cow being able to stand for short periods with the aid of a sling. However, severe pressure necrosis of the udder and ongoing mastitis made performance of a complete mastectomy necessary. After surgery, the cow's condition improved, although assistance in standing was still required. Radiography of the distal phalanges revealed severe rotation in the right lateral and left medial digits of the hind limbs. The laminitis was nonresponsive to medical management; therefore, a deep digital flexor tenotomy was performed in the affected claws. The procedure provided almost immediate relief of signs of foot pain and resulted in ability to stand without assistance. Deep digital flexor tenotomy should be considered when treating cows with severe laminitis.
Lin, D; Williams, C; Zaw, H
Tarsal tunnel syndrome (TTS) is a rare entrapment neuropathy of the tibial nerve within the fibro-osseous tarsal tunnel for which multiple etiologies, including trauma, congenital foot abnormalities and space occupying lesions, have been described. We present an unusual case of TTS caused by an accessory Flexor Hallucis Longus (FHL) tendon. Surgical excision led to a complete resolution of symptoms and improved the quality of life of our patient.
Beck, Travis W; Ye, Xin; Wages, Nathan P
The purpose of this study was to compare the electromyographic (EMG) intensity patterns after unilateral concentric vs. eccentric exercise in the dominant (DOM) and nondominant (NONDOM) forearm flexors. Twenty-six men (mean ± SD: age, 24.0 ± 3.7 years) volunteered to perform a maximal isometric muscle action of the DOM and NONDOM forearm flexors before (PRE) and immediately after (POST) a series of maximal concentric isokinetic or maximal eccentric isokinetic muscle actions of the DOM forearm flexors. The concentric isokinetic and eccentric isokinetic muscle actions were performed on separate days that were randomly ordered. However, in both cases, the subjects performed 6 sets of 10 maximal muscle actions. A bipolar surface EMG signal was detected from the biceps brachii of the DOM and NONDOM limbs during the PRE and POST isometric muscle actions. The signals were then analyzed with a wavelet analysis, and the resulting intensity patterns were classified with a paired pattern classification procedure. The results indicated that the EMG intensity patterns could be correctly classified into their respective PRE vs. POST categories with an accuracy rate that was significantly better than random (20 of 26 patterns = 76.9% accuracy) but only for the DOM limb following the eccentric muscle actions. All other classifications were not significantly better than random. These findings indicated that eccentric exercise had a significant influence on the muscle activation pattern for the forearm flexors. It is possible that the muscle damage resulting from eccentric exercise affects muscle spindle or golgi tendon organ or both activity, thereby altering the muscle activation pattern.
Mendis, M Dilani; Wilson, Stephen J; Hayes, David A; Watts, Mark C; Hides, Julie A
Acetabular labral tears are a source of hip pain and are considered to be a precursor to hip osteoarthritis. Hip flexor muscles contribute to hip joint stability and function but it is unknown if their size and function is altered in the presence of labral pathology. This study aimed to investigate hip flexor muscle size, strength and recruitment pattern in patients with hip labral pathology compared to control subjects. 12 subjects diagnosed with an unilateral acetabular labral tear were compared to 12 control subjects matched for age and gender. All subjects underwent magnetic resonance imaging (MRI) of their lumbo-pelvic region. Average muscle cross-sectional area (CSA) of the iliacus, psoas, iliopsoas, sartorius, tensor fascia latae and rectus femoris muscles were measured. Hip flexion strength was measured by an externally fixed dynamometer. Individual muscle recruitment pattern during a resisted hip flexion exercise task was measured by muscle functional MRI. Hip flexor muscle strength was found to be decreased in patients with labral pathology compared to control subjects (p < 0.01). No difference between groups or sides was found for hip flexor muscle size (all p > 0.17) and recruitment pattern (all p > 0.53). Decreased hip flexor muscle strength may affect physical function in patients with hip labral pathology by contributing to altered gait patterns and functional tasks. Clinical rehabilitation of these patients may need to include strengthening exercises for the hip flexor muscles.
Schweizer, A; Frank, O; Ochsner, P E; Jacob, H A C
A method was developed to indirectly measure friction between the flexor tendons and pulleys of the middle and ring finger in vivo. An isokinetic movement device to determine maximum force of wrist flexion, interphalangeal joint flexion (rolling in and out) and isolated proximal interphalangeal (PIP) joint flexion was built. Eccentric and concentric maximum force of these three different movements where gliding of the flexor tendon sheath was involved differently (least in wrist flexion) was measured and compared. Fifty-one hands in 26 male subjects were evaluated. The greatest difference between eccentric and concentric maximum force (29.9%) was found in flexion of the PIP joint. Differences in the rolling in and out movement (26.8%) and in wrist flexion (14.5%) were significantly smaller. The force of friction between flexor tendons and pulleys can be determined by the greater difference between eccentric and concentric maximum force provided by the same muscles in overcoming an external force during flexion of the interphalangeal joints and suggests the presence of a non-muscular force, such as friction. It constitutes of 9% of the eccentric flexion force in the PIP joint and therefore questions the low friction hypothesis at high loads.
Nunley, J A; Levin, L S; Devito, D; Goldner, R D; Urbaniak, J R
Between 1976 and 1986, 38 consecutive acute isolated flexor pollicis longus lacerations were repaired. This study excluded all replanted or mutilated digits and all lacerations with associated fracture. Average follow-up was 26 months. Tendon rehabilitation was standardized. Range of motion and pinch strength were measured postoperatively. Seventy-four percent (28/38) of the flexor pollicis longus injuries occurred in zone II. Neurovascular injury occurred in 82% of the lacerations, and this correlated with the zone of tendon injury. In 21% of the patients (8/38) both digital nerves and arteries were transected. Postoperative thumb interphalangeal motion averaged 35 degrees and key pinch strength was 81% that of the uninjured thumb. One rupture occurred in a child. Laceration of the flexor pollicis longus is likely to involve damage to neurovascular structures, and repair may be necessary. Direct end-to-end repairs within the pulley system do at least as well as delayed tendon reconstruction and do not require additional procedures.
Patel, Biren A; Larson, Susan G; Stern, Jack T
Some non-human primates use digitigrade hand postures when walking slowly on the ground. As a component of an extended limb, a digitigrade posture can help minimize wrist joint moments thereby requiring little force production directly from wrist flexors (and/or from the assistance of finger flexors) to maintain limb posture. As a consequence, less active muscle volume would be required from these anti-gravity muscles and overall metabolic costs associated with locomotion could be reduced. To investigate whether the use of digitigrade hand postures during walking in primates entails minimal use of anti-gravity muscles, this study examined electromyography (EMG) patterns in both the wrist and finger flexor muscles in facultatively digitigrade olive baboons (Papio anubis) across a range of speeds. The results demonstrate that baboons can adopt a digitigrade hand posture when standing and moving at slow speeds without requiring substantial EMG activity from distal anti-gravity muscles. Higher speed locomotion, however, entails increasing EMG activity and is accompanied by a dynamic shift to a more palmigrade-like limb posture. Thus, the ability to adopt a digitigrade hand posture by monkeys is an adaptation for ground living, but it was never co-opted for fast locomotion. Rather, digitigrady in primates appears to be related to energetic efficiency for walking long distances.
Zhao, Chunfeng; Ozasa, Yasuhiro; Shimura, Haruhiko; Reisdorf, Ramona L.; Thoreson, Andrew R.; Jay, Gregory; Moran, Steven L.; An, Kai-Nan; Amadio, Peter C.
The purpose of the study was to test a novel treatment that carbodiimide-derivatized-hyaluronic acid-lubricin (cd-HA-lubricin) combined cell-based therapy in an immobilized flexor tendon repair in a canine model. Seventy-eight flexor tendons from 39 dogs were transected. One tendon was treated with cd-HA-lubricin plus an interpositional graft of 8 × 105 BMSCs and GDF-5. The other tendon was repaired without treatment. After 21 day of immobilization, 19 dogs were sacrificed; the remaining 20 dogs underwent a 21-day rehabilitation protocol before euthanasia. The work of flexion, tendon gliding resistance, and adhesion score in treated tendons were significantly less than the untreated tendons (p < 0.05). The failure strength of the untreated tendons was higher than the treated tendons at 21 and 42 days (p < 0.05). However, there is no significant difference in stiffness between two groups at day 42. Histologic analysis of treated tendons showed a smooth surface and viable transplanted cells 42 days after the repair, whereas untreated tendons showed severe adhesion formation around the repair site. The combination of lubricant and cell treatment resulted in significantly improved digit function, reduced adhesion formation. This novel treatment can address the unmet needs of patients who are unable to commence an early mobilization protocol after flexor tendon repair. PMID:26177854
Samukawa, Mina; Hattori, Masaki; Sugama, Naoko; Takeda, Naoki
Dynamic stretching is commonly used in warm-up routines for athletic activities. Even though several positive effects of dynamic stretching on athletic performance have been reported, the effects on the muscle-tendon unit (MTU) itself are still unclear. The objective of this study is to determine the effects of dynamic stretching on the ankle plantar flexor muscle-tendon properties by use of ultrasonography. Twenty healthy male subjects participated in the present study. The subjects were asked to engage in dynamic stretching of plantar flexors for 30 s and to repeat for 5 sets. Ankle dorsiflexion ROM was measured before and after the dynamic stretching. Changes in the displacement of the myotendinous junction (MTJ), pennation angle, and fascicle length were also determined by using ultrasonography. Ankle dorsiflexion ROM increased significantly after the dynamic stretching (p < 0.0001). A significant distal displacement of the MTJ was observed until the second stretching set (p < 0.001) with no significant changes thereafter. Pennation angle, and fascicle length were unaffected by the dynamic stretching. Dynamic stretching was shown to be effective in increasing ankle joint flexibility. Outcomes that could have indicated changes in muscle tissue (such as the pennation angle and fascicle length) were unaltered. However, a significant displacement of the MTJ was found, indicating some change in the tendon tissues. Therefore, dynamic stretching of the plantar flexors was considered an effective means of lengthening the tendon tissues.
Ayad, K. E.; El Gohary, H. M.; Abd Elrahman, M.; Abd El Mejeed, S. F.; Bekheet, A. B.
Flexor tendon injury is a common problem requiring suturing repair followed by early postoperative mobilization. Muscle atrophy, joint stiffness, osteoarthritis, infection, skin necrosis, ulceration of joint cartilage and tendocutaneous adhesion are familiar complications produced by prolonged immobilization of surgically repaired tendon ruptures. The purpose of this study was to clarify the importance of low level laser therapy after hand flexor tendon repair in zone II. Thirty patients aging between 20 and 40 years were divided into two groups. Patients in group A (n = 15) received a conventional therapeutic exercise program while patients in group B (n = 15) received low level laser therapy combined with the same therapeutic exercise program. The results showed a statistically significant increase in total active motion of the proximal and distal interphalangeal joints as well as maximum hand grip strength at three weeks and three months postoperative, but improvement was more significant in group B. It was concluded that the combination of low level laser therapy and early therapeutic exercises was more effective than therapeutic exercises alone in improving total active motion of proximal and distal interphalangeal joints and hand grip strength after hand flexor tendon repair.
Ayad, K. E.; Abd El Mejeed, S. F.; El Gohary, H. M.; Abd Elrahman, M.; Bekheet, A. B.
Flexor tendon injury is a common problem requiring suturing repair followed by early postoperative mobilization. Muscle atrophy, joint stiffness, osteoarthritis, infection, skin necrosis, ulceration of joint cartilage and tendocutaneous adhesion are familiar complications produced by prolonged immobilization of surgically repaired tendon ruptures. The purpose of this study was to clarify the importance of low level laser therapy after hand flexor tendon repair in zone II. Thirty patients aging between 20 and 40 years were divided into two groups. Patients in group A (n = 15) received a conventional therapeutic exercise program while patients in group B (n = 15) received low level laser therapy combined with the same therapeutic exercise program. The results showed a statistically significant increase in total active motion of the proximal and distal interphalangeal joints as well as maximum hand grip strength at three weeks and three months postoperative, but improvement was more significant in group B. It was concluded that the combination of low level laser therapy and early therapeutic exercises was more effective than therapeutic exercises alone in improving total active motion of proximal and distal interphalangeal joints and hand grip strength after hand flexor tendon repair.
James, Rob S; Kohlsdorf, Tiana; Cox, Val M; Navas, Carlos A
Caffeine ingestion by human athletes has been found to improve endurance performance primarily acting via the central nervous system as an adenosine receptor antagonist. However, a few studies have implied that the resultant micromolar levels of caffeine in blood plasma (70 microM maximum for humans) may directly affect skeletal muscle causing enhanced force production. In the present study, the effects of 70 microM caffeine on force and power output in isolated mouse extensor digitorum longus muscle were investigated in vitro at 35 degrees C. Muscle preparations were subjected to cyclical sinusoidal length changes with electrical stimulation conditions optimised to produce maximal work. 70 microM caffeine caused a small but significant increase (2-3%) in peak force and net work produced during work loops (where net work represents the work input required to lengthen the muscle subtracted from the work produced during shortening). However, these micromolar caffeine levels did not affect the overall pattern of fatigue or the pattern of recovery from fatigue. Our results suggest that the plasma concentrations found when caffeine is used to enhance athletic performance in human athletes might directly enhance force and power during brief but not prolonged activities. These findings potentially confirm previous in vivo studies, using humans, which implied caffeine ingestion may cause acute improvements in muscle force and power output but would not enhance endurance.
Nonaka, Koji; Une, S; Tatsuta, N; Ito, K; Akiyama, J
We investigated muscle atrophy, major antioxidant enzymes and lipid peroxidation in the extensor digitorum longus (EDL, predominantly fast fibers) and soleus (predominantly slow fibers) muscle of streptozotocin-diabetic rats. Female Wistar rats were divided into a control (n = 5) and streptozotocin-induced diabetic group (n = 5). Eight weeks after diabetes induction the EDL and soleus muscles were removed and catalase (CAT), glutathione peroxidase (GPX) and superoxide dismutase activity (SOD), and thiobarbituric acid reactive substances (TBARS) levels measured. The CAT activity increased in both the EDL and soleus muscles of the diabetic rats (p < 0.01), whereas the GPX and SOD activities were increased only in the EDL muscle (p < 0.01 and p < 0.05). The TBARS levels were only increased in the EDL muscle of the diabetic rats (p < 0.01). Both muscles showed significant atrophy but the EDL muscle elicited the greatest atrophy. In conclusion, it appears that adaptive responses to oxidative stress were adequate in the soleus muscle, but not in the EDL muscle, of diabetic rats. Thus fast twitch muscle fibers may be more susceptible to oxidative stress than slow twitch muscle fibers and this may contribute to muscle atrophy under diabetic conditions.
Severo, Antônio Lourenço; Arenhart, Rodrigo; Silveira, Daniela; Ávila, Aluísio Otávio Vargas; Berral, Francisco José; Lemos, Marcelo Barreto; Piluski, Paulo César Faiad; Lech, Osvandré Luís Canfield; Fukushima, Walter Yoshinori
Objective: Analyzing suture time, biomechanics (deformity between the stumps) and the histology of three groups of tendinous surgical repair: Brazil-2 (4-strands) which the end knot (core) is located outside the tendon, Indiana (4-strands) and Tsai (6-strands) with sutures technique which the end knot (core) is inner of the tendon, associated with early active mobilization. Methods: The right calcaneal tendons (plantar flexor of the hind paw) of 36 rabbits of the New Zealand breed (Oryctolagus cuniculus) were used in the analysis. This sample presents similar size to human flexor tendon that has approximately 4.5 mm (varying from 2mm). The selected sample showed the same mass (2.5 to 3kg) and were male or female adults (from 8 ½ months). For the flexor tendons of the hind paws, sterile and driven techniques were used in accordance to the Committee on Animal Research and Ethics (CETEA) of the University of the State of Santa Catarina (UDESC), municipality of Lages, in Brazil (protocol # 1.33.09). Results: In the biomechanical analysis (deformity) carried out between tendinous stumps, there was no statistically significant difference (p>0.01). There was no statistical difference in relation to surgical time in all three suture techniques with a mean of 6.0 minutes for Tsai (6- strands), 5.7 minutes for Indiana (4-strands) and 5.6 minutes for Brazil (4-strands) (p>0.01). With the early active mobility, there was qualitative and quantitative evidence of thickening of collagen in 38.9% on the 15th day and in 66.7% on the 30th day, making the biological tissue stronger and more resistant (p=0.095). Conclusion: This study demonstrated that there was no histological difference between the results achieved with an inside or outside end knot with respect to the repaired tendon and the number of strands did not affect healing, vascularization or sliding of the tendon in the osteofibrous tunnel, which are associated with early active mobility, with the repair techniques
Lackmy-Vallée, Alexandra; Klomjai, Wanalee; Bussel, Bernard; Katz, Rose; Roche, Nicolas
Transcranial direct current stimulation (tDCS) is used as a noninvasive tool to modulate brain excitability in humans. Recently, several studies have demonstrated that tDCS applied over the motor cortex also modulates spinal neural network excitability and therefore can be used to explore the corticospinal control acting on spinal neurons. Previously, we showed that reciprocal inhibition directed to wrist flexor motoneurons is enhanced during contralateral anodal tDCS, but it is likely that the corticospinal control acting on spinal networks controlling wrist flexors and extensors is not similar. The primary aim of the study was to explore the effects of anodal tDCS on reciprocal inhibition directed to wrist extensor motoneurons. To further examine the supraspinal control acting on the reciprocal inhibition between wrist flexors and extensors, we also explored the effects of the tDCS applied to the ipsilateral hand motor area. In healthy volunteers, we tested the effects induced by sham and anodal tDCS on reciprocal inhibition pathways innervating wrist muscles. Reciprocal inhibition directed from flexor to extensor muscles and the reverse situation, i.e., reciprocal inhibition, directed from extensors to flexors were studied in parallel with the H reflex technique. Our main finding was that contralateral anodal tDCS induces opposing effects on reciprocal inhibition: it decreases reciprocal inhibition directed from flexors to extensors, but it increases reciprocal inhibition directed from extensors to flexors. The functional result of these opposite effects on reciprocal inhibition seems to favor wrist extension excitability, suggesting an asymmetric descending control onto the interneurons that mediate reciprocal inhibition.
Philippe, Marc; Wegst, Daniel; Müller, Tom; Raschner, Christian; Burtscher, Martin
Climbing performance relies to a great extent on the performance of the finger flexor muscles. Only a few studies investigated this performance in top class climbers and only one study compared gender-specific differences. This study investigated the climbing-specific finger flexor strength and endurance and related muscular oxygenation in 12 elite female and male climbers and 12 non-climbers. After the assessment of maximum voluntary finger flexor contraction (MVC), two isometric finger flexor endurance tests were performed at 40% MVC until exhaustion. A continuous isometric test was followed by an intermittent isometric test (10 s contraction, 3 s rest). Changes in oxygenation of finger flexor muscles were recorded using near infrared spectroscopy. MVC and strength-to-weight ratio were greater in climbers than non-climbers (P = 0.003; P < 0.001) and greater in men than women (P < 0.001; P = 0.002). Time to task failure for the intermittent test and the force-time integrals for the continuous and the intermittent test were also significantly greater in climbers (P = 0.030; P = 0.027; P = 0.005). During the intermittent test, re-oxygenation of the working muscles was faster in climbers (P < 0.05) without gender-specific differences. Close correlations were demonstrated between the best on-sight climbing performance and strength-to-weight ratio (r (2) = 0.946, P < 0.001) only in female climbers. The superior intermittent finger flexor endurance of climbers over non-climbers may be explained by the faster re-oxygenation of the finger flexor muscles during the short rest phases.
Barber, Lee A; Barrett, Rod S; Gillett, Jarred G; Cresswell, Andrew G; Lichtwark, Glen A
The aim of this study was to compare voluntary and involuntary force generating capacity of the triceps surae muscles in healthy young and older adult participants during isometric and isokinetic contractions. Ultrasound was used to measure medial gastrocnemius (MG) fascicle length during maximal voluntary isometric contractions and supra-maximal isometric twitch contractions at five ankle angles throughout the available range of motion, as well as isokinetic concentric and eccentric contractions at four ankle velocities. Maximum voluntary activation of the plantar flexors was assessed using the twitch interpolation technique. Peak plantar flexor torque was significantly lower in older adults compared to young participants by 42%, 28% and 43% during maximal voluntary isometric contractions, supra-maximal isometric twitch and concentric contractions respectively. No age-related differences in eccentric torque production were detected. When age-related differences in triceps surae muscle volume determined from MRI were taken into account, the age-related peak plantar flexor torque deficits for maximum voluntary isometric, supra-maximal twitch, and concentric contractions were 24%, 19% and 24% respectively. These age-related differences in torque were not explained by torque-length-velocity behaviour of the MG muscle fascicles, passive plantar flexor torque-angle properties, decreased neural drive of the plantar flexor muscles or antagonistic co-activation of the tibialis anterior muscle. The residual deficit in isometric and concentric plantar flexor torques in healthy older adults may involve reduced muscle quality. A significant reduction in supra-maximal twitch torque at longer MG fascicle lengths as well as a lower MG fascicle velocity during eccentric contractions in older adults was detected, which could possibly be a function of the reported increased Achilles tendon compliance in older adults.
Molenaar, Joery P; McNeil, Chris J; Bredius, Marlous S; Gandevia, Simon C
Data are equivocal on whether voluntary activation is preserved or decreased in old compared to young adults. Further, data are scant on the effect of age on the rate of muscle relaxation when the muscle is contracting voluntarily. Assessment of both measures with transcranial magnetic stimulation (TMS) yields information which cannot be obtained with traditional peripheral nerve stimulation. Hence, voluntary activation and peak relaxation rate of the elbow flexors were assessed with TMS during repeated maximal efforts in 30 men and 28 women between the ages of 22-84 years. Voluntary activation was similar for the two sexes (P = 0.154) and was not affected by age in men (96.2 ± 2.7 %; P = 0.887) or women (95.1 ± 3.0 %; P = 0.546). Men had a significantly faster peak rate of relaxation than women in absolute units (-880.0 ± 223.2 vs. -360.2 ± 78.5 Nm/ s, respectively; P < 0.001) and when normalized to subject strength (-12.5 ± 2.1 vs. -8.7 ± 1.0 s(-1), respectively; P < 0.001). Absolute and normalized relaxation rates slowed with age in men (P = 0.002 and P = 0.006, respectively), but not women (P = 0.142 and P = 0.950, respectively). Across the age range studied, all subjects, regardless of age or sex, were able to achieve high voluntary activation scores for the elbow flexors (~95 %). In contrast, peak relaxation rate was markedly faster in men than women and slowed with age in men but not women. Normalization of relaxation rates to strength did not affect the influence of age or sex.
De Luca, Annamaria; Pierno, Sabata; Liantonio, Antonella; Cetrone, Michela; Camerino, Claudia; Simonetti, Simonetta; Papadia, Francesco; Camerino, Diana Conte
No clear data is available about functional alterations in the calcium-dependent excitation-contraction (e-c) coupling mechanism of dystrophin-deficient muscle of mdx mice. By means of the intracellular microelectrode ‘point' voltage clamp method, we measured the voltage threshold for contraction (mechanical threshold; MT) in intact extensor digitorum longus (EDL) muscle fibres of dystrophic mdx mouse of two different ages: 8–12 weeks, during the active regeneration of hind limb muscles, and 6–8 months, when regeneration is complete. The EDL muscle fibres of 8–12-week-old wildtype animals had a more negative rheobase voltage (potential of equilibrium for contraction- and relaxation-related calcium movements) with respect to control mice of 6–8 months. However, at both ages, the EDL muscle fibres of mdx mice contracted at more negative potentials with respect to age-matched controls and had markedly slower time constants to reach the rheobase. The in vitro application of 60 mM taurine, whose normally high intracellular muscle levels play a role in e-c coupling, was without effect on 6–8-month-old wildtype EDL muscle, while it significantly ameliorated the MT of mdx mouse. HPLC determination of taurine content at 6–8 months showed a significant 140% rise of plasma taurine levels and a clear trend toward a decrease in amino acid levels in hind limb muscles, brain and heart, suggesting a tissue difficulty in retaining appropriate levels of the amino acid. The data is consistent with a permanent alteration of e-c coupling in mdx EDL muscle fibres. The alteration could be related to the proposed increase in intracellular calcium, and can be ameliorated by taurine, suggesting a potential therapeutic role of the amino acid. PMID:11226135
De Luca, A; Pierno, S; Liantonio, A; Cetrone, M; Camerino, C; Simonetti, S; Papadia, F; Camerino, D C
No clear data is available about functional alterations in the calcium-dependent excitation-contraction (e-c) coupling mechanism of dystrophin-deficient muscle of mdx mice. By means of the intracellular microelectrode "point" voltage clamp method, we measured the voltage threshold for contraction (mechanical threshold; MT) in intact extensor digitorum longus (EDL) muscle fibres of dystrophic mdx mouse of two different ages: 8 - 12 weeks, during the active regeneration of hind limb muscles, and 6 - 8 months, when regeneration is complete. The EDL muscle fibres of 8 - 12-week-old wildtype animals had a more negative rheobase voltage (potential of equilibrium for contraction- and relaxation-related calcium movements) with respect to control mice of 6 - 8 months. However, at both ages, the EDL muscle fibres of mdx mice contracted at more negative potentials with respect to age-matched controls and had markedly slower time constants to reach the rheobase. The in vitro application of 60 mM taurine, whose normally high intracellular muscle levels play a role in e-c coupling, was without effect on 6 - 8-month-old wildtype EDL muscle, while it significantly ameliorated the MT of mdx mouse. HPLC determination of taurine content at 6 - 8 months showed a significant 140% rise of plasma taurine levels and a clear trend toward a decrease in amino acid levels in hind limb muscles, brain and heart, suggesting a tissue difficulty in retaining appropriate levels of the amino acid. The data is consistent with a permanent alteration of e-c coupling in mdx EDL muscle fibres. The alteration could be related to the proposed increase in intracellular calcium, and can be ameliorated by taurine, suggesting a potential therapeutic role of the amino acid.
Tomaz, Marcelo A; Fernandes, Fabrício F A; El-Kik, Camila Z; Moraes, Raphael A M; Calil-Elias, Sabrina; Saturnino-Oliveira, Jeison; Martinez, Ana Maria B; Ownby, Charlotte L; Melo, Paulo A
We investigated the myotoxicity of Bothrops jararacussu crude venom and other cytolytic agents on mouse isolated extensor digitorum longus (EDL) and soleus (SOL) muscles, which present distinct properties: EDL is a fast-twitch, white muscle with predominantly glycolytic fibers, while SOL is slow-twitch, red muscle with predominantly oxidative fibers. Muscles were exposed to B. jararacussu crude venom (25 microg/ml) and other crotaline venoms (Agkistrodon contortrix laticinctus; Crotalus viridis viridis; Crotalus durissus terrificus) at the same concentration. Basal creatine kinase (CK) release to bathing solution was 0.43+/-0.06 for EDL and 0.29+/-0.06 for SOL (U g(-)(1) h(-)(1), n=36 for each muscle). Sixty minutes after exposure to B. jararacussu venom, EDL presented higher increase in the rate of CK release than SOL, respectively, 13.2+/-1.5 and 2.9+/-0.7 U g(-)(1)h(-)(1), n=10-12. Muscle denervation, despite decreasing CK content, did not affect sensitivities to B. jararacussu venom. Ouabain and potassium channel blockers (TEA; clotrimazole; glibenclamide) increased the rate of CK release by B. jararacussu in EDL and SOL muscles, decreasing and almost abolishing the different sensitivity. When we exposed EDL or SOL muscles to Naja naja, Apis mellifera venoms (25 microg/ml), or Triton X-100 (0.01%), they showed similar rate of CK release. Our present data suggest that a mechanism involving intracellular calcium regulation or potassium channels may participate in the different sensitivity of EDL and SOL to B. jararacussu venom.
Low, T H; Hales, P F
We reviewed the incidence and treatment of flexor carpi radialis tendinitis in 77 patients (81 thumbs) who had trapeziectomy and abductor pollicis longus suspensionplasty for thumb carpometacarpal joint arthritis. Eighteen patients, 20 wrists (25%) had flexor carpi radialis tendinitis. The onset was 2-10 months (mean 4.7) after surgery. Two cases had preceding trauma. Eight cases (40%) responded to splinting and steroid injection. Ten patients, 12 wrists (60%) underwent surgery after failing non-operative treatment. Eleven wrists had frayed or partially torn flexor carpi radialis tendon and one had a complete tendon rupture with pseudotendon formation. Flexor carpi radialis tenotomy and pseudotendon excision were performed. All operated patients obtained good pain relief initially post-operatively. However, the pain recurred in two patients after 8 months. One required a local steroid injection for localized tenderness at the site of the proximal tendon stump. The other patient required a revision operation for scaphotrapezoid impingement. Both obtained complete pain relief. Our study has shown a high incidence of flexor carpi radialis tendinitis following trapeziectomy and abductor pollicis longus suspensionplasty. Patients should be warned about this potential complication.
Bartle, B K; Telepun, G M; Goldberg, N H
Reconstruction or replacement of the damaged pulley is a difficult surgical problem because of the need to find suitable biological material, the bulkiness of the repair, and adhesion formation between the pulley and flexor tendons. Therefore, a method was developed to reconstruct the fibro-osseous pulleys with polytetrafluoroethylene (PTFE) membrane. Twenty White Leghorn chickens had the A3 pulley of the long digit excised; this was followed by a standard injury to the flexor profundus tendon. The A3 pulley was then reconstructed with PTFE membrane. In the opposite foot, the A3 pulley was transected laterally, the tendon injured in the same manner, and the native pulley sutured. Seven control chickens had a PTFE pulley reconstruction without tendon injury in one foot and the opposite foot did not undergo surgery. At postoperative days 0, 21, and 35, the animals were killed to evaluate the effectiveness of the PTFE pulleys. Flexor tendon function was assessed by determining the active range of motion of the digit. There was no significant difference between the PTFE pulleys and suture repair of the native pulleys at postoperative days 21 and 35. This indicates that the PTFE pulleys were capable of preventing tendon bow-stringing and did not significantly impair tendon gliding. The breaking strength of the PTFE pulley was less than that of the normal A3 pulleys, but it was sufficient to allow immediate mobilization of the digits postoperatively without fear of pulley rupture. The synthetic PTFE pulley appears to have the potential to function as an effective immediate replacement for the fibro-osseous pulleys.
Clarke, R W; Harris, J
This study was designed to investigate the relationship between the location of a noxious stimulus and the magnitude and duration of the plastic effects induced by that stimulus in withdrawal reflexes acting about the knee and the ankle, in rabbits. Reflexes were evoked in the nerves to the anterior tibial and semitendinosus flexor muscles by electrical stimulation at the toes. Repetitive, high intensity electrical stimulation of nerve trunks (sural, medial gastrocnemius, superficial peroneal, tibial, 100 pulses, 20 V, 1 ms at 0.5 Hz) was generally found to be a poor method for inducing central sensitization in these flexor reflexes. 'Natural' noxious stimulation induced more reliable enhancement of both reflexes. Mechanical (clamp) or chemical (mustard oil) stimulation of the heel induced prolonged (median duration >30 min) increases in reflexes to both muscles. Mechanical (clamp and superficial pinch) or chemical (mustard oil) stimulation of the toes, and injection of bradykinin into the gastrocnemius muscles or into the soft tissues of the sole of the foot, also led to enhancement of both reflexes, with the median duration of potentiation between 7 and 30 min. The effects obtained from deep tissue stimulation were generally weaker than those obtained after stimulation of superficial structures. These data show that there were no major differences in the effects obtained from the heel vs the toes, or between the two reflexes. It appears that the spatial organization of the spinal mechanisms underlying central sensitization of flexor withdrawal reflexes is rather more crudely drawn than that pertaining to the reflexes themselves. Furthermore, the data indicate that in the present preparation, afferents from deep tissues are no more effective in generating central sensitization than those from superficial structures.
Gibbons, C E R; Thompson, D; Sandow, M J
The integrity of the repair is critical to maintain coaptation of the severed flexor tendon end until healing has advanced sufficiently. In our hospital, we use a modified Savage repair (four-strand Adelaide technique) using 3-0 Ethibond (Ethicon, Somerville, NJ, USA) for acute flexor tenorrhaphy and an active postrepair mobilization protocol. To explain the apparent differences between the theoretical and actual repair strength of a multistrand repair in a single tension test and the reduced strength of a repair subjected to cyclic loading, we compared single and cyclical tensile loading with different suture in vitro configurations of 3-0 Ethibond (Ethicon, Somerville, NJ, USA; one, two, and four strands) and an ex vivo four-strand repair of freshly divided porcine tendon to calculate the ultimate tensile strength (UTS). Mechanical testing was repeated 15 times with both single tensile and cyclical loading for each suture configuration and porcine repair. In the in vitro model, the presence of a knot in a single strand reduced the UTS by 50%. The stiffness of a knotted strand was substantially less than the unknotted strand but became identical after cyclical loading. There was no statistical significance of the UTS between single and cyclical loading with different numbers of strands in this model. In the ex vivo four-strand porcine repair model, there was a significant reduction in UTS with cyclical loading, which equated to the number of strands times the strength of the knotted strand. This discrepancy can be explained by the change in stiffness of the knotted strand after cyclical loading and has important implications for previous studies of suture tendon repair using single tensile loading where the UTS may have been overestimated. We believe that cyclical loading is more representative of physiological loading after acute flexor tendon repair and should be the testing model of choice in suture tenorrhaphy studies.
Gajendran, Varun K; Bishop, Julius A
Terrible triad elbow injuries, consisting of fractures of the radial head and coronoid with ulnohumeral dislocation, are challenging to treat. They require a comprehensive understanding of the complex anatomy of the elbow to effectively treat all of the pathology and create a stable, congruent joint. The authors present a case of a terrible triad injury with avulsion of the triceps and flexor-pronator mass after a low-energy fall in a young patient. Although most terrible triad fracture-dislocations can be successfully treated with coronoid fixation, radial head fixation or replacement, and repair of the lateral collateral ligament complex, this case involved a completely circumferential injury to the elbow. The coronoid and anterior capsule were disrupted anteriorly, the radial head and lateral collateral ligament complex were disrupted laterally, the triceps was disrupted posteriorly, and the flexor-pronator mass was disrupted medially. Although the authors prefer to address most terrible triad injuries through a lateral approach, they suspected a circumferential injury preoperatively and elected to use a single posterior incision to address all of the pathology conveniently. This injury required treatment of all disrupted structures, because the elbow remained unstable until the triceps and flexor-pronator mass avulsions were ultimately repaired. With any elbow fracture-dislocation, surgeons should look for evidence of additional injuries that do not fit the commonly described patterns, because they may necessitate modifications to the treatment plan. Given the relatively common complications of stiffness and instability despite modern surgical techniques, additional injuries may further compromise functional outcomes unless they are addressed properly.
Oshita, Kazushige; Yano, Sumio
The purpose of this study was to assess the effect of low-frequency force steadiness practice in the plantar flexor muscles on postural sway during quiet standing. Healthy young 21 men (21±1 yrs) were randomly assigned to a practice group (n=14) and a nonexercising control group (n=7). Practice groups were divided by frequency of practice: 7 participants practiced once a week, and the other 7 twice a week, for 4 weeks. Steadiness practice required practice group to 5 sets of 60-s contraction at levels corresponding to 10% and 20% maximal voluntary contraction (MVC) in the plantar flexor muscles. The 4-week-long practice period reduced the force fluctuations (assessed as the standard deviation (SD) of the outputted force during steady isometric plantar flexion) and postural sway (assessed as SD of the center of mass velocity during quiet standing). However, these practice effects were not significantly affected by the practice frequencies (1 vs. 2 sessions per week) examined in this study. Further, a linear regression analysis revealed the association between prepractice postural sway and the relative change in postural sway by the practice (r=-0.904) in the practice group. These results suggest that the steadiness practice in plantar flexor muscles improves postural stability during quiet standing, even though the practice is low-frequency (once a week) and low-intensity (within 20% MVC). These practice effects are dependent on prepractice postural stability. Further, the present results have provided the functional significance of force fluctuation in lower limb muscles.
Cherniak, Meir; Anglister, Lili; Lev-Tov, Aharon
The ability to improve motor function in spinal cord injury patients by reactivating spinal central pattern generators (CPGs) requires the elucidation of neurons and pathways involved in activation and modulation of spinal networks in accessible experimental models. Previously we reported on adrenoceptor-dependent sacral control of lumbar flexor motoneuron firing in newborn rats. The current work focuses on clarification of the circuitry and connectivity involved in this unique modulation and its potential use. Using surgical manipulations of the spinal gray and white matter, electrophysiological recordings, and confocal microscopy mapping, we found that methoxamine (METH) activation of sacral networks within the ventral aspect of S2 segments was sufficient to produce alternating rhythmic bursting (0.15-1 Hz) in lumbar flexor motoneurons. This lumbar rhythm depended on continuity of the ventral funiculus (VF) along the S2-L2 segments. Interrupting the VF abolished the rhythm and replaced it by slow unstable bursting. Calcium imaging of S1-S2 neurons, back-labeled via the VF, revealed that ∼40% responded to METH, mostly by rhythmic firing. All uncrossed projecting METH responders and ∼70% of crossed projecting METH responders fired with the concurrent ipsilateral motor output, while the rest (∼30%) fired with the contralateral motor output. We suggest that METH-activated sacral CPGs excite ventral clusters of sacral VF neurons to deliver the ascending drive required for direct rhythmic activation of lumbar flexor motoneurons. The capacity of noradrenergic-activated sacral CPGs to modulate the activity of lumbar networks via sacral VF neurons provides a novel way to recruit rostral lumbar motoneurons and modulate the output required to execute various motor behaviors.
Krajcs, N; Hernádi, L; Elekes, K; Kimura, S; Kiss, T
Recently, three novel flexor muscles (M1, M2 and M3) in the posterior tentacles of the snail have been described, which are responsible for the patterned movements of the tentacles of the snail, Helix pomatia. In this study, we have demonstrated that the muscles received a complex innervation pattern via the peritentacular and olfactory nerves originating from different clusters of motoneurons of the cerebral ganglia. The innervating axons displayed a number of varicosities and established neuromuscular contacts of different ultrastructural forms. Contractions evoked by nerve stimulation could be mimicked by external acetylcholine (ACh) and glutamate (Glu), suggesting that ACh and Glu are excitatory transmitters at the neuromuscular contacts. Choline acetyltransferase and vesicular glutamate transporter immunolabeled axons innervating flexor muscles were demonstrated by immunohistochemistry and in Western blot experiments. Nerve- and transmitter-evoked contractions were similarly attenuated by cholinergic and glutamatergic antagonists supporting the dual excitatory innervation. Dopamine (DA, 10⁻⁵ M) oppositely modulated thin (M1/M2) and thick (M3) muscle responses evoked by stimulation of the olfactory nerve, decreasing the contractions of the M1/M2 and increasing those of M3. In both cases, the modulation site was presynaptic. Serotonin (5-HT) at high concentration (10⁻⁵ M) increased the amplitude of both the nerve- and the ACh-evoked contractions in all muscles. The relaxation rate was facilitated suggesting pre- and postsynaptic site of action. Our data provided evidence for a DAergic and 5-HTergic modulation of cholinergic nerves innervating flexor muscles of the tentacles as well as the muscles itself. These effects of DA and 5-HT may contribute to the regulation of sophisticated movements of tentacle muscles lacking inhibitory innervation.
Zhang, Jacques X; Gray, Jason; Lalonde, Donald H; Carr, Nicholas
The literature generally supports the safety of epinephrine injection in the digits, but recent case reports describe ischemic adverse events associated with the use of lidocaine and epinephrine in which phentolamine rescue was not performed. We present a case of finger necrosis and subsequent amputation in a patient after 1% lidocaine with 1:100,000 epinephrine was injected in the fat and flexor sheaths in the palm for a 3-finger trigger release. Phentolamine rescue was not performed. All surgeons who use epinephrine in the finger should be prepared to reverse vasoconstriction with phentolamine rescue if there is persistently inadequate perfusion of the fingertip.
Schöffl, Volker Rainer; Schöffl, Isabelle
Closed traumatic ruptures of finger flexor tendon pulleys began to be recognized specifically over the past several decades. This injury, although rare in the general population, is seen more commonly in rock climbers. This article analyzes this type of injury and the current diagnostic and therapeutic criteria. Ultrasound and magnetic resonance imaging are used to differentiate between a pulley strain, partial rupture, complete rupture, or multiple ruptures. Grade I to III injuries (strains, partial rupture, single ruptures) are treated conservatively with initial immobilization and early functional therapy under pulley protection. Grade IV injuries (multiple ruptures) require surgical repair.
Oki, H; Miyake, T; Kasashima, Y; Sasaki, Y
The superficial digital flexor tendon (SDFT) injury causes considerable wastage of racing Thoroughbreds. In this study, the heritability of SDFT injury of the forelimbs was estimated in the Thoroughbred racehorses based on the Bayesian analysis with Gibbs sampling using threshold animal models. New horse patients of SDFT injury at the age of 2-5 years accommodated in the training centers in 2005 were used for the analyses. Based on clinical data of 8198 horses, heritability of SDFT was estimated to be the order of 0.17 (posterior mode) to 0.19 +/- 0.05 (posterior mean +/- posterior SD).
Aliu, Oluseyi; Samra, Saleh; Lewis, Eric
A 1-year-old boy presented to us with congenital inability to flex his elbow. He had bilaterally absent biceps brachii and brachialis muscles, a rare condition. We performed pedicle latissimus dorsi musculocutaneous flaps to the left and right volar upper arm at 21 and 24 months of age, respectively, to create elbow flexors. By 4 years of age, he had excellent elbow flexion bilaterally with strength grade in excess of 4.5. In addition to discussing our patient’s treatment options, we discuss other potential causes of weak elbow flexion when faced with this clinical dilemma. PMID:18780113
McClinton, Shane; Collazo, Christopher; Vincent, Ebonie; Vardaxis, Vassilios
Study Design Controlled laboratory study. Background Plantar heel pain is one of the most common foot and ankle conditions seen in clinical practice, and many individuals continue to have persisting or recurrent pain after treatment. Impaired foot plantar flexor muscle performance is a factor that may contribute to limited treatment success, but reliable methods to identify impairments in individuals with plantar heel pain are needed. In addition, foot orthoses are commonly used to treat this condition, but the implications of orthosis use on muscle performance have not been assessed. Objectives To assess ankle plantar flexor and toe flexor muscle performance in individuals with plantar heel pain using clinically feasible measures and to examine the relationship between muscle performance and duration of foot orthosis use. Methods The rocker-board plantar flexion test (RBPFT) and modified paper grip test for the great toe (mPGTGT) and lesser toes (mPGTLT) were used to assess foot plantar flexor muscle performance in 27 individuals with plantar heel pain and compared to 27 individuals without foot pain who were matched according to age, sex, and body mass. Pain ratings were obtained before and during testing, and self-reported duration of foot orthosis use was recorded. Results Compared to the control group, individuals with plantar heel pain demonstrated lower performance on the RBPFT (P = .001), the mPGTGT (P = .022), and the mPGTLT (P = .037). Longer duration of foot orthosis use was moderately correlated to lower performance on the RBPFT (r = -0.52, P = .02), the mPGTGT (r = -0.54, P = .01), and the mPGTLT (r = -0.43, P = .03). Conclusion Ankle plantar flexor and toe flexor muscle performance was impaired in individuals with plantar heel pain and associated with longer duration of self-reported foot orthosis use. J Orthop Sports Phys Ther 2016;46(8):681-688. Epub 3 Jul 2016. doi:10.2519/jospt.2016.6482.
Guilhem, Gaël; Giroux, Caroline; Couturier, Antoine; Maffiuletti, Nicola A
This study aimed to evaluate the validity and test-retest reliability of trunk muscle strength testing performed with a latest-generation isokinetic dynamometer. Eccentric, isometric, and concentric peak torque of the trunk flexor and extensor muscles was measured in 15 healthy subjects. Muscle cross sectional area (CSA) and surface electromyographic (EMG) activity were respectively correlated to peak torque and submaximal isometric torque for erector spinae and rectus abdominis muscles. Reliability of peak torque measurements was determined during test and retest sessions. Significant correlations were consistently observed between muscle CSA and peak torque for all contraction types (r=0.74-0.85; P<0.001) and between EMG activity and submaximal isometric torque (r ⩾ 0.99; P<0.05), for both extensor and flexor muscles. Intraclass correlation coefficients were comprised between 0.87 and 0.95, and standard errors of measurement were lower than 9% for all contraction modes. The mean difference in peak torque between test and retest ranged from -3.7% to 3.7% with no significant mean directional bias. Overall, our findings establish the validity of torque measurements using the tested trunk module. Also considering the excellent test-retest reliability of peak torque measurements, we conclude that this latest-generation isokinetic dynamometer could be used with confidence to evaluate trunk muscle function for clinical or athletic purposes.
Weller, Cynthia; Hochhaus, A Maren; Wright, T Michael; Mulloney, Brian
Action potentials and the postsynaptic potentials they evoke fill the pages of neuroscience textbooks, but students have relatively few opportunities to record these phenomena on their own. However, the act of making such recordings can be key events in a student's scientific education. The crayfish abdominal slow flexor muscle system is a well-established platform for recording spikes and PSPs. It enables students to see nerves and the muscles they innervate, record spontaneous spikes from several motor axons in these nerves as well as PSPs in their postsynaptic muscle fibers, and interpret these recordings quantitatively. Here we describe an improved method for preparing the slow-flexor system for recording that employs transmitted illumination through the stereo microscope's conventional substage lighting. Oblique transmitted lighting allows students to see the nerve and muscles fibers in each segment clearly and position recording electrodes accurately under visual control. Because students can see the nerves, muscles, and recording electrodes, broken electrode tips are relatively uncommon and the first successful recordings come more quickly. Many kinds of neurons in the CNS have the same pattern of multineuronal, multiterminal innervation that occurs on these muscle fibers. To visualize these innervation patterns on these fibers, we describe an immunohistochemical protocol that labels the GABAergic inhibitory motor axon and all the synaptic vesicles in the synaptic terminals on these muscle fibers. Dual-color images reveal extensive branching of the axons and fields of presynaptic terminals, only some of which are double-labeled for GABA.
S.A., Gunnal; A.U., Siddiqui; S.R., Daimi; M.S., Farooqui; R.N., Wabale
Introduction: The present study was planned to analyze the Accessory Head of the Flexor Pollicis Longus muscle’ (AHFPL) or Gantzer’s muscle and its incidence. It is an additional muscle in the forearm which might cause pressure symptoms to the underlying structures, especially to the anterior interosseus nerve. Materials and Methods: This study was performed on 180 upper limbs (90 right and 90 left). The morphology and the morphometry of AHFPL was done. In this investigation, we observed the various shapes, origins, insertions, nerve supplies and relations of the muscle. Observations and Results: The incidence of the accessory head of the flexor pollicis longus muscle was seen in 92 cases (51.11%). It was found bilaterally in 66 (71.73%) cases and unilaterally in 26 cases (28.26%), among which, in 16, it was seen on the right side and in 10 on the left side. With the increasing incidence of the Gantzer’s muscle, one can call it as an evolutionary muscle. Conclusion: The present study supplements the knowledge on the morphology of AHFPL muscle and its relationship with the anterior interosseus nerve. An increased incidence of this muscle may be the causative factor for the complete anterior interosseous nerve syndrome. PMID:23634387
Objective To evaluate and compare the effects of stretching and combined therapy (stretching and massage) on postural balance in people aged 50 to 65 years. Methods Twenty-three subjects participated in this nonrandomized clinical trial study. Each participant randomly received plantar flexor muscle stretching (3 cycles of 45 seconds with a 30-second recovery period between cycles) alone and in combination with deep stroking massage (an interval of at least 30 minutes separated the two interventions). The data were recorded with a force platform immediately after each condition with eyes open and closed. The center of pressure displacement and velocity along the mediolateral and anteroposterior axes were calculated under each condition. The data were analyzed with multiple-pair t-tests. Results The center of pressure displacement and velocity along the mediolateral axis increased after both stretching and the combined intervention. There were significant differences in both values between participants in the stretching and combined interventions (p<0.05). Conclusion Plantar flexor muscle stretching (for 45 seconds) combined with deep stroking massage may have more detrimental effects on postural balance than stretching alone because each intervention can intensify the effects of the other. PMID:27847714
Sade, Ilgin; İnanir, Murat; Şen, Suzan; Çakmak, Esra; Kablanoğlu, Serkan; Selçuk, Barin; Dursun, Nigar
[Purpose] The primary aim of this study was to assess rehabilitation outcomes for early and two-stage repair of hand flexor tendon injuries. The secondary purpose of this study was to compare the findings between treatment groups. [Subjects and Methods] Twenty-three patients were included in this study. Early repair (n=14) and two-stage repair (n=9) groups were included in a rehabilitation program that used hand splints. This retrospective evaluated patients according to their demographic characteristics, including age, gender, injured hand, dominant hand, cause of injury, zone of injury, number of affected fingers, and accompanying injuries. Pain, range of motion, and grip strength were evaluated using a visual analog scale, goniometer, and dynamometer, respectively. [Results] Both groups showed significant improvements in pain and finger flexion after treatment compared with baseline measurements. However, no significant differences were observed between the two treatment groups. Similar results were obtained for grip strength and pinch grip, whereas gross grip was better in the early tendon repair group. [Conclusion] Early and two-stage reconstruction of patients with flexor tendon injuries can be performed with similarly favorable responses and effective rehabilitation programs. PMID:27630400
Rempel, D; Serina, E; Klinenberg, E; Martin, B J; Armstrong, T J; Foulke, J A; Natarajan, S
The design of the force-displacement characteristics or 'feel' of keyboard keyswitches has been guided by preference and performance data; there has been very little information on how switch 'feel' alters muscle activity or applied force. This is a laboratory-based repeated measures design experiment to evaluate the effect of computer keyboard keyswitch design on applied finger force and muscle activity during a typing task. Ten experienced typists typed on three keyboards which differed in keyswitch make force (0.34, 0.47 and 1.02 N) while applied fingertip force and finger flexor electromyograms were recorded. The keyboard testing order was randomized and subjects typed on each keyboard for three trials, while data was collected for a minimum of 80 keystrokes per trial. No differences in applied fingertip force or finger flexor EMG were observed during typing on keyboards with switch make force of 0.34 or 0.47 N. However, applied fingertip force increased by approximately 40% (p < 0.05) and EMG activity increased by approximately 20% (p < 0.05) when the keyswitch make force was increased from 0.47 to 1.02 N. These results suggest that, in order to minimize the biomechanical loads to forearm tendons and muscles of keyboard users, keyswitches with a make force of 0.47 N or less should be considered over switches with a make force of 1.02 N.
The effects of centrally acting muscle relaxants on the flexor reflex mediated by group II afferent fibers (group II flexor reflex) in anesthetized intact rats and on the intrathecal noradrenaline-HCl-induced facilitation of the group II flexor reflex in anesthetized spinal rats were investigated. In anesthetized intact rats, mephenesin, tolperisone-HCl, chlorpromazine-HCl and baclofen inhibited the group II flexor reflex dose-dependently, whereas the inhibitory effect of tizanidine-HCl was bell-shaped. The effect of diazepam tended to be saturated. In anesthetized spinal rats, mephenesin, tolperisone-HCl, chlorpromazine-HCl, diazepam and baclofen also depressed the group II flexor reflex, but tizanidine-HCl slightly increased it. The intrathecal noradrenaline-HCl-induced facilitation of the group II flexor reflex was not affected by mephenesin or diazepam, but was inhibited by tizanidine-HCl, tolperisone-HCl, chlorpromazine-HCl and baclofen. These results suggest that compounds with centrally acting muscle relaxant activity depress the group II flexor reflex in different manners, and the inhibition of descending noradrenergic tonic facilitation within the spinal cord participates in the depressant action of the group II flexor reflex produced by tolperisone-HCl, tizanidine-HCl, chlorpromazine-HCl and baclofen.
Lau, Wing Yin; Blazevich, Anthony J.; Newton, Michael J.; Wu, Sam Shi Xuan; Nosaka, Kazunori
Context: Delayed-onset muscle soreness (DOMS) is a common muscle pain that many people experience and is often used as a model of acute muscle pain. Researchers have reported the effects of various interventions on DOMS, but different DOMS assessment protocols used in these studies make it difficult to compare the effects. Objective: To investigate DOMS characteristics after elbow-flexor eccentric exercise to establish a standardized DOMS assessment protocol. Design: Descriptive laboratory study. Setting: Research laboratory. Patients or Other Participants: Ten healthy, untrained men (21–39 years). Intervention(s): Participants performed 10 sets of 6 maximal isokinetic eccentric contractions of the elbow flexors. Main Outcome Measure(s): Indirect muscle-damage markers were maximal voluntary isometric contraction torque, range of motion, and serum creatine kinase activity. Muscle pain was assessed before exercise, immediately postexercise, and 1 to 5 days postexercise using (1) a visual analog scale (VAS), (2) a category ratio-10 scale (CR-10) when applying static pressure and palpation at different sites (3, 9, and 15 cm above the elbow crease), and (3) pressure-pain thresholds (PPTs) at 50 sites (pain mapping). Results: Maximal voluntary isometric contraction and range of motion decreased and creatine kinase activity increased postexercise, indicating muscle damage. Palpation induced greater pain than static pressure, and longitudinal and transverse palpations induced greater pain than circular palpation (P < .05). The PPT was lower in the medial region before exercise, but the pain-sensitive regions shifted to the central and distal regions of the biceps brachii at 1 to 3 days postexercise (P < .05). The VAS was correlated with the CR-10 scale (r = 0.91, P < .05) but not with the PPT (r = −0.28, P = .45). Conclusions: The way in which muscles are assessed affects the pain level score. This finding suggests that pain level and pain threshold cannot be used
Tijs, Chris; van Dieën, Jaap H.; Baan, Guus C.; Maas, Huub
Force transmission between rat ankle plantar-flexors has been found for physiological muscle lengths and relative positions, but only with all muscles maximally activated. The aims of this study were to assess intermuscular mechanical interactions between ankle plantar-flexors during (i) fully passive conditions, (ii) excitation of soleus (SO), (iii) excitation of lateral gastrocnemius (LG), and (iv) during co-activation of SO, and LG (SO&LG). We assessed effects of proximal lengthening of LG and plantaris (PL) muscles (i.e., simulating knee extension) on forces exerted at the distal SO tendon (FSO) and on the force difference between the proximal and distal LG+PL tendons (ΔFLG+PL) of the rat. LG+PL lengthening increased FSO to a larger extent (p = 0.017) during LG excitation (0.0026 N/mm) than during fully passive conditions (0.0009 N/mm). Changes in FSO in response to LG+PL lengthening were lower (p = 0.002) during SO only excitation (0.0056 N/mm) than during SO&LG excitation (0.0101 N/mm). LG+PL lengthening changed ΔFLG+PL to a larger extent (p = 0.007) during SO excitation (0.0211 N/mm) than during fully passive conditions (0.0157 N/mm). In contrast, changes in ΔFLG+PL in response to LG+PL lengthening during LG excitation (0.0331 N/mm) were similar (p = 0.161) to that during SO&LG excitation (0.0370 N/mm). In all conditions, changes of FSO were lower than those of ΔFLG+PL. This indicates that muscle forces were transmitted not only between LG+PL and SO, but also between LG+PL and other surrounding structures. In addition, epimuscular myofascial force transmission between rat ankle plantar-flexors was enhanced by muscle activation. However, the magnitude of this interaction was limited. PMID:27708589
de Souza, Clécio Gabriel; Borges, Daniel Tezoni; de Brito Macedo, Liane; Brasileiro, Jamilson Simões
Low-level laser therapy (LLLT) has been suggested as a resource capable of increasing resistance to fatigue and enhancing muscle performance through its metabolic and photochemical effects. This study evaluated the immediate effects of the application of LLLT on neuromuscular performance of the plantar ankle flexors in healthy subjects through a fatigue-induced protocol. This is a randomized controlled clinical trial, attended by 60 young and physically active volunteers of both genders. The subjects were randomly assigned into three groups, control, placebo, and laser, and underwent a preliminary evaluation of the isokinetic performance of plantar flexors and electromyographic activity of the soleus muscle to ensure homogeneity between groups. After the application of the respective intervention protocols, participants were induced to fatigue by performing 100 isokinetic concentric contractions of ankle plantar flexors at a speed of 90°/s. The dynamometric fatigue index (DFI) and median frequency were recorded during the fatigue protocol for comparison between groups. The group receiving the laser application showed significantly lower dynamometric fatigue index (p = 0.036) when compared to control and placebo groups. In relation to the median frequency during the fatigue test, there was a decrease in all groups, however with no differences between them. We suggest that LLLT being applied prior to exercise can reduce the fatigue index in the ankle plantar flexors of healthy subjects.
Zetterberg, H.; Frykberg, G. E.; Gäverth, J.; Lindberg, P. G.
Objective. The NeuroFlexor is a novel method incorporating a biomechanical model for the measurement of neural and nonneural contributions to resistance induced by passive stretch. In this study, we used the NeuroFlexor method to explore components of passive movement resistance in the wrist and finger muscles in subjects with Parkinson's disease (PD). Methods. A cross-sectional comparison was performed in twenty-five subjects with PD with clinically identified rigidity and 14 controls. Neural (NC), elastic (EC), and viscous (VC) components of the resistance to passive extension of the wrist were calculated using the NeuroFlexor. Measurements were repeated during a contralateral activation maneuver. Results. PD subjects showed greater total resistance (P < 0.001) and NC (P = 0.002) compared to controls. EC and VC did not differ significantly between groups. Contralateral activation maneuver resulted in increased NC in the PD group but this increase was due to increased resting tension. Total resistance and NC correlated with clinical ratings of rigidity and with bradykinesia. Conclusions. The findings suggest that stretch induced reflex activity, but not nonneural resistance, is the major contributor to rigidity in wrist muscles in PD. The NeuroFlexor is a potentially valuable clinical and research tool for quantification of rigidity. PMID:25685778
Zhang, Jingming; Lanuza, Guillermo M; Britz, Olivier; Wang, Zhi; Siembab, Valerie C; Zhang, Ying; Velasquez, Tomoko; Alvarez, Francisco J; Frank, Eric; Goulding, Martyn
Reciprocal activation of flexor and extensor muscles constitutes the fundamental mechanism that tetrapod vertebrates use for locomotion and limb-driven reflex behaviors. This aspect of motor coordination is controlled by inhibitory neurons in the spinal cord; however, the identity of the spinal interneurons that serve this function is not known. Here, we show that the production of an alternating flexor-extensor motor rhythm depends on the composite activities of two classes of ventrally located inhibitory neurons, V1 and V2b interneurons (INs). Abrogating V1 and V2b IN-derived neurotransmission in the isolated spinal cord results in a synchronous pattern of L2 flexor-related and L5 extensor-related locomotor activity. Mice lacking V1 and V2b inhibition are unable to articulate their limb joints and display marked deficits in limb-driven reflex movements. Taken together, these findings identify V1- and V2b-derived neurons as the core interneuronal components of the limb central pattern generator (CPG) that coordinate flexor-extensor motor activity.
Todhunter, P G; Schumacher, J; Finn-Bodner, S T
Chronic lameness was determined to be caused by desmitis of the accessory ligament of the deep digital flexor tendon and adhesions associated with these 2 structures. Desmotomy of the accessory ligament, resection of adhesions, and controlled exercise during convalescence resulted in return to normal use without apparent lameness. Images Figure 1. Figure 2. PMID:9332748
Manal, Kurt; Gardinier, Emily; Buchanan, Thomas S.; Snyder-Mackler, Lynn
Objective To evaluate if the peak knee flexor moment provides unique and meaningful information about peak medial compartment loading above and beyond what is obtained from the peak knee adduction moment. Methods Standard video-based motion capture and EMG recordings were collected for 10 ACL reconstructed subjects walking at a self-selected speed. Knee joint moments were obtained using inverse dynamics and medial contact force was computed using an EMG-driven musculoskeletal model. Linear regression with the peak adductor moment entered first was implemented to isolate the unique contribution of the peak flexor moment to peak medial loading. Results Peak moments and medial contact force occurred during weight acceptance at approximately 23% of stance. The peak adduction moment (pKAM) was a significant predictor of peak medial loading (p = 0.004) accounting for approximately 63% of the variance. The peak knee flexor moment (pKFM) was also a significant predictor (p = 0.009) accounting for an additional 22% of the variance. When entered together pKAM and pKFM accounted for more than 85% of the variance in peak medial compartment loading. Conclusion The combined use of the peak knee flexor and adductor moments provides a significantly more accurate estimate of peak medial joint loading than the peak adduction moment alone. More accurate inferences of joint contact force will assist clinicians and researchers investigating relationships between joint loading and the onset and progression of knee OA. PMID:25862486
Mulon, Pierre-Yves; Achard, Damien; Babkine, Marie
A 17-month-old Holstein heifer was presented for persistent enlargement above the right hind fetlock of 1-month's duration. Diffuse plantar soft tissue swelling was present on the radiographs and ultrasonography revealed the presence of multiple porcupine quill extremities embedded in the subcutaneous tissue within the flexor tendon sheath wall. Surgical removal was performed.
Kaya, Taciser; Goksel Karatepe, Altinay; Gunaydin, Rezzan; Koc, Aysegul; Altundal Ercan, Ulku
The Modified Ashworth Scale (MAS) is commonly used in clinical practice for grading spasticity. However, it was modified recently by omitting grade "1+" of the MAS and redefining grade "2". The aim of this study was to investigate the inter-rater reliability of MAS and modified MAS (MMAS) for the assessment of poststroke elbow flexor spasticity.…
Mitsionis, G; Bastidas, J A; Grewal, R; Pfaeffle, H J; Fischer, K J; Tomaino, M M
We investigated the effect of partial excision of the A2 and A4 digital pulleys, separately and in combination, on finger angular rotation and the energy for finger flexion. Statistically significant decreases in angular rotation resulted only after 50% and 75% excision of A2, A4, or A2 and A4 in combination. Work of flexion trends were weak and none of the changes were statistically significant. Although optimal finger function relies on the integrity of the A2 and A4 pulleys to maintain the efficiency of the digital flexor system, these data suggest that the A2 and A4 pulleys can be excised up to 25%, either separately or in combination, without significant effects on angular rotation. Decreases in total angular range of motion after 50% and 75% pulley excision were small, even for combined pulley excision (9 degrees +/- 3 degrees and 15 degrees +/- 5 degrees [mean +/- SD], respectively), and may be clinically acceptable.
de Lima Lopes, Clécio; Arantes, Gabriel; de Oliveira, Rodrigo Victor Lapenda; Pinto, Dilamar Moreira; Gonçalves, Marcelo Carvalho Krause; Gonçalves, Romeu Carvalho Krause
Objectives To evaluate the prevalence of a vascular network adjacent to the insertion of the pes anserinus, so that it could be used as an anatomical reference point to facilitate harvesting flexor grafts for arthroscopic reconstruction of the anterior cruciate ligament (ACL). Methods Thirty patients with ACL tears who were going to undergo ACL reconstruction using the tendons of the semitendinosus and gracilis muscles as grafts were selected randomly. During the harvesting of these tendons, the presence or absence of this anatomical reference point was noted. Results All the patients presented a vascular network of greater or lesser diameter. Conclusion The vascular network seems to be a good reference point during harvesting of the tendons of the semitendinosus and gracilis muscles, for facilitating graft harvesting. PMID:26229911
Kang, Yeoun-Seung; Park, Yoon-Ghil; Lee, Bum-Suk; Park, Hyung-Soon
The wrist-driven flexor hinge orthosis (WDFHO) is a device used to restore hand function in persons with tetraplegic spinal cord injury by furnishing three-point prehension. We assessed the effectiveness and biomechanical properties of the WDFHO in 24 persons with cervical 6 or 7 tetraplegia who have severely impaired hand function. This study introduces a mechanical operating model to assess the efficiency of the WDFHO. Experimental results showed that pinch force increased significantly (p < 0.001) after using the WDFHO and was found to positively correlate with the strength of wrist extensor muscles (r = 0.41, p < 0.001). However, when the strength of the wrist extensors acting on the WDFHO was greater, the reciprocal wrist and finger motion that generates three-point prehension was less effective (r = 0.79, p < 0.001). Reliable and valid biomechanical evaluation of the WDFHO could improve our understanding of its biomechanics.
Maas, Huub; Huijing, Peter A.
Summary We investigated the extent of mechanical interaction between rat flexor carpi ulnaris (FCU) and palmaris longus (PL) muscles following transfer of FCU to the distal tendons of extensor carpi radialis brevis and longus (ECRB/L) muscles. Five weeks after recovery from surgery, isometric forces exerted at the distal tendons of FCU and PL were quantified at various FCU lengths. PL was kept at a constant length. Changing the muscle-tendon complex length of transferred FCU (by maximally 3.5 mm) decreased PL force significantly (by 7%). A linear relationship was found between changes in FCU muscle belly length, being a measure of muscle relative positions, and PL force. These results indicate that despite transfer of FCU muscle to the extensor side of the forearm, changing FCU length still affects force transmission of its, now, antagonistic PL muscle. We conclude that a transferred muscle may still be mechanically linked to its former synergistic muscles. PMID:23738260
Lu, Hui; Chen, Qiang; Shen, Hui
Abstract Rationale: Gouty tophi is a rare cause of CTS. We first report a unique case of repeated CTS with gouty tophi in flexor tendon. In the previous literature, the symptoms cases of CTS were gradually increased. Patient concerns: We report a 44-year-old male porter presented with mass on his left distal forearm combined a repeated carpal tunnel syndrome for 5 years. He felt numbness in fingers and his left palmar. The CTS symptoms had been eased through rest and dugs medication. It recurred twice. Diagnoses: Monosodium urate crystal deposits were found in surgery. Histologic findings confirmed the diagnosis of gout. Interventions: We removed partial of gouty tophus and retained the integrity of the tendon. Outcomes: Two years after the surgery, the patient had not experienced any symptom recurrence. Lessons: Early diagnosis and control of gout are necessary to avoid irreversible complications. The surgery combined with decreasing trioxypurine treatment can improve the treatment outcome of gouty tophus. PMID:28248892
Workman, J Chad; Docherty, David; Parfrey, Kevin C; Behm, David G
A pelvic position has been sought that optimizes abdominal muscle activation while diminishing hip flexor activation. Thus, the objective of the study was to investigate the effect of pelvic position and the Janda sit-up on trunk muscle activation. Sixteen male volunteers underwent electromyographic (EMG) testing of their abdominal and hip flexor muscles during a supine isometric double straight leg lift (DSLL) with the feet held approximately 5 cm above a board. The second exercise (Janda sit-up) was a sit-up action where participants simultaneously contracted the hamstrings and the abdominal musculature while holding an approximately 45 degrees angle at the knee. Root mean square surface electromyography was calculated for the Janda sit-up and DSLL under 3 pelvic positions: anterior, neutral, and posterior pelvic tilt. The selected muscles were the upper and lower rectus abdominis (URA, LRA), external obliques, lower abdominal stabilizers (LAS), rectus femoris, and biceps femoris. The Janda sit-up position demonstrated the highest URA and LRA activation and the lowest rectus femoris activation. The Janda sit-up and the posterior tilt were significantly greater (p < 0.01 and p < 0.05, respectively) than the anterior tilt for the URA and LRA muscles. Activation levels of the URA and LRA in neutral pelvis were significantly (p < 0.01 and p < 0.05, respectively) less than the Janda sit-up position, but not significantly different from the posterior tilt. No significant differences in EMG activity were found for the external obliques or LAS. No rectus femoris differences were found in the 3 pelvis positions. The results of this study indicate that pelvic position had a significant effect on the activation of selected trunk and hip muscles during isometric exercise, and the activation of the biceps femoris during the Janda sit-up reduced the activation of the rectus femoris while producing high levels of activation of the URA and LRA.
Saka, Tolga; Akova, Bedrettin; Yazici, Zeynep; Sekir, Ufuk; Gür, Hakan; Ozarda, Yesim
The aim of this study was to investigate the difference in the magnitude of muscle damage between maximal eccentric exercises of the elbow flexors (EF) and knee extensors (KE). Twelve sedentary male volunteers participated in the study. Range of motion (ROM), isometric peak torque (IPT), delayed onset of muscle soreness (DOMS), creatine kinase activity (CK), and myoglobin concentration (Mb) were evaluated before, immediately after, and on the 1st , 2nd, 3rd , and 7th days following exercise. Total work (TW) during exercises was recorded and corrected by muscle volume (TWc). TWc was greater (p < 0.01) for EF [24 (2) joule·cm-3] than for KE [7 (0.4) joule·cm-3]. Increases in CK on the 2nd , 3rd , and 7th days (p < 0.01) and increases in Mb on the 1st , 2nd , 3rd , and 7th days were significantly (p<0.01) larger for EF than for KE. The decline in IPT was greater (p < 0.05- 0.01) for EF at all test occasions compared with KE. The results of this study demonstrate that the magnitude of muscle damage is greater and the recovery is slower following maximal eccentric exercise of the EF than of the KE for sedentary males. Key points The magnitude of muscle damage is greater and the recovery is slower following maximal eccentric exercise of the EF than of the KE for sedentary males. This may be because of the higher total eccentric work per muscle unit in elbow flexors. PMID:24150563
Thomopoulos, Stavros; Zampiakis, Emmanouil; Das, Rosalina; Silva, Matthew J.; Gelberman, Richard H.
SUMMARY Previous tendon and ligament studies demonstrated a role for mechanical loading in tissue homeostasis and healing. In uninjured musculoskeletal tissues, increased loading leads to an increase in mechanical properties, while decreased loading leads to a decrease in properties. The role of loading on healing tissues is less clear. We studied tendon-to-bone healing in a canine flexor tendon-to-bone injury and repair model. To examine the effect of muscle loading on healing, repaired tendons were either cut proximally to remove all load from the distal phalanx repair site (unloaded group) or left intact proximally (loaded group). All paws were cast post-operatively and subjected to daily passive motion rehabilitation. Specimens were tested to determine functional properties, biomechanical properties, repair-site gapping, and bone mineral density. Loading across the repair site led to improved functional and biomechanical properties (e.g., stiffness for the loaded group was 8.2 ± 3.9 vs. 5.1 ± 2.5 N/mm for the unloaded group). Loading did not affect bone mineral density or gapping. The formation of a gap between the healing tendon and bone correlated with failure properties. Using a clinically relevant model of flexor tendon injury and repair, we found that muscle loading was beneficial to healing. Complete removal of load by proximal transection resulted in tendon-to-bone repairs with less range of motion and lower biomechanical properties compared to repairs in which the muscle-tendon-bone unit was left intact. PMID:18524009
Thomopoulos, Stavros; Zampiakis, Emmanouil; Das, Rosalina; Silva, Matthew J; Gelberman, Richard H
Previous tendon and ligament studies have demonstrated a role for mechanical loading in tissue homeostasis and healing. In uninjured musculoskeletal tissues, increased loading leads to an increase in mechanical properties, whereas decreased loading leads to a decrease in mechanical properties. The role of loading on healing tissues is less clear. We studied tendon-to-bone healing in a canine flexor tendon-to-bone injury and repair model. To examine the effect of muscle loading on tendon-to-bone healing, repaired tendons were either cut proximally (unloaded group) to remove all load from the distal phalanx repair site or left intact proximally (loaded group). All paws were casted postoperatively and subjected to daily passive motion rehabilitation. Specimens were tested to determine functional properties, biomechanical properties, repair-site gapping, and bone mineral density. Loading across the repair site led to improved functional and biomechanical properties (e.g., stiffness for the loaded group was 8.2 +/- 3.9 versus 5.1 +/- 2.5 N/mm for the unloaded group). Loading did not affect bone mineral density or gapping. The formation of a gap between the healing tendon and bone correlated with failure properties. Using a clinically relevant model of flexor tendon injury and repair, we found that muscle loading was beneficial to healing. Complete removal of load by proximal transection resulted in tendon-to-bone repairs with less range of motion and lower biomechanical properties compared to repairs in which the muscle-tendon-bone unit was left intact.
Kirane, Y M; Michelson, J D; Sharkey, N A
Studying mechanics of the muscles spanning multiple joints provides insights into intersegmental dynamics and movement coordination. Multiarticular muscles are thought to function at "near-isometric" lengths to transfer mechanical energy between the adjacent body segments. Flexor hallucis longus (FHL) is a multiarticular flexor of the great toe; however, its potential isometric function has received little attention. We used a robotic loading apparatus to investigate FHL mechanics during simulated walking in cadaver feet, and hypothesized that physiological force transmission across the foot can occur with isometric FHL function. The extrinsic foot tendons, stripped of the muscle fibers, were connected to computer-controlled linear actuators. The FHL activity was controlled using force-feedback (FC) based upon electromyographic data from healthy subjects, and subsequently, isometric positional feedback (PC), maintaining the FHL myotendinous junction stationary during simulated walking. Tendon forces and excursions were recorded, as were the strains within the first metatarsal. Forces in the metatarsal and metatarsophalangeal joint were derived from these strains. The FHL tendon excursion under FC was 6.57+/-3.13mm. The forces generated in the FHL tendon, metatarsal and metatarsophalangeal joint with the FHL under isometric PC were not significantly different in pattern from FC. These observations provide evidence that physiological forces could be generated along the great toe with isometric FHL function. A length servo mechanism such as the stretch reflex could likely control the isometric FHL function during in vivo locomotion; this could have interesting implications regarding the conditions of impaired stretch reflex such as spastic paresis and peripheral neuropathies.
Butcher, M T; Chase, P B; Hermanson, J W; Clark, A N; Brunet, N M; Bertram, J E A
Equine digital flexor muscles have independent tendons but a nearly identical mechanical relationship to the main joint they act upon. Yet these muscles have remarkable diversity in architecture, ranging from long, unipennate fibers ("short" compartment of DDF) to very short, multipennate fibers (SDF). To investigate the functional relevance of the form of the digital flexor muscles, fiber contractile properties were analyzed in the context of architecture differences and in vivo function during locomotion. Myosin heavy chain (MHC) isoform fiber type was studied, and in vitro motility assays were used to measure actin filament sliding velocity (V(f)). Skinned fiber contractile properties [isometric tension (P(0)/CSA), velocity of unloaded shortening (V(US)), and force-Ca(2+) relationships] at both 10 and 30°C were characterized. Contractile properties were correlated with MHC isoform and their respective V(f). The DDF contained a higher percentage of MHC-2A fibers with myosin (heavy meromyosin) and V(f) that was twofold faster than SDF. At 30°C, P(0)/CSA was higher for DDF (103.5 ± 8.75 mN/mm(2)) than SDF fibers (81.8 ± 7.71 mN/mm(2)). Similarly, V(US) (pCa 5, 30°C) was faster for DDF (2.43 ± 0.53 FL/s) than SDF fibers (1.20 ± 0.22 FL/s). Active isometric tension increased with increasing Ca(2+) concentration, with maximal Ca(2+) activation at pCa 5 at each temperature in fibers from each muscle. In general, the collective properties of DDF and SDF were consistent with fiber MHC isoform composition, muscle architecture, and the respective functional roles of the two muscles in locomotion.
Avrahami, Daniel; Potvin, Jim R.
Background: Many patients have tight hip flexors with or without low back pain. Manual fascial-muscular lengthening therapy (FMLT) is one commonly used treatment for this population. Objective: Investigate the clinical and biomechanical effects of manual FMLT on tight hip flexor patients with and without low back pain. Methods: A nonrandomized trial, before-and-after experiment with multiple baselines conducted on two different patient populations: 1) Mechanical low back pain patients with tight hip flexors (n = 10) and 2) Asymptomatic group with tight hip flexors (n = 8). Four treatments of manual FMLT were performed on the hip flexor of the two groups of patients over a two-week period. Primary outcome measures over the two-week period were 1) Maximum voluntary trunk flexor and extensor moments, 2) Disability (Roland Morris Disability Questionnaire) and pain (10-cm Visual Analogue Scale), 3) Passive hip extension mobility. Results: Primary outcome analysis involved within-groups comparisons. Maximum voluntary trunk extension demonstrated increases for the low back pain patients. The low back pain patients demonstrated a small, but significant, reduction in disability and pain. Both groups demonstrated an increase in passive hip extension measurements. Conclusion: This preliminary study demonstrated interesting results from manual FMLT on two tight hip flexor patient populations with and without low back pain. However, there were several significant limitations from this study, which restrict the ability to generalize the results. PMID:25550670
Kietrys, David M.; Barr-Gillespie, Ann E.; Amin, Mamta; Wade, Christine K.; Popoff, Steve N.; Barbe, Mary F.
We sought to determine if tendon inflammatory and histopathological responses increase in aged rats compared to young rats performing a voluntary upper extremity repetitive task, and if these changes are associated with motor declines. Ninety-six female Sprague-Dawley rats were used in the rat model of upper extremity overuse: 67 aged and 29 young adult rats. After a training period of 4 weeks, task rats performed a voluntary high repetition low force (HRLF) handle-pulling task for 2 hrs/day, 3 days/wk for up to 12 weeks. Upper extremity motor function was assessed, as were inflammatory and histomorphological changes in flexor digitorum and supraspinatus tendons. The percentage of successful reaches improved in young adult HRLF rats, but not in aged HRLF rats. Forelimb agility decreased transiently in young adult HRLF rats, but persistently in aged HRLF rats. HRLF task performance for 12 weeks lead to increased IL-1beta and IL-6 in flexor digitorum tendons of aged HRLF rats, compared to aged normal control (NC) as well as young adult HRLF rats. In contrast, TNF-alpha increased more in flexor digitorum tendons of young adult 12-week HRLF rats than in aged HRLF rats. Vascularity and collagen fibril organization were not affected by task performance in flexor digitorum tendons of either age group, although cellularity increased in both. By week 12 of HRLF task performance, vascularity and cellularity increased in the supraspinatus tendons of only aged rats. The increased cellularity was due to increased macrophages and connective tissue growth factor (CTGF)-immunoreactive fibroblasts in the peritendon. In conclusion, aged rat tendons were overall more affected by the HRLF task than young adult tendons, particularly supraspinatus tendons. Greater inflammatory changes in aged HRLF rat tendons were observed, increases associated temporally with decreased forelimb agility and lack of improvement in task success. PMID:23056540
Jacobsen, Else; Dart, Andrew J.; Mondori, Takamitsu; Horadogoda, Neil; Jeffcott, Leo B.; Little, Christopher B.; Smith, Margaret M.
It is not known how extensively a localised flexor tendon injury affects the entire tendon. This study examined the extent of and relationship between histopathologic and gene expression changes in equine superficial digital flexor tendon after a surgical injury. One forelimb tendon was hemi-transected in six horses, and in three other horses, one tendon underwent a sham operation. After euthanasia at six weeks, transected and control (sham and non-operated contralateral) tendons were regionally sampled (medial and lateral halves each divided into six 3cm regions) for histologic (scoring and immunohistochemistry) and gene expression (real time PCR) analysis of extracellular matrix changes. The histopathology score was significantly higher in transected tendons compared to control tendons in all regions except for the most distal (P ≤ 0.03) with no differences between overstressed (medial) and stress-deprived (lateral) tendon halves. Proteoglycan scores were increased by transection in all but the most proximal region (P < 0.02), with increased immunostaining for aggrecan, biglycan and versican. After correcting for location within the tendon, gene expression for aggrecan, versican, biglycan, lumican, collagen types I, II and III, MMP14 and TIMP1 was increased in transected tendons compared with control tendons (P < 0.02) and decreased for ADAMTS4, MMP3 and TIMP3 (P < 0.001). Aggrecan, biglycan, fibromodulin, and collagen types I and III expression positively correlated with all histopathology scores (P < 0.001), whereas lumican, ADAMTS4 and MMP14 expression positively correlated only with collagen fiber malalignment (P < 0.001). In summary, histologic and associated gene expression changes were significant and widespread six weeks after injury to the equine SDFT, suggesting rapid and active development of tendinopathy throughout the entire length of the tendon. These extensive changes distant to the focal injury may contribute to poor functional outcomes and re
Caiozzo, V. J.; Haddad, F.; Lee, S.; Baker, M.; Baldwin, K. M.
The goal of this project was to examine the effects of artificial gravity (2.5 g) on skeletal muscle strength and key anabolic/catabolic markers known to regulate muscle mass. Two groups of subjects were selected for study: 1) a 21 day-bed rest (BR) control (C) group (N=7); and 2) an AG group (N=8), which was exposed to 21 days of bed-rest plus daily 1 hr exposures to AG (2.5 g). This particular experiment was part of an integrated AG Pilot Project sponsored by NASA/Johnson Space Center. The in vivo torque-velocity relationships of the knee extensors and plantar flexors of the ankle were determined pre and post treatment. Also, pre- and post treatment biopsy samples were obtained from both the vastus lateralis and soleus muscles and were used, in part, for a series of analyses on gene expression (mRNA abundance) of key factors implicated in the anabolic versus catabolic state of the muscle. Post/Pre toque-velocity determinations revealed greater decrements in knee extensor performance in the C versus AG group (P less than 0.04). The plantar flexor muscle group of the AG subjects actually demonstrated a net gain in torque-velocity relationship; whereas, in the C group the overall post/pre responses declined (AG vs C; P less than 0.001). Measurements of muscle fiber cross-sectional area (for both muscles) demonstrated a loss of approx. 20% in the C group while no losses were evident in the AG group. RT-PCR analyses of muscle biopsy specimens demonstrated that markers of growth and cytoskeletal integrity (IGF-1, IGF-1 BP4, mechano growth factor, total RNA, and pro-collagen 3a) were higher in the AG group, whereas catabolic markers (myostatin and atrogen) were elevated in the C group. Importantly, these patterns were seen in both muscles. Based on these observations we conclude that paradigms of AG have the potential to maintain the functional, biochemical, and structural homeostasis of skeletal muscle in the face of chronic unloading states. These findings also
Fukutani, Atsuki; Misaki, Jun; Isaka, Tadao
Isometric muscle force attained during isometric contractions decreases after active shortening compared to that attained during purely isometric contractions. This phenomenon is called residual force depression. The aim of this study was to examine whether residual force depression occurs in human plantar flexors in both plantar flexed and dorsiflexed region. In addition, the magnitude of fascicle shortening was evaluated because not only muscle force but also fascicle shortening during active shortening are considered to affect force depression. Eleven male subjects were recruited. All muscle contractions were evoked by muscle belly-electrical stimulation. In the reference trials, isometric plantar flexion (PF) was performed at 0° and 15° of PF. In the residual force depression trials, the following two contractions were conducted: (1) muscles were activated isometrically at 15° of dorsiflexion, then actively shortened to 0° of PF (long condition) and (2) muscles were activated isometrically at 0° of PF, then actively shortened to 15° of PF (short condition). Isometric joint torque obtained 4.9 s after the onset of contraction was compared between the reference and residual force depression trials at the same joint angle to calculate the magnitude of residual force depression. At the same time point, fascicle length and pennation angle were obtained from ultrasonographic images to examine whether the muscle architecture affected residual force depression. As a result, residual force depression was confirmed in both the long and short length conditions (long: 87.1 ± 9.1%, short: 92.1 ± 7.8%) while the magnitude was not different (p = 0.182). The fascicle length and pennation angle were not different between the reference and residual force depression trials (p = 0.291–0.906). These results indicate that residual force depression occurs in the physiological range of motion in the human plantar flexors, and this phenomenon is not related to muscle
Jacobson, Else; Jacobsen, Else; Dart, Andrew J; Mondori, Takamitsu; Horadogoda, Neil; Jeffcott, Leo B; Little, Christopher B; Smith, Margaret M
It is not known how extensively a localised flexor tendon injury affects the entire tendon. This study examined the extent of and relationship between histopathologic and gene expression changes in equine superficial digital flexor tendon after a surgical injury. One forelimb tendon was hemi-transected in six horses, and in three other horses, one tendon underwent a sham operation. After euthanasia at six weeks, transected and control (sham and non-operated contralateral) tendons were regionally sampled (medial and lateral halves each divided into six 3 cm regions) for histologic (scoring and immunohistochemistry) and gene expression (real time PCR) analysis of extracellular matrix changes. The histopathology score was significantly higher in transected tendons compared to control tendons in all regions except for the most distal (P ≤ 0.03) with no differences between overstressed (medial) and stress-deprived (lateral) tendon halves. Proteoglycan scores were increased by transection in all but the most proximal region (P < 0.02), with increased immunostaining for aggrecan, biglycan and versican. After correcting for location within the tendon, gene expression for aggrecan, versican, biglycan, lumican, collagen types I, II and III, MMP14 and TIMP1 was increased in transected tendons compared with control tendons (P < 0.02) and decreased for ADAMTS4, MMP3 and TIMP3 (P < 0.001). Aggrecan, biglycan, fibromodulin, and collagen types I and III expression positively correlated with all histopathology scores (P < 0.001), whereas lumican, ADAMTS4 and MMP14 expression positively correlated only with collagen fiber malalignment (P < 0.001). In summary, histologic and associated gene expression changes were significant and widespread six weeks after injury to the equine SDFT, suggesting rapid and active development of tendinopathy throughout the entire length of the tendon. These extensive changes distant to the focal injury may contribute to poor functional outcomes and re
van Doornik, Johan; Kukke, Sahana; McGill, Kevin; Rose, Jessica; Sherman-Levine, Sara; Sanger, Terence D
Although spasticity is a common symptom in children with cerebral palsy, weakness may be a much greater contributor to disability. We explore whether a treatment that reduces spasticity may also have potential benefit for improving strength. Ten children with cerebral palsy and spasticity in the ankle plantar flexor muscles were treated with oral baclofen for 4 weeks. We tested voluntary ability to activate ankle plantar flexor muscles using the ratio of the surface electromyographic signal during isometric maximal voluntary contraction to the M-wave during supramaximal electrical stimulation of the tibial nerve and tested muscle strength using maximal isometric plantar flexion torque. Mean maximal voluntary neuromuscular activation increased from 1.13 +/- 1.02 to 1.60 +/- 1.30 ( P < .05) after treatment, corresponding to an increase in 9 of 10 subjects. Mean maximal plantar flexion torque did not change. We conjecture that antispasticity agents could facilitate strength training by increasing the ability to voluntarily activate muscle.
Lui, Tun Hing
Chronic tendinopathy is characterized by pain in the tendon, generally at the start and completion of exercise. However, tendinosis may lead to decreased blood flow, increased stiffness of the tendon and reduced tensile strength, and predispose to rupture. Operative treatment is indicated to restore the function of the Achilles tendon and alleviate the prerupture heel cord pain. A case of acute Achilles tendon rupture with extensive tendinosis that was successfully treated with minimally invasive flexor hallucis longus transfer is reported.
Background Flexor tenotomy is a minimally invasive surgical alternative for the treatment of neuropathic diabetic foot ulcers on the distal end of the toe. The influence of infection on healing and time to heal after flexor tenotomy is unknown. Flexor tenotomy can also be used as a prophylactic treatment. The effectiveness as a prophylactic treatment has not been described before. Methods A retrospective study was performed with the inclusion of all consecutive flexor tenotomies from one hospital between January 2005 and December 2011. Results From 38 ulcers, 35 healed (92%), with a mean time to heal of 22 ± 26 days. The longest duration for healing was found for infected ulcers that were penetrating to bone (35 days; p = .042). Cases of prophylactic flexor tenotomies (n=9) did not result in any ulcer or other complications during follow-up. Conclusions The results of this study suggest that flexor tenotomy may be beneficial for neuropathic diabetic foot ulcers on the distal end of the toe, with a high healing percentage and a short mean time to heal. Infected ulcers that penetrated to bone took a significantly longer time to heal. Prospective research, to confirm the results of this retrospective study, should be performed. PMID:23347589
Kang, Taewook; Seo, Youngjoon; Park, Jaehoon; Dong, Eunseok; Seo, Byungdo; Han, Dongwook
[Purpose] This research investigated the effect of angular variation of flexion of the elbow joint on the muscle activation of elbow flexor muscles. [Subjects] The research subjects were 24 male college students with a dominant right hand who had no surgical or neurological disorders and gave their prior written consent to participation with full knowledge of the method and purpose of this study. [Methods] The subjects' shoulder joints stayed in the resting position, and the elbow joint was positioned at angles of 55°, 70°, and 90°. The angle between the pulley with weights and forearm stayed at 90°. Surface electromyography was used to measure muscle activities. Three measurements were made at each elbow angle, and every time the angle changed, two minutes rest was given. [Result] The muscle activities of the elbow flexors showed significant changes with change in the elbow joint angle, except for the biceps brachii activities between the angles of 55° and 70° of elbow flexion. The muscle activities of the biceps brachii and brachioradialis showed angle-related changes in the order of 55°, which showed the biggest value, followed by 70° and 90°. [Conclusion] In order to improve muscle strength of the elbow flexor using a pulley system, it seems more effective to have a 90° angle between the pulley with weights and the forearm when the muscle is stretched to a length 20% greater than its resting position.
Background Several tests have been suggested to assess the isometric endurance of the cervical flexor (NFME) and extensors (NEE) muscles. This study proposes to determine whether neck flexors endurance is related to extensor endurance, and whether cervical muscle endurance is related to disability, pain amount and pain stage in subjects with neck pain. Methods Thirty subjects (18 women, 12 men, mean ± SD age: 43 ± 12 years) complaining of neck pain filled out the Visual Analogue Scale (VAS) and the Neck Pain and Disability Scale-Italian version (NPDS-I). They also completed the timed endurance tests for the cervical muscles. Results The mean endurance was 246.7 ± 150 seconds for the NEE test, and 44.9 ± 25.3 seconds for the NMFE test. A significant correlation was found between the results of these two tests (r = 0.52, p = 0.003). A positive relationship was also found between VAS and NPDS-I (r = 0.549, p = 0.002). The endurance rates were similar for acute/subacute and chronic subjects, whereas males demonstrated significantly higher values compared to females in NFME test. Conclusions These findings suggest that neck flexors and extensors endurance are correlated and that the cervical endurance is not significantly altered by the duration of symptoms in subjects with neck pain. PMID:24581272
Kubo, Keitaro; Kanehisa, Hiroaki; Fukunaga, Tetsuo
The purposes of this study were to compare the elasticity of tendon and aponeurosis in human knee extensors and ankle plantar flexors in vivo and to examine whether the maximal strain of tendon was correlated to that of aponeurosis. The elongation of tendon and aponeurosis during isometric knee extension (n = 23) and ankle plantar flexion (n = 22), respectively, were determined using a real-time ultrasonic apparatus, while the participants performed ramp isometric contractions up to voluntary maximum. To calculate the strain values from the measured elongation, we measured the respective length of tendon and aponeurosis. For the knee extensors, the maximal strain of aponeurosis (12.1 +/- 2.8 %) was significantly greater than that of the patella tendon (8.3 +/- 2.4 %), p < 0.001. On the contrary, the maximal strain of Achilles tendon (5.9 +/- 1.4 %) was significantly greater than that of aponeurosis in ankle plantar flexors (2.7 +/- 1.4 %), p < 0.001. Furthermore, for both knee extensors and ankle plantar flexors there was no significant correlation between maximal strain of tendon and aponeurosis. These results would be important for understanding the different roles of tendon and aponeurosis during human movements and for more accurate muscle modeling.
Ishida, Hiroshi; Suehiro, Tadanobu; Ono, Koji; Kurozumi, Chiharu; Watanabe, Susumu
The purpose of this study was to clarify the relationship between the thickness of the deep cervical flexor muscles (longus capitis and longus colli) at rest and sternocleidomastoid activity during the craniocervical flexion test (CCFT). Thirteen healthy males participated in this study. The thickness of the deep cervical flexor muscles was measured by ultrasound imaging in a relaxed supine position. Activity of the sternocleidomastoid was measured by electromyography during the CCFT at five incremental levels (22, 24, 26, 28, and 30 mm Hg). Correlations between normalized muscle thickness relative to body mass index and sternocleidomastoid activity were determined. Significant negative correlations were observed between normalized muscle thickness and activity of the sternocleidomastoid at 26 (r = -0.622, P = 0.023) and 28 mmHg (r = -0.653, P = 0.015). Individuals with smaller deep cervical flexor muscles exhibited increased activity in the sternocleidomastoid during the CCFT.
Kang, Taewook; Seo, Youngjoon; Park, Jaehoon; Dong, Eunseok; Seo, Byungdo; Han, Dongwook
[Purpose] This research investigated the effect of angular variation of flexion of the elbow joint on the muscle activation of elbow flexor muscles. [Subjects] The research subjects were 24 male college students with a dominant right hand who had no surgical or neurological disorders and gave their prior written consent to participation with full knowledge of the method and purpose of this study. [Methods] The subjects' shoulder joints stayed in the resting position, and the elbow joint was positioned at angles of 55°, 70°, and 90°. The angle between the pulley with weights and forearm stayed at 90°. Surface electromyography was used to measure muscle activities. Three measurements were made at each elbow angle, and every time the angle changed, two minutes rest was given. [Result] The muscle activities of the elbow flexors showed significant changes with change in the elbow joint angle, except for the biceps brachii activities between the angles of 55° and 70° of elbow flexion. The muscle activities of the biceps brachii and brachioradialis showed angle-related changes in the order of 55°, which showed the biggest value, followed by 70° and 90°. [Conclusion] In order to improve muscle strength of the elbow flexor using a pulley system, it seems more effective to have a 90° angle between the pulley with weights and the forearm when the muscle is stretched to a length 20% greater than its resting position. PMID:24259930
Stefanidi, A V; Skoromets, A A; Dukhovnikova, I M
The acute low back pain is considered as a consequence of the disorganization between flexors and extensors of the body emerged as a result of wrong afferent stimulation. In definite conditions, when muscle proprioceptors send the contradictory information to the CNS, there is a possibility of the simultaneous reduction of both muscles-agonists and muscles-antagonists which can lead to the reduction of flexors of the body during lumbar extension. The authors suggest a method of treatment of acute pain syndrome in the lower part of the back by the manual relaxation of flexors of the body (muscle (m) rectus, m. obliquus abdominis, m. iliopsoas). Using this method, 119 patients with pain syndrome in the lumbar-sacral part (without symptoms of failure of function of spinal roots) first occurred less than a month ago were treated. After three sessions, the pain in the lower part of the back completely vanished in more than a third of patients (38%), significantly decreased in 48% and remained unchanged only in 14% of cases.
Foisneau-Lottin, A; Touillet, A; Paysant, J; Dautel, G
The repair of the finger flexor tendons can be complicated by the appearance of ruptures and peritendinous adhesions. Ruptures are often treated with tendon grafts. Peritendinous adhesions can require tenolysis. Following these two surgical procedures, there is a risk of new adhesions and rupture. Rehabilitation after this secondary surgery consists of a tailored, closely supervised protocol. Protocols used by the team at the Physical Medicine and Rehabilitation Department of the Regional Rehabilitation Institute and the team at the Plastic and Reconstructive Surgery Department of the Emile-Gallé Surgical Center of Nancy (France) are described. A close collaboration between these teams of surgeons and physical therapists is essential. After tendon grafting, protected early motion helps to move the transplant immediately while still protecting it. After tenolysis, immediate (several times a day) and extended rehabilitation ensures that the mobility obtained intraoperatively is maintained. It is performed in a specialized rehabilitation center during the first three postoperative weeks. The goal is to prevent new adhesions from forming while taking into account tendon's fragility.
Rispler, D; Greenwald, D; Shumway, S; Allan, C; Mass, D
The efficiency of the flexor tendon system was examined in a human cadaver model. Pulleys were randomly sectioned, and the results were evaluated on the basis of the tendon excursion, force generated at the fingertip, and the work (force multiplied by distance) involved, as compared to the intact pulley system. When a single minor pulley (A1 or A5) was cut, there was no statistical difference in work efficiency or excursion efficiency from controls. Cutting all minor pulleys (A1, A3, A5) lead to a significant loss in excursion efficiency. The intact three pulley systems of A2, A3, and A4 were near normal and statistically better than A2 and A4 together for work efficiency. Cutting one of the major pulleys (A2, A4) resulted in significant changes in efficiency, but what was unexpected was to find an 85% loss of both work and excursion efficiency for the loss of A4 but only an excursion difference of 94% for the loss of A2. Our findings demonstrated that in this model, with the influence of the skin removed, A4 absence produced the largest biomechanically measured efficiency changes and that a combination of A2, A3, and A4 was necessary to preserve both work and excursion efficiency.
Arora, R; Fritz, D; Zimmermann, R; Lutz, M; Kamelger, F; Klauser, A S; Gabl, M
The rare injury of closed rupture of the A2 and A3 flexor pulleys was treated using two non-encircling techniques of pulley reconstruction. Thirteen patients were treated with an extensor retinaculum graft (Group A). At a mean follow-up time of 48 months, the average PIP flexion was 97%, the power grip strength 96%, the pinch grip strength 100% and the thickening 94% of the uninjured side. Ten patients were treated with a free palmaris longus tendon grafts (Group B). At a mean follow-up time of 57 months, the average PIP flexion was 94%, the power grip strength 98%, the pinch grip strength 100% and the thickening 95% of the uninjured side. In both groups, finger extension was unrestricted. The Buck Gramcko score included 10 excellent, two good and one fair result in Group A and seven excellent, two good and one fair result in Group B. Both techniques proved beneficial. All climbers returned to their previous standard and all non-climbers regained full finger dexterity in their previous job.
Tamura, N; Kuroda, T; Kotoyori, Y; Fukuda, K; Nukada, T; Kato, T; Kuwano, A; Kasashima, Y
Sonoelastography can assess the inner stiffness of tissues. Sonoelastographic evaluation of injured equine superficial digital flexor tendons (SDFTs) is considered to be useful for assessing the stiffness of a lesion even during late-stage rehabilitation. The purpose of this study was to investigate and compare the sonoelastographic appearance of injured SDFTs over time from the onset of the injury. Eighteen horses were classified into three groups according to the length of time from injury onset: group A, within two weeks after injury; group B, approximately five months after injury; and group C, approximately nine months after injury. Longitudinal and transverse images of all injured SDFTs were obtained using grey-scale ultrasonography and sonoelastography. Grey-scale and sonoelastographic images were evaluated by two observers using echogenicity-grading and colour-grading systems, respectively. The authors evaluated the interobserver agreement and compared the grades among the three groups. The results indicated almost perfect interobserver agreement. Significant differences were found in the sonoelastography among the three groups, whereas no significant difference was found in the grey-scale ultrasonography between groups B and C. Sonoelastography is a feasible and useful modality to evaluate the equine injured SDFTs in vivo and to distinguish between them among the different phases even during the chronic phase.
Kim, Jin Young; Kwag, Kwang Il
[Purpose] The purpose of this study was to investigate clinical effects of deep cervical flexor (DCF) muscles exercise on pain, Neck Disability Index (NDI), and neck and shoulder postures in patients with chronic neck pain. [Subjects and Methods] Twenty-eight patients with chronic neck pain were randomly assigned into either the general strengthening exercise (GSE) group or the DCF activation group as control and experimental groups, respectively. All exercises were performed three times per week over 4 weeks. NDI and numeric rating scale (NRS) score for pain were determined and radiological assessment of neck-shoulder postures (head tilt angle [HTA], neck flexion angle [NFA], and forward shoulder angle [FSA]) was performed before (baseline), 4 weeks after, and 8 weeks after exercise in order to directly compare the exercise effects between the groups. [Results] In the DCF group, the NDI, NRS score, and neck-shoulder postures (analyzed by uisng HTA, NFA, and FSA) were significantly improved. [Conclusion] DCF activation exercise was effective to alleviate pain, recover functions, and correct forward head posture in the patients with neck pain. Hence, it might be recommended in the rehabilitation of patients with chronic neck pain.
Yates, J W; Gladden, L B; Cresanta, M K
The isometric endurance of the elbow flexors was determined in a control condition and subsequent to a maximal effort exercise bout on a cycle ergometer in seven subjects. Maximum voluntary contraction (MVC), peak rate of tension development (+dP/dt), peak rate of tension relaxation (-dP/dt), one-half contraction time, and one-half relaxation time were also measured. Each subject was tested on four occasions: two control and two experimental sessions. During the control sessions each subject held 40% of MVC to exhaustion, whereas the experimental session included a 1-min maximal effort exercise bout on a cycle ergometer 6 min prior to the isometric endurance task. Arterialized blood samples were drawn and analyzed for lactate, pH, PCO2, and PO2. Plasma bicarbonate was calculated from the Henderson-Hasselbalch equation. Subsequent to the cycle ergometer bout, blood lactate concentration rose from 0.8 to 11 mM, pH decreased from 7.43 to 7.20, PCO2 decreased from 40 to 32 Torr, and plasma bicarbonate decreased from 26 to 12 mM. When compared with the control values, no significant changes were evident for any muscle contractile properties following the cycle ergometer bout. However, isometric endurance was significantly reduced from 115.0 +/- 7.2 to 86.3 +/- 7.3 s.(ABSTRACT TRUNCATED AT 250 WORDS)
Hardeman, L C; van der Meij, B R; Lamers, A A H; van der Kolk, J H; Back, W; Wijnberg, I D
In equine medicine the use of Botox® is experimental. Dosages are determined from human treatment-protocols and limited numbers of equine studies. Determination of target-muscle volume can be helpful to extrapolate human dosages. The aim of the study was to calculate a formula enabling the estimation of the deep digital flexor muscle (DDFM) volume based on distances between anatomical landmarks. Nineteen cadaveric limbs were collected and distance A (top of olecranon to Os carpi accessorium) and B (circumference of limb) were measured. Converting mathematical formulas, C was calculated: π × (((0.5B)/π)(2)) × A. DDFM volume was determined by water displacement. Linear Regression Analysis was used to analyse data. The line best fitting the observed points was: Ln(volume[ml]) = -1.89 + 0.98 × Ln(value C[cm(3)]). Correlation was highest when natural logarithm was applied to both variables and was 0.97. The calculated formula enables estimating DDFM volume of a living horse. This estimated volume can be useful to apply human Botox® treatment-protocols.
Baláš, Jiří; Michailov, Michail; Giles, David; Kodejška, Jan; Panáčková, Michaela; Fryer, Simon
This study aimed to (1) evaluate the effect of hand shaking during recovery phases of intermittent testing on the time-force characteristics of performance and muscle oxygenation, and (2) assess inter-individual variability in the time to achieve the target force during intermittent testing in rock climbers. Twenty-two participants undertook three finger flexor endurance tests at 60% of their maximal voluntary contraction until failure. Performances of a sustained contraction and two intermittent contractions, each with different recovery strategies, were analysed by time-force parameters and near-infrared spectroscopy. Recovery with shaking of the forearm beside the body led to a significantly greater intermittent test time (↑ 22%, P < .05), force-time integral (↑ 28%, P < .05) and faster muscle re-oxygenation (↑ 32%, P < .05), when compared to the hand over hold condition. Further, the ratio of intermittent to continuous test time distinguished specific aerobic muscular adaptations among sport climbers (2.02), boulderers (1.74) and lower grade climbers (1.25). Lower grade climbers and boulderers produced shorter duration contractions due to the slower development of target force during the intermittent test, indicating worse kinaesthetic differentiation. Both the type of recovery and climbing discipline determined muscle re-oxygenation and intermittent performance in rock climbers.
Hu, Hai; Meijer, Onno G; van Dieën, Jaap H; Hodges, Paul W; Bruijn, Sjoerd M; Strijers, Rob L; Nanayakkara, Prabath W B; van Royen, Barend J; Wu, Wen Hua; Xia, Chun
Psoas function is a topic of considerable relevance in sports and clinical science. However, the literature on psoas function is not sufficiently consistent. Questions are, amongst others, if during hip flexion the psoas always has the same function as the iliacus, and if the psoas affects the hip more than the lumbar spine. In the present study, 17 healthy women, 20-40 years, performed the active straight leg raise (ASLR), with the right or the left leg ("Side"), and without or with weight added above the ankle ("Condition"). Electromyographic (EMG) activity of psoas and iliacus were recorded with fine-wire electrodes, and of rectus femoris and adductor longus with surface electrodes, all on the right side. Movements of the leg were recorded with active markers and a camera system. During ASLR, the iliacus, rectus femoris, adductor longus and psoas were active ipsilaterally, but psoas was also active contralaterally. All muscles started to contract before movement onset, the iliacus, rectus femoris, and adductor longus largely at the same time, before the psoas. There was no significant difference between the amplitude or time of onset of ipsilateral and contralateral psoas EMG activity, nor was there a significant interaction between Side and Condition for the psoas. Although ipsilateral psoas activity is consistent with the psoas being a hip flexor, contralateral activity is not. The most simplest explanation of the pattern found is that the psoas is bilaterally recruited to stabilize the lumbar spine, probably in the frontal plane.
Huang, Han-Wei; Ju, Ming-Shaung; Lin, Chou-Ching K
The aim of this study was to evaluate the flexor and extensor muscle tone of the upper limbs in patients with spasticity or rigidity and to investigate the difference in hypertonia between spasticity and rigidity. The two experimental groups consisted of stroke patients and parkinsonian patients. The control group consisted of age and sex-matched normal subjects. Quantitative upper limb pendulum tests starting from both flexed and extended joint positions were conducted. System identification with a simple linear model was performed and model parameters were derived. The differences between the three groups and two starting positions were investigated by these model parameters and tested by two-way analysis of variance. In total, 57 subjects were recruited, including 22 controls, 14 stroke patients and 21 parkinsonian patients. While stiffness coefficient showed no difference among groups, the number of swings, relaxation index and damping coefficient showed changes suggesting significant hypertonia in the two patient groups. There was no difference between these two patient groups. The test starting from the extended position constantly manifested higher muscle tone in all three groups. In conclusion, the hypertonia of parkinsonian and stroke patients could not be differentiated by the modified pendulum test; the elbow extensors showed a higher muscle tone in both control and patient groups; and hypertonia of both parkinsonian and stroke patients is velocity dependent.
Kim, Jin Young; Kwag, Kwang Il
[Purpose] The purpose of this study was to investigate clinical effects of deep cervical flexor (DCF) muscles exercise on pain, Neck Disability Index (NDI), and neck and shoulder postures in patients with chronic neck pain. [Subjects and Methods] Twenty-eight patients with chronic neck pain were randomly assigned into either the general strengthening exercise (GSE) group or the DCF activation group as control and experimental groups, respectively. All exercises were performed three times per week over 4 weeks. NDI and numeric rating scale (NRS) score for pain were determined and radiological assessment of neck-shoulder postures (head tilt angle [HTA], neck flexion angle [NFA], and forward shoulder angle [FSA]) was performed before (baseline), 4 weeks after, and 8 weeks after exercise in order to directly compare the exercise effects between the groups. [Results] In the DCF group, the NDI, NRS score, and neck-shoulder postures (analyzed by uisng HTA, NFA, and FSA) were significantly improved. [Conclusion] DCF activation exercise was effective to alleviate pain, recover functions, and correct forward head posture in the patients with neck pain. Hence, it might be recommended in the rehabilitation of patients with chronic neck pain. PMID:26957772
Russmann, Heike; Shamim, Ejaz A.; Meunier, Sabine; Hallett, Mark
Enhancements in the strength of corticospinal projections to muscles are induced in conscious humans by paired associative stimulation (PAS) to the motor cortex. Although most of the previous studies support the hypothesis that the increase of the amplitude of motor evoked potentials (MEPs) by PAS involves long-term potentiation (LTP)-like mechanism in cortical synapses, changes in spinal excitability after PAS have been reported, suggestive of parallel modifications in both cortical and spinal excitability. In a first series of experiments (experiment 1), we confirmed that both flexor carpi radialis (FCR) MEPs and FCR H reflex recruitment curves are enhanced by PAS. To elucidate the mechanism responsible for this change in the H reflex amplitude, we tested, using the same subjects, the hypothesis that enhanced H reflexes are caused by a down-regulation of the efficacy of mechanisms controlling Ia afferent discharge, including presynaptic Ia inhibition and postactivation depression. To address this question, amounts of both presynaptic Ia inhibition of FCR Ia terminals (D1and D2 inhibitions methods; experiment 2) and postactivation depression (experiment 3) were determined before and after PAS. Results showed that PAS induces a significant decrease of presynaptic Ia inhibition of FCR terminals, which was concomitant with the facilitation of the H reflex. Postactivation depression was unaffected by PAS. It is argued that enhancement of segmental excitation by PAS relies on a selective effect of PAS on the interneurons controlling presynaptic inhibition of Ia terminals. PMID:20538768
Deane, Russell S; Chow, John W; Tillman, Mark D; Fournier, Kim A
Although hip flexion is integral in sports, hip flexion exercises are seldom emphasized in strength and conditioning for sports performance. This study aimed to determine whether a hip flexor resistance-training program could improve performance on a variety of tasks. Thirteen men and 11 women completed an 8-week hip flexion resistance-training program. Eleven men and 13 women served as controls. Isometric hip flexion strength, 40-yd dash time and the time for the first 10-yds, 4 x 5.8-m shuttle run time, and vertical jump height were evaluated at the beginning and end of the training and control period. Improvements were observed in the training group but not in the control group. Individuals in the training group improved hip flexion strength by 12.2% and decreased their 40-yd and shuttle run times by 3.8% and 9.0%, respectively. An increase in hip flexion strength can help to improve sprint and agility performance for physically active, untrained individuals.
Jacoby, Sidney M; Sivalingam, Jocelyn J; Raikin, Steven Mark
Mycobacterium fortuitum (M. fortuitum), a rapidly growing non-tuberculous mycobacterium is a well-recognized, yet uncommon cause of soft tissue infection. The incidence of post surgical wound infections from this organism is increasing. The presentation of infection is atypical and failure to consider this pathogen can cause diagnostic delay and increased morbidity. Achilles tendon debridement with FHL augmentation is commonly used in patients with chronic Achilles tendinosis. Wound-edge necrosis is the most common surgical complication of this procedure, and superficial and deep infections are potentially devastating complications. We report the case of a patient who underwent Achilles tendon debridement with flexor hallucis longus augmentation, whose postoperative course was complicated by a deep M. FORTUITUM infection. Critical to the identification and ultimate treatment of this particular pathogen is the utilization of appropriate intraoperative cultures and microbiologic testing. In addition, repeat aggressive irrigation and debridement procedures coupled with removal of foreign materials and the appropriate use of prolonged antibiotic therapy can result in a successful long-term outcome.
Mulder, Edwin R; Horstman, Astrid M; Gerrits, Karin; Massa, Mark; Kleine, Bert U; de Haan, Arnold; Belavý, Daniel L; Felsenberg, Dieter; Zwarts, Machiel; Stegeman, Dick F
This study evaluated the effectiveness of resistance training to preserve submaximal plantar flexor (PF) torque steadiness following 60 days of bed rest (BR). Twenty-two healthy male subjects underwent either BR only (CTR, n=8), or BR plus resistance training (RT, n=14). The magnitude of torque fluctuations during steady submaximal isometric PF contractions (20%, 40%, 60% and 80% of maximum) were assessed before and after BR. Across contraction intensities, torque fluctuations (coefficient of variation, CV) increased more (P<0.05) after BR for CTR (from 0.31±0.10 to 0.92±0.63; P<0.001), than for RT (from 0.30±0.09 to 0.54±0.27; P<0.01). A shift in the spectral content of torque fluctuations towards increased rhythmic activity between 6.5 and 20Hz was observed in CTR only (P<0.05). H-reflex amplitude (H(max)/M(max) ratio) declined across groups from 0.57±0.18 before BR to 0.44±0.14 following BR (P<0.01) without correlation to CV. The present study showed that increased torque fluctuation after BR resulted from enhanced physiological tremor. Resistance training prevented the spectral shift in isometric PF torque fluctuation and offset ∼50% of the decline in performance associated with long-term BR.
Hunter, Angus M; Galloway, Stuart D R; Smith, Iain J; Tallent, Jamie; Ditroilo, Massimiliano; Fairweather, Malcolm M; Howatson, Glyn
Exercise induced muscle damage (EIMD) impairs maximal torque production which can cause a decline in athletic performance and/or mobility. EIMD is commonly assessed by using maximal voluntary contraction (MVC), creatine kinase (CK) and muscle soreness. We propose as an additional technique, tensiomyography (TMG), recently introduced to measure mechanical and muscle contractile characteristics. The purpose of this study was to determine the validity of TMG in detecting changes in maximal torque following EIMD. Nineteen participants performed eccentric elbow flexions to achieve EIMD on the non- dominant arm and used the dominant elbow flexor as a control. TMG parameters, MVC and rate of torque development (RTD) were measured prior to EIMD and repeated for another six consecutive days. Creatine kinase, muscle soreness and limb girth were also measured during this period. Twenty four hours after inducing EIMD, MVC torque, RTD and TMG maximal displacement had significantly (p<0.01) declined by 37%, 44% and 31%, respectively. By day 6 MVC, RTD and TMG recovered to 12%, 24% and 17% of respective pre-EIMD values. In conclusion, as hypothesised TMG maximal displacement significantly followed other standard EIMD responses. This could therefore be useful in detecting muscle damage from impaired muscle function and its recovery following EIMD.
Bottagisio, Marta; Lovati, Arianna B
Tendon is a connective tissue mainly composed of collagen fibers with peculiar mechanical properties essential to functional movements. The increasing incidence of tendon traumatic injuries and ruptures-associated or not with the loss of tissue-falls on the growing interest in the field of tissue engineering and regenerative medicine. The use of animal models is mandatory to deepen the knowledge of the tendon healing response to severe damages or acute transections. Thus, the selection of preclinical models is crucial to ensure a successful translation of effective and safe innovative treatments to the clinical practice. The current review is focused on animal models of tendon ruptures and lacerations or defective injuries with large tissue loss that require surgical approaches or grafting procedures. Data published between 2000 and 2016 were examined. The analyzed articles were compiled from Pub Med-NCBI using search terms, including animal model(s) AND tendon augmentation OR tendon substitute(s) OR tendon substitution OR tendon replacement OR tendon graft(s) OR tendon defect(s) OR tendon rupture(s). This article presents the existing preclinical models - considering their advantages and disadvantages-in which translational progresses have been made by using bioactive sutures or tissue engineering that combines biomaterials with cells and growth factors to efficiently treat transections or large defects of Achilles and flexor tendons.
Wu, Jingheng; Thoreson, Andrew R.; Reisdorf, Ramona L.; An, Kai-Nan; Moran, Steven L.; Amadio, Peter C.; Zhao, Chunfeng
The purpose of this study was to investigate the biomechanical properties of modified repair techniques for flexor tendon reconstruction and the effects of surface modification using carbodiimide-derivatized synovial fluid plus gelatin (cd-SF-G), compared to the traditional repair techniques. The second and fifth digits from 16 canine forepaws were randomly divided into 4 groups: (1) traditional graft repairs (TGR group) including distal Bunnell repair and proximal Pulvertaft weave repair; (2) modified graft repairs (MGR group) including distal graft bony attachment repair and proximal step-cut repair; (3) group TGR coated with cd-SF-G (TGR-C group); and (4) group MGR coated with cd-SF-G (MGR-C group). Digit normalized work of flexion (nWOF), ultimate failure strength, and stiffness were measured. The nWOF in MGR group was significantly less than TGR group (p < 0.05). The nWOF in groups treated with cd-SF-G was significantly less than their untreated counterparts (p < 0.05). Ultimate load to failure of the MGR-C group was significantly greater than the TGR-C group (p < 0.05), but no significant difference in stiffness was found between these two groups. The modified techniques cannot only improve tendon gliding abilities but can also improve breaking strength. Additionally, surface modification with cd-SF-G significantly decreased the work of flexion. PMID:25665071
Watanabe, Takafumi; Hosaka, Yoshinao; Yamamoto, Etsuko; Ueda, Hiromi; Tangkawattana, Prasarn; Takehana, Kazushige
The Golgi tendon organ (GTO) is an encapsulated fusiform mechanoreceptor siding in the musculo-tendinous junction of many animal species. Inhibitory function of afferent nerve fibers distributed from nearby motor units, the organ responds to active tension exerted onto the muscle. The morphological features of the equine GTO have not yet been elucidated. Additionally, there is some controversy regarding to the existence of the GTO in the equine superficial digital flexor tendon (SDFT). Therefore, immunohistochemistry and immunoelectron microscopy using alcian blue (pH 2.5) staining and the silver-enhanced colloidal gold method were carried out to determine both the location and characteristics of the GTO at the musculo-tendinous junction of the SDFT. A GTO with a fusiform structure of approximately 3 mm in length was found in the tendinous part. The lumen of the GTO was divided into compartments by septal cells. Each compartment contained collagen fibrils, nerve fibers and Schwann cells. This is the first report of the equine GTO.
Barroso, Renato; Roschel, Hamilton; Ugrinowitsch, Carlos; Araújo, Rubens; Nosaka, Kazunori; Tricoli, Valmor
Eccentric exercise induces muscle damage, but controversy exists concerning the effect of contraction velocity on the magnitude of muscle damage, and little is known about the effect of contraction velocity on the repeated-bout effect. This study examined slow (60 degrees.s(-1)) and fast (180 degrees.s(-1)) velocity eccentric exercises for changes in indirect markers of muscle damage following 3 exercise bouts that were performed every 2 weeks. Fifteen young men were divided into 2 groups based on the velocity of eccentric exercise: 7 in the Ecc60 (60 degrees.s(-1)) group, and 8 in the Ecc180 (180 degrees.s(-1)) group. The exercise consisted of 30 maximal eccentric contractions of the elbow flexors at each velocity, in which the elbow joint was forcibly extended from 60 degrees to 180 degrees (full extension) on an isokinetic dynamometer. Changes in maximal voluntary isometric contraction strength, range of motion, muscle soreness, and plasma creatine kinase activity before and for 4 days after the exercise were compared in the 2 groups using a mixed-model analysis (groupxboutxtime). No significant differences between groups were evident for changes in any variables following exercise bouts; however, the changes were significantly smaller (p<0.05) after the second and third bouts than after the first bout. These results indicate that the contraction velocity does not influence muscle damage or the repeated-bout effect.
McKinnon, Neal B.; Graham, Mitchell T.; Tiidus, Peter M.
We investigated effects of creatine (Cr) supplementation (CrS) on exercise-induced muscle damage. Untrained males and females (N = 27) ages 18-25, with no CrS history in the past 4 months, were randomly assigned to CrS (creatine and carbohydrate) (n = 9), placebo (P) (carbohydrate only) (n = 9), or control (C) (no supplements) groups (n = 9). Participants followed a 5-day Cr loading protocol of 40 g·day-1, divided for 5 days prior to exercise, reduced to 10 g g·day-1 for 5 days following exercise. Testing consisted of 5 maximal isometric contractions at 90 arm flexion with the preferred arm on a CYBEX NORM dynamometer, assessed prior to, immediately following, and 24, 48, 72, and 96 hours post muscle-damaging procedures. Damage was induced to the elbow flexor muscles using 6 sets of 10 eccentric contractions at 75 °/sec, 90 °/sec and 120 °/sec. Participants were asked to rate their muscle soreness on a scale of 1-10. Data was analyzed using repeated-measures ANOVA, with an alpha of 0.05. No significant differences were found between muscle force loss and rate of recovery or muscle soreness between groups over the 96 hr recovery period (p > 0.05). Across all 3 experimental groups an initial decrease in force was observed, followed by a gradual recovery. Significant differences were found between baseline and all others times (p = 0.031,0 .022, 0.012, 0.001 respectively), and between the 48 hour and 96 hour time periods (p = 0.034). A weak negative correlation between subjectively rated muscle soreness and mean peak isometric force loss (R2 = 0.0374 at 96 hours), suggested that muscle soreness and muscle force loss may not be directly related. In conclusion, 5 days of Cr loading, followed by a Cr maintenance protocol did not reduce indices of muscle damage or speed recovery of upper body muscles following eccentrically induced muscle damage. Key points Creatine supplementation has been suggested as a means to diminish exercise induced muscle damage and speed
Miller, Jonathan D; Herda, Trent J; Trevino, Michael A; Mosier, Eric M
This study examined the effects of passive stretching only (PS+CON) and passive stretching with the addition of continuous vibration (VIB) during post-passive stretching tests (PS+VIB) on peak torque (PT), percent voluntary inactivation (%VI), single stimulus twitch torque (TTSINGLE), and doublet stimuli twitch torque (TTDOUBLET) of the plantar flexors at a short (20° plantar flexion (PF)) and long muscle length (15° dorsiflexion (DF)). Fourteen healthy men (age = 22 ± 3 years) performed isometric maximal voluntary contractions at PF and DF, and passive range of motion (PROM) assessments before and after 8 × 30-s passive stretches without (PS+CON) or with VIB (PS+VIB) administered continuously throughout post-passive stretching tests. The passive properties of the muscle tendon unit were assessed pre- and post-passive stretching via PROM, passive torque (PASSTQ), and musculotendinous stiffness (MTS) measurements. PT, TTSINGLE, and TTDOUBLET decreased, whereas, %VI increased following passive stretching at PF and DF (P < 0.05) with no significant differences between PS+CON and PS+VIB. PASSTQ and MTS decreased while PROM increased post-passive stretching during both trials (P < 0.05). The stretching-induced force/torque deficit and increases in %VI were evident following passive stretching at short and long muscle lengths. Although not statistically significant, effect size calculations suggested large and moderate differences in the absolute changes in PT (Cohen's d = 1.14) and %VI (Cohen's d = 0.54) from pre- to post-passive stretching between treatments, with PS+VIB having greater decreases of PT and higher %VI than PS+CON. The decrement in PT following passive stretching may be primarily neural in origin.
Hart, Corey R; Layec, Gwenael; Trinity, Joel D; Liu, Xin; Kim, Seong-Eun; Groot, H Jonathan; Le Fur, Yann; Sorensen, Jacob R; Jeong, Eun-Kee; Richardson, Russell S
Studies examining the effect of aging on skeletal muscle oxidative capacity have yielded equivocal results; however, these investigations may have been confounded by differences in oxygen (O(2)) delivery, physical activity, and small numbers of participants. Therefore, we evaluated skeletal muscle oxidative capacity and O(2) delivery in a relatively large group (N = 40) of young (22 ± 2 years) and old (73 ± 7 years) participants matched for physical activity. After submaximal dynamic plantar flexion exercise, phosphocreatine (PCr) resynthesis ((31)P magnetic resonance spectroscopy), muscle reoxygenation (near-infrared spectroscopy), and popliteal artery blood flow (Doppler ultrasound) were measured. The phosphocreatine recovery time constant (Tau) (young: 33 ± 16; old: 30 ± 11 seconds), maximal rate of adenosine triphosphate (ATP) synthesis (young: 25 ± 9; old: 27 ± 8 mM/min), and muscle reoxygenation rates determined by the deoxyhemoglobin/myoglobin recovery Tau (young: 48 ± 5; old: 47 ± 9 seconds) were similar between groups. Similarly, although tending to be higher in the old, there were no significant age-related differences in postexercise popliteal blood flow (area under the curve: young: 1,665 ± 227 vs old: 2,404 ± 357 mL, p = .06) and convective O(2) delivery (young: 293 ± 146 vs old: 404 ± 191 mL, p = .07). In conclusion, when physical activity and O(2) delivery are similar, oxidative capacity in the plantar flexors is not affected by aging. These findings reveal that diminished skeletal muscle oxidative capacity is not an obligatory accompaniment to the aging process.
Prasartwuth, O; Taylor, J L; Gandevia, S C
Muscle damage reduces voluntary force after eccentric exercise but impaired neural drive to the muscle may also contribute. To determine whether the delayed-onset muscle soreness, which develops approximately 1 day after exercise, reduces voluntary activation and to identify the possible site for any reduction, voluntary activation of elbow flexor muscles was examined with both motor cortex and motor nerve stimulation. We measured maximal voluntary isometric torque (MVC), twitch torque, muscle soreness and voluntary activation in eight subjects before, immediately after, 2 h after, 1, 2, 4 and 8 days after eccentric exercise. Motor nerve stimulation and motor cortex stimulation were used to derive twitch torques and measures of voluntary activation. Eccentric exercise immediately reduced the MVC by 38 +/- 3% (mean +/- s.d., n = 8). The resting twitch produced by motor nerve stimulation fell by 82 +/- 6%, and the estimated resting twitch by cortical stimulation fell by 47 +/- 15%. While voluntary torque recovered after 8 days, both measures of the resting twitch remained depressed. Muscle tenderness occurred 1-2 days after exercise, and pain during contractions on days 1-4, but changes in voluntary activation did not follow this time course. Voluntary activation assessed with nerve stimulation fell 19 +/- 6% immediately after exercise but was not different from control values after 2 days. Voluntary activation assessed by motor cortex stimulation was unchanged by eccentric exercise. During MVCs, absolute increments in torque evoked by nerve and cortical stimulation behaved differently. Those to cortical stimulation decreased whereas those to nerve stimulation tended to increase. These findings suggest that reduced voluntary activation contributes to the early force loss after eccentric exercise, but that it is not due to muscle soreness. The impairment of voluntary activation to nerve stimulation but not motor cortical stimulation suggests that the activation
Pantović, Milan; Popović, Boris; Madić, Dejan; Obradović, Jelena
Neuromuscular electrical stimulation (NMES) has recently drawn a lot of attention as means for strengthening of voluntary muscle contraction both in sport and rehabilitation. NMES training increases maximal voluntary contraction (MVC) force output through neural adaptations. On the other hand, positive effects of resistance training (RT) on muscle strength are well known. The aim of this study was to investigate effects of a 5-week program of NMES compared to RT program of same duration. Sample of 15 students' of faculty of sport and physical education (age 22 ± 2) were randomized in two groups: NMES (N = 7) and RT (N = 8). NMES group performed NMES superimposed over voluntary muscle contraction, RT group performed resistance training with submaximal loads. Subjects were evaluated for knee isokinetic dynamometry on both sides (60° and 180° s). After intervention no significant difference between groups were observed in isokinetic dynamometry (p = 0.177). However, applying pair sample t test within each group revealed that peak torque increased in NMES-group (p = 0.002 for right knee extensors muscles, p = 0.003 for left, respectively, at 60° and p = 0.004 for left knee extensors muscles, at angular velocity 180°). In RT group (p = 0.033 for right knee extensors muscles, p = 0.029 for right knee flexor muscles, at angular velocity 60°). Our results indicate that NMES has equal potential if not in some way better than classical RT having in mind that overload on locomotor apparatus during NMES is minimal and force of muscle contraction is equal on both sides, for enhancement of knee muscles concentric peak torque.
Prasartwuth, O; Taylor, JL; Gandevia, SC
Muscle damage reduces voluntary force after eccentric exercise but impaired neural drive to the muscle may also contribute. To determine whether the delayed-onset muscle soreness, which develops ∼1 day after exercise, reduces voluntary activation and to identify the possible site for any reduction, voluntary activation of elbow flexor muscles was examined with both motor cortex and motor nerve stimulation. We measured maximal voluntary isometric torque (MVC), twitch torque, muscle soreness and voluntary activation in eight subjects before, immediately after, 2 h after, 1, 2, 4 and 8 days after eccentric exercise. Motor nerve stimulation and motor cortex stimulation were used to derive twitch torques and measures of voluntary activation. Eccentric exercise immediately reduced the MVC by 38 ± 3% (mean ±s.d., n = 8). The resting twitch produced by motor nerve stimulation fell by 82 ± 6%, and the estimated resting twitch by cortical stimulation fell by 47 ± 15%. While voluntary torque recovered after 8 days, both measures of the resting twitch remained depressed. Muscle tenderness occurred 1–2 days after exercise, and pain during contractions on days 1–4, but changes in voluntary activation did not follow this time course. Voluntary activation assessed with nerve stimulation fell 19 ± 6% immediately after exercise but was not different from control values after 2 days. Voluntary activation assessed by motor cortex stimulation was unchanged by eccentric exercise. During MVCs, absolute increments in torque evoked by nerve and cortical stimulation behaved differently. Those to cortical stimulation decreased whereas those to nerve stimulation tended to increase. These findings suggest that reduced voluntary activation contributes to the early force loss after eccentric exercise, but that it is not due to muscle soreness. The impairment of voluntary activation to nerve stimulation but not motor cortical stimulation suggests that the activation deficit lies in the
Baur, Heiner; Muller, Steffen; Pilz, Frederike; Mayer, Patrizia; Mayer, Frank
Seventy percent of motor sports athletes report low back pain. Information on the physical capacity of race car drivers is limited. The purpose of this study was to compare the maximum trunk extensor and flexor strength of elite race car drivers and physically active controls. Thirteen elite race car drivers and 13 controls were measured in concentric mode for maximal trunk flexion and extension at 60° x s(-1) and 120° x s(-1). Peak torque (mean ± s) at 60° x s(-1) in trunk extension was 283 ± 80 N x m in the drivers and 260 ± 88 N x m in controls (P > 0.05). At 120° x s(-1), drivers produced peak torques of 248 ± 55 N x m compared with 237 ± 74 N x m for controls (P > 0.05). Peak torques in flexion were less than in extension for both groups (60° x s(-1): drivers 181 ± 56 N x m, controls 212 ± 54 N x m, P > 0.05; 120° x s(-1): drivers 191 ± 57 N x m, controls 207 ± 48 N x m, P > 0.05). Individual ratios of flexion to extension forces exhibited ratios of 0.88 (60° x s(-1)) and 0.93 (120° x s(-1)) for controls and 0.66 (60° x s(-1)) and 0.77 (120° x s(-1)) for drivers (60° x s(-1): P > 0.05; 120° x s(-1): P > 0.05). The maximum strength performance capacity of the trunk muscles of elite motor sport athletes competing in long-distance racing did not differ from that of anthropometrically matched and physically active controls.
Lim, Edwin Choon Wyn; Sterling, Michele; Stone, Andrew; Vicenzino, Bill
Chronic musculoskeletal conditions are increasingly conceived as involving altered central nervous system processing, and impaired nociceptive flexor reflex (NFR) appears to reflect altered central nervous system processing. The primary objective was to synthesize the evidence for impaired NFR in these conditions. The secondary objective was to evaluate the NFR stimuli parameters employed by reviewed studies. Electronic databases: MEDLINE, CINAHL, Embase, PEDro, Google Scholar, and Cochrane library were searched from the mid-1960s to June 2010. Experimental reports were systematically reviewed and meta-analysis (where possible) was performed. NFR thresholds and parameters of NFR stimuli were extracted. Sixteen trials were identified, 11 of which were suitable for inclusion in the meta-analysis. Compared to healthy controls, standardized mean differences in NFR threshold were significantly lower in subjects with primary headache (-0.45; 95% confidence interval [CI] -0.77 to -0.13, P=0.005), fibromyalgia (-0.63; 95% CI -0.93 to -0.34, P<0.0001), knee pain (-1.51; 95% CI -2.10 to -0.93, P<0.00001) and whiplash (-0.73; 95% CI -1.11 to -0.35, P=0.0002). Employed stimuli parameters vary between studies, with inter-pulse duration (P=0.044) being identified by multiple regression analysis as independent predictors of the variability in NFR threshold in healthy controls. The results indicate that there is evidence of central hyperexcitability in people with chronic musculoskeletal pain. Our review also suggests that shorter inter-pulse duration tends to yield smaller variability in NFR threshold. However, further research investigating optimal stimulation parameters is still warranted.
Xu, Lin; Cardinale, Marco; Rabotti, Chiara; Beju, Bogdan; Mischi, Massimo
Vibration exercise (VE) has been suggested as an effective method to improve strength and power capabilities. However, the underlying mechanisms in response to VE are still unclear. A pulley-like VE system, characterized by sinusoidal force applications has been developed and tested for proof of concept in a previous study. The aim of this study was to evaluate the effects of such force modulation on elbow flexors strength and compare it with conventional methods. Forty subjects were randomly divided into 4 groups of 10: the vibration group (VG), the no-vibration group (NVG), the dumbbell group (DG), and the control group (CG). Biceps curl exercises were used to train the elbow flexors 2 times a week for 8 weeks. Subjects in the VG were trained using a ramp-up baseline with superimposed 30 Hz sinusoidal vibration whereas the subjects in the NVG were trained using the same baseline but without vibration. Subjects in the DG were trained using dumbbells, and the subjects in the CG were not trained. The isometric break force (IBF) and 1 repetition maximum (1RM) of the subject's dominant arm were assessed before and after the 8-week training period. The VG achieved 1RM improvement (22.7%) larger than the NVG (10.8%) and comparable with the DG (22.3%). Differences in IBF gains following the training period among the training groups were found to be not significant. Our results support the inclusion of the proposed VE in strength training programs aimed at improving dynamic strength on the elbow flexors.
Thompson, Brennan J; Conchola, Eric C; Stock, Matt S
Short-term strength and power recovery patterns following fatigue have received little research attention, particularly as they pertain to age-specific responses, and the leg flexors (i.e., hamstrings) muscle group. Thus, research is warranted addressing these issues because both age-related alterations in the neuromuscular system and mode of muscle action (e.g., eccentric, concentric, isometric) may differentially influence recovery responses from fatigue. The aim of this study was to investigate the strength and power recovery responses for eccentric, concentric, and isometric muscle actions of the leg flexors in young and older men following an isometric, intermittent fatigue-inducing protocol. Nineteen young (age = 25 ± 3 years) and nineteen older (71 ± 4) men performed maximal voluntary contractions (MVCs) for eccentric, concentric, and isometric muscle actions followed by a fatigue protocol of intermittent (0.6 duty cycle) isometric contractions of the leg flexors at 60% of isometric MVC. MVCs of each muscle action were performed at 0, 7, 15, and 30 min following fatigue. Peak torque (PT) and mean power values were calculated from the MVCs and the eccentric/concentric ratio (ECR) was derived. For PT and mean power, young men showed incomplete recovery at all time phases, whereas the older men had recovered by 7 min. Eccentric and isometric muscle actions showed incomplete recovery at all time phases, but concentric recovered by 7 min, independent of age. The ECR was depressed for up to 30 min following fatigue. More rapid and pronounced recovery in older men and concentric contractions may be related to physiological differences specific to aging and muscle action motor unit patterns. Individuals and clinicians may use these time course responses as a guide for recovery following activity-induced fatigue.
Schoeffl, V; Klee, S; Strecker, W
Background: Chronic exertional compartment syndromes (CECS) are well known in sports medicine. Most commonly affected is the tibialis anterior muscle compartment in runners and walkers. Only a few cases of CECS of the forearm flexor muscles have been reported. Objectives: To determine pressure levels inside the deep flexor compartment of the forearms during a sport specific stress test. Method: Ten healthy, high level climbers were enrolled in a prospective study. All underwent climbing specific ergometry, using a rotating climbing wall (step test, total climbing time 9–15 minutes). Pressure was measured using a slit catheter placed in the deep flexor compartment of the forearm. Pressure, blood lactate, and heart rate were recorded every three minutes and during recovery. Results: In all the subjects, physical exhaustion of the forearms defined the end point of the climbing ergometry. Blood lactate increased with physical stress, reaching a mean of 3.48 mmol/l. Compartment pressure was related to physical stress, exceeding 30 mm Hg in only three subjects. A critical pressure of more than 40 mm Hg was never observed. After the test, the pressure decreased to normal levels within three minutes in seven subjects. The three with higher pressure levels (>30 mm Hg) required a longer time to recover. Conclusions: For further clinical and therapeutic consequences, an algorithm was derived. Basic pressure below 15 mm Hg and stress pressure below 30 mm Hg as well as pressures during the 15 minute recovery period below 15 mm Hg are physiological. Pressures of 15–30 mm Hg during recovery suggest high risk of CECS, and pressures above 30 mm Hg confirm CECS. PMID:15273176
Carroll, Timothy J; Baldwin, Evan R L; Collins, David F
In humans, the flexor carpi radialis (FCR) and extensor carpi radialis (ECR) muscles act as antagonists during wrist flexion-extension and as functional synergists during radial deviation. In contrast to the situation in most antagonist muscle pairs, Renshaw cells innervated by the motor neurons of each muscle inhibit the motoneurons, but not Ia inhibitory interneurons, of the opposite motor pool. Here we compared gain regulation of spinal circuits projecting to FCR motoneurons during two tasks: flexion and radial deviation of the wrist. We also investigated the functional consequences of this organisation for maximal voluntary contractions (MVCs). Electromyographic (EMG) recordings were taken from FCR, ECR longus and ECR brevis using fine-wire electrodes and electrical stimulation was delivered to the median and radial nerves. Ten volunteers participated in three experiments. 1. To study the regulation of the Renshaw cell-mediated, inhibitory pathway from ECR to FCR motoneurons, forty stimuli were delivered to the radial nerve at 50% of the maximal M-wave amplitude for ECR brevis. Stimuli were delivered during both isometric wrist flexions and radial deviation actions with an equivalent EMG amplitude in FCR (approximately 5% wrist flexion MVC). 2. To explore the homonymous Ia afferent pathway to FCR motoneurons, 50 stimuli were delivered to the median nerve at intensities ranging from below motor threshold to at least two times that which evoked a maximal M-wave during wrist flexion and radial deviation (matched FCR EMG at approximately 5% wrist flexion MVC). 3. EMG amplitude was measured during MVCs in wrist flexion, extension and radial deviation. There was no significant difference in the inhibition of FCR EMG induced via ECR-coupled Renshaw cells between radial deviation and wrist flexion. However, the mean FCR H-reflex amplitude was significantly (P<0.05) greater during wrist flexion than radial deviation. Furthermore, EMG amplitude in FCR and ECR brevis was
Halperin, Israel; Aboodarda, Saied Jalal; Button, Duane C.; Andersen, Lars L.
Background: Limited dorsiflexion range of motion (ROM) has been linked to lower limb injuries. Improving limited ankle ROM may decrease injury rates. Static stretching (SS) is ubiquitously used to improve ROM but can lead to decreases in force and power if performed prior to the activity. Thus, alternatives to improve ROM without performance decrements are needed. Objectives/Purpose: To compare the effects of SS and self massage (SM) with a roller massage of the calf muscles on ankle ROM, maximal voluntary contraction (MVC) force F100 (force produced in the first 100 ms of the MVC), electromyography (EMG of soleus and tibialis anterior) characteristics of the plantar flexors, and a single limb balance test. Methods: Fourteen recreationally trained subjects were tested on two separate occasions in a randomized cross‐over design. After a warm up, subjects were assessed for passive dorsiflexion ROM, MVC, and a single‐limb balance test with eyes closed. The same three measurements were repeated after 10 minutes (min) of rest and prior to the interventions. Following the pre‐test, participants randomly performed either SS or SM for 3 sets of 30 seconds (s) with 10s of rest between each set. At one and 10 min post‐interventions the participants repeated the three measurements, for a third and fourth cycle of testing. Results: Roller massage increased and SS decreased maximal force output during the post‐test measurements, with a significant difference occurring between the two interventions at 10 min post‐test (p < 0.05, ES = 1.23, 8.2% difference). Both roller massage (p < 0.05, ES = 0.26, ~4%) and SS (p < 0.05, ES = 0.27, ~5.2%) increased ROM immediately and 10 min after the interventions. No significant effects were found for balance or EMG measures. Conclusions: Both interventions improved ankle ROM, but only the self‐massage with a roller massager led to small improvements in MVC force relative to SS at 10 min post‐intervention. These results
Musalem, Lindsay L; Stankovic, Tatjana; Glisic, Drazen; Cook, Gillian E; Beach, Tyson A
The objective of this study was to investigate why holding times on 2 different tests of isometric trunk flexor endurance capacity (prone plank and v-sit) are weakly correlated. Body position and ground reaction force data from 10 men and 10 women were used to conduct static biomechanical analyses of both test postures, and bilateral activations of the rectus abdominis, internal and external obliques, latissimus dorsi, and lumbar and thoracic erector spinae were measured in a second sample of 15 men and 15 women while holding the test postures. No between-posture differences in net low back flexor moments were found (P = .111), but the lumbar spine was 28° more flexed in the v-sit than in the plank (P < .001). No between-posture differences were detected in the rectus abdominis (P = .397), external obliques (P = .204), internal obliques (P = .226), or lumbar erector spinae (P = .116) activation levels, but those of the thoracic erector spinae (P = .0253) and latissimus dorsi (P < .001) were greater in the plank than in the v-sit. Altogether, the findings suggest that differences between plank and v-sit holding times are most likely related to between-test differences in lumbar spine postures and shoulder demands.
Hennecke, Kathleen; Redeker, Joern; Kuhbier, Joern W.; Strauss, Sarah; Allmeling, Christina; Kasper, Cornelia; Reimers, Kerstin; Vogt, Peter M.
Repair success for injuries to the flexor tendon in the hand is often limited by the in vivo behaviour of the suture used for repair. Common problems associated with the choice of suture material include increased risk of infection, foreign body reactions, and inappropriate mechanical responses, particularly decreases in mechanical properties over time. Improved suture materials are therefore needed. As high-performance materials with excellent tensile strength, spider silk fibres are an extremely promising candidate for use in surgical sutures. However, the mechanical behaviour of sutures comprised of individual silk fibres braided together has not been thoroughly investigated. In the present study, we characterise the maximum tensile strength, stress, strain, elastic modulus, and fatigue response of silk sutures produced using different braiding methods to investigate the influence of braiding on the tensile properties of the sutures. The mechanical properties of conventional surgical sutures are also characterised to assess whether silk offers any advantages over conventional suture materials. The results demonstrate that braiding single spider silk fibres together produces strong sutures with excellent fatigue behaviour; the braided silk sutures exhibited tensile strengths comparable to those of conventional sutures and no loss of strength over 1000 fatigue cycles. In addition, the braiding technique had a significant influence on the tensile properties of the braided silk sutures. These results suggest that braided spider silk could be suitable for use as sutures in flexor tendon repair, providing similar tensile behaviour and improved fatigue properties compared with conventional suture materials. PMID:23613793
Vieira, Amilton; Siqueira, Angelina F.; Ferreira-Junior, João B.; Pereira, Paulo; Wagner, Dale; Bottaro, Martim
ABSTRACT Background Different ultrasound parameters have been frequently used to assess changes associated with training, aging, immobilization, and neuromuscular diseases. However, an exploratory reliability analysis of the echo intensity (EI) and muscle thickness (MT) of the forearm flexors is scarce, especially in women. Objective The purpose of the present study was to determine the intra-rater reliability of MT and EI assessed by ultrasound in young women. Method Ultrasonographic MT and EI were acquired in the forearm flexors of 41 young women (22±2 yrs). Reliability was calculated using intraclass correlation coefficient (ICC2,1), standard error of measurement (SEM), coefficient of variation (CV), smallest detectable change (SDC), and Bland and Altman plot analysis. Results ICC values for MT and EI were 0.88 (95% CI: 0.78-0.93). The SEM and CV values were lower than 10%. Bland and Altman analysis revealed that ultrasound mean differences were 0.27 mm (Limits of Agreement - LOA 95%: - 2.6 to 3.2 mm) and -0.09 a.u. (LOA 95%: - 10.9 to 10.7 a.u.). Conclusion MT and EI assessed by ultrasonography in young women appear to be reliable and may be used to monitor changes in muscle mass induced by strength training when these changes exceed the precision of ultrasound. PMID:27683836
Lenschow, Constanze; Cazalets, Jean-René; Bertrand, Sandrine S.
Activity-dependent synaptic plasticity (ADSP) is paramount to synaptic processing and maturation. However, identifying the ADSP capabilities of the numerous synapses converging onto spinal motoneurons (MNs) remain elusive. Using spinal cord slices from mice at two developmental stages, 1–4 and 8–12 postnatal days (P1–P4; P8–P12), we found that high-frequency stimulation of presumed reticulospinal neuron axons in the ventrolateral funiculus (VLF) induced either an NMDA receptor-dependent-long-term depression (LTD), a short-term depression (STD) or no synaptic modulation in limb MNs. Our study shows that P1–P4 cervical MNs expressed the same plasticity profiles as P8–P12 lumbar MNs rather than P1–P4 lumbar MNs indicating that ADSP expression at VLF-MN synapses is linked to the rostrocaudal development of spinal motor circuitry. Interestingly, we observed that the ADSP expressed at VLF-MN was related to the functional flexor or extensor MN subtype. Moreover, heterosynaptic plasticity was triggered in MNs by VLF axon tetanisation at neighbouring synapses not directly involved in the plasticity induction. ADSP at VLF-MN synapses specify differential integrative synaptic processing by flexor and extensor MNs and could contribute to the maturation of spinal motor circuits and developmental acquisition of weight-bearing locomotion. PMID:27329279
Iqbal, Zaheen Ahmed; Rajan, Reena; Khan, Sohrab Ahmed; Alghadir, Ahmad H.
[Purpose] The job of secondary school teachers involves a lot of head down posture as frequent reading, assignment correction, computer use and writing on a board put them at risk of developing occupational related neck pain. Available studies of neck pain experienced by teachers are limited. The purpose of this study was to determine whether training of deep cervical flexor muscles with pressure biofeedback has any significant advantage over conventional training for pain and disability experienced by school teachers with neck pain. [Subjects] Thirty teachers aged 25–45 years with neck pain and poor craniocervical flexion test participated in this study. [Methods] A pretest posttest experimental group design was used in which experimental group has received training with pressure biofeedback and conventional exercises while control group received conventional exercises only. Measurements of dependent variables were taken at baseline, and after 2 and 4 weeks of training. Pain intensity was assessed using a numeric pain rating scale and functional disability was assessed using the neck disability index. [Results] The data analysis revealed that there was significant improvement in pain and disability in both the groups and the results were better in the experimental group. [Conclusion] Addition of pressure biofeedback for deep cervical flexor muscles training gave a better result than conventional exercises alone. Feedback helps motor learning which is the set of processes associated with practice or experience leading to permanent changes in ability to respond. PMID:24259822
Jordana, M; Cornillie, P; Oosterlinck, M; Simoens, P; Pille, F; Martens, A
During endoscopy (tenoscopy) of the distal aspect of the equine digital flexor tendon sheath (DFTS), the digital manica flexoria can be visualized connecting the distal branches of the superficial digital flexor tendon. However, this structure has been inconsistently described and variably named in the veterinary literature. The objectives of this study were to describe the presence, configuration and variability of the digital manica flexoria in the equine distal limb. Dissection of 144 equine cadaveric limbs revealed the presence of this structure in all the feet, although different types and conformations were identified. In the forelimbs, a membranous digital manica flexoria predominated (94%; P < 0.001), in particular a synovial bridge type (83%; P < 0.001). In the hindlimbs, a tendinous digital manica flexoria predominated (93%; P < 0.001), in particular the oblique-crossing of tendinous bundles (61%; P < 0.001). Passage dorsal to the digital manica flexoria towards the distal DFTS was only possible in 22 of the 144 limbs, all forelimbs. Clinicians should be aware of the intra- and inter-individual anatomical variations of the digital manica flexoria to avoid misinterpretation during ultrasonographic and tenoscopic examinations of the DFTS.
Gomes Júnior, Nelson Pelozo; Andreoli, Carlos Vicente; Pochini, Alberto de Castro; Raduan, Fernando Cipolini; Ejnisman, Benno; Cohen, Moisés
The presence of accessory tendons in the foot and ankle needs to be recognized, given that depending on their location, they may cause disorders relating either to pain processes or to handling of the surgical findings. We describe the presence of an accessory flexor tendon of the toes, seen in surgical exposure for transferring the long flexor tendon of the hallux to the calcaneus, due to the presence of a disorder of tendinopathy of the insertion of the calcaneal tendon in association with Haglund's syndrome. PMID:26962495
Demirseren, Mustafa Erol; Afandiyev, Kamran; Durgun, Mustafa; Kilicarslan, Kasim; Yorubulut, Mehmet
In this paper, we report a case of a 14-year-old girl with congenital aplasia of the flexor pollicis longus tendon who had no other associated anomalies of thumb hypoplasia and no trauma history. Flexor pollicis longus tendon anomalies are rare; several types of this congenital anomaly have been reported in the literature. The diagnosis should be considered if a patient is unable to flex the interphalangeal joint of the thumb. A hypoplastic thumb or an absent interphalangeal joint crease may be a diagnostic feature in such cases. Besides physical examination, we also used direct radiography and magnetic resonance imaging to diagnose this rare congenital anomaly in our patient.
Gomes Júnior, Nelson Pelozo; Andreoli, Carlos Vicente; Pochini, Alberto de Castro; Raduan, Fernando Cipolini; Ejnisman, Benno; Cohen, Moisés
The presence of accessory tendons in the foot and ankle needs to be recognized, given that depending on their location, they may cause disorders relating either to pain processes or to handling of the surgical findings. We describe the presence of an accessory flexor tendon of the toes, seen in surgical exposure for transferring the long flexor tendon of the hallux to the calcaneus, due to the presence of a disorder of tendinopathy of the insertion of the calcaneal tendon in association with Haglund's syndrome.
Netscher, D; Mosharrafa, A; Lee, M; Polsen, C; Choi, H; Steadman, A K; Thornby, J
A three-part study is described that examines postoperative weakness after open carpal tunnel release and investigates the role of the transverse carpal ligament in the digital flexor pulley system. The effect of this ligament on flexor tendon excursion is evaluated in a cadaver study. Magnetic resonance imaging analysis is used to determine whether division of the transverse carpal ligament promotes volar migration of the median nerve and flexor tendons. Finally, the effects of ligament division and various methods of transverse carpal ligament reconstruction on the return of grip and pinch strengths after open carpal tunnel release are evaluated. The authors were able to determine that transverse carpal ligament reconstruction, particularly the transposition flap repair technique, after open carpal tunnel release confers a mechanical advantage and that the transverse carpal ligament is an important pulley for flexor tendon excursion. Based on the magnetic resonance imaging studies, volar displacement of carpal contents is reduced in patients undergoing transverse carpal ligament reconstruction by means of a transposition flap compared with those undergoing no ligament reconstruction and those undergoing reconstruction using the palmar aponeurosis. Postoperative grip and pinch strength values for the transposition flap repair group surpassed those of the other two groups at 12 weeks.
Kobayashi, Y; Ueyasu, Y; Yamashita, Y; Akagi, R
This study aimed to investigate the effect of a 4-week explosive-type strength training program for the plantar flexors on the rate of torque development and postural stability. The participants were 56 elderly men and women divided into training (17 men and 15 women) and control (14 men and 10 women) groups. The participants in the training group underwent explosive-type strength training of the plantar flexors 2 days per week for 4 weeks. Training consisted of 3 sets of 10 repetitions of explosive plantar flexion lasting less than 1 s. The following parameters were determined: muscle volume of the plantar flexors estimated by the muscle thickness and lower leg length, maximal voluntary contraction torque and rate of torque development of plantar flexion, and one-leg standing ability. The training increased the maximal voluntary contraction torque and rate of torque development, but corresponding increases in muscle volume and one-leg standing ability were not found. These results suggest that, for elderly individuals, the 4-week explosive-type strength training of the plantar flexors is effective for increasing the maximal voluntary contraction torque and rate of torque development of plantar flexion but is not effective for improving postural stability.
Arellano, Christopher J; Caha, David; Hennessey, Joseph E; Amiridis, Ioannis G; Baudry, Stéphane; Enoka, Roger M
The purpose of this study was to determine the adjustments in the level of coactivation during a steadiness task performed by young and old adults after the torque-generating capacity of the antagonist muscles was reduced by a fatiguing contraction. Torque steadiness (coefficient of variation) and electromyographic activity of the extensor and flexor carpi radialis muscles were measured as participants matched a wrist extensor target torque (10% maximum) before and after sustaining an isometric contraction (30% maximum) with wrist flexors to task failure. Time to failure was similar (P = 0.631) for young (417 ± 121 s) and old (452 ± 174 s) adults. The reduction in maximal voluntary contraction torque (%initial) for the wrist flexors after the fatiguing contraction was greater (P = 0.006) for young (32.5 ± 13.7%) than old (21.8 ± 6.6%) adults. Moreover, maximal voluntary contraction torque for the wrist extensors declined for old (-13.7 ± 12.7%; P = 0.030), but not young (-5.4 ± 13.8%; P = 0.167), adults. Torque steadiness during the matching task with the wrist extensors was similar before and after the fatiguing contraction for both groups, but the level of coactivation increased after the fatiguing contraction for old (P = 0.049) but not young (P = 0.137) adults and was twice the amplitude for old adults (P = 0.002). These data reveal that old adults are able to adjust the amount of antagonist muscle activity independent of the agonist muscle during steady submaximal contractions.
Messina, A; Messina, J C
The direct midlateral approach and the lateral enlarging procedure of the pulley system have been utilized in our service since 1972. The incision runs directly behind the neurovascular pedicle, which is left in the palmar skin flap of the anterior compartment of the finger, in order to ensure its blood supply and sensibility. The transverse digital lamina of Landsmeer's skin anchoring system and Cleland's ligament are preserved and are used to perform a lateral enlargement of the pulleys after tendon repair. The technique allows wide surgical exposure of the digital fibro-osseous tunnel, enlargement and reconstruction of the pulley system and tendon sheath, flexor tendon repair (using the technique of choice) and reduces postoperative impingement in zone 2.
Sofos, Stratos S; Riaz, Muhammad
Purpose. We present an extremely rare anatomical variation of unilateral flexor carpi radialis (FCR) absence. This rare anatomical variation posed a clinical dilemma to us and we highlight the importance of the surgeon being aware of this anatomical variation of an important structure both as a reconstruction tool and as an anatomical landmark. Methods. This anatomical variation of the unilaterally absent FCR was found upon dissection during a carpometacarpal arthroplasty of the thumb. Results. Upon the discovery of an absent FCR tendon, we proceeded with a simple trapeziectomy. Conclusions. We present an extremely rare anatomical variation of unilateral FCR absence. This rare anatomical variation may pose clinical dilemmas to the operating surgeon who aims to utilise the FCR either for tendon transfer, for tendon graft, or, as seen in our case, in the reconstruction of a carpometacarpal excision at the thumb. We highlight this diagnosis of suspicion, which may influence the clinical procedure.
Jun, Ilsub; Kim, Kyoung
[Purpose] The purpose of the present study was to examine the amount of change in the thicknesses of the deep cervical flexor (DCF) and sternocleidomastoid (SCM) muscles in subjects with neck pain and subjects without neck pain during craniocervical flexion exercise (CCFE). [Subjects] The total number of subjects was 40, comprising 20 in the no-pain group (males 11, females 9) and 20 in the pain group (males 8, females 12). [Methods] Muscle images were obtained using ultrasound, and the thicknesses of the individual muscles were measured using the NIH ImageJ software. [Results] During CCFE, as pressure increased, the no-pain group recruited the DCF more than the pain group, while the pain group recruited the SCM more. [Conclusion] Selective DCF contraction exercises are considered very useful in the treatment of patients with neck pain.
Nayak, Satheesha B; Shetty, Prakashchandra; Maloor, Prasad A; Dsouza, Melanie R
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
Lui, Tun Hing
Loose bodies of the posterior ankle can occur either at the posterior recess of the ankle or subtalar joint or at the posterior ankle extra-articular space. Loose bodies at the extra-articular space can be a result of tenosynovial chondromatosis of the tendons of the posterior ankle, especially the flexor hallucis longus tendon. Endoscopic removal of loose bodies of the posterior ankle extra-articular space is indicated for symptomatic cases that are not improved by conservative treatment. It is contraindicated if there is active infection at the planned portal sites or the surgeon is not familiar with the technique of posterior ankle endoscopy. Systematic assessment of the different parts of the posterior ankle will minimize the risk of loose body retention.
Wong, Jason; Bennett, William; Ferguson, Mark W J; McGrouther, Duncan A
Mice are currently the species of choice for the in vivo study of injury, but few detailed anatomical descriptions have been made of rodent digits, limiting their use for the investigation of intrasynovial tendon healing. In this study a detailed microscopic and histological investigation was performed using C57/BL6 and Tie2 LacZ reporter gene transgenic mice. Serial-sectioned mouse hindpaw digits were characterized using haematoxylin and eosin, Masson's trichrome (collagen), Alcian blue (fibrocartilage), Miller's stain (elastin) and TRITC-phalloidin (cellular cytoskeleton) staining. Digital vasculature was demonstrated using FITC-labelled dextran perfusion studies supplemented with LacZ expression in Tie2 LacZ transgenic mice digits. Imaging of the digit used a combination of brightfield and confocal microscopy with three-dimensional reconstruction. Our findings demonstrated that the mouse hindpaw possesses deep and superficial flexor tendons within a synovial sheath comparable with that found in other mammalian species. The intrasynovial tendons were avascular and had regions of fibrocartilaginous specialization relating to areas of compression. Corresponding vascular networks were demonstrated around the sheath using Tie2 LacZ mice and FITC-perfused hindpaws. Furthermore, there is an area of digit where both deep and superficial tendons reside between two pulleys, similar to zone 2 in the human hand where it would be possible to study intrasynovial tendon injury and adhesion formation. In conclusion, although the dimensions of the mouse digit pose technical challenges for surgical intervention, we have identified a model for the study of flexor tendon injury that will permit future genetic manipulation studies. PMID:17005025
TAKAHASHI, Toshiyuki; MUKAI, Kazutaka; OHMURA, Hajime; AIDA, Hiroko; HIRAGA, Atsushi
ABSTRACT The purpose of this study was to create a lower forelimb model of the Thoroughbred horse for measuring the force in the superficial and deep digital flexor tendons (SDFT and DDFT), and the suspensory ligament (SL) during a trot. The mass, centers of gravity, and inertial moments in the metacarpus, pastern, and hoof segments were measured in 4 Thoroughbred horses. The moment arms of the SDFT, DDFT, and SL in the metacarpophalangeal (fetlock) and distal interphalangeal (coffin) joints were measured in 7 Thoroughbred horses. The relationship between the fetlock joint angle and the force in the SL was assessed in 3 limbs of 2 Thoroughbred horses. The forces in the SDFT, DDFT, and SL during a trot were also measured in 7 Thoroughbred horses. The mass of the 3 segments, and the moment arms of the SDFT and DDFT in the fetlock joint of the Thoroughbred horses were smaller than those of the Warmblood horses, whereas the other values were almost the same in the 2 types. The calculated force in the SDFT with this Thoroughbred model reached a peak (4,615 N) at 39.3% of the stance phase, whereas that in the DDFT reached a peak (5,076 N) at 51.2% of the stance phase. The force in the SL reached a peak (11,957 N) at 49.4% of the stance phase. This lower forelimb model of the Thoroughbred can be applied to studying the effects of different shoe types and change of hoof angle for the flexor tendon and SL forces. PMID:24834009
Butcher, Michael T.; Bertram, John E.A.; Syme, Douglas A.; Hermanson, John W.; Chase, P. Bryant
Abstract The digital flexors of horses must produce high force to support the body weight during running, and a need for these muscles to generate power is likely limited during locomotion over level ground. Measurements of power output from horse muscle fibers close to physiological temperatures, and when cyclic strain is imposed, will help to better understand the in vivo performance of the muscles as power absorbers and generators. Skinned fibers from the deep (DDF) and superficial (SDF) digital flexors, and the soleus (SOL) underwent sinusoidal oscillations in length over a range of frequencies (0.5–16 Hz) and strain amplitudes (0.01–0.06) under maximum activation (pCa 5) at 30°C. Results were analyzed using both workloop and Nyquist plot analyses to determine the ability of the fibers to absorb or generate power and the frequency dependence of those abilities. Power absorption was dominant at most cycling frequencies and strain amplitudes in fibers from all three muscles. However, small amounts of power were generated (0.002–0.05 Wkg−1) at 0.01 strain by all three muscles at relatively slow cycling frequencies: DDF (4–7 Hz), SDF (4–5 Hz) and SOL (0.5–1 Hz). Nyquist analysis, reflecting the influence of cross‐bridge kinetics on power generation, corroborated these results. The similar capacity for power generation by DDF and SDF versus lower for SOL, and the faster frequency at which this power was realized in DDF and SDF fibers, are largely explained by the fast myosin heavy chain isoform content in each muscle. Contractile function of DDF and SDF as power absorbers and generators, respectively, during locomotion may therefore be more dependent on their fiber architectural arrangement than on the physiological properties of their muscle fibers. PMID:25293602
De Groote, F; Van Campen, A; Jonkers, I; De Schutter, J
We assessed and compared sensitivities of dynamic simulations to musculotendon (MT) parameters for gait and dynamometer experiments. Our aim with this comparison was to investigate whether dynamometer experiments could provide information about MT-parameters that are important to reliably study MT-function during gait. This would mean that dynamometer experiments could be used to estimate these parameters. Muscle contribution to the joint torque (MT-torque) rather than relative MT-force primarily affects the resulting gait pattern and torque measured by the dynamometer. In contrast to recent studies, therefore, we assessed the sensitivity of the MT-torque, rather than the sensitivity of the relative MT-force. Based on sensitivity of the MT-torque to a parameter perturbation, MT-parameters of the knee flexors and extensors were classified in three categories: low, medium, and high. For gait, classification was based on the average sensitivity during a gait cycle. For isometric and isokinetic dynamometer experiments, classification was based on the highest sensitivity found in the experiments. The calculated muscle contributions to the knee torque during gait and dynamometer experiments had a high sensitivity to only a limited number of MT-parameters of the knee flexors and extensors, suggesting that not all MT-parameters need to be estimated. In general, the highest sensitivity was found for tendon slack length. However, for some muscles the sensitivity to the optimal fibre length or the maximal isometric muscle force was also high or medium. The classification of the individual MT-parameters for gait and dynamometer experiments was largely similar. We therefore conclude that dynamometer experiments provide information about MT-parameters important to reliably study MT-function during gait, so that subject-specific estimates of MT-parameters could be made based on dynamometer experiments.
Driss, Tarak; Lambertz, Daniel; Rouis, Majdi; Vandewalle, Henry
The importance of maximal voluntary torque (T (MVC)), maximal rate of torque development (MRTD) and musculo-tendinous stiffness of the triceps surae for maximal power output on a cycle ergometre (Pmax) was studied in 21 healthy subjects by studying the relationships between maximal cycling power related to body mass (Pmax BM(-1)) with T (MVC), MRTD and different indices of musculo-tendinous stiffness of the ankle flexor. Pmax BM(-1) was calculated from the data of an all-out force-velocity test on a Monark cycle ergometre. T (MVC) and MRTD were measured on a specific ankle ergometre. Musculo-tendinous stiffness was estimated by means of quick releases at 20, 40, 60 and 80% T (MVC) on the same ankle ergometre. Pmax BM(-1) was significantly and positively correlated with MRTD related to body mass but the positive correlation between Pmax BM(-1) and T (MVC) did not reach the significance level (0.05). Pmax BM(-1) was significantly and positively correlated with the estimation of stiffness at 40% T (MVC) (S(0.4)), but not with stiffness at 20, 60 and 80% T (MVC). The results of the present study suggest that maximal power output during cycling is significantly correlated with the level of musculo-tendinous stiffness which corresponds to torque range around peak torque at optimal pedal rate. However, the low coefficient of determination (r2 = 0.203) between Pmax BM(-1) and S (0.4) BM(-1) suggested that Pmax BM(-1) largely depended on other factors than the musculo-tendinous stiffness of the only plantar flexors.
Trajano, Gabriel S; Seitz, Laurent; Nosaka, Kasunori; Blazevich, Anthony J
The purpose of the present research was to identify the contribution of central vs. peripheral factors to the force loss after passive muscle stretching. Thirteen men randomly performed both a 5-min constant-torque stretch of the plantar flexors on an isokinetic dynamometer and a resting condition on 2 separate days. The triceps surae electromyogram (EMG) was recorded simultaneously with plantar flexor isometric torque. Measures of central drive, including the EMG amplitude normalized to the muscle compound action potential amplitude (EMG/M), percent voluntary activation and first volitional wave amplitude, and measures of peripheral function, including the twitch peak torque, 20-to-80-Hz tetanic torque ratio and torque during 20-Hz stimulation preceded by a doublet, were taken before and immediately and 15 min after each condition. Peak torque (-15.7%), EMG/M (-8.2%), and both twitch (-9.4%) and 20-Hz peak torques (-11.5%) were reduced immediately after stretch but recovered by 15 min. There were strong correlations between the torque loss and the reductions in central drive parameters (r = 0.65-0.93). Torque recovery was also strongly correlated with the recovery in EMG/M and percent voluntary activation (r = 0.77-0.81). The moderate decreases in measures of peripheral function were not related to the torque loss or recovery. These results suggest that 1) central factors were strongly related to the torque reduction immediately after stretch and during torque recovery; and 2) the muscle's contractile capacity was moderately reduced, although these changes were not associated with the torque reduction, and changes in excitation-contraction coupling efficiency were not observed.
Zijdewind, Inge; Butler, Jane E; Gandevia, Simon C; Taylor, Janet L
During strong voluntary contractions, activity is not restricted to the target muscles. Other muscles, including contralateral muscles, often contract. We used transcranial magnetic stimulation (TMS) to analyse the origin of these unintended contralateral contractions (termed "associated" contractions). Subjects (n = 9) performed maximal voluntary contractions (MVCs) with their right elbow-flexor muscles followed by submaximal contractions with their left elbow flexors. Electromyographic activity (EMG) during the submaximal contractions was matched to the associated EMG in the left biceps brachii during the right MVC. During contractions, TMS was delivered to the motor cortex of the right or left hemisphere and excitatory motor evoked potentials (MEPs) and inhibitory (silent period) responses recorded from left biceps. Changes at a spinal level were investigated using cervicomedullary stimulation to activate corticospinal paths (n = 5). Stimulation of the right hemisphere produced silent periods of comparable duration in associated and voluntary contractions (218 vs 217 ms, respectively), whereas left hemisphere stimulation caused a depression of EMG but no EMG silence in either contraction. Despite matched EMG, MEPs elicited by right hemisphere stimulation were approximately 1.5-2.5 times larger during associated compared to voluntary contractions (P < 0.005). Similar inhibition of the associated and matched voluntary activity during the silent period suggests that associated activity comes from the contralateral hemisphere and that motor areas in this (right) hemisphere are activated concomitantly with the motor areas in the left hemisphere. Comparison of the MEPs and subcortically evoked potentials implies that cortical excitability was greater in associated contractions than in the matched voluntary efforts.
Duclay, Julien; Pasquet, Benjamin; Martin, Alain; Duchateau, Jacques
This study investigated the influence of the torque produced by plantar flexor muscles on cortical and spinal excitability during lengthening and shortening voluntary contractions. To that purpose, modulations of motor-evoked potential (MEP) and Hoffmann (H) reflex were compared in the soleus (SOL) and medial gastrocnemius (MG) during anisometric submaximal and maximal voluntary contraction (MVC) of the plantar flexor muscles. For the submaximal shortening and lengthening contractions, the target torque was set at 50% of their respective MVC force. The results indicate that the amplitudes of both MEP and H-reflex responses, normalized to the maximal M wave, were significantly (P < 0.05) lower during lengthening compared with shortening submaximal contraction. For these two parameters, the reduction reached, respectively, 22.1 and 31.9% for the SOL and 34.5 and 29.3% for the MG. During MVC, normalized MEP and H reflex of the SOL were both reduced significantly by 19.9% (P < 0.05) and 29.9% (P < 0.001) during lengthening and shortening contraction, respectively, whereas no significant change (P > 0.05) was observed for MG. In addition, the silent period in the ongoing electromyogram (EMG) activity following the MEP was significantly (P < 0.01) briefer during lengthening than shortening contractions but did not differ (P > 0.05) between contraction intensities and muscles. Together, these results indicate that cortical and spinal mechanisms involved in the modulation of muscle activation during shortening and lengthening contractions differ between synergistic muscles according to the torque produced. Data further document previous studies reporting that the specific modulation of muscle activation during lengthening contraction is not torque dependent.
Turner, Tanya S; Tucker, Kylie J; Rogasch, Nigel C; Semmler, John G
The purpose of this study was to examine the effect of exercise-induced damage of the elbow flexor muscles on steady motor performance during isometric, shortening, and lengthening contractions. Ten healthy individuals (age 22+/-4 yr) performed four tasks with the elbow flexor muscles: a maximum voluntary contraction, a one repetition maximum (1 RM), an isometric task at three joint angles (short, intermediate, and long muscle lengths), and a constant-load task during slow (approximately 7 degrees/s) shortening and lengthening contractions. Task performance was quantified as the fluctuations in wrist acceleration (steadiness), and electromyography was obtained from the biceps and triceps brachii muscles at loads of 10, 20, and 40% of 1 RM. Tasks were performed before, immediately after, and 24 h after eccentric exercise that resulted in indicators of muscle damage. Maximum voluntary contraction force and 1-RM load declined by approximately 45% immediately after exercise and remained lower at 24 h ( approximately 30% decrease). Eccentric exercise resulted in reduced steadiness and increased biceps and triceps brachii electromyography for all tasks. For the isometric task, steadiness was impaired at the short compared with the long muscle length immediately after exercise (P<0.01). Furthermore, despite no differences before exercise, there was reduced steadiness for the shortening compared with the lengthening contractions after exercise (P=0.01), and steadiness remained impaired for shortening contractions 24 h later (P=0.01). These findings suggest that there are profound effects for the performance of these types of fine motor tasks when recovering from a bout of eccentric exercise.
Hashish, Rami; Samarawickrame, Sachithra D.; Wang, Man-Ying; Yu, Sean S-Y; Salem, George J.
INTRODUCTION As a measure of both strength and muscle endurance of the plantar flexors, the unilateral heel rise (UHR) test has been suggested as a method to evaluate balance capabilities in older adults. Thus, the purpose of this study was to examine the association between UHR performance with biomechanical measures of balance in seniors. MATERIALS AND METHODS Twenty-two older adults completed two testing sessions. The first visit included UHR performance; the second visit included dynamic and static motion analysis. RESULTS UHR performance was significantly associated with dynamic balance capability as measured by medial-lateral inclination angle during gait. As indicated by an analysis of center of pressure, there were significant associations between UHR performance and measures of static balance. DISCUSSION AND CONCLUSION Balance is influenced by plantar flexor performance as measured by the UHR test. We therefore suggest incorporating the UHR test in analyses of balance in seniors. PMID:25457285
Jiménez-Moreno, Ramón; Wang, Zhong-Ming; Messi, María Laura; Delbono, Osvaldo
The endoplasmic/sarcoplasmic reticulum (ER/SR) plays a crucial role in cytoplasmic signalling in a variety of cells. It is particularly relevant to skeletal muscle fibres, where this organelle constitutes the main Ca2+ store for essential functions, such as contraction. In this work, we expressed the cameleon biosensor D1ER by in vivo electroporation in the mouse flexor digitorum brevis (FDB) muscle to directly assess SR Ca2+ depletion in response to electrical and pharmacological stimulation. The main conclusions are: (1) D1ER is expressed in the SR of FDB fibres according to both di-8-(amino naphthyl ethenyl pyridinium) staining experiments and reductions in the Förster resonance energy transfer signal consequent to SR Ca2+ release; (2) the amplitude of D1ER citrine/cyan fluorescent protein (CFP) ratio evoked by either 4-chloro-m-cresol (4-CmC) or electrical stimulation is directly proportional to the basal citrine/CFP ratio, which indicates that SR Ca2+ modulates ryanodine-receptor-isoform-1-mediated SR Ca2+ release in the intact muscle fibre; (3) SR Ca2+ release, measured as D1ER citrine/CFP signal, is voltage-dependent and follows a Boltzmann function; and (4) average SR Ca2+ depletion is 20% in response to 4-CmC and 6.4% in response to prolonged sarcolemmal depolarization. These results indicate that significantly depleting SR Ca2+ content under physiological conditions is difficult.
Le Floch-Prigent, P
The action of the iliopsoas muscle (Musculus iliopsoas) on movements of the hip is studied by direct traction on fresh cadavers (10 still-born and 10 adults). The psoas muscle is a powerful flexor of the hip but also an external rotator. The action of external rotation is moderate but obvious in every position of the femur (Os femoris) and more important if previously in abduction and internal rotation.
Chang, Song Ho; Naito, Masashi
This report presents a case of stenosing tenosynovitis of the flexor hallucis longus tendon associated with the plantar capsular accessory ossicle at the interphalangeal joint of the great toe, which was confirmed by intraoperative observation and was successfully treated with surgical resection of the ossicle. As the plantar capsular accessory ossicle was not visible radiographically due to the lack of ossification, ultrasonography was helpful for diagnosing this disorder. PMID:28255483
The ratio of change in muscle thickness between superficial and deep cervical flexor muscles during the craniocervical flexion test and a suggestion regarding clinical treatment of patients with musculoskeletal neck pain.
Goo, Miran; Kim, Seong-Gil; Jun, Deokhoon
[Purpose] The purpose of this study was to identify the imbalance of muscle recruitment in cervical flexor muscles during the craniocervical flexion test by using ultrasonography and to propose the optimal level of pressure in clinical craniocervical flexion exercise for people with neck pain. [Subjects and Methods] A total of 18 students (9 males and 9 females) with neck pain at D University in Gyeongsangbuk-do, South Korea, participated in this study. The change in muscle thickness in superficial and deep cervical flexor muscles during the craniocervical flexion test was measured using ultrasonography. The ratio of muscle thickness changes between superficial and deep muscles during the test were obtained to interpret the imbalance of muscle recruitment in cervical flexor muscles. [Results] The muscle thickness ratio of the sternocleidomastoid muscle/deep cervical flexor muscles according to the incremental pressure showed significant differences between 22 mmHg and 24 mmHg, between 24 mmHg and 28 mmHg, between 24 mmHg and 30 mmHg, and between 26 mmHg and 28 mmHg. [Conclusion] Ultrasonography can be applied for examination of cervical flexor muscles in clinical environment, and practical suggestion for intervention exercise of craniocervical flexors can be expected on the pressure level between 24 mmHg and 26 mmHg enabling the smallest activation of the sternocleidomastoid muscle.
Mao, Haijiao; Shi, Zengyuan; Xu, Dachuan; Liu, Zhenxin
Neglected Achilles Tendon Ruptures are commonly seen by orthopaedic surgeons. In cases resistant to conservative treatment, a variety of surgical procedures have been utilized in the past. The senior -surgeon at our institution has utilized a technique -employing two turndown fascia flaps fashioned from the proximal Achilles tendon augmented by a tenomyodesis of the flexor hallucis longus and plantaris tendon. The purpose of this study was to assess the clinical outcome of all patients who underwent this procedure. The medical records of 10 cases that underwent this procedure were retrospectively reviewed. We completed data collection sets using the American Orthopaedic Foot and Ankle Society ankle-hind foot scores, isokinetic evaluation, and postoperative magnetic resonance imaging (MRI) at 1 year of follow-up. The mean American Orthopaedic Foot and Ankle Society ankle-hind foot scores improved from 64.4±3.54. Isokinetic testing at 30º/sec and 120º/sec revealed an mean deficits of 24.5%, respectively, in the plantar flexion peak torque of the involved ankle than non-involved ankle. The flexor hallucis longus tendon, gastrocnemius fascia flap and plantaris were well -integrated into the Achilles tendon forming a homogenous tendon, which was confirmed in MRI. Our subjective and objective data indicate that the reconstructive technique using flexor hallucis longus transfer with two turndown gastrocnemius fascia flaps and plantaris tendon is a good option for repairing large gap defect of Achilles tendon.
Crevier-Denoix, N; Ravary-Plumioën, B; Vergari, C; Camus, M; Holden-Douilly, L; Falala, S; Jerbi, H; Desquilbet, L; Chateau, H; Denoix, J-M; Pourcelot, P
The incidence of superficial digital flexor tendon (SDFT) injuries is one of the highest of all equine musculoskeletal conditions. Horses with SDFT injuries commonly show no improvement of lameness on soft ground, unlike those suffering from distal bone or joint lesions. The aim of this study was to compare the SDFT loading in five horses at the walk and trot on asphalt and sand using a non-invasive ultrasonic tendon force measurement device. Three horses were equipped with the ultrasonic device, whereas the other two horses were equipped with the ultrasonic device and a dynamometric horseshoe (DHS); the DHS was used to calibrate the measured values of tendon speed of sound (SOS) converted to tendon force, while a previously established ground reaction force pattern was used to calibrate SOS measurements for the other three horses. Although the horses tended to be slower on S, maximal tendon force was higher on sand than on asphalt at the trot (+6%); there was no significant difference between the two surfaces at the walk. The duration of tendon loading was longer on S (+5%) and the area under the tendon force-time curve was larger on S (+10%) at both walk and trot. SDFT loading is significantly affected by the ground surface and the observed increase in SDFT loading on sand compared with asphalt is consistent with clinical observations in horses with SDFT injuries.
Romero Nakagaki, Wilson; Rosa Pimentel, Edson; Pereira Benevides, Gustavo; Gomes, Laurecir
The aim of this study was to evaluate if spontaneous (nonforced active) exercise and age (maturation process) alter the biomechanical and biochemical properties of superficial digital flexor tendon. Chickens aged 1, 5, and 8 months were divided into two groups: caged and penned. The caged group was reared in an area of 0.5 m(2) (3 animals/cage), while the penned group was reared in an area of 60 m(2) (3 animals/area). For biochemical analysis, the tendon was divided into tensile and compressive regions for quantification of hydroxyproline and glycosaminoglycan content. Biomechanical properties were analyzed from tensile tests of intact tendons. The biomechanical measurements were taken at maximum load and maximum stress. In both the caged and penned groups, maximum load and energy absorption increased with maturation; however, the elastic modulus, maximum stress, and maximum strain did not increase with maturation. Exercise resulted in a higher load, stress, and elastic modulus in the fifth month. Collagen content increased with age in the penned group and with exercise in the fifth and eighth months. Exercise results in a higher expression of glycosaminoglycans in young tendons compared to mature tendons. Thus, low-intensity mechanical stimuli promote the synthesis and possible rearrangement of molecules in immature tendons, whereas inactivity leads to deleterious effects on the material properties (maximum stress and elastic modulus) during growth and maturation.
Farris, Dominic James; Lichtwark, Glen A; Brown, Nicholas A T; Cresswell, Andrew G
Humans utilise elastic tendons of lower limb muscles to store and return energy during walking, running and jumping. Anuran and insect species use skeletal structures and/or dynamics in conjunction with similarly compliant structures to amplify muscle power output during jumping. We sought to examine whether human jumpers use similar mechanisms to aid elastic energy usage in the plantar flexor muscles during maximal vertical jumping. Ten male athletes performed maximal vertical squat jumps. Three-dimensional motion capture and a musculoskeletal model were used to determine lower limb kinematics that were combined with ground reaction force data in an inverse dynamics analysis. B-mode ultrasound imaging of the lateral gastrocnemius (GAS) and soleus (SOL) muscles was used to measure muscle fascicle lengths and pennation angles during jumping. Our results highlighted that both GAS and SOL utilised stretch and recoil of their series elastic elements (SEEs) in a catapult-like fashion, which likely serves to maximise ankle joint power. The resistance of supporting of body weight allowed initial stretch of both GAS and SOL SEEs. A proximal-to-distal sequence of joint moments and decreasing effective mechanical advantage early in the extension phase of the jumping movement were observed. This facilitated a further stretch of the SEE of the biarticular GAS and delayed recoil of the SOL SEE. However, effective mechanical advantage did not increase late in the jump to aid recoil of elastic tissues.
Beggs, A L; Steinmetz, J E; Patterson, M M
Previous studies have shown flexor nerve response increases produced by classical conditioning procedures in spinal cats when the conditioned stimulus (CS) was delivered to the superficial peroneal nerve and the unconditioned stimulus (US) was delivered to the ankle skin. In this study, these effects were produced when the CS was delivered to the whole tibial nerve or to the medial plantar branch. The finding that response increases followed by extinction effects could be obtained when either the superficial peroneal or the tibial nerve was utilized allowed the assessment of the effects of a differential conditioning paradigm. The responses to CS-US presentations on the superficial peroneal nerve increased, whereas responses to CS presentations on the tibial nerve remained unchanged. However, lack of extinction effects in the superficial peroneal data suggested that stimulation of the tibial nerve potentiated superficial peroneal evoked responses. Furthermore, responses evoked by stimulation of either nerve increased when paired trials were given on the tibial nerve. These data demonstrate that stimulation of the tibial nerve potentiates responses to superficial peroneal nerve stimulation but that superficial peroneal nerve stimulation has no effect on responses to CS presentations to the tibial nerve.
Lu, Tung-Wu; Chien, Hui-Lien; Chang, Ling-Ying; Hsu, Horng-Chaung
The purposes of this study were to test whether an examiner's strength may affect the validity of the knee muscle strength measurements using a hand-held dynamometer (HHD) and whether enhancing the forces applied by an examiner using a resistance-enhanced dynamometer (RED) would improve measurement validity. Twenty-five young male volunteers (mean [±SD] age: 22.5 ± 1.7 years) without a history of injury to the test limb and 6 male and 6 female experienced examiners participated in this study. Maximum resisting forces of the knee flexors and extensors were measured using RED, HHD, and a dynamometer (Kin-Com). For all testing conditions, poor to moderate associations were found between the HHD and Kin-Com, whereas there was a good to excellent relationship between RED and Kin-Com. The systematic variations between RED and Kin-Com were also smaller than those between HHD and Kin-Com. The force values measured by RED were very close to those measured by Kin-Com. An examiner's strength affects the validity of the measurements using HHD. Enhancing the forces applied by the examiner to the tested segment using RED appeared to improve the validity of muscle strength measurements.
Welsh, Claire E; Lewis, Thomas W; Blott, Sarah C; Mellor, Dominic J; Stirk, Anthony J; Parkin, Timothy D H
A retrospective cohort study of distal limb fracture and superficial digital flexor tendon (SDFT) injury in Thoroughbred racehorses was conducted using health records generated by the British Horseracing Authority (BHA) between 2000 and 2010. After excluding records of horses that had both flat and jump racing starts, repeated records were reduced to a single binary record per horse (n = 66,507, 2982 sires), and the heritability of each condition was estimated using residual maximum likelihood (REML) with animal logistic regression models. Similarly, the heritability of each condition was estimated for the flat racing and jump racing populations separately. Bivariate mixed models were used to generate estimates of genetic correlations between SDFT injury and distal limb fracture. The heritability of distal limb fracture ranged from 0.21 to 0.37. The heritability of SDFT injury ranged from 0.31 to 0.34. SDFT injury and distal limb fracture were positively genetically correlated. These findings suggest that reductions in the risk of the conditions studied could be attempted using targeted breeding strategies.
Reardon, R J M; Boden, L A; Mellor, D J; Love, S; Newton, J R; Stirk, A J; Parkin, T D H
The objective of this study was to identify risk factors for superficial digital flexor (SDF) tendinopathy in Thoroughbred horses in steeplechase races in the United Kingdom. Potential risk factors for SDF tendinopathy were studied between 1st January 2001 and 31st December 2009 using a cohort study design with 648 injuries sustained in 102,894 starts. Potential risk factors were screened using univariable logistic regression prior to multivariable model building. In the final multivariable model, 12 statistically significant risk factors were identified. Variables that increased the odds of SDF tendinopathy included firmer going, increased horse age, and racing in the summer compared to other seasons. Variables that decreased the odds included having a higher official rating and the number of starts in the preceding days. Fewer and different risk factors were identified than in an equivalent model of SDF tendinopathy in hurdle racing, highlighting potential differences between these disciplines. Further collection of training and racecourse information would be beneficial and may help to explain further some of the associations identified in this study. The results will facilitate the development of strategies to improve overall safety of horses in UK steeplechase racing.
de Castro, Renato Luiz Bevilacqua; Acras, Sandor Dosa
Objective: The aim of this study was to analyze the results of ACL (anterior cruciate ligament) reconstruction using quadruple flexor tendons as grafts, with ligament fixation in the femur using a rigid guide transverse screw and in the tibia, using a cancellous screw with a fixing washer. Methods: 173 knees (166 from males and seven from females) that had undergone surgery with ACL reconstruction using this technique between December 2002 and February 2007 were evaluated. The mean age was 30 years (from 13 to 56 years), and the mean follow-up time was 30 months (6-55 months). We divided the knees into three groups, which were assessed using the Lysholm scale: Group A with six months of follow-up; Group B with 12 months of follow-up; and Group C with 24 months of follow-up. Results: We evaluated the results, and groups A, B and C received 94, 95 and 95 points respectively on the Lysholm scale. Conclusions: The surgical technique proved to be safe and easy to perform, with good results and a low complication rate. Also, its results were maintained throughout the study period of 24 months. PMID:27027002
Sassu, Paolo; Acland, Robert D; Salgado, Christopher John; Mardini, Samir; Ozyurekoglu, Tuna
Contracture as well as weakness of the flexor hallucis longus (FHL) are possible complications following free fibula flap harvest. Possible causes have been related to fibrotic change of the muscle either due to devascularization or compartment-like syndrome after a tight wound closure. This study elucidates the vascularization and nerve supply of the FHL muscle after fibula flap harvest in a fresh cadaver model.A fibula bone flap was harvested through a lateral approach in 20 fresh limbs. The popliteal artery was isolated and injected with a silicone compound, the muscle isolated, and its neurovascular supply visualized.The distal third and fourth portion of the FHL muscle was always found to be located in a more compressed and deeper compartment. The peroneal artery was entirely filled by the silicone compound in 17 fresh cadaver limbs with at least one branch supplying the distal fourth of the FHL. The posterior tibialis artery was filled in all limbs and an average of 2 branches was found to supply the muscle. In all dissections, the nerve supplying the FHL originated from the tibialis nerve with an average of three branches perforating the muscle.Following fibula harvest, the FHL muscle will maintain vascular supply through the distal portion of the peroneal artery and the posterior tibialis artery. Nerve injury to the FHL muscle is unlikely during flap harvest.
Otayek, Salma; Pierrart, Jérôme; Masmejean, Emmanuel H.
Introduction: The Percutaneous Needle Aponeurotomy (PNA) is a known and validated non-surgical treatment for Dupuytren’s disease with a low rate of complications. Initially described for purely palmar forms, the indications extended to digital adhesions. Numerous surgeons remain hesitant about performing the PNA for digital treatment because of the risk of lesions in the noble structures. In literature, one complication is still rare, even non-existent, i.e. the tendon rupture. Case Presentation: We are reporting here the case of a rupture of the deep common flexor tendon, secondary to a needle aponeurotomy, for a recurring digital form in a 72-year-old woman. We performed surgical treatment by tenodesis of the distal stump and resection of the proximal stump. The result was satisfactory. Conclusion: The purpose of describing this case is to report this rare complication leading to surgical revision. Within our team, we do not recommend performing PNAs for digital cases, and even less so for recurrences. For those who wish to perform the PNA, they need to know some technical artifices that enable these complications to be reduced, albeit not eliminated. PMID:28116281
Pontén, Eva; Lindström, Mona; Kadi, Fawzi
Spastic cerebral palsy can be divided into diagnostic groups by the relative severity of the arm impairment. This study investigates if hemiplegic, tetraplegic or diplegic cerebral palsy (CP) results in different patterns of myosin heavy chain (MyHC) expression in the flexor carpi ulnaris muscle from 17 young patients with CP. Using enzyme-immunohistochemistry and gel electrophoresis techniques we found a higher percentage of fibers expressing fast MyHC IIx (52%) in tetraplegic CP compared to hemiplegic patients (32%), (p<0.05). Tetraplegic CP also resulted in a lower amount of fibers expressing slow MyHC I (18%) compared to hemiplegic CP (40%), (p<0.005). The proportion of muscle fibers containing fetal MyHC was higher in tetraplegic CP compared to other groups, (p<0.005). Taken together theses results indicate that tetraplegic CP is associated with a shift from slow to fast myosins and that regenerative events are more prominent in tetraplegic CP compared with milder brain damage.
Keenan, M A
Spasticity that interferes with upper extremity function is common in adults following stroke, brain injury, or anoxia. During the period of neurologic recovery definitive surgical procedures are avoided. Techniques to temporarily reduce spasticity include the implantation of a MicroPort reservoir and catheter for repeated branchial plexus blocks and phenol nerve blocks, which provide longer lasting relief of noxious muscle tone. Percutaneous blocks of the musculocutaneous and recurrent median nerves and motor point blocks of the pectoralis major, the brachioradialis, and forearm flexor muscles are easily performed at bedside. The motor branch of the ulnar nerve can be injected surgically with phenol to diminish intrinsic spasticity. When neurologic recovery has plateaued, hand placement can be improved in many patients following proximal release of the brachioradialis muscle and lengthening of the biceps and branchialis tendons. Hand function is enhanced by fractional lengthening of spastic wrist and finger flexors. Intrinsic spasticity must be addressed at the same time by phenol block or intrinic release. When extensor function is lacking, a tenodesis of the wrist extensors is helpful. The thumb-in-palm deformity requires proximal release of the thenar muscles as well as lengthening of the flexor pollicis longus. Contracture releases in the nonfunctional arm improve hygiene and ease care.
Nie, Mingbo; Chen, Liang; Gu, Yudong
Clinically, injuries of C5-C7 of the brachial plexus cause falling of the wrist and fingers in infants but not in adults unless 4 consecutive spinal nerves are injured. The purpose of this study was to compare the constituent difference of spinal nerves in the radial nerve between pup and adult rats.A group of 16 pup rats and a group of 16 adult rats were each divided into 2 groups of 8 (P1 and A1 groups, C5-C6 were divided; P2 and A2 groups, C5-C7 were divided]). A nerve conduction study and histological examination were performed to evaluate radial nerve innervation to the extensor digitorum communis muscle after dividing the spinal nerves. Retrograde tracing with 5% cholera toxin B for anterior horn motoneurons of the spinal cord innervating the radial nerve was performed in 8 pup rats and 8 adult rats. Results showed that the division of C5-C7 caused more significant damage to radial nerve innervation to the extensor digitorum communis in pups than in adults, although the division of C5-C6 did not. In pups, the percentages (median with interquartile) of anterior horn motoneurons of the spinal cord innervating the radial nerve were 36.4 (28.3-38.5) in C5-C6, 28.1 (24.5-32.5) in C7, and 37.5 (36.5-39.3) in C8-T1. In adults, they were 24.2 (23.6-27.8) in C5-C6, 21.8 (19.5-26.3) in C7, and 50.7 (48.7-55.5) C8-T1.This study implies that C7 innervation in the radial nerve in humans may be more critical to the function of this nerve in infants than in adults.
Bojsen-Møller, Jens; Hansen, Philip; Aagaard, Per; Svantesson, Ulla; Kjaer, Michael; Magnusson, S Peter
The human triceps surae muscle-tendon complex is a unique structure with three separate muscle compartments that merge via their aponeuroses into the Achilles tendon. The mechanical function and properties of these structures during muscular contraction are not well understood. The purpose of the study was to investigate the extent to which differential displacement occurs between the aponeuroses of the medial gastrocnemius (MG) and soleus (Sol) muscles during plantar flexion. Eight subjects (mean +/- SD; age 30 +/- 7 yr, body mass 76.8 +/- 5.5 kg, height 1.83 +/- 0.06 m) performed maximal isometric ramp contractions with the plantar flexor muscles. The experiment was performed in two positions: position 1, in which the knee joint was maximally extended, and position 2, in which the knee joint was maximally flexed (125 degrees ). Plantarflexion moment was assessed with a strain gauge load cell, and the corresponding displacement of the MG and Sol aponeuroses was measured by ultrasonography. Differential shear displacement of the aponeurosis was quantified by subtracting displacement of Sol from that of MG. Maximal plantar flexion moment was 36% greater in position 1 than in position 2 (132 +/- 20 vs. 97 +/- 11 N.m). In position 1, the displacement of the MG aponeurosis at maximal force exceeded that of the Sol (12.6 +/- 1.7 vs. 8.9 +/- 1.5 mm), whereas in position 2 displacement of the Sol was greater than displacement of the MG (9.6 +/- 1.0 vs. 7.9 +/- 1.2 mm). The amount and "direction" of shear between the aponeuroses differed significantly between the two positions across the entire range of contraction, indicating that the Achilles tendon may be exposed to intratendinous shear and stress gradients during human locomotion.
Csapo, R.; Malis, V.; Hodgson, J.
The aim of the present study was to test the hypothesis that the age-associated decrease of tendon stiffness would necessitate greater muscle fascicle strains to produce similar levels of force during isometric contraction. Greater fascicle strains could force sarcomeres to operate in less advantageous regions of their force-length and force-velocity relationships, thus impairing the capacity to generate strong and explosive contractions. To test this hypothesis, sagittal-plane dynamic velocity-encoded phase-contrast magnetic resonance images of the gastrocnemius medialis (GM) muscle and Achilles tendon (AT) were acquired in six young (YW; 26.1 ± 2.3 yr) and six senior (SW; 76.7 ± 8.3 yr) women during submaximal isometric contraction (35% maximum voluntary isometric contraction) of the plantar flexor muscles. Multiple GM fascicle lengths were continuously determined by automatically tracking regions of interest coinciding with the end points of muscle fascicles evenly distributed along the muscle's proximo-distal length. AT stiffness and Young's modulus were measured as the slopes of the tendon's force-elongation and stress-strain curves, respectively. Despite significantly lower AT stiffness at older age (YW: 120.2 ± 52.3 N/mm vs. SW: 53.9 ± 44.4 N/mm, P = 0.040), contraction-induced changes in GM fascicle lengths were similar in both age groups at equal levels of absolute muscular force (4–5% fascicle shortening in both groups), and even significantly larger in YW (YW: 11–12% vs. SW: 6–8% fascicle shortening) at equal percentage of maximum voluntary contraction. These results suggest that factors other than AT stiffness, such as age-associated changes in muscle composition or fascicle slack, might serve as compensatory adaptations, limiting the degree of fascicle strains upon contraction. PMID:24505104
de Souza Leao, Marcos George; Pampolha, Abelardo Gautama Moreira; Orlando Junior, Nilton
Objectives To evaluate knee function in patients undergoing reconstruction of the anterior cruciate ligament (ACL) using the central third of the patellar ligament or the medial flexor tendons of the knee, i.e. quadruple ligaments from the semitendinosus and gracilis (ST-G), by means of the Knee Society Score (KSS) and the Lysholm scale. Methods This was a randomized prospective longitudinal study on 40 patients who underwent arthroscopic ACL reconstruction between September 2013 and August 2014. They comprised 37 males and three females, with ages ranging from 16 to 52 years. The patients were numbered randomly from 1 to 40: the even numbers underwent surgical correction using the ST-G tendons and the odd numbers, using the patellar tendon. Functional evaluations were made using the KSS and Lysholm scale, applied in the evening before the surgical procedure and six months after the operation. Results From the statistical analysis, it could be seen that the patients’ functional capacity was significantly greater after the operation than before the operation. There was strong evidence that the two forms of therapy had similar results (p = >0.05), in all the comparisons. Conclusions The results from the ACL reconstructions were similar with regard to functional recovery of the knee and improvement of quality of life, independent of the type of graft. It was not possible to identify the best method of surgical treatment. The surgeon's clinical and technical experience and the patient are the factors that determine the choice of graft type for use in ACL surgery. PMID:27218084
Kawano, Cezar Teruyuki; de Moraes Barros Fucs, Patrícia Maria; Severino, Nilson Roberto
Pretensioning of the flexor tendon graft of the knee is used to improve the stability of anterior cruciate ligament (ACL) reconstructions. The objective was to demonstrate the pretensioning of grafts of the semitendinosus and gracilis in situ with range of flexion and extension of 0-110°, and determine the appropriate number of cycles in two types of femoral fixation. ACL reconstruction was performed in 60 patients, aged 16-48 years, 90% male, with 50% right knees and 50% left knees, divided into two groups of 30 patients: One with the femur fixed using interference screws (direct form) and the other with the transcondylar cross-pin screw (from a distance). Total length of the grafts, their circumference and the measurements on the radiographs of length of the grafts submitted to pretensioning and the measurements with ten, 25 and 50 cycles of flexion and extension were determined. There was no significant difference in relation to the total tendon lengths and their circumferences. The lengths of the portions submitted to pretensioning were significantly different: 7.90 cm for the interference and 10.92 cm for the transcondylar (mean). After tensioning, in the interference and transcondylar groups, respectively, lengthening was 3.57 mm/3.97 mm with ten, 6.30 mm/7.03 mm with 25, and 6.83 mm/7.7 mm with 50 cycles. The greater the length of the graft, the greater the lengthening on pretensioning throughout the substance; the shorter the length, the earlier the end of the lengthening was achieved, close to 25 cycles; more than ten cycles were necessary, 25 being sufficient.
Marr, C M
Microwave thermographs were recorded from 77 normal horses. In 51% the lowest temperature was recorded in the mid-metacarpal region, and in 41% it was in the distal metacarpal region. The mean temperature of the normal limbs ranged from 25.04 to 37.4 degrees C. Maximum temperature differences between symmetrical points in both forelimbs ranged from 0 to 5.33 degrees C and differences in mean limb temperatures between both forelimbs ranged from 0 to 2.91 degrees C. In 48 horses with acute (less than 4 weeks' duration) injury of the superficial digital flexor tendon (SDFT) (36 unilateral, 12 bilateral) and 12 horses with acute injury of the soft tissues of the palmar metacarpal region other than the SDFT (all unilateral) 66% of forelimbs had acute SDFT injury, and 50% of those with other soft tissue injuries, had elevations of the temperature in the mid- or distal metacarpal region. Abnormal values for mean limb temperature, difference in mean limb temperature and maximum temperature difference between locations in opposite forelimbs were detected in 75% of the horses with SDFT injury and in only 16% of the horses with other soft tissue injury. The sensitivity of microwave thermography for the detection of SDFT injury was 81% and the specificity 74%. When 30 horses in National Hunt training were examined weekly for 5 weeks, 2 horses sustained SDFT injury during that period. The microwave thermographs recorded from these 2 horses, at 1 and 2 weeks before the onset of clinical signs, were abnormal. However, 16 horses which did not develop tendon injury also displayed thermographic abnormalities.
Šambaher, Nemanja; Aboodarda, Saied Jalal; Behm, David George
Exercise-induced fatigue affects muscle performance and modulates corticospinal excitability in non-exercised muscles. The purpose of this study was to investigate the effect of bilateral knee extensor fatigue on dominant elbow flexor (EF) maximal voluntary force production and corticospinal excitability. Transcranial magnetic, transmastoid electrical and brachial plexus electrical stimulation (BPES) were used to investigate corticospinal, spinal, and muscle excitability of the dominant EF before and after a bilateral knee extensor fatiguing protocol or time matched rest period (control). For both sessions three stimuli were delivered every 1.5 s during the three pre-test time points and during the 1st, 3rd, 6th, 9th and 12th post-test 5 s EF isometric maximal voluntary contractions (MVC). In both conditions, overall, EF MVC force (p < 0.001) decreased progressively from repetition #1 to #12 during the post-test MVC protocol. EF MVC force (p < 0.001, ES = 0.9, Δ10.3%) decrements were more pronounced in the knee extensor fatigue intervention condition. In addition, there were no significant differences between conditions for biceps brachii electromyographic (EMG) activity (p = 0.43), motor evoked potentials (MEPs) amplitude (p = 0.908) or MEP silent period (SP; p = 0.776). However, the fatigue condition exhibited a lower MEP/cervicomedullary MEP (CMEP) ratio (p = 0.042, ES = 2.5, Δ25%) and a trend toward higher CMEP values (p = 0.08, ES = 0.5, Δ20.4%). These findings suggest that bilateral knee extensor fatigue can impair performance and modulate corticospinal excitability of the EF. PMID:26869902
Kawashima, Noritaka; Nakazawa, Kimitaka
The purpose of the present study was to investigate how stretch reflex (SR) responses in the ankle extensor (soleus: SOL) and flexor (tibialis anterior: TA) muscles would be modulated with temporal and/or spatial predictions of external perturbations and whether their effects are specific to the standing posture. SR responses in the SOL/TA were elicited by imposing quick ankle toes-up/toes-down rotations while standing upright and in the supine position. We designed four experimental conditions based on pre-information about perturbations: no information (No Cue), the timing of the perturbation onset (TIM), the direction of the perturbation (DIR), and both the timing and direction of the perturbation (TIM/DIR). Each condition was separated and its order was counterbalanced. In the SR of TA evoked by toes-down rotation, integrated electromyography activities of the late component were significantly reduced in the TIM and TIM/DIR conditions as compared with those in the No Cue and DIR conditions. The occurrence rate of late SR components that reflects how often the reflex response was observed was also lower in the TIM and TIM/DIR conditions as compared with that in the No Cue and DIR conditions. On the other hand, no significant changes were seen among the four conditions in the early SR component in the TA and both SR components in the SOL. The same results in the occurrence rate were found in the supine position. The present results suggest (1) only temporal predictions have a remarkable effect on the SR excitability of the TA, and (2) this effect is independent of posture. PMID:27385043
Lapole, Thomas; Ahmaidi, Said; Gaillien, Benjamin; Leprêtre, Pierre-Marie
Dorsiflexion shoes could be useful to increase jumping performance. The aim of the present study was to investigate the impact of wearing shoes inducing moderate dorsiflexion (2°) on neuromuscular fatigue induced by volleyball exercises involving multiple stretch-shortening cycles. Squat jump (SJ) and countermovement jump (CMJ) performance, and plantar flexors isometric voluntary and evoked contractile properties were assessed in 10 unfamiliarized trained volleyball players before and after a 10-minute intensive combined tapping-jumping volleyball exercise performed, in blinded randomized conditions, with neutral (0°) or moderate dorsiflexion (2°). No significant difference was observed on SJ performance in neutral and moderate dorsiflexion conditions. However, CMJ height was initially lower with 2° dorsiflexion compared with 0° (p < 0.05). Height in CMJ was increased after exercise with 2° dorsiflexion shoes and remained unchanged in neutral 0° condition. Combined tapping-jumping volleyball exercise also induced a significant decrease in maximal voluntary contraction (p < 0.001), peak-twitch torque (p = 0.009), contraction time (p < 0.001) and twitch relaxation rate (p = 0.001) values without any significant difference between neutral and dorsiflexion conditions. Voluntary activation level (p = 0.014) and rate of force development (p = 0.05) were also decreased in both conditions. In conclusion, acute moderate dorsiflexion had no effect on jumping performance and neuromuscular fatigue in unfamiliarized trained subjects and altered the elastic energy store in plyometric condition (CMJ). Future studies are necessary to investigate the chronic effect of moderate dorsiflexion on jumping performance and neuromuscular fatigue in trained volleyball players.
Swanstrom, Michael D; Zarucco, Laura; Stover, Susan M; Hubbard, Mont; Hawkins, David A; Driessen, Bernd; Steffey, Eugene P
The superficial (SDF) and deep digital flexor (DDF) muscles are critical for equine forelimb locomotion. Knowledge of their mechanical properties will enhance our understanding of limb biomechanics. Muscle contractile properties derived from architectural-based algorithms may overestimate real forces and underestimate shortening capacity because of simplistic assumptions regarding muscle architecture. Therefore, passive and active (=total - passive) force-length properties of the SDF and DDF muscles were measured directly in vivo. Muscles from the right forelimbs of four Thoroughbred horses were evaluated during general anesthesia. Limbs were fixed to an external frame with the muscle attached to a linear actuator and load cell. Each muscle was stretched from an unloaded state to a range of prefixed lengths, then stimulated while held at that length. The total force did not exceed 4000 N, the limit for the clamping device. The SDF and DDF muscles produced 716+/-192 and 1577+/-203 N maximum active isometric force (F(max)), had ascending force-length ranges (R(asc)) of 5.1+/-0.2 and 9.1+/-0.4 cm, and had passive stiffnesses of 1186+/-104 and 1132+/-51 N/cm, respectively. The values measured for F(max) were much smaller than predicted based on conservative estimates of muscle specific tension and muscle physiological cross-sectional area. R(asc) were much larger than predicted based on muscle fiber length estimates. These data suggest that accurate prediction of the active mechanical behavior of architecturally complex muscles such as the equine DDF and SDF requires more sophisticated algorithms.
Kato, Emika; Vieillevoye, Stéphanie; Balestra, Costantino; Guissard, Nathalie; Duchateau, Jacques
This paper examines the acute effect of a bout of static stretches on torque fluctuation during an isometric torque-matching task that required subjects to sustain isometric contractions as steady as possible with the plantar flexor muscles at four intensities (5, 10, 15, and 20% of maximum) for 20 s. The stretching bout comprised five 60-s passive stretches, separated by 10-s rest. During the torque-matching tasks and muscle stretching, the torque (active and passive) and surface electromyogram (EMG) of the medial gastrocnemius (MG), soleus (Sol), and tibialis anterior (TA) were continuously recorded. Concurrently, changes in muscle architecture (fascicle length and pennation angle) of the MG were monitored by ultrasonography. The results showed that during stretching, passive torque decreased and fascicle length increased gradually. Changes in these two parameters were significantly associated (r(2) = 0.46; P < 0.001). When data from the torque-matching tasks were collapsed across the four torque levels, stretches induced greater torque fluctuation (P < 0.001) and enhanced EMG activity (P < 0.05) in MG and TA muscles with no change in coactivation. Furthermore, stretching maneuvers produced a greater decrease (∼15%; P < 0.001) in fascicle length during the torque-matching tasks and change in torque fluctuation (CV) was positively associated with changes in fascicle length (r(2) = 0.56; P < 0.001), MG and TA EMG activities, and coactivation (r(2) = 0.35, 0.34, and 0.35, respectively; P < 0.001). In conclusion, these observations indicate that repeated stretches can decrease torque steadiness by increasing muscle compliance and EMG activity of muscles around the joint. The relative influence of such adaptations, however, may depend on the torque level during the torque-matching task.
Effect of thoracic manipulation and deep craniocervical flexor training on pain, mobility, strength, and disability of the neck of patients with chronic nonspecific neck pain: a randomized clinical trial
Lee, Kwan-Woo; Kim, Won-Ho
[Purpose] To investigate the effects of thoracic manipulation and deep craniocervical flexor training on the muscle strength and endurance, range of motion, and the disability index of the neck of patients with chronic nonspecific neck pain. [Subjects and Methods] Forty-six patients with chronic neck pain participated. They received an intervention for 35 minutes a day, three times a week for 10 weeks. Subjects were randomly assigned to one control and two experimental groups: group A (thoracic manipulation combined with deep craniocervical flexor training, n=16), group B (deep craniocervical flexor training, n=15), and group C (active self-exercise as a control group, n=15). Muscle strength and endurance, pain, neck disability index, and range of motion of the cervical and thoracic spine were measured before and after the intervention. [Results] Group A showed significant increases in muscle strength, endurance, and cervical and thoracic range of motion, and significant decreases in the pain and neck disability index, compared with groups B and C. [Conclusion] Although deep craniocervical flexor training is effective at improving neck function, thoracic manipulation combined with deep craniocervical flexor training was a more effective intervention for pain relief and improving the range of motion, muscle function, and neck disability of patients with nonspecific chronic neck pain. PMID:26957752
For evaluation of the state of excitability of motoneurons in the dorsal flexor of the foot in patients with drug-induced muscle rigidity curves of excitability of motoneurons in the anterior tibial muscle were plotted in 10 patients not receiving psychotropic agents (controls) and 10 patients treated with chlorpromazine. Two variants of experiment wase used: in the 1st variant stimulation of the peroneal nerve behind the fibular capitulum served as the conditioning and testing stimulus, in the 2nd variant stimulation of the tibial nerve in the popliteal fossa was the conditioning stimulus and stimulation of the peroneal nerve in the above way was the testing stimulus. The investigations were carried out before and 30-50 min after intramuscular injection of ethylbenzatropine 5 mg. In the 1st variant the curve of excitability of the motoneurons of the anterior tibial muscle showed the same configuration as the curve of excitability of motoneurons of the soleus muscle in the control group as well as in the treated group. Similarly as in the excitability curve of the soleus muscle five phases could be differentiated in it. Phase III of depression was, however, deeper and phase IV of returning excitability was more evident. In variant II in phase III depression was observed lasting only 40 msec., then in place of return of excitability its decrease was observed. These results were similar to these obtained in the case of conditioning stimulation of afferent fibres of the anterior tibialis muscle, and testing stimulation of the afferent fibres of the soleus muscle. After ethylbenzatropine injection no changes were found in variant I, on the other hand, in variant II a rise of excitability was present in phase III in the control group and in phases III and IV in treated patients. Ethylbenzatropine seemed, thus, to have no effect on the excitability of motoneurons in the dorsal flexor of the foot in the case of conditioning afferent stimulation of the dorsae flexor of the
Janecki, Damian; Jaskólska, Anna; Marusiak, Jarosław; Jaskólski, Artur
The aim of this study was to assess low-frequency fatigue as a double to single twitch ratio after repeated eccentric exercise of the elbow flexors. Maximal isometric torque, single and double twitch responses and low-frequency fatigue were assessed on the elbow flexors in 16 untrained male volunteers before, immediately after, 24 and 48 hours following two bouts of eccentric exercise consisted of 30 repetitions of lowering a dumbbell adjusted to ~75% of each individual’s maximal isometric torque. Maximal isometric torque and electrically evoked responses decreased significantly in all measurements after the first bout of eccentric exercise (p < 0.05). In measurements performed at 24 and 48 hours after the second bout both maximal voluntary isometric torque and electrically evoked contractions were significantly higher than in measurements performed after the first bout (p < 0.05). Although low-frequency fatigue significantly increased up to 48 hours after each bout of eccentric exercise, its values at 24 and 48 hours after the second bout were significantly lower than at respective time points after the first bout (p < 0.05). Double to single twitch ratio could be used as a sensitive tool in the evaluation of muscle recovery and adaptation to repeated eccentric exercise. Key points First bout of eccentric (ECC) exercise of the elbow flexors muscles induced repeated bout effect that lead to faster recovery of the low-frequency fatigue, the maximal torque of voluntary and electrically evoked contractions, and smaller soreness sensation, when the exercise are repeated 2-3 weeks later. Double (DT) to single twitch (ST) ratio could be used as a sensitive tool in the evaluation of muscle recovery and adaptation to repeated eccentric exercise. The single twitch and DT to ST ratios seem to be more susceptible for minimal force deficits that could occur even after repeated ECC where repeated bout effect should confer the protection after subsequent muscle damage. PMID
Ruediger, Thomas; Alsalaheen, Bara; Bean, Ryan
Background More than one million adolescent athletes participated in organized high school sanctioned football during the 2014-15 season. These athletes are at risk for sustaining concussion. Although cervical spine active range of motion (AROM) and deep neck flexor endurance may serve a preventative role in concussion, and widespread clinical use of measurements of these variables, reference values are not available for this population. Cost effective, clinically relevant methods for measuring neck endurance are also well established for adolescent athletes. Purpose The purpose of this study was to report reference values for deep cervical flexor endurance and cervical AROM in adolescent football players and examine whether differences in these measures exist in high school football players with and without a history of concussion. Methods Concussion history, cervical AROM, and deep neck flexor endurance were measured in 122 high school football players. Reference values were calculated for AROM and endurance measures; association were examined between various descriptive variables and concussion. Results No statistically significant differences were found between athletes with a history of concussion and those without. A modest inverse correlation was seen between body mass and AROM in the sagittal and transverse planes. Conclusion The results of this study indicate that the participants with larger body mass had less cervical AROM in some directions. While cervical AROM and endurance measurements may not be adequate to identify adolescents with a history of previous concussions among high school football players. However, if a concussion is sustained, these measures can offer a baseline to examine whether cervical AROM is affected as compared to healthy adolescents. Level of Evidence 2c PMID:27104049
... rash is a sign of a similar condition, dermatomyositis . Common symptoms include: Muscle weakness in the shoulders ... in the treatment of refractory adult and juvenile dermatomyositis and adult polymyositis: a randomized, placebo-phase trial. ...
Zhou, Zhihao; Sun, Yao; Wang, Ninghua; Gao, Fan; Wei, Kunlin; Wang, Qining
In this paper, we aim to investigate the effect of proprioceptive neuromuscular facilitation (PNF)-based rehabilitation for ankle plantar flexors spasticity by using a Robotic Ankle-foot Rehabilitation System (RARS). A modified robot-assisted system was proposed, and seven poststroke patients with hemiplegic spastic ankles participated in a 3-month robotic PNF training. Their impaired sides were used as the experimental group, while their unimpaired sides as the control group. A robotic intervention for the experimental group started from a 2-min passive stretching to warming-up or relaxing the soleus and gastrocnemius muscles and also ended with the same one. Then a PNF training session including 30 trials was activated between them. The rehabilitation trainings were carried out three times a week as an addition to their regular rehabilitation exercise. Passive range of motion, resistance torque, and stiffness were measured in both ankles before and after the interventions. The changes in Achilles tendon length, walking speed, and lower limb function were also evaluated by the same physician or physiotherapist for each participant. Biomechanical measurements before interventions showed significant difference between the experimental group and the control group due to ankle spasticity. For the control group, there was no significant difference in the 3 months with no robotic intervention. But for the experimental group, passive dorsiflexion range of motion increased (p < 0.01), resistance torque under different dorsiflexion angle levels (0°, 10°, and 20°) decreased (p < 0.05, p < 0.001, and p < 0.001, respectively), and quasi-static stiffness under different dorsiflexion angle levels (0°, 10°, and 20°) also decreased (p < 0.01, p < 0.001, and p < 0.001, respectively). Achilles's tendon length shortened (p < 0.01), while its thickness showed no significant change (p > 0.05). The robotic rehabilitation also improved the
OLAVE, E.; DEL SOL, M.; GABRIELLI, C.; MANDIOLA, E.; RODRIGUES, C. F. S.
During surgical exposure of the carpal tunnel it is possible to injure the neurovascular structures closely related to the flexor retinaculum, such as the superficial palmar arch and the communicating branch between the ulnar and median nerves. Because of the importance of these structures and with the purpose of increasing knowledge of anatomical details concerning to their location, a biometric study was performed on the retinaculum and the communicating branch, and between the communicating branch and the distal wrist crease, as well as between the retinaculum and the superficial palmar arch. We dissected 56 hands from 28 Brazilian formalin-preserved cadavers of both sexes (24 male) at the Federal University of São Paulo–Escola Paulista de Medicina, Brazil. The communicating branch was observed in 96.4% of cases and the superficial palmar arch in 78.6%. The communicating branch was found between the common palmar digital nerve of the 4th interosseous space (from the ulnar nerve) to the homonymous nerve of the 3rd interosseous space (from the median nerve). In males, the distance between the distal wrist crease and the site where the communicating branch originates from the ulnar component had an average of 33.9±5.5 mm on the right side and 30.2±8.2 mm on the left. The distance between the distal wrist crease and the junction of the communicating branch with the common palmar digital nerve of the 3rd interosseous space was 43.6±6.9 mm on the right and 40.2±6.2 mm on the left side. Conversely, in 14.8% of cases (1 female), the communicating branch was observed to emerge from the common palmar digital nerve of the 3rd interosseous space. The distance between the retinaculum and the superficial palmar arch in the axial line of the 4th metacarpal bone was on average 7.3±4.3 mm on the right and 8.3±3.5 mm on the left side. At the same level, the distance between the retinaculum and the communicating branch was 6.2±3.7 mm on the right side and 5.1±2.8 mm on
Zhou, Zhihao; Sun, Yao; Wang, Ninghua; Gao, Fan; Wei, Kunlin; Wang, Qining
In this paper, we aim to investigate the effect of proprioceptive neuromuscular facilitation (PNF)-based rehabilitation for ankle plantar flexors spasticity by using a Robotic Ankle–foot Rehabilitation System (RARS). A modified robot-assisted system was proposed, and seven poststroke patients with hemiplegic spastic ankles participated in a 3-month robotic PNF training. Their impaired sides were used as the experimental group, while their unimpaired sides as the control group. A robotic intervention for the experimental group started from a 2-min passive stretching to warming-up or relaxing the soleus and gastrocnemius muscles and also ended with the same one. Then a PNF training session including 30 trials was activated between them. The rehabilitation trainings were carried out three times a week as an addition to their regular rehabilitation exercise. Passive range of motion, resistance torque, and stiffness were measured in both ankles before and after the interventions. The changes in Achilles tendon length, walking speed, and lower limb function were also evaluated by the same physician or physiotherapist for each participant. Biomechanical measurements before interventions showed significant difference between the experimental group and the control group due to ankle spasticity. For the control group, there was no significant difference in the 3 months with no robotic intervention. But for the experimental group, passive dorsiflexion range of motion increased (p < 0.01), resistance torque under different dorsiflexion angle levels (0°, 10°, and 20°) decreased (p < 0.05, p < 0.001, and p < 0.001, respectively), and quasi-static stiffness under different dorsiflexion angle levels (0°, 10°, and 20°) also decreased (p < 0.01, p < 0.001, and p < 0.001, respectively). Achilles’s tendon length shortened (p < 0.01), while its thickness showed no significant change (p > 0.05). The robotic rehabilitation also improved the
Tresch, Ursina A.; Perreault, Eric J.; Honeycutt, Claire F.
Abstract Little attention has been given to how age affects the neural processing of movement within the brainstem. Since the brainstem plays a critical role in motor control throughout the whole body, having a clear understanding of deficits in brainstem function could provide important insights into movement deficits in older adults. A unique property of the startle reflex is its ability to involuntarily elicit planned movements, a phenomenon referred to as startReact. The noninvasive startReact response has previously been used to probe both brainstem utilization and motor planning. Our objective was to evaluate deficits in startReact hand extension movements in older adults. We hypothesized that startReact hand extension will be intact but delayed. Electromyography was recorded from the sternocleidomastoid (SCM) muscle to detect startle and the extensor digitorum communis (EDC) to quantify movement onset in both young (24 ± 1) and older adults (70 ± 11). Subjects were exposed to a startling loud sound when prepared to extend their hand. Trials were split into those where a startle did (SCM+) and did not (SCM−) occur. We found that startReact was intact but delayed in older adults. SCM+ onset latencies were faster than SCM− trials in both the populations, however, SCM+ onset latencies were slower in older adults compared to young (Δ = 8 msec). We conclude that the observed age‐related delay in the startReact response most likely arises from central processing delays within the brainstem. PMID:24907294
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You, Young Youl; Chung, Sin Ho; Lee, Hyung Jin
[Purpose] This study was to examine the changes in the gait lines and plantar pressures in static and dynamic circumstances, according to the differences in the strengths of the plantar flexors in the ankle joints on the affected sides of hemiplegic patients, and to determine their impacts on walking symmetry. [Subjects and Methods] A total of thirty hospitalized stroke patients suffering from hemiplegia were selected in this study. The subjects had ankylosing patterns in the ankle joints of the affected sides. Fifteen of the patients had plantar flexor manual muscle testing scores between poor and fair, while fifteen of the patients had zero and trace. [Results] The contact pattern of the plantar surface with the ground is a reliable method for walking analysis, which is an important index for understanding the ankle mechanism and the relationship between the plantar surface and the ground. [Conclusion] The functional improvement of patients with stroke could be supported through a verification of the analysis methods of the therapy strategy and walking pattern.
You, Young Youl; Chung, Sin Ho; Lee, Hyung Jin
[Purpose] This study was to examine the changes in the gait lines and plantar pressures in static and dynamic circumstances, according to the differences in the strengths of the plantar flexors in the ankle joints on the affected sides of hemiplegic patients, and to determine their impacts on walking symmetry. [Subjects and Methods] A total of thirty hospitalized stroke patients suffering from hemiplegia were selected in this study. The subjects had ankylosing patterns in the ankle joints of the affected sides. Fifteen of the patients had plantar flexor manual muscle testing scores between poor and fair, while fifteen of the patients had zero and trace. [Results] The contact pattern of the plantar surface with the ground is a reliable method for walking analysis, which is an important index for understanding the ankle mechanism and the relationship between the plantar surface and the ground. [Conclusion] The functional improvement of patients with stroke could be supported through a verification of the analysis methods of the therapy strategy and walking pattern. PMID:27942112
Akagi, Ryota; Takai, Yohei; Kato, Emika; Wakahara, Taku; Ohta, Megumi; Kanehisa, Hiroaki; Fukunaga, Tetsuo; Kawakami, Yasuo
The present study examined the age-related changes in muscle thickness (MT) and volume (MV) of elbow flexors and developed a prediction equation of the MV based on the MT applicable to men and women with a wide range of age. The MT and MV were determined from a single ultrasonographic image and multiple magnetic resonance imaging scans, respectively, in 72 men and 75 women aged 19-77 year. As a result of examining the age-MT and age-MV relationships by calculation of partial correlation coefficients with the control variable of gender, MV was decreased with aging whereas the corresponding decline in MT was not significant. The subjects were randomly separated into either a validation (38 men and 42 women) or a cross-validation (34 men and 33 women) group, and a multiple regression equation to estimate MV using not only MT but also upper arm length (L), age and gender as independent variables [MV (cm(3)) = 60.8 x MT (cm) + 6.48 x L (cm) - 0.709 x age (year) + 51.4 x gender (0 women, 1 men) - 187.4] was validated and cross-validated. Thus, the prediction equation for MV of elbow flexors newly developed was shown to be applicable to men and women with a wide range of age.
Ramesh, R; Kumar, N; Sharma, A K; Maiti, S K; Singh, G R
Sixteen tenorrhaphies were performed at the mid-metatarsal region in eight buffalo calves under lignocaine epidural analgesia. A 2 cm long gap was created in the superficial digital flexor (SDF) tendon and immediately repaired with acellular grafts in animals of group I, 1% glutaraldehyde-preserved tendon allografts in group II. In group III, the defect was repaired with autografts. This group served as control. The contralateral limb in each animal was operated after an interval of 60 days and the animals underwent the same procedure according to the designed groups. Diclofenac sodium and Enrofloxacin was given post-operatively for 5 days. Clinical examination revealed significant increase (P < 0.05) in rectal temperature, heart and respiratory rate for 3-4 postoperative days in all the animals. Mild pain and exudation as well as early restoration of tendon gliding movements and weight-bearing were observed earlier in group I in comparison with group II. Air-tendograms revealed early organization, minimal adhesion formation and lesser thickening of tendon at the reconstructive site in the acellular group whereas in the glutaraldehyde group dense homogenous swelling with adhesions was seen along the flexors. Angiography on day 30 showed that the area of proximal and distal host tendon graft junction appeared hypervascularized, whereas the area occupied by the graft appeared relatively less vascularized. Normal vascularization was observed on day 90 in all the three groups.
Yang, Jin Mo; Cha, Hyun-Gyu; Kim, Myoung-Kwon
[Purpose] This study examined the effects of manipulation of the thorax and the intensity of the pressure biofeedback unit on the superficial cervical flexors muscle during craniocervical flexion exercise. [Subjects and Methods] Thirty three subjects participated in the experiment. Thirty three healthy people without any orthopedic history were also selected. The subjects could monitor the pressure applied to cervical vertebra 3 of the craniocervical junction by markings on the pressure biofeedback unit. Craniocervical flexion exercise was performed for 20 seconds per pressure, and two minutes of rest was allowed after exercise to reduce muscle fatigue. [Results] Significant differences in the post-training gains in the sternocleidomastoid and scalene were observed between the thorax fixation group and thorax non-fixation group. The thorax fixation group showed that muscle activation of the sternocleidomastoid and scalene was increased when the pressure biofeedback unit intensity was 40 mmHg than when pressure biofeedback unit intensity was 20 mmHg and 30 mmHg in the post-hoc result. The thorax non-fixation group showed that muscle activation of the sternocleidomastoid and scalene was higher when the pressure biofeedback unit intensity was 40mmHg compared to that when the pressure biofeedback unit intensity was 20mmHg in the post-hoc result. [Conclusion] Craniocervical flexion exercise is a clinically effective method that reduces the superficial neck flexor muscle activation. PMID:28265158
Rudomin, P; Jiménez, I; Enriquez, M
1. In the chloralose anesthetized cat, conditioning stimulation of group I flexor afferents depresses the monosynaptic potentials generated by Ia afferents in single spinal motoneurons or in populations of motoneurons without affecting the monosynaptic potentials produced by stimulation of descending fibers in the ipsilateral ventromedial fasciculus (VMF). 2. Heterosynaptic facilitation of monosynaptic reflexes was used to test changes in the presynaptic effectiveness of excitatory inputs with direct connections with motoneurons. We found that the heterosynaptic facilitation of Ia origin was reduced by conditioning stimulation of group I afferents from flexors, without affecting the heterosynaptic facilitation produced by stimulation of the VMF. 3. These results confirm and expand previous observations showing that the synaptic effectiveness of descending fibers synapsing with motoneurons is not subjected to a presynaptic control mechanism of the type acting on Ia fiber terminals, and provide further basis for the use of changes in heterosynaptic facilitation of monosynaptic reflexes of Ia origin as an estimate of changes in presynaptic inhibition of Ia fibers (Hultborn et al. 1987a).
Janecki, Damian; Jaskólska, Anna; Marusiak, Jarosław; Jaskólski, Artur
The aim of this study was to assess low-frequency fatigue as a double to single twitch ratio after repeated eccentric exercise of the elbow flexors. Maximal isometric torque, single and double twitch responses and low-frequency fatigue were assessed on the elbow flexors in 16 untrained male volunteers before, immediately after, 24 and 48 hours following two bouts of eccentric exercise consisted of 30 repetitions of lowering a dumbbell adjusted to ~75% of each individual's maximal isometric torque. Maximal isometric torque and electrically evoked responses decreased significantly in all measurements after the first bout of eccentric exercise (p < 0.05). In measurements performed at 24 and 48 hours after the second bout both maximal voluntary isometric torque and electrically evoked contractions were significantly higher than in measurements performed after the first bout (p < 0.05). Although low-frequency fatigue significantly increased up to 48 hours after each bout of eccentric exercise, its values at 24 and 48 hours after the second bout were significantly lower than at respective time points after the first bout (p < 0.05). Double to single twitch ratio could be used as a sensitive tool in the evaluation of muscle recovery and adaptation to repeated eccentric exercise.
Sudoł-Szopińska, Iwona; Zaniewicz-Kaniewska, Katarzyna; Kwiatkowska, Brygida
Summary Background Enthesitis is considered a characteristic presentation of the second most common group of rheumatoid disorders, i.e. spondyloarthropathies (SpAs), particularly peripheral spondyloarthropathies. At the initial stages, enthesitis may be the only symptom of SpA, particularly in patients lacking the HLA-B27 receptor. Material/Methods In light of diagnostic difficulties with detecting enthesitis in clinical examinations and laboratory investigations, many studies point out the high specificity of imaging studies, and particularly ultrasonography. Results A total of 20% Achilles tendon entheses, 45% plantar aponeurosis entheses and 89.5% of flexor digiti brevis tendon entheses were unremarkable. In the remaining cases, the presentation of pathological lesions was not specific to enthesitis and might more likely correspond to degeneration or microinjuries of the entheses, beside the most obvious cases of achillobursitis or Kager’s fat pad inflammation. Conclusions The studies demonstrated that ultrasound scans rarely confirm the clinical diagnosis of enthesitis. PMID:25674194
Powell, Douglas; DeVita, Paul; Hortobagyi, Tibor
This study examined the neuromuscular adaptations of young and old adults in response to a challenge to balance during gait. 12 young (22.2 +/- 2.0 yr.) and 10 old adults (78.8 +/- 6.3 yr.) performed five level walking trials with and without a challenge to balance which consisted of adding a load bilaterally to the participants' ankles and increasing gait speed (1.5 m/sec. and 1.7 m/sec.). Onset, duration, and amplitude of muscle activity in the vastus lateralis, rectus femoris, biceps femoris, and semimembranosus were calculated. Old adults responded to the added load by increasing the activation intensity of their vastus lateralis and semimembranosus disproportionately when compared with young adults. Also, old adults activated their knee flexors earlier and all muscles for a longer period of time than young adults. These findings suggest old adults alter both magnitude of activation and duration of lower extremity musculature in response to increased inertial and velocity demands, and these response characteristics differ from those of young adults.
Lima, Bráulio N; Lucareli, Paulo R G; Gomes, Willy A; Silva, Josinaldo J; Bley, Andre S; Hartigan, Erin H; Marchetti, Paulo H
The aim of this study was to investigate the acute effects of unilateral ankle plantar flexors static- stretching on surface electromyography (sEMG) and the center of pressure (COP) during a single-leg balance task in both lower limbs. Fourteen young healthy, non-athletic individuals performed unipodal quiet standing for 30s before and after (stretched limb: immediately post-stretch, 10 and 20 minutes and non-stretched limb: immediately post-stretch) a unilateral ankle plantar flexor static- stretching protocol [6 sets of 45s/15s, 70-90% point of discomfort (POD)]. Postural sway was described using the COP area, COP speed (antero-posterior and medio-lateral directions) and COP frequency (antero-posterior and medio-lateral directions). Surface EMG (EMG integral [IEMG] and Median frequency[FM]) was used to describe the muscular activity of gastrocnemius lateralis. Ankle dorsiflexion passive range of motion increased in the stretched limb before and after the static-stretching protocol (mean ± SD: 15.0° ± 6.0 and 21.5° ± 7.0 [p < 0.001]). COP area and IEMG increased in the stretch limb between pre-stretching and immediately post-stretching (p = 0.015 and p = 0.036, respectively). In conclusion, our static- stretching protocol effectively increased passive ankle ROM. The increased ROM appears to increase postural sway and muscle activity; however these finding were only a temporary or transient effect. Key PointsThe postural control can be affected by static- stretching protocol.The lateral gastrocnemius muscle action was increased after the static- stretching protocol.The static- stretching effects remain for less than 10 minutes.
Zwipp, H; Sabauri, G; Amlang, M
Cases of posttraumatic pes equinovarus after compartment syndrome have become more frequent in the last 3 decades because limb-saving procedures like compartment splitting, vascular repair, and microvascular free flaps have become well established in trauma surgery, thus reducing early below knee amputations. But if the deep flexor compartment is not split completely or if the muscles are crushed by direct trauma severe necrosis and subsequent muscle contractures result in a very severe clubfoot deformity. Metatarsalgia of fifth, fourth, and third metatarsal head even in well-fitted orthopaedic shoes occurs as well as painful bunions and fatigue fractures of the fifth metatarsal. Infected ulcers below the fifth/fourth metatarsal bone in a numb plantar sole often require head resection because of osteomyelitis.From 1994 to 2007 a total of 24 patients with severe pes equinovarus after compartment and/or postischemic syndrome were treated operatively. Only in 5 cases was a triple, Chopart, or Lisfranc arthrodesis necessary; 19 cases however could be treated only by soft tissue procedures like tenolysis, tendon lengthening, medial release of the scarred flexor retinacula and contracted capsules of the posterior ankle, subtalar and talonavicular joint to reorientate all axes of the foot. By temporary K-wire transfixation (6 weeks), initial external tibiotarsal transfixation of the foot (10 days), and additional tendon transfer for active foot elevation excellent and good long-term (5 years) results are achievable.The results according to the McKay Score are not significantly different regarding the triple arthrodesis group versus the pure soft tissue release group. Nevertheless, saving joints in the latter group seems to be very important.
Caiozzo, V J; Haddad, F; Lee, S; Baker, M; Paloski, William; Baldwin, K M
The goal of this project was to examine the effects of artificial gravity (AG) on skeletal muscle strength and key anabolic/catabolic markers known to regulate muscle mass. Two groups of subjects were selected for study: 1) a 21 day-bed rest (BR) group (n = 7) and 2) an AG group (n = 8), which was subjected to 21 days of 6 degrees head-down tilt bed rest plus daily 1-h exposures to AG (2.5 G at the feet). Centrifugation was produced using a short-arm centrifuge with the foot plate approximately 220 cm from the center of rotation. The torque-velocity relationships of the knee extensors and plantar flexors of the ankle were determined pre- and posttreatment. Muscle biopsy samples obtained from the vastus lateralis and soleus muscles were used for a series of gene expression analyses (mRNA abundance) of key factors implicated in the anabolic vs. catabolic state of the muscle. Post/pre torque-velocity determinations revealed greater decrements in knee extensor performance in the BR vs. AG group (P < 0.04). The plantar flexors of the AG subjects actually demonstrated a net gain in the torque-velocity relationship, whereas in the BR group, the responses declined (AG vs. BR, P < 0.001). Muscle fiber cross-sectional area decreased by approximately 20% in the BR group, whereas no losses were evident in the AG group. RT-PCR analyses of muscle biopsy specimens demonstrated that markers of growth and cytoskeletal integrity were higher in the AG group, whereas catabolic markers were elevated in the BR group. Importantly, these patterns were seen in both muscles. We conclude that paradigms of AG have the potential to maintain the functional, biochemical, and structural homeostasis of skeletal muscle in the face of chronic unloading.
Mogk, Jeremy P M; Johanson, M Elise; Hentz, Vincent R; Saul, Katherine R; Murray, Wendy M
Biomechanical simulations of tendon transfers performed following tetraplegia suggest that surgical tensioning influences clinical outcomes. However, previous studies have focused on the biomechanical properties of only the transferred muscle. We developed simulations of the tetraplegic upper limb following transfer of the brachioradialis (BR) to the flexor pollicis longus (FPL) to examine the influence of residual upper limb strength on predictions of post-operative transferred muscle function. Our simulations included the transfer, ECRB, ECRL, the three heads of the triceps, brachialis, and both heads of the biceps. Simulations were integrated with experimental data, including EMG and joint posture data collected from five individuals with tetraplegia and BR-FPL tendon transfers during maximal lateral pinch force exertions. Given a measured co-activation pattern for the non-paralyzed muscles in the tetraplegic upper limb, we computed the highest activation for the transferred BR for which neither the elbow nor the wrist flexor moment was larger than the respective joint extensor moment. In this context, the effects of surgical tensioning were evaluated by comparing the resulting pinch force produced at different muscle strength levels, including patient-specific scaling. Our simulations suggest that extensor muscle weakness in the tetraplegic limb limits the potential to augment total pinch force through surgical tensioning. Incorporating patient-specific muscle volume, EMG activity, joint posture, and strength measurements generated simulation results that were comparable to experimental results. Our study suggests that scaling models to the population of interest facilitates accurate simulation of post-operative outcomes, and carries utility for guiding and developing rehabilitation training protocols.
Taylor, Sarah Elizabeth; García, Eugenio Cillán; Reardon, Richard J.M.
Objective To evaluate the frequency of inadvertent penetration of the digital flexor tendon sheath (DFTS) and/or distal interphalangeal joint (DIPJ) when using a direct endoscopic approach to the navicular bursa, and to evaluate an alternate direct approach to the navicular bursa. Study Design Cadaveric study. Sample Population Equine cadaver limbs (n = 40 for direct; n = 12 for alternate approach). Methods Four surgeons performed the direct endoscopic approach to the navicular bursa on 10 limbs each. Frequencies of inadvertent synovial penetration and iatrogenic damage were compared between surgeons. Use of an alternate direct approach, adopting a straight parasagittal trajectory, was evaluated by 2 surgeons. Results Inadvertent synovial penetration occurred in 45% of limbs (DFTS 37.5%; DIPJ 17.5%; and both structures 10%). Successful bursa entry was achieved on the first attempt in 45% of limbs. Significant variation in frequency of inadvertent synovial penetration was observed between surgeons (range 10–80%). Inadvertent synovial penetration did not occur when using the alternate direct technique. Iatrogenic damage to navicular bone fibrocartilage and/or deep digital flexor tendon occurred in 55% of limbs using the direct endoscopic approach and in 0% of limbs using the alternate direct approach. Conclusion Because of the considerable risk of inadvertent penetration of the DFTS and/or the DIPJ when making a direct endoscopic approach to the navicular bursa, it is advisable to investigate for inadvertent penetration when treating navicular bursa sepsis using a direct approach. The alternate direct technique may reduce the risk of inadvertent penetration; however, the view within the bursa may be restricted. PMID:26971252
Campos de Oliveira, Laís; Gonçalves de Oliveira, Raphael; Pires-Oliveira, Deise Aparecida de Almeida
[Purpose] The aim of the present study was to determine the effects of Pilates on lower leg strength, postural balance and the health-related quality of life (HRQoL) of older adults. [Subjects and Methods] Thirty-two older adults were randomly allocated either to the experimental group (EG, n = 16; mean age, 63.62 ± 1.02 years), which performed two sessions of Pilates per week for 12 weeks, or to the control group (CG, n = 16; mean age, 64.21 ± 0.80), which performed two sessions of static stretching per week for 12 weeks. The following evaluations were performed before and after the interventions: isokinetic torque of knee extensors and flexors at 300°/s, the Timed Up and Go (TUG) test, the Berg Balance Scale, and the Health Survey assessment (SF-36). [Results] In the intra-group analysis, the EG demonstrated significant improvement in all variables. In the inter-group analysis, the EG demonstrated significant improvement in most variables. [Conclusion] Pilates exercises led to significant improvement in isokinetic torque of the knee extensors and flexors, postural balance and aspects of the health-related quality of life of older adults. PMID:25931749
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Wang, Tiantian; Du, Lin; Shan, Ling; Dong, Hanyu; Feng, Junyan; Kiessling, Maren C.; Angstman, Nicholas B.; Schmitz, Christoph; Jia, Feiyong
Abstract To assess the effects of radial extracorporeal shock wave therapy (rESWT) on plantar flexor muscle spasticity and gross motor function in very young patients with cerebral palsy (CP). The design was case-control study (level of evidence 3). The setting was the Department of Pediatric Neurology and Neurorehabilitation, First Hospital of Jilin University, Changchun, China. Those with a diagnosis of CP and spastic plantar flexor muscles were recruited between April 2014 and April 2015. According to the parents’ decision, patients received 1 ESWT session per week for 3 months, with 1500 radial shock waves per ESWT session and leg with positive energy flux density of 0.03 mJ/mm2, combined with traditional conservative therapy (rESWT group) or traditional conservative therapy alone (control group). The Modified Ashworth Scale (MAS) (primary outcome measure) and passive range of motion (pROM) measurements were collected at baseline (BL), 1 month (M1), and 3 months (M3) after BL. The Gross Motor Function Measure (GMFM)-88 was collected at BL and M3. Sixty-six patients completed the final review at 3 months and were included in the study. Subjects ranged in age from 12 to 60 months (mean age 27.0 ± 13.6 months; median age 22.0 months; 33.3% female). For the rESWT group (n = 34), mean MAS grades at BL, M1, and M3 were 2.6, 1.9, and 1.5 on the left side and 1.9, 1.7, and 1.2 on the right side. For the control group (n = 32), mean MAS grades at BL, M1, and M3 were 2.5, 2.4, and 2.1 on the left side and 1.8, 1.8, and 1.5 on the right side. The within-subject effects time × side and time × treatment were statistically significant (P < 0.01). Similar results were found for the improvement of mean pROM. GMFM-88 improved from BL to M3, but showed no statistically significant difference between the groups. There were no significant complications. This study demonstrates that the combination of rESWT and traditional conservative therapy is more
Wu, Y F; Mao, W F; Zhou, Y L; Wang, X T; Liu, P Y; Tang, J B
Adhesion formation after digital flexor tendon injury greatly affects gliding function of the tendon, which is a major clinical complication after hand surgery. Transforming growth factor beta 1 (TGF-β1) has a critical role in adhesion formation during tendon healing. Persistent regulation of TGF-β1 through application of microRNA (miRNA) specifically inhibiting the function of TGF-β1 (TGF-β1-miRNA) holds promise for treatment of such a complication. Adeno-associated virus (AAV) was used to transfer TGF-β1-miRNA to the chicken digital flexor tendons, which had been injured and surgically repaired. Four doses of AAV2-TGF-β1-miRNA (2 × 10¹¹, 2 × 10¹⁰, 2 × 10⁹ and 2 × 10⁸ vector genomes (vg)) were used to determine the transfection efficiency. At postoperative 3 weeks, we found a positive correlation between the administered AAV2-TGF-β1-miRNA doses and transfection efficiency. The transfection rate ranged from 10% to 77% as the doses increased. Production of TGF-β1 protein in the tendons decreased on increasing vector dosage. When 2 × 10¹¹ and 2 × 10¹⁰) vg were injected into the tendon, gliding excursion of the repaired tendon and work of flexion of chicken toes were significantly increased and adhesion score decreased 6 and 8 weeks later, indicating the improvement of tendon gliding and decreases in adhesion formations. However, the ultimate strength of the tendons transfected at the dose of 2 × 10¹⁰ vg was 12-24% lower than that of the control tendons. The results of this study demonstrate that application of TGF-β1-miRNA had a mixed impact on tendon healing: adhesion around the tendon is reduced but strength of the tendon healing is adversely affected. Future studies should aim at maintaining the beneficial effects of reducing tendon adhesions, while eliminating the adverse effects of decreasing the healing strength.
Hartman, Michael J; Ryan, Eric D; Cramer, Joel T; Bemben, Michael G
The purpose of this study was to compare the effects of fatigue of the plantar flexors on peak torque and voluntary activation in untrained (UT) and resistance-trained (RT) men. Six men with no previous resistance training experience and 8 men with similar histories of chronic resistance training (9.8 ± 5.9 years, 3.8 ± 0.7 days/week) volunteered for this study. Subjects performed isometric maximal voluntary contractions (MVCs) before and immediately after unilateral dynamic isotonic contractions performed at 40% of MVC until volitional exhaustion. Voluntary activation of the plantar flexors was assessed using the interpolated twitch method (ITT) and central activation ratio (CAR). Surface electromyographic (EMG) amplitude of the soleus and medial gastrocnemius (MG) was measured during the MVC. There were significant reductions in MVC torque in both UT and RT groups after the fatiguing exercise (-10.7 ± 6.8%, p < 0.02; -9.1 ± 8.7%, p < 0.02, respectively), with no difference in the number of repetitions performed between groups. The UT and RT men experienced a significant decrease in ITT after the fatiguing exercise bout (-14.2 ± 11.8%, p = 0.03; -7.8 ± 9.3%, p = 0.045, respectively). The UT group experienced a significant decrease in CAR (99.5 ± 0.8% to 91.4 ± 6.4%, p = 0.025) with no change (p > 0.05) in the RT group. There was also a fatigue-induced decrease in normalized EMG amplitude for the soleus and MG muscles in both groups (p < 0.05). However, no differences were determined between groups for ITT, CAR, or EMG. Despite similar reductions in MVC torque postexercise, the UT men had a significant decrease in CAR and experienced nearly twice the decline in ITT than the RT men. These results indicate that the neural adaptations associated with chronic resistance training may lead to less susceptibility to central fatigue as measured by ITT and CAR.
Use of the Taguchi method for biomechanical comparison of flexor-tendon-repair techniques to allow immediate active flexion. A new method of analysis and optimization of technique to improve the quality of the repair.
Singer, G; Ebramzadeh, E; Jones, N F; Meals, R
The current trend toward early active flexion after repair of the flexor tendons necessitates a stronger repair than that provided by a modified Kessler technique with use of 4-0 nylon suture. The purpose of the current study was to determine, with use of the Taguchi method of analysis, the strongest and most consistent repair of the flexor tendons. Flexor tendons were obtained from fresh-frozen hands of human cadavera. Eight flexor tendons initially were repaired with the modified Kessler technique with use of 4-0 nylon core suture and 6-0 nylon epitenon suture. A test matrix was used to analyze a total of twenty variables in sixty-four tests. These variables included eight techniques for core-suture repair, four types of core suture, two sizes of core suture, four techniques for suture of the epitenon, and two distances from the repair site for placement of the core suture. After each repair, the specimens were mounted in a servohydraulic mechanical testing machine for tension-testing to failure. The optimum combination of variables was determined, with the Taguchi method, to be an augmented Becker technique with use of 3-0 Mersilene core suture, placed 0.75 centimeter from the cut edge with volar epitenon suture. The four-strand, double modified Kessler technique provided the second strongest repair. Five tendons that had been repaired with use of the optimum combination then were tested and compared with tendons that had been repaired with the standard modified Kessler technique. With the optimum combination of variables, the strength of the repair improved from a mean (and standard deviation) of 17.2 +/- 2.9 to 128 +/- 5.6 newtons, and the stiffness improved from a mean of 4.6 to 16.2 newtons per millimeter.
Protocol for an investigator-blinded, randomised, 3-month, parallel-group study to compare the efficacy of intraoperative tendon sheath irrigation only with both intraoperative and postoperative irrigation in the treatment of purulent flexor tenosynovitis
Jokihaara, Jarkko; Kaivorinne, Antti; Havulinna, Jouni; Göransson, Harry
Introduction The management of purulent flexor tenosynovitis of the hand consists of surgical debridement followed by antibiotic treatment. Usually, the debridement is carried out by irrigating the tendon sheath in a proximal to distal direction facilitated by two small incisions. It is unclear whether intraoperative irrigation by itself is adequate for healing or if it should be combined with postoperative irrigation in the ward. The hypothesis of this prospective randomised trial is that intraoperative catheter irrigation alone is as effective as a combination of intraoperative and postoperative intermittent catheter irrigation in the treatment of purulent flexor tenosynovitis. Methods and analysis In this investigator-blinded, prospective randomised trial, 48 patients suffering from purulent flexor tenosynovitis are randomised in two groups. Intraoperative catheter irrigation of the flexor tendon sheath and antibiotic treatment is identical in both groups, whereas only the patients in one group are subjected to intermittent postoperative catheter irrigation three times a day for 3 days. The primary outcome measure is total active range of movement of the affected finger after 3 months of surgery. The secondary outcome is the need for reoperation. Ethics and dissemination The research ethics committee of Pirkanmaa Hospital District has approved the study protocol. The protocol has been registered with ClinicalTrials.gov registry (#NCT02320929). All participants will give written informed consent. The study results will elucidate the role of postoperative irrigation, which can be criticised as being labour consuming and unpleasant to the patient. The results of the study will be disseminated as a published article in a peer-reviewed journal. Trial registration number: NCT02320929; pre-results. PMID:26671952
Bischof, Ledford J.
This volume comprehensively reviews the research on the psychology of the middle aged (ages 40-65). Topics include the concept of maturity and maturation models, the measurement and influences of adult self image; marriage and sexual patterns; intergenerational relationships between and children; vocations and avocations (work, retirement, play,…
Yamane, Motoi; Teruya, Hiroyasu; Nakano, Masataka; Ogai, Ryuji; Ohnishi, Norikazu; Kosaka, Mitsuo
The influence of regular post-exercise cold application to exercised muscles trained by ergometer cycling (leg muscles) or handgrip exercise using a weight-loaded handgrip ergometer (forearm flexor muscles) was studied in human volunteers. Muscle loads were applied during exercise programs three to four times a week for 4-6 weeks. Besides measuring parameters characterizing muscle performance, femoral and brachial artery diameters were determined ultrasonographically. Training effects were identified by comparing pre- and post-training parameters in matched groups separately for the trained limbs cooled after exercise by cold-water immersion and the corresponding trained limbs kept at room temperature. Significant training effects were three times more frequent in the control than in the cold group, including increases in artery diameters in the control but not in the cold group. It is concluded that training-induced molecular and humoral adjustments, including muscle hyperthermia, are physiological, transient and essential for training effects (myofiber regeneration, muscle hypertrophy and improved blood supply). Cooling generally attenuates these temperature-dependent processes and, in particular, hyperthermia-induced HSP formation. This seems disadvantageous for training, in contrast to the beneficial combination of rest, ice, compression and elevation in the treatment of macroscopic musculo-tendinous damage.
da Silva, Ary Gomes; Machado, Elbe Rodrigues; de Almeida, Leonardo Mendes; Nunes, Ricardo Marcelo Menezes; Giesbrecht, Patrícia Caldeira Pena; Costa, Regina Mamed; Costa, Helber B; Romão, Wanderson; Kuster, Ricardo Machado
One of the Brazilian arnicas, Solidago chilensis Meyen, is a species of the Asteraceae family. This plant is known by this common name because it shares remarkably similar organoleptic properties with the genus Arnica L., also within the family Asteraceae. We examined the effectiveness of the S. chilensis fluid extract used externally for treating tendinitis of flexor and extensor tendons of wrist and hand in placebo-controlled double-blind clinical pharmacological studies. This study was approved by the Ethical Committee for Scientific Research in Human Beings at University Vila Velha-UVV. Two daily skin applications on the arm skin of a gel cream containing a 5% glycolic plant extract were administered to eight volunteers for 21 days. Among the volunteers, one of their arms was used as the placebo group, and the other one was used as a test group. Statistical data analyses demonstrated a significant reduction in the perception of pain in the arms in the test group, when it was compared to those receiving only the placebo.
Sherlock, C E; Mair, T S
Recognition of artefacts is an essential component of the accurate interpretation of diagnostic images. This study aimed to investigate the presence of magic angle effect in the superficial digital flexor tendon (SDFT) in the equine proximal pastern region. The proximal pastern of four cadaver limbs was imaged using a 0.27 Tesla magnet with high-resolution sequences that are commonly utilised in clinical equine practice. The limbs were imaged in a neutral position and positions that simulated the horse 'leaning in', 'leaning out' and having internal and external rotation of the distal limb. Signal intensity changes in the SDFT were described and compared. The simulated 'leaning in' and external rotation positions resulted in increased signal intensity in the axial and middle thirds of the lateral half of the SDFT on sequences with short echo times. The simulated 'leaning out' and internal rotation positions resulted in increased signal intensity in the axial and middle thirds of the medial half of the SDFT on sequences with short echo times. These signal intensity changes did not occur or were only mild and inconsistent on T2 fast spin echo sequences with longer echo times. The increases in signal intensity in the SDFT are consistent with a position-induced magic angle artefact that has been noted in clinical cases. Attention to positioning of the equine distal limb is essential during clinical imaging; radiologists should be aware of position-induced artefacts to ensure accurate image interpretation.
Funasaki, Hiroki; Hayashi, Hiroteru; Sakamoto, Kanako; Tsuruga, Rei; Marumo, Keishi
Stenosing tenosynovitis of the flexor hallucis longus (FHL) tendon is known as a major overuse lesion in female dancers. We describe arthroscopic surgical techniques in relation to the dynamic pathology of the disease. Crepitus and pain on moving the great toe with the ankle in plantar flexion on preoperative examination confirm the diagnosis of FHL stenosing tenosynovitis even if the os trigonum is not evident. The ankle is approached through standard posterolateral and posteromedial portals. A 4.0-mm-diameter 30° arthroscope is used. Soft tissues around the talus are cleared with a motorized shaver and a radiofrequency device. The posterior aspects of the talus, os trigonum, and FHL tendon surrounded by the tendon sheath are visualized. The dynamic pathology of the FHL tendon is well observed on passive motion of the great toe. The prominent bone fragment of the talus is removed and the tendon sheath is cut with a retrograde knife and a motorized shaver from the superior border down to the entrance of the fibro-osseous tunnel. Arthroscopic release of the FHL tendon sheath is a useful and easy method to directly approach the dynamic pathology of FHL tenosynovitis in female ballet dancers.
Kang, Jeong-il; Jeong, Dae-Keun; Choi, Hyun
[Purpose] This study aimed to simultaneously investigate the activities of the sternocleidomastoid muscle and scalenus anterior muscle, which are agonists of neck and breathing accessory muscles, by implementing breathing exercises. [Subjects and Methods] Thirteen subjects were selected for the experimental group, which performed feedback respiratory exercises with McKenzie exercises, and 12 subjects were selected for the control group, which performed McKenzie exercises alone. The intervention program was performed for 30 minutes a session, once a day, four times a week, and for 2 weeks before conducting the experiment. Before intervention, muscle activity was measured using surface electromyogram, and the neck disability index was evaluated. [Results] There were meaningful differences in activities of the sternocleidomastoid muscle and the scalenus anterior muscle, craniovertebral angle, and neck disability index within both the experimental group and control group after intervention. There also were meaningful differences in sternocleidomastoid muscle and neck disability index changes between groups. [Conclusion] Neck flexors as accessory respiratory muscle can affect inefficient respiratory imbalance of forward head posture patients. Multimodal intervention method should be studied continually and not be exposed to upper chest breathing patterns by preventing such phenomenon. PMID:27799674
Kang, Jeong-Il; Jeong, Dae-Keun; Choi, Hyun
[Purpose] This study aimed to simultaneously investigate the activities of the sternocleidomastoid muscle and scalenus anterior muscle, which are agonists of neck and breathing accessory muscles, by implementing breathing exercises. [Subjects and Methods] Thirteen subjects were selected for the experimental group, which performed feedback respiratory exercises with McKenzie exercises, and 12 subjects were selected for the control group, which performed McKenzie exercises alone. The intervention program was performed for 30 minutes a session, once a day, four times a week, and for 2 weeks before conducting the experiment. Before intervention, muscle activity was measured using surface electromyogram, and the neck disability index was evaluated. [Results] There were meaningful differences in activities of the sternocleidomastoid muscle and the scalenus anterior muscle, craniovertebral angle, and neck disability index within both the experimental group and control group after intervention. There also were meaningful differences in sternocleidomastoid muscle and neck disability index changes between groups. [Conclusion] Neck flexors as accessory respiratory muscle can affect inefficient respiratory imbalance of forward head posture patients. Multimodal intervention method should be studied continually and not be exposed to upper chest breathing patterns by preventing such phenomenon.
Crevier-Denoix, N; Ruel, Y; Dardillat, C; Jerbi, H; Sanaa, M; Collobert-Laugier, C; Ribot, X; Denoix, J-M; Pourcelot, P
The objective of this study was to test the hypothesis that tendon echogenicity is associated with the material properties of the corresponding tendon site, especially in case of lesions, due to local changes in tendon matrix composition. Four normal and nine spontaneously injured equine superficial digital flexor tendons (SDFT) were isolated then ultrasonographically examined under tension, in a special device placed in a water bath. Ultrasonographic transversal images (7.5MHz linear transducer) of five segments along each tendon were digitized, and analyzed in order to measure the mean cross-sectional area (MCSA) and mean echogenicity (ME) of each segment. The tendons were then tested in traction until rupture in a testing machine. For each segment, stress and strain were determined throughout the test, and the elastic modulus (EM) was evaluated. The tendon lesions were also documented by histology. No correlation was found between ME and the material properties of normal tendon segments. At the rupture sites of the nine diseased tendons, ME was positively correlated with maximal stress and EM, whereas no correlation was demonstrated with maximal strain. Besides, a positive correlation was demonstrated between ME and both MCSA and EM, when the three metacarpal segments of the diseased tendons were considered. Although ME gives only rough information about tendon matrix structure, it does show, under these in vitro conditions, significant correlations with material properties of pathological tendon segments, which may improve the functional significance and therefore the prognostic value of the ultrasonographic examination of tendon lesions.
Chong, Hyun Ju; Kim, Soo Ji; Lee, Eun Kyoung; Yoo, Ga Eul
Although instrument playing-based training has been repeatedly reported to improve functional hand movements including grasping, the attempts to present quantitative information on physiological mechanism of grasping have been relatively insufficient to determine the type and the intensity of the exercises involved. This study aimed to examine the muscle activation during hand percussion playing depending on the grasping type and the playing tempo. A total of twelve healthy older adults with a mean age of 71.5 years participated in this study. Surface electrodes were placed on three grasping-related muscles: Flexor digitorum superficialis, extensor digitorum, and flexor pollicis brevis. Participants were instructed to play with the egg shaker, paddle drum mallet and clave involving different types of grasp at three different tempi (i.e., 80, 100, and 120 bpm) and sEMG data were collected during each playing. Significantly greater muscle activation was generated with the small sphere type of egg shaker, compared to the handle type of paddle drum mallet and the small cylinder type of clave. Playing at faster tempo also elicited significantly greater muscle activation than at slower tempo. With regard to the rise time of muscle activation, while tempo significantly affected the rise time, the time to peak muscle did not significantly change depending on the grasping type. This study confirmed that grasping pattern and the tempo of movement significantly influence the muscular activation of grasping involved in instrument playing. Based on these results, clinical implication for instrument selection and structured instrument playing would be suggested.
BEAL, CATHERINE; AND OTHERS
UNITS ON MIGRANT ADULT EDUCATION, AND A UNIT ON ORGANIZING INFORMAL GROUPS OF MIGRANT WOMEN TO DISCUSS MAINTAINING AND IMPROVING THEIR TEMPORARY HOMES, ARE PRESENTED. THE GOALS OF THE UNIT ON EDUCATION FOR MIGRANT MEN ARE ECONOMIC INDEPENDENCE, BETTER HEALTH AND WELL-BEING, AND BETTER HANDLING OF RESPONSIBILITIES. THE MAIN DIVISIONS OF THE…
Kanitz, Ana Carolina; Delevatti, Rodrigo Sudatti; Reichert, Thais; Liedtke, Giane Veiga; Ferrari, Rodrigo; Almada, Bruna Pereira; Pinto, Stephanie Santana; Alberton, Cristine Lima; Kruel, Luiz Fernando Martins
This study aimed to investigate the effects of two deep water training programs on cardiorespiratory and muscular strength responses in older adults. Thirty-four older adults men were placed into two groups: deep water endurance training (ET; n = 16; 66 ± 4 years) and deep water strength prior to endurance training (concurrent training: CT; n = 18; 64 ± 4 years). The training period lasted 12 weeks, with three sessions a week. The resting heart rate and the oxygen uptake at peak (VO2peak) and at the second ventilatory threshold (VO2VT2) were evaluated during a maximal incremental test on a cycle ergometer before and after training. In addition, maximal dynamic strength (one repetition maximum test--1RM) and local muscular resistance (maximum repetitions at 60% 1RM) of the knee extensors and flexors were evaluated. After the training period, the heart rate at rest decreased significantly, while the VO2peak and VO2VT2 showed significant increases in both groups (p<0.05). Only the VO2VT2 resulted in significantly greater values for the ET compared to the CT group after the training (p<0.05). In addition, after training, there was a significant increase in the maximal dynamic strength of the knee extensors and the local muscular endurance of the knee extensors and flexors, with no difference between the groups (p > 0.05). In summary, the two training programs were effective at producing significant improvements in cardiorespiratory and muscular strength responses in older adult men. However, deep water endurance training at high intensities provides increased cardiorespiratory responses compared to CT and results in similar muscular strength responses.
Hunter, Sandra K; Todd, Gabrielle; Butler, Jane E; Gandevia, Simon C; Taylor, Janet L
This study compared the contribution of supraspinal fatigue to muscle fatigue in old and young adults. Transcranial magnetic stimulation (TMS) of motor cortex was used to assess voluntary activation during maximal voluntary contractions (MVCs) of elbow flexor muscles in 17 young adults (25.5 +/- 3.6 yr; mean +/- SD) and 7 old adults (73.0 +/- 3.3 yr). Subjects performed a fatigue task involving six sustained MVCs (22-s duration, separated by 10 s). Young adults exhibited greater reductions in maximal voluntary torque (67 +/- 15% of baseline) than the old (37 +/- 6%; P < 0.001). Increments in torque (superimposed twitch) generated by TMS during sustained MVCs increased for the young and old (P < 0.001) but were larger for the old adults at the start of the sustained contractions and during recovery (P < 0.05). Voluntary activation was less for the old adults at the start of some sustained contractions and during recovery (P = 0.02). Motor-evoked potential area increased similarly with age during the fatiguing task but was greater for the old adults than young during recovery. Silent period duration lengthened less for the old adults during the fatigue task. At the end of the fatiguing task, peak relaxation rate of muscle fibers had declined more in the young than the old adults. The greater endurance with age is largely due to a difference in mechanisms located within the muscle. However, recovery from the fatiguing exercise is impaired for old adults because of greater supraspinal fatigue than in the young.
... Autism Spectrum Disorder (ASD) Eating Disorders Among Adults - Anorexia Nervosa Eating Disorders Among Adults - Binge Eating Disorder ... Autism Spectrum Disorder (ASD) Eating Disorders Among Adults - Anorexia Nervosa Eating Disorders Among Adults - Binge Eating Disorder ...
Sleep apnea - obstructive - adults; Apnea - obstructive sleep apnea syndrome - adults; Sleep-disordered breathing - adults; OSA - adults ... When you sleep, all of the muscles in your body become more relaxed. This includes the muscles that help keep your ...
Roberson, Donald N., Jr.
This summary of adult development covers a wide range of authors. Adult development is one way of understanding how the internal and external changes in our lives have an impact on learning. Of particular importance in this work are the developmental issues of older adults. I present various theories of adult development such as linear and…
Park, J.H.; Park, C.R.; Brown, R.L.; Chance, B.
Functional compartments of fast and slow twitch fibers have been observed by /sup 31/P-NMR spectroscopy during exercise of the wrist flexor muscles in a sedentary, young male subject. Values of Pi, phosphocreatine (PCr) and adenine nucleotides were determined at rest and during an exercise protocol. The subject flexed his wrist muscles at 20% of maximum strength every 5 sec for 6 min and then increased his effort in the next two 6 min intervals to 40% and 60% of maximum. With exercise, the Pi/PCr rose rapidly to the exceptionally high value of 2.2 at 60% effort. As the Pi increased, the initial single peak (pH 7.0-6.9) split into two distinct components with pH values of 6.8 and 6.3. Quantitatively, distribution of the Pi was 40% in the pH 6.8 peak and 60% in the pH 6.3 peak as determined by area estimation following curve fitting. This presumably reflects two pools of Pi corresponding to the oxidative (slow twitch, high pH) and glycolytic (fast twitch, low pH) fibers. In the second identical exercise sequence which followed immediately, only one Pi peak (pH 6.8-6.9) appeared. This suggested that the glycolytic contribution to energy production was largely exhausted and the residual energy was derived from oxidative metabolism. During exercise at high levels, total phosphate decreased due primarily to loss of NMR visible adenine nucleotides. Similar phenomena have been observed in three other sedentary individuals, but not in trained athletes.
West, Daniel W. D.; Burd, Nicholas A.; Tang, Jason E.; Moore, Daniel R.; Staples, Aaron W.; Holwerda, Andrew M.; Baker, Steven K.
The aim of our study was to determine whether resistance exercise-induced elevations in endogenous hormones enhance muscle strength and hypertrophy with training. Twelve healthy young men (21.8 ± 1.2 yr, body mass index = 23.1 ± 0.6 kg/m2) trained their elbow flexors independently for 15 wk on separate days and under different hormonal milieu. In one training condition, participants performed isolated arm curl exercise designed to maintain basal hormone concentrations (low hormone, LH); in the other training condition, participants performed identical arm exercise to the LH condition followed immediately by a high volume of leg resistance exercise to elicit a large increase in endogenous hormones (high hormone, HH). There was no elevation in serum growth hormone (GH), insulin-like growth factor (IGF-1), or testosterone after the LH protocol but significant (P < 0.001) elevations in these hormones immediately and 15 and 30 min after the HH protocol. The hormone responses elicited by each respective exercise protocol late in the training period were similar to the response elicited early in the training period, indicating that a divergent postexercise hormone response was maintained over the training period. Muscle cross-sectional area (CSA) increased by 12% in LH and 10% in HH (P < 0.001) with no difference between conditions (condition × training interaction, P = 0.25). Similarly, type I (P < 0.01) and type II (P < 0.001) muscle fiber CSA increased with training with no effect of hormone elevation in the HH condition. Strength increased in both arms, but the increase was not different between the LH and HH conditions. We conclude that exposure of loaded muscle to acute exercise-induced elevations in endogenous anabolic hormones enhances neither muscle hypertrophy nor strength with resistance training in young men. PMID:19910330
Gali, Julio Cesar; Resina, André França; Pedro, Gabriel; Neto, Ildefonso Angelo Mora; Almagro, Marco Antonio Pires; da Silva, Phelipe Augusto Cintra; Caetano, Edie Benedito
Objective To describe the path of the infrapatellar branch of the saphenous nerve (IBSN) using the medial joint line, anterior tibial tuberosity (ATT), tibial collateral ligament and a horizontal line parallel to the medial joint line that passes over the ATT, as reference points, in order to help surgeons to diminish the likelihood of injuring this nerve branch during reconstruction of the anterior cruciate ligament (ACL) using flexor tendons. Methods Ten frozen knees that originated from amputations were examined. Through anatomical dissection performed with the specimens flexed, we sought to find the IBSN, from its most medial and proximal portion to its most lateral and distal portion. Following this, the anatomical specimens were photographed and, using the ImageJ software, we determined the distance from the IBSN to the medial joint line and to a lower horizontal line going through the ATT and parallel to the first line. We also measured the angle of the direction of the path of the nerve branch in relation to this lower line. Results The mean angle of the path of the nerve branch in relation to the lower horizontal line was 17.50 ± 6.17°. The mean distance from the IBSN to the medial joint line was 2.61 ± 0.59 cm and from the IBSN to the lower horizontal line, 1.44 ± 0.51 cm. Conclusion The IBSN was found in all the knees studied. In three knees, we found a second branch proximal to the first one. The direction of its path was always from proximal and medial to distal and lateral. The IBSN was always proximal and medial to the ATT and distal to the medial joint line. The medial angle between its direction and a horizontal line going through the ATT was 17.50 ± 6.17°. PMID:26229872
Marr, C M; Love, S; Boyd, J S; McKellar, Q
Ultrasonographic examination was used to define the severity of injuries to the superficial digital flexor tendon in 73 National Hunt or point-to-point racehorses and the factors influencing the outcome of the cases were examined. Thirty-four of the horses (46 per cent) returned to work with an average time out of training of 13.5 months. The rate of recurrence of the injury was 35 per cent. The severity of the lesions was related to the outcome; all the mildly affected horses returned to work, with 63 per cent of them racing and an average time out of training of 10.2 months; 50 per cent of the moderately affected horses returned to work, and 30 per cent raced with an average time out of training of 11.3 months; 30 per cent of the severely affected horses worked, and 23 per cent raced with an average time out of training of 18.3 months. The differences in outcome between unilateral and bilateral injuries within each severity group were not statistically significant. Seventy-six per cent of horses treated with polysulphated glycosaminoglycans returned to work, compared with 46 per cent of conservatively managed horses and 50 per cent of horses treated with laser therapy. However, these differences were not statistically significant and the rate of recurrence of the injury in the horses treated with polysulphated glycosaminoglycans was 50 per cent compared with only 31 per cent in the conservatively managed horses. Seventy per cent of the mares and 47 per cent of the geldings were retired from racing.
Khristy, Windyanne; Ali, Noore J.; Bravo, Arlene B.; de Leon, Ray; Roy, Roland R.; Zhong, Hui; London, Nik J. L.; Edgerton, V. Reggie; Tillakaratne, Niranjala J. K.
GABA signaling plays an important role in the spinal cord response to injury and subsequent motor training. Since benzodiazepines are commonly used to treat muscle spasticity in spinal cord injured subjects and the γ2 subunit of the GABAA receptor is necessary for benzodiazepine binding, this subunit may be an important factor modulating sensorimotor function after an injury. Changes in γ2 levels in muscle-specific motoneurons and surrounding astrocytes were determined ~3 months after a complete mid-thoracic spinal cord transection at P5 in non-trained and in step-trained spinal rats. Soleus (ankle extensor) and tibialis anterior (TA, ankle flexor) motor pools were identified using retrograde labeling via intramuscular injections of Fast Blue or Fluoro Gold, respectively. Lumbar spinal cord sections showed γ2 immunostaining in both soleus and TA motoneurons and astrocytes. γ2 immunoreactivity on the soma of soleus and TA motoneurons in spinal rats was differentially modulated. Compared to intact rats, spinal rats had higher levels of γ2 in TA, and lower levels in soleus motoneurons. Step training restored GABAA γ2 levels towards control values in motoneuronal pools of both muscles. In contrast, the γ2 levels were elevated in surrounding astrocytes of both motor pools in spinal rats, and step training had no further effect. Thus, motor training had a specific effect on those neurons that were directly involved with the motor task. Since the γ2 subunit is involved with GABAA receptor trafficking and synaptic clustering, it appears that this subunit could be an important component of the activity-dependent response of the spinal cord after a spinal injury. PMID:19358834
Effects of sodium-hyaluronate and glucosamine-chondroitin sulfate on remodeling stage of tenotomized superficial digital flexor tendon in rabbits: a clinical, histopathological, ultrastructural, and biomechanical study.
Oryan, Ahmad; Moshiri, Ali; Meimandiparizi, Abdul-Hamid
This study was designed to evaluate the effects of sodium-hyaluronate (NaH) combined with glucosamine HCl-chondroitin sulfate (GlcN-CS) on the post-surgical repair of tendon rupture on day 84 post injury. Twenty white New Zealand female rabbits were divided randomly into two equal groups of injured treated and injured untreated. After tenotomy and surgical repair, using the modified Kessler technique and running pattern, the injured legs were casted for 14 days. NaH was injected subcutaneously over the lesion on days 3, 7, and 10 and was followed by daily oral administration of GlcN-CS on days 3 to 23 post injury. The control animals received normal saline injection and oral placebo similarly. The weight of the animals, tendon diameter, clinical manifestations, and radiographic and ultrasonographic evaluations were conducted for 12 weeks. The rabbits were euthanized 84 days post injury and the tendons were evaluated at macroscopic, histopathologic, and ultrastructural level and were assessed for biomechanical and percentage dry-weight parameters. Treatment significantly reduced the tendon diameter and ultimate and yield strain, and increased the echogenicity, dry-weight content, ultimate and yield strength, and stress and stiffness of the injured tendons compared to those of the untreated ones. Treatment also significantly enhanced the maturation rate of the tenoblasts, fibrillogenesis, the diameters of the collagen fibrils, and fibrillar density. These findings suggest that a combined treatment of NaH and GlcN-CS could be effective in restoring the morphological and biomechanical properties of injured superficial digital flexor tendon of rabbits and might be helpful for future clinical trial studies in tendon ruptures.
Crevier-Denoix, Nathalie; Ravary-Plumioën, Bérangère; Evrard, Delphine; Pourcelot, Philippe
A non-invasive ultrasonic (US) technique of tendon force measurement has been recently developed. It is based on the relationship demonstrated between the speed of sound (SOS) in a tendon and the traction force applied to it. The objectives of the present study were to evaluate the variability of this non-linear relationship among 7 equine superficial digital flexor (SDF) tendons, and the reproducibility of SOS measurements in these tendons over successive loading cycles and tests. Seven SDF tendons were equipped with an US probe (1MHz), secured in contact with the skin overlying the tendon metacarpal part. The tendons were submitted to a traction test consisting in 5 cycles of loading/unloading between 50 and 4050N. Four tendons out of the 7 were submitted to 5 additional cycles up to 5550N. The SOS-tendon force relationships appeared similar in shape, although large differences in SOS levels were observed among the tendons. Reproducibility between cycles was evaluated from the root mean square of the standard deviations (RMS-SD) of SOS values observed every 100N, and of force values every 2m/s. Reproducibility of SOS measurements revealed high between successive cycles: above 500N the RMS-SD was less than 2% of the corresponding traction force. Reproducibility between tests was lower, partly due to the experimental set-up; above 500N the difference between the two tests stayed nevertheless below 15% of the corresponding mean traction force. The reproducibility of the US technique here demonstrated in vitro has now to be confirmed in vivo.
Verdaguer-Codina, Joan; Mirallas, Jaume A.
The technique of execution of any movement in Judo is extremely important. The coaches want tests and tools easy to use and cheaper, to evaluate the progress of a judoist in the tatame. In this paper we present a test developed by Mirallas, which has his name 'Test of Mirallas' to evaluate the maximal power capacity of the judoist. The near infrared spectroscopy (NIRS) signals were obtained to have a measurement of the metabolic work of the flexor carpi ulnaris and radialis muscles, during the execution of the ippon-seoi-nage movement, allowing this measurement to assess by NIRS the maximal oxygen uptake. Also obtained were tympanic, skin forehead, and biceps brachii temperatures during the test time and recovery phase to study the effects of ambient conditions and the post-exercise oxygen consumption. The deoxygenation and blood volume signals obtained gave different results, demonstrating the hypothesis of the coaches that some judoist do the execution of the ippon-seoi-nage movement correctly and the rest didn't. The heart rate frequency obtained in the group of judoist was between 190-207 bpm, and in the minute five of post-exercise was 114-137 bpm; the time employed in the MIrallas's test were from 7 feet 14 inches to 13 feet 49 inches, and the total of movements were from 199 to 409. The data obtained in the skin forehead, and skin biceps brachii confirms previous works that the oxygen consumption remains after exercise in the muscle studied. According to the results, the test developed by Mirallas is a good tool to evaluate the performance of judoist any time, giving better results compared with standard tests.
Ditroilo, Massimiliano; Watsford, Mark; De Vito, Giuseppe
The purpose of this study was to assess the validity and inter-day reliability of musculo-articular stiffness (MAS) in the knee-extensor (KE) and knee-flexor (KF) muscle groups, measured with a free-oscillation technique. Fourteen participants were measured, on two occasions, for KE and KF maximal isometric voluntary contraction, rate of torque development (RTD) and electromechanical delay (EMD), along with MAS using multiple sub-maximal loads relative to the individual's maximal voluntary contraction (MAS(%MVC)). Furthermore, 18 participants were tested for MAS using one fixed assessment load for each muscle group (MAS(FL)) during a separate series of tests on three occasions. MAS(%MVC) was significantly increased as load increased both in KE and in KF (p<0.01) fitting a curvilinear relationship as depicted in similar studies. Validity was demonstrated relating MAS(%MVC) to RTD (r=0.51-0.71, p<0.05) and to EMD (r=-0.56 to -0.67, p<0.05). While MAS(%MVC) reliability (ICC=0.62-0.89; CV=8.1-13.1%) was questionable to acceptable, MAS(FL) exhibited good to excellent reliability (ICC=0.81-0.94; CV=3.7-6.5%). No significant systematic bias was detected for any of the variables considered. The assessment of KE and KF MAS using the free-oscillation technique appears to be valid and reliable, with the use of MAS(FL) yielding higher reliability than the use of MAS(%MVC).
Silvestre, Rony; Fuentes, Jorge; da Costa, Bruno R.; Gadotti, Inae C.; Warren, Sharon; Major, Paul W.; Thie, Norman M.R.; Magee, David J.
Background Most patients with temporomandibular disorders (TMD) have been shown to have cervical spine dysfunction. However, this cervical dysfunction has been evaluated only qualitatively through a general clinical examination of the cervical spine. Purpose The purpose of this study was to determine whether patients with TMD had increased activity of the superficial cervical muscles when performing the craniocervical flexion test (CCFT) compared with a control group of individuals who were healthy. Design A cross-sectional study was conducted. Methods One hundred fifty individuals participated in this study: 47 were healthy, 54 had myogenous TMD, and 49 had mixed TMD. All participants performed the CCFT. Data for electromyographic activity of the sternocleidomastoid (SCM) and anterior scalene (AS) muscles were collected during the CCFT for all participants. A 3-way mixed-design analysis of variance for repeated measures was used to evaluate the differences in EMG activity for selected muscles while performing the CCFT under 5 incremental levels. Effect size values were calculated to evaluate the clinical relevance of the results. Results Although there were no statistically significant differences in electromyographic activity in the SCM or AS muscles during the CCFT in patients with mixed and myogenous TMD compared with the control group, those with TMD tended to have increased activity of the superficial cervical muscles. Limitations The results obtained in this research are applicable for the group of individuals who participated in this study under the protocols used. They could potentially be applied to people with TMD having characteristics similar to those of the participants of this study. Conclusion This information may give clinicians insight into the importance of evaluation and possible treatment of the deep neck flexors in patients with TMD. However, future research should test the effectiveness of this type of program through a randomized controlled
Bergantin, Leandro Bueno; Figueiredo, Leonardo Bruno; Godinho, Rosely Oliveira
The molecular regulation of skeletal muscle proteolysis and the pharmacological screening of anticatabolic drugs have been addressed by measuring tyrosine release from prepubertal rat skeletal muscles, which are thin enough to allow adequate in vitro diffusion of oxygen and substrates. However, the use of muscle at accelerated prepubertal growth has limited the analysis of adult muscle proteolysis or that associated with aging and neurodegenerative diseases. Here we established the adult rat lumbrical muscle (4/hindpaw; 8/rat) as a new in situ experimental model for dynamic measurement of skeletal muscle proteolysis. By incubating lumbrical muscles attached to their individual metatarsal bones in Tyrode solution, we showed that the muscle proteolysis rate of adult and aged rats (3-4 to 24 mo old) is 45-25% of that in prepubertal animals (1 mo old), which makes questionable the usual extrapolation of proteolysis from prepubertal to adult/senile muscles. While acute mechanical injury or 1- to 7-day denervation increased tyrosine release from adult lumbrical muscle by up to 60%, it was reduced by 20-28% after 2-h incubation with β-adrenoceptor agonists, forskolin or phosphodiesterase inhibitor IBMX. Using inhibitors of 26S-proteasome (MG132), lysosome (methylamine), or calpain (E64/leupeptin) systems, we showed that ubiquitin-proteasome is accountable for 40-50% of total lumbrical proteolysis of adult, middle-aged, and aged rats. In conclusion, the lumbrical model allows the analysis of muscle proteolysis rate from prepubertal to senile rats. By permitting eight simultaneous matched measurements per rat, the new model improves similar protocols performed in paired extensor digitorum longus (EDL) muscles from prepubertal rats, optimizing the pharmacological screening of drugs for anticatabolic purposes.
Martin, P E; Siler, W L; Hoffman, D
A predominant archery coaching tenet holds that the most effective means of releasing the bow string is by relaxation of the finger flexor muscles without activation of finger extensors. To evaluate the validity of this view, EMG patterns of the flexor digitorum superficialis and extensor digitorum muscles of the draw arm were examined using surface EMG electrodes in 15 highly skilled archers as each performed six shots. Each archer displayed consistent EMG patterns from shot-to-shot and two distinct flexor-extensor patterns were exhibited by the sample. The first, characterized by eight of the archers, supported the relaxation principle. For these archers, both flexor and extensor digitorum activity decreased markedly immediately prior to or at arrow release. The second pattern, characteristic of the remaining seven archers, contradicted the coaching tenet. While the flexor digitorum pattern was essentially the same as that described for the first pattern, the extensor digitorum displayed a marked increase in activity just prior to release, indicating that string release was facilitated by an active extension of the fingers. It was concluded that highly skilled archers do not predominantly reflect a release consistent with the coaching canon and that factors other than the string release mechanism discriminate the performances of skilled archers.
Cornish, Stephen M; Chilibeck, Philip D
Increased inflammation with aging has been linked to sarcopenia. The purpose of this study was to evaluate the effects of supplementing older adults with alpha-linolenic acid (ALA) during a resistance training program, based on the hypothesis that ALA decreases the plasma concentration of the inflammatory cytokine tumor necrosis factor (TNF)-alpha and interleukin (IL)-6, which in turn would improve muscle size and strength. Fifty-one older adults (65.4 +/- 0.8 years) were randomized to receive ALA in flax oil (~14 g.day-1) or placebo for 12 weeks while completing a resistance training program (3 days a week). Subjects were evaluated at baseline and after 12 weeks for muscle thickness of knee and elbow flexors and extensors (B-mode ultrasound), muscle strength (1 repetition maximum), body composition (dual energy X-ray absorptiometry), and concentrations of TNF-alpha and IL-6. Males supplementing with ALA decreased IL-6 concentration over the 12 weeks (62 +/- 36% decrease; p = 0.003), with no other changes in inflammatory cytokines. Chest and leg press strength, lean tissue mass, muscle thickness, hip bone mineral content and density, and total bone mineral content significantly increased, and percent fat and total body mass decreased with training (p < 0.05), with the only benefit of ALA being a significantly greater increase in knee flexor muscle thickness in males (p < 0.05). Total-body bone mineral density improved in the placebo group, with no change in the ALA group (p = 0.05). ALA supplementation lowers the IL-6 concentration in older men but not women, but had minimal effect on muscle mass and strength during resistance training.
Grabowski, Stanley M.; And Others
Model programs are described for two areas of adult education--the preparation of adult educators and the training conducted by adult educators. In Chapter One, Phyllis Caldwell reviews the literature concerning the preservice training of adult educators, concentrating on the competencies of adult education administrators and teachers. In Chapter…
Pascoe, Michael A; Gould, Jeffrey R; Enoka, Roger M
The purpose of the study was to compare the discharge characteristics of biceps brachii motor units of young and old adults when they performed steady, submaximal contractions while the arm supported different inertial loads. Young (28 ± 4 yr; n = 16) and old (75 ± 4 yr; n = 14) adults performed steady contractions with the elbow flexors at target forces set at either small (11.7 ± 4.4% maximum) or large (17.8 ± 6.5% maximum) differences below the recruitment threshold force of the motor unit (n = 40). The task was to maintain an elbow angle at 1.57 rad until the motor unit was recruited and discharged action potentials for ∼120 s. Time to recruitment was longer for the larger target force difference (187 ± 227 s vs. 23 ± 46 s, P < 0.001). Once recruited, motor units discharged action potentials either repetitively or intermittently, with a greater proportion of motor units exhibiting the repetitive pattern for old adults. Discharge rate at recruitment and during the steady contraction was similar for the two target force differences for old adults but was greater for the small target force difference for young adults. Discharge variability was similar at recruitment for the two age groups but less for the old adults during the steady contraction. The greatest difference between the present results and those reported previously when the arm pulled against a rigid restraint was that old adults modulated discharge rate less than young adults across the two contraction intensities for both load types.
Kumar, N; Sharma, A K; Sharma, A K; Kumar, S
The efficacy of carbon fibres and plasma-preserved tendon allografts for gap repair in the superficial digital flexor tendon in the mid-metatarsal region was evaluated in 12 crossbred calves. Experimental tenectomies were performed, followed by implantation of carbon fibres in group I (12 legs) and plasma-preserved tendon allografts in group II (12 legs). Gross observations in group I showed filling of the defect with granulation tissue with more vascularity on day 7, which was less prominent at day 14. On day 30, the neotendon formed was slightly thicker and comparable to normal tendon in appearance and texture. On day 90, it exhibited all the characteristics of a fully developed tendon. Whereas, in group II increased vascularity at the site and encapsulation of the graft with connective tissue in early periods was observed. The gap between graft and host was filled with fibrous connective tissue. Peritendinous adhesions were maximum on day 7 which were gradually reduced in both groups. Microscopically, an acute inflammatory reaction in the periphery of carbon fibres was observed on day 7. Immature fibroblasts were arranged in a haphazard pattern at this stage. By day 14, numerous newly formed capillaries and comparatively more mature fibroblasts were present in between and around the carbon fibres which were aligning parallel to the longitudinal axis of the tendon. By day 30 the healing tissue exhibited longitudinal orientation of collagen fibres and was at a more advance stage of maturation. By day 90, the neotendon formed simulated the picture of normal tendon. In the grafted tendon group, there was normal healing tissue at the functional sites between host and grafted tendon. The fibroblastic activity appeared to be both extrinsic and intrinsic in origin. The connective tissue had invaded the graft to a variable distance and there was resorption of graft which was replaced by newly formed connective tissue on day 90. Scanning electron microscopic observation
... Vestibular schwannoma (acoustic neuroma) - adults; Meningioma - adults; Cancer - brain tumor (adults) ... Primary brain tumors include any tumor that starts in the brain. Primary brain tumors can start from brain cells, ...
... Page Resize Text Printer Friendly Online Chat Adult Day Care Adult Day Care Centers are designed to provide care and ... adults who need assistance or supervision during the day. Programs offer relief to family members and caregivers, ...
Still's disease - adult; AOSD ... than 1 out of 100,000 people develop adult-onset Still's disease each year. It affects women more often than men. The cause of adult Still's disease is unknown. No risk factors for ...
Kaufman, Juliet, Ed.; And Others
Findings of an American College Testing Program 1981 survey on college recruitment of adult students are summarized, and 12 articles on adult recruitment are presented. Titles and authors are as follows: "Adult Recruitment Practices: A Report of a National Survey" (Patricia Spratt, Juliet Kaufmann, Lee Noel); "Three Programs for Adults in Shopping…
Brown, Ato Ampomah
Objective. The purpose of this study was to examine the relationship between the location of the MTSS pain (posteromedial border of tibia) and the muscles that originate from that site. Method. The study was conducted in the Department of Anatomy of the School of Medical Sciences, University of Cape Coast, and involved the use of 22 cadaveric legs (9 paired and 4 unpaired) from 11 males and 2 females. Findings. The structures that were thus observed to attach directly to the posteromedial border of the tibia were the soleus, the flexor digitorum longus, and the deep crural fascia. The soleus and flexor digitorum longus muscles were observed to attach directly to the posteromedial border of the tibia. The tibialis posterior muscle had no attachment to this site. Conclusion. The findings of this study suggest that if traction is the cause of MTSS then soleus and the flexor digitorum muscles and not the tibialis posterior muscle are the likely cause of MTSS. PMID:27066291
Lee, Hwang-Jae; Lee, Suhyun; Chang, Won Hyuk; Seo, Keehong; Shim, Youngbo; Choi, Byung-Ok; Ryu, Gyu-Ha; Kim, Yun-Hee
The aims of this study were to investigate the effectiveness of a newly developed wearable hip assist robot that uses an active assist algorithm to improve gait function, muscle effort, and cardiopulmonary metabolic efficiency in elderly adults. Thirty elderly adults (15 males/15 females) participated in this study. The experimental protocol consisted of overground gait at comfortable speed under three different conditions: free gait without robot assistance, robot-assisted gait with zero torque (RAG-Z), and full robot-assisted gait (RAG). Under all conditions, muscle effort was analyzed using a 12-channel surface electromyography system. Spatio-temporal data were collected at 120 Hz using a 3D motion capture system with six infrared cameras. Metabolic cost parameters were collected as oxygen consumption per unit (ml/min/kg) and aerobic energy expenditure (Kcal/min). In the RAG condition, participants demonstrated improved gait function, decreased muscle effort, and reduced metabolic cost. Although the hip assist robot only provides assistance at the hip joint, our results demonstrated a clear reduction in knee and ankle muscle activity in addition to decreased hip flexor and extensor activity. Our findings suggest that this robot has the potential to improve stabilization of the trunk during walking in elderly adults.
Mickle, Karen J; Steele, Julie R
There is evidence to suggest being overweight or obese places adults at greater risk of developing foot complications such as osteoarthritis, tendonitis and plantar fasciitis. However, no research has comprehensively examined the effects of overweight or obesity on the feet of individuals older than 60 years of age. Therefore we investigated whether foot pain, foot structure, and/or foot function is affected by obesity in older adults. Three hundred and twelve Australian men and women, aged over 60 years, completed validated questionnaires to establish the presence of foot pain and health related quality of life. Foot structure (anthropometrics and soft tissue thickness) and foot function (ankle dorsiflexion strength and flexibility, toe flexor strength, plantar pressures and spatiotemporal gait parameters) were also measured. Obese participants (BMI >30) were compared to those who were overweight (BMI=25-30) and not overweight (BMI <25). Obese participants were found to have a significantly higher prevalence of foot pain and scored significantly lower on the SF-36. Obesity was also associated with foot-related functional limitation whereby ankle dorsiflexion strength, hallux and lesser toe strength, stride/step length and walking speed were significantly reduced in obese participants compared to their leaner counterparts. Therefore, disabling foot pain and altered foot structure and foot function are consequences of obesity for older adults, and impact upon their quality of life. Interventions designed to reduce excess fat mass may relieve loading of the foot structures and, in turn, improve foot pain and quality of life for older obese individuals.
Edgerton, V. R.; Roy, R. R.; Hodgson, J. A.; Prober, R. J.; de Guzman, C. P.; de Leon, R.
The neural circuitry of the lumbar spinal cord can generate alternating extension and flexion of the hindlimbs. The hindlimbs of adult cats with complete transection of the spinal cord at a low thoracic level (T12-T13) can perform full weight-supporting locomotion on a treadmill belt moving at a range of speeds. Some limitations in the locomotor capacity can be associated with a deficit in the recruitment level of the fast extensors during the stance phase and the flexors during the swing phase of a step cycle. The level of locomotor performance, however, can be enhanced by daily training on a treadmill while emphasizing full weight-support stepping and by providing appropriately timed sensory stimulation, loading, and/or pharmacologic stimulation of the hindlimb neuromuscular apparatus. Furthermore, there appears to be an interactive effect of these interventions. For example, the maximum treadmill speed that a spinal adult cat can attain and maintain is significantly improved with daily full weight-supporting treadmill training, but progressive recruitment of fast extensors becomes apparent only when the hindlimbs are loaded by gently pulling down on the tail during the stepping. Stimulation of the sural nerve at the initiation of the flexion phase of the step cycle can likewise markedly improve the locomotor capability. Administration of clonidine, in particular in combination with an elevated load, resulted in the most distinct and consistent alternating bursts of electromyographic activity during spinal stepping. These data indicate that the spinal cord has the ability to execute alternating activation of the extensor and flexor musculature of the hindlimbs (stepping) and that this ability can be improved by several interventions such as training, sensory stimulation, and use of some pharmacologic agents. Thus, it appears that the spinal cord, without supraspinal input, is highly plastic and has the potential to "learn," that is, to acquire and improve its
Charles, John; Morrison, Joanna
Presents a list of adult mystery titles for young adult readers. Includes first titles in a series (for reading in order); new and lesser-known mystery authors' works are the focus. Annotations include plot summary. The rest of each annotation is for professional use (includes date and name of award bestowed). (AEF)
Gill, Sam D.
Argues that young adult literature can play a significant role in the emotional and mental health of an adolescent as well as help young males become more literate. Offers a 19-item annotated list of young adult novels with male protagonists, sorted by themes: nature and adventure stories, sports stories, genre stories, historical stories, and…
Stickle, Fred; Onedera, Jill D.
The purpose of this article is to address selected aspects of depression in older adults. Specifically, symptoms, risk factors, diagnosis, and interventions for depression in older adults are reviewed.
... ACIP Vaccination Recommendations Why Immunize? Vaccines: The Basics Immunization Schedules for Adults in Easy-to-read Formats ... previous immunizations. View or Print a Schedule Recommended Immunizations for Adults (19 Years and Older) by Age ...
Hall, Clyde W.
Summarized are speeches dealing with adult education's stiff-necked adherence to middle-class values; the need for upgraded management skills; and a report of a study of adult education in area vocational schools in Georgia. (Author/AJ)
Miller, Harry; And Others
Folk high schools, study circles, labor market training, union education, and municipal adult schools are the major providers of adult education in Sweden. For the most part, these programs are financed by the government and are tuition free. Folk high schools, which are the oldest type, were founded to provide young adults with a general civic…
The 14 chapters of this textbook chronicle adult development from youth through old age, emphasizing both research and interviews with adults at various stages in their lives. Topics covered include the following: (1) the academic field of adult development; (2) theories and research methods; (3) aging and disease prevention; (4) sexuality and…
Walsko, Gregory M.
The purpose of this instrument is to supplement data from the Adult Basic Learning Examination in assessing the functional level of adults in daily situations. It may also be used as a teaching tool for adults requesting tutoring in specific concepts and skills presented in the instrument. This instrument is an informal assessment instrument and…
Seita, John R.; Brendtro, Larry K.
Kids who distrust adults are highly skilled at hiding their real nature and resisting change. Most adults shun such youths or get mired in conflict with them. Punitive get tough practices as well as traditional flaw-fixing treatment are reactive strategies that often drive these youths further from adult bonds and reinforce oppositional and…
Short, W. Fisher
The impact of urbanization, the main tasks facing the adult educator in an urban context, identifying the casualties of urbanization, recognizing and dealing with social deprivation, and the various agencies involved in adult education are relevant considerations for adult educators. (MW)
Foley, Griff, Ed.
This broad introduction to adult and postcompulsory education offers an overview of the field for students, adult educators and workplace trainers. The book establishes an analytical framework to emphasize the nature of learning and agency of learners; examines the core knowledge and skills that adult educators need; discusses policy, research and…
Sutherland, Peter, Ed.
This book on adult learning is divided into six sections. Section 1, Cognitive Processes, includes the following chapters: "Cognitive Processes: Contemporary Paradigms of Learning" (Jack Mezirow); "Information Processing, Memory, Age and Adult Learning" (Gillian Boulton-Lewis); "Adult Learners' Metacognitive Behaviour in Higher Education" (Barry…
Kirmayer, Paul, Ed.; And Others
This volume contains 13 articles that reflect the development of adult education in Israel during recent years. The material relates to the principal areas with which the Division of Adult Education deals: formal and nonformal education for adults, language and cultural absorption of new immigrants, and training of facilitators for parental…
Notar, Charles E.; Padgett, Sharon
Do adults play a role in bullying? Do parents, teachers, school staff, and community adult leaders influence bullying behavior in children and teenagers? This article will focus on research regarding all adults who have almost daily contact with children and teens and their part in how bullying is identified, addressed, and prevented. This article…
The central aim of this article is to analyse the current situation of adult education in Greece. The article focuses on the following points: (a) the degree of participation in programmes of continuing professional training and general adult education courses, (b) the quality and the outcomes of the adult education provision in Greece, and (c)…
Bureau of Occupational and Adult Education (DHEW/OE), Washington, DC. Div. of Adult Education.
A compilation of abstracts of 120 current Adult Performance Level (APL) and Adult Competency Education (ACE) federally supported projects being conducted in 34 States and the District of Columbia, this project profile was developed for adult and secondary education administrators, teachers, and program developers who are beginning or are currently…
Bureau of Occupational and Adult Education (DHEW/OE), Washington, DC. Div. of Adult Education.
A compilation of brief descriptions of 20 current resources for Adult Performance Level (APL) and Adult Competency Education (ACE) programs, this guide was developed for adult and secondary education administrators, teachers, and program developers who are beginning or are already involved with APL/ACE programs. Each citation contains information…
Cora, Marie T., Ed.; Wood, Nicole R., Ed.
This handbook was written specifically for volunteer tutors but is appropriate for teachers, student interns, coordinators, and others working with Adult Basic Education (ABE) and English-as-a-Second-Language (ESL) adult learners. It presents an overview of adult and non-traditional education models, some principles of reading and writing, a…
Brooke, W. Michael, Comp.
"Trends," a publication of the Canadian Association for Adult Education, is a collection of abstracts on selected subjects affecting adult education; this issue is on adult basic education (ABE). It covers teachers and teacher training, psychological factors relating to the ABE teacher and students, manuals for teachers, instructional…
Boegen, Anne, Ed.
Designed to offer guidelines, ideas and help to those who provide library service to young adults, this manual includes information about the provision of young adult (YA) services in six sections. The first section, which addresses planning and administration, includes a definition of a young adult and a checklist for determining community needs…
Which competences do professional adult educators need? This research note discusses the topic from a comparative perspective, finding that adult educators' required competences are wide-ranging, heterogeneous and complex. They are subject to context in terms of national and cultural environment as well as the kind of adult education concerned…
South Carolina Literacy Resource Center, Columbia.
This curriculum framework for adult literacy was written by 21 South Carolina adult English-as-a-Second-Language (ESL) instructors, as submitted to the South Carolina Literacy Resource Center. It is based on current theories in the fields of adult education and second language acquisition and is designed to be flexible so that it may be adapted to…
Presazzi, A; Bortolotto, C; Zacchino, M; Madonia, L; Draghi, F
The carpal tunnel is an osteofibrous canal situated in the volar wrist. The boundaries are the carpal bones and the flexor retinaculum. In addition to the medial nerve, the carpal tunnel contains nine tendons: the flexor pollicis longus, the four flexor digitorum superficialis and the four flexor digitorum profundus. Ultrasound (US) study of the carpal tunnel generally involves short-axis imaging of the tendons, and in the presence of disease, long-axis imaging and dynamic maneuvers are added. There are numerous reports of anatomical variants of the wrist involving vessels, nerves, tendons and muscles, and they can all be studied by US. Some are particularly relevant from a clinical point of view and will therefore be accurately described. The anatomy is complex, and the US operator should therefore be thoroughly familiar with the normal anatomy as well as the anatomical variants that may have a role in the pathogenesis of carpal tunnel syndrome or influence treatment.
Yoon, Tejin; Schlinder-Delap, Bonnie; Keller, Manda L; Hunter, Sandra K
This study determined the contribution of supraspinal fatigue and contractile properties to the age difference in neuromuscular fatigue during and recovery from a low-intensity sustained contraction. Cortical stimulation was used to evoke measures of voluntary activation and muscle relaxation during and after a contraction sustained at 20% of maximal voluntary contraction (MVC) until task failure with elbow flexor muscles in 14 young adults (20.9 ± 3.6 yr, 7 men) and 14 old adults (71.6 ± 5.4 yr, 7 men). Old adults exhibited a longer time to task failure than the young adults (23.8 ± 9.0 vs. 11.5 ± 3.9 min, respectively, P < 0.001). The time to failure was associated with initial peak rates of relaxation of muscle fibers and pressor response (P < 0.05). Increments in torque (superimposed twitch; SIT) generated by transcranial magnetic stimulation (TMS) during brief MVCs, increased during the fatiguing contraction (P < 0.001) and then decreased during recovery (P = 0.02). The increase in the SIT was greater for the old adults than the young adults during the fatiguing contraction and recovery (P < 0.05). Recovery of MVC torque was less for old than young adults at 10 min post-fatiguing contraction (75.1 ± 8.7 vs. 83.6 ± 7.8% of control MVC, respectively, P = 0.01) and was associated with the recovery of the SIT (r = -0.59, r(2) = 0.35, P < 0.001). Motor evoked potential (MEP) amplitude and the silent period elicited during the fatiguing contraction increased less for old adults than young adults (P < 0.05). The greater fatigue resistance with age during a low-intensity sustained contraction was attributable to mechanisms located within the muscle. Recovery of maximal strength after the low-intensity fatiguing contraction however, was impeded more for old adults than young because of greater supraspinal fatigue. Recovery of strength could be an important variable to consider in exercise prescription of old populations.
... Autism Spectrum Disorder (ASD) Eating Disorders Among Adults - Anorexia Nervosa Eating Disorders Among Adults - Binge Eating Disorder ... Autism Spectrum Disorder (ASD) Eating Disorders Among Adults - Anorexia Nervosa Eating Disorders Among Adults - Binge Eating Disorder ...
Justice, Jamie N; Mani, Diba; Pierpoint, Lauren A; Enoka, Roger M
Declines in neuromuscular function, including measures of mobility, muscle strength, steadiness, and patterns of muscle activation, accompany advancing age and are often associated with reduced quality of life and mortality. Paradoxically, older adults are less fatigable than young adults in some tasks. The purpose of this study was to determine the influence of age on fatigability of the dorsiflexors and to evaluate the ecological validity of this test by comparing it to motor function subdomains known to decline with advancing age. The community-dwelling older adults (n=52, 75.2±6.0years) were more fatigable than young adults (n=26, 22.2±3.7years), as assessed by endurance time for supporting a submaximal load (20% of one-repetition maximum; 1-RM) with an isometric contraction of the dorsiflexor muscles (8.9±0.6min and 15.5±0.9min, p<0.001), including participants matched for 1-RM load and sex (Y: 13.3±4.0min, O: 8.5±6.1min, n=11 pairs, 6 women, p<0.05). When the older adults were separated into two groups (65-75 and 76-90years), however, only endurance time for the oldest group was less than that for the other two groups (p<0.01). All measures of motor function were significantly correlated (all p<0.05) with dorsiflexor endurance time for the older adults, and multiple regression analysis revealed that the variance in endurance time was most closely associated with age, steadiness, and knee flexor strength (R(2)=0.50, p<0.001). These findings indicate that dorsiflexor fatigability provides a valid biomarker of motor function in older adults.
Kobayashi, H; Koyama, Y; Enoka, R M; Suzuki, S
Beginning Movement Load (BML) training is a unique form of light-load training that comprises a lengthening-shortening sequence of muscle actions about multiple degrees of freedom. The purpose of the study was to determine the effectiveness of BML training at improving the performance of old adults on four functional tasks and to identify some of the neuromuscular adaptations that contributed to these gains. Healthy old adults (67.5 ± 5.23 years) were randomly assigned to either a BML training group (n = 17) or a control group (n = 7). The training group exercised with a 30% of the one repetition-maximum (1-RM) load and performed five to seven sets of 15 repetitions, three times per week for 8 weeks. BML training increased maximal voluntary contraction (MVC) force significantly for the knee extensors (31.6%), but not the elbow flexors (9.8%), and improved the steadiness of isometric contractions (10%, 30%, and 65% MVC forces). Training-associated changes in times for ascending and descending stairs and one-legged balance, but not the chair rise, were predicted by changes in selected combinations of MVC force and steadiness. The attributes of BML training that enabled it to elicit functionally meaningful adaptations in the neuromuscular system of older adults should be explored with more mechanistic studies.
ESCAPS study protocol: a feasibility randomised controlled trial of ‘Early electrical stimulation to the wrist extensors and wrist flexors to prevent the post-stroke complications of pain and contractures in the paretic arm’
Fletcher-Smith, Joanna C; Walker, Dawn-Marie; Sprigg, Nikola; James, Marilyn; Walker, Marion F; Allatt, Kate; Mehta, Rajnikant; Pandyan, Anand D
Introduction Approximately 70% of patients with stroke experience impaired arm function, which is persistent and disabling for an estimated 40%. Loss of function reduces independence in daily activities and impacts on quality of life. Muscles in those who do not recover functional movement in the stroke affected arm are at risk of atrophy and contractures, which can be established as early as 6 weeks following stroke. Pain is also common. This study aims to evaluate the feasibility of a randomised controlled trial to test the efficacy and cost-effectiveness of delivering early intensive electrical stimulation (ES) to prevent post-stroke complications in the paretic upper limb. Methods and analysis This is a feasibility randomised controlled trial (n=40) with embedded qualitative studies (patient/carer interviews and therapist focus groups) and feasibility economic evaluation. Patients will be recruited from the Stroke Unit at the Nottingham University Hospitals National Health Service (NHS) Trust within 72 h after stroke. Participants will be randomised to receive usual care or usual care and early ES to the wrist flexors and extensors for 30 min twice a day, 5 days a week for 3 months. The initial treatment(s) will be delivered by an occupational therapist or physiotherapist who will then train the patient and/or their nominated carer to self-manage subsequent treatments. Ethics and dissemination This study has been granted ethical approval by the National Research Ethics Service, East Midlands Nottingham1 Research Ethics Committee (ref: 15/EM/0006). To our knowledge, this is the first study of its kind of the early application (within 72 h post-stroke) of ES to both the wrist extensors and wrist flexors of stroke survivors with upper limb impairment. The results will inform the design of a definitive randomised controlled trial. Dissemination will include 2 peer-reviewed journal publications and presentations at national conferences. Trial
Antonopoulos, Christos; Patikas, Dimitrios; Koutlianos, Nikolaos; Papadopoulou, Sofia D.; Chatzopoulos, Dimitrios; Hatzikotoulas, Konstantinos; Bassa, Eleni; Kotzamanidis, Christos
The aim of this study was to investigate the effect of fatigue on electromyographic (EMG) parameters of healthy young adults during obstacle crossing of two different heights. Twelve untrained male adults (23 ± 5 years of age) were fatigued running on a treadmill with increasing speed and inclination and walked over an obstacle with a height set at 10% and 20% of each individual’s lower limb length. Maximal plantar flexor torque and EMG of the medial gastrocnemius, soleus, and tibialis anterior muscles of the trailing limb were assessed during obstacle crossing. Data were captured before, immediately after and 5 minutes after a fatigue session. Fatigue induced significant reduction on the plantar flexor torque output immediately after and 5 minutes after exhaustion. After fatigue gait speed was not affected, the minimum distance between the obstacle and the trailing or leading foot remained unchanged, and the trailing foot contacted the ground closer to the obstacle immediately after fatigue. Regarding the EMG, medial gastrocnemius became after fatigue more active during swing phase when increasing the obstacle height, whereas this was not the case before or 5 minutes after fatigue. No other significant difference was observed for any of the examined muscles. It is concluded that the assessed fatigue protocol induced only minimal changes in the EMG activity of the examined muscles during obstacle crossing. Therefore, it is suggested that the neuromuscular system of healthy young individuals is able to respond to the decreased force capacity after fatigue during obstacle crossing of heights up to the 20% of the limb length. Key Points Exhaustion after running on a treadmill induces significant reduction in plantar flexion strength and changes in the positioning of the feet relative to the obstacle during obstacle crossing. EMG activity of the calf muscles of the trailing limb does not change significantly after fatigue during the stance phase During swing phase
Maclellan, M J; Ivanenko, Y P; Cappellini, G; Sylos Labini, F; Lacquaniti, F
Interlimb coordination of crawling kinematics in humans shares features with other primates and nonprimate quadrupeds, and it has been suggested that this is due to a similar organization of the locomotor pattern generators (CPGs). To extend the previous findings and to further explore the neural control of bipedal vs. quadrupedal locomotion, we used a crawling paradigm in which healthy adults crawled on their hands and feet at different speeds and at different surface inclinations (13°, 27°, and 35°). Ground reaction forces, limb kinematics, and electromyographic (EMG) activity from 26 upper and lower limb muscles on the right side of the body were collected. The EMG activity was mapped onto the spinal cord in approximate rostrocaudal locations of the motoneuron pools to characterize the general features of cervical and lumbosacral spinal cord activation. The spatiotemporal pattern of spinal cord activity significantly differed between quadrupedal and bipedal gaits. In addition, participants exhibited a large range of kinematic coordination styles (diagonal vs. lateral patterns), which is in contrast to the stereotypical kinematics of upright bipedal walking, suggesting flexible coupling of cervical and lumbosacral pattern generators. Results showed strikingly dissimilar directional horizontal forces for the arms and legs, considerably retracted average leg orientation, and substantially smaller sacral vs. lumbar motoneuron activity compared with quadrupedal gait in animals. A gradual transition to a more vertical body orientation (increasing the inclination of the treadmill) led to the appearance of more prominent sacral activity (related to activation of ankle plantar flexors), typical of bipedal walking. The findings highlight the reorganization and adaptation of CPG networks involved in the control of quadrupedal human locomotion and a high specialization of the musculoskeletal apparatus to specific gaits.
Casimiro-Lopes, G; Lisboa, P C; Koury, J C; Boaventura, G; Passos, M C F; Moura, E G
Maternal prolactin inhibition at the end of lactation programs for metabolic syndrome and hypothyroidism in adult offspring, which could negatively affect exercise performance. We evaluated the effects of maternal hypoprolactinemia in late lactation on physical performance in adult progeny. Lactating Wistar rats were treated with bromocriptine (BRO, 1 mg per day) or saline on days 19, 20, and 21 of lactation and offspring were followed until 180 days old. Physical performance was recorded in untrained rats at 90 and 180 days by an acute exhaustive swimming test (exercise group-Ex). At day 90, BRO offspring showed higher visceral fat mass, higher plasma thiobarbituric acid reactive substances, lower total antioxidant capacity, higher liver glycogen, lower glycemia, and normal insulinemia. Although thyroid hormones (TH) levels were unchanged, mitochondrial glycerol phosphate dehydrogenase (mGPD) activity was lower in muscle and in brown adipose tissue (BAT). At this age, BRO-Ex offspring showed higher exercise capacity, lower blood lactate, higher serum T3, and higher muscle and BAT mGPD activities. At day 180, BRO offspring showed central obesity, hypothyroidism, insulin resistance, and lower EDL (extensor digitorum longus) muscle glycogen with unaltered plasma oxidative stress markers. This group showed no alteration of exercise capacity or blood lactate. After exercise, EDL and liver glycogen were lower, while T3 levels, BAT and muscle mGPD activities were normalized. Liver glycogen seem to be related with higher exercise capacity in younger BRO offspring, while the loss of this temporary advantage maybe related to the hypothyroidism and insulin resistance developed with age.
California Community Colleges, Chancellor's Office, 2015
For more than one hundred and fifty years, until 2008, California was an undisputed national leader in its commitment to adult education. The state's investment in adult learners topped $750 million, a sum greater than the combined total of every other state in the nation. However, for the past several years recession and fiscal crisis have left…
The Bookmark, 1985
Eight articles in this Spring 1985 issue of The Bookmark focus on young adult library services. In addition to these thematic articles, an introduction and three reports are presented. The issue contains: (1) "In Perspective" (E. J. Josey); (2) "Young Adult Literature in the 1980's--Awesome!" (Ellin Chu); (3) "Young Adult…
As a foundation for discussing transpersonal adult development, the author traces her trajectory, involvement in, and contribution to the modern transpersonal movement and her introduction of it to the adult learning literature, beginning during the early 1980s. Highlighted are the transpersonal domain and a differentiation between transpersonal…
A Smart Choice Adult Day Services Comparison At-a-Glance 1 Adult Day Services Assisted Living Home Care Nursing Homes Live at home with family ... supervision Nursing care available as needed during the day Flexibility to receive care only on days when ...
For over 2 years, Blak Hawk College (Illinois) has provided high school equivalency (GED) candidates and recipients, older returning students, and underprepared high school graduates with a Tech Prep curriculum to give them the skills to make the transition from adult basic education to college or work. The Adult Tech Prep (ATP) core curriculum…
This paper is concerned with the relationship between authenticity and adult learning and prompted by some studies in which adult "authentic learning" is a central concept. The implication revealed by them is that real-worldness of learning contexts, learning content and learning tasks is perceived as conferring authenticity on learning. Here,…
Rubenson, Kjell, Ed.
As individuals and societies try to respond to fundamental economic and social transformation, the field of adult learning and education is rapidly getting increased attention and new topics for research on adult learning have emerged. This collection of articles from the International Encyclopedia of Education 3e offers practitioners and…
Who are the adult students in career and technical education (CTE) today? There is not one simple answer to that question. Some are young with little life experience, while others are returning to the workforce and learning new skills to reinvent themselves. Whatever the case, educating adult students is an integral part of ACTE's mission, and the…
Saadat, Ahmed H.
The philosophy behind adult literacy in Zanzibar is that adult literacy is a process whereby the illiterate is empowered to become aware of his or her potential. Literacy activities emphasize a relation to work, sometimes known as functional literacy. Specific objectives of literacy programs are to improve living conditions, impart self-reliant…
Proposes a "spatial-temporal" model conceiving adult vocational development as a complex and constant readjustment in always changing perception of personal space-time, based on interviews of 786 adults. Presents two propositions of this model: the continuous alternation between states of instability and interaction of influences.…
This review presents various resources about working with adult adoptees in order to inform counselors in their practice. Topics covered include basics of adoption, including types of adoption and adoption statistics; possible issues adult adoptees may face; and suggestions and implications for counselors. The article addresses some of the serious…
Flint, Thomas A.; Frey, Ruth
The Council for Adult and Experiential Learning is currently cataloguing alternative programming features that are most effective with adult students in a best practices inventory organized around a framework of high-level descriptive principles of effectiveness. This chapter identifies a few interesting features from a quick survey of this…
Hinzen, Heribert, Ed.
This document contains 19 papers on adult education and development worldwide. The following papers are included: "Editorial" (Heribert Hinzen); "Lifelong Learning in Europe: Moving towards EFA (Dakar Framework for Action on Education for All) Goals and the CONFINTEA V Agenda" (Sofia Conference on Adult Education);…
Ever since the first ideas of national independence appeared in Finland, adult education has played an essential role in shaping the destiny of the Finns. With a history of almost 130 years, during which it has continuously increased in quality and quantity, the Finnish adult education system has ensured that Finland stays among the most…
The 2008 EFA Global Monitoring Report recognises adult literacy as the most neglected of the EFA goals. It is neglected most obviously in respect of the financial allocations made by governments and donors. This shortage of financing creates a dangerous situation in which adult educators seek to convince politicians to invest, based on false…
Zucker, Kenneth J; Lawrence, Anne A; Kreukels, Baudewijntje P C
Gender dysphoria (GD), a term that denotes persistent discomfort with one's biologic sex or assigned gender, replaced the diagnosis of gender identity disorder in the Diagnostic and Statistical Manual of Mental Disorders in 2013. Subtypes of GD in adults, defined by sexual orientation and age of onset, have been described; these display different developmental trajectories and prognoses. Prevalence studies conclude that fewer than 1 in 10,000 adult natal males and 1 in 30,000 adult natal females experience GD, but such estimates vary widely. GD in adults is associated with an elevated prevalence of comorbid psychopathology, especially mood disorders, anxiety disorders, and suicidality. Causal mechanisms in GD are incompletely understood, but genetic, neurodevelopmental, and psychosocial factors probably all contribute. Treatment of GD in adults, although largely standardized, is likely to evolve in response to the increasing diversity of persons seeking treatment, demands for greater client autonomy, and improved understanding of the benefits and limitations of current treatment modalities.
Fiske, Amy; Wetherell, Julie Loebach; Gatz, Margaret
Depression is less prevalent among older adults than among younger adults but can have serious consequences. Over half of cases represent a first onset in later life. Although suicide rates in the elderly are declining, they are still higher than in younger adults and more closely associated with depression. Depressed older adults are less likely to endorse affective symptoms and more likely to display cognitive changes, somatic symptoms, and loss of interest than are younger adults. Risk factors leading to the development of late life depression likely comprise complex interactions among genetic vulnerabilities, cognitive diathesis, age-associated neurobiological changes, and stressful events. Insomnia is an often overlooked risk factor for late life depression. We suggest that a common pathway to depression in older adults, regardless of which predisposing risks are most prominent, may be curtailment of daily activities. Accompanying self-critical thinking may exacerbate and maintain a depressed state. Offsetting the increasing prevalence of certain risk factors in late life are age-related increases in psychological resilience. Other protective factors include higher education and socioeconomic status, engagement in valued activities, and religious or spiritual involvement. Treatments including behavioral therapy, cognitive behavioral therapy, cognitive bibliotherapy, problem-solving therapy, brief psychodynamic therapy, and life review/reminiscence therapy are effective but too infrequently used with older adults. Preventive interventions including education for individuals with chronic illness, behavioral activation, cognitive restructuring, problem-solving skills training, group support, and life review have also received support. PMID:19327033
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The paper examines the role of adult education and the contribution it can make to the solution of current problems in developing countries, particularly the problems of economic under-development and over-population. (Author/AG)
Taylor, J. Rodney
The author reviews theories of human motivation: Lewin's force field analysis, Skinner's operant reinforcement theory, and Maslow's hierarchy of needs. He then extracts the implications of these theories for adult learning. SK)
... find more information? Reprints Share Older Adults and Depression Download PDF Download ePub Order a free hardcopy ... depression need treatment to feel better. Types of Depression There are several types of depression. The most ...
Epstein, Connie C.
Considers the similarities between science fiction writing and young adult literature, and points out that several well-known authors, such as Robert Heinlein and Jane Yolen, write in both genres. (NKA)
This book approaches adult cardiac disease from the correlative imaging perspective. It includes chest X-rays and angiographs, 2-dimensional echocardiograms with explanatory diagrams for clarity, plus details on digital radiology, nuclear medicine techniques, CT and MRI. It also covers the normal heart, valvular heart disease, myocardial disease, pericardial disease, bacterial endocarditis, aortic aneurysm, cardiac tumors, and congenital heart disease of the adult. It points out those aspects where one imaging technique has significant superiority.
Which competences do professional adult educators need? This research note discusses the topic from a comparative perspective, finding that adult educators' required competences are wide-ranging, heterogeneous and complex. They are subject to context in terms of national and cultural environment as well as the kind of adult education concerned (e.g. basic education, work-related education etc.). However, it seems that it is possible to identify certain competence requirements which transcend national, cultural and functional boundaries. This research note summarises these common or "core" requirements, organising them into four thematic subcategories: (1) communicating subject knowledge; (2) taking students' prior learning into account; (3) supporting a learning environment; and (4) the adult educator's reflection on his or her own performance. At the end of his analysis of different competence profiles, the author notes that adult educators' ability to train adult learners in a way which then enables them to apply and use what they have learned in practice (thus performing knowledge transfer) still seems to be overlooked.
Kuitert, R B
The number of adults undergoing orthodontic treatment has increased strongly and the average age that adult patients undergo orthodontic treatment increased steadily although 3/4 is still younger than 27 years. In adults the facial skeletal pattern can only be changed in a very confined way, consequently in case of an abnormal skeletal pattern one has to choose between a combined orthodontic-surgical approach (which is the case in 18% of the patients) and a compromised orthodontic treatment, if necessary combined with other disciplines. It is still controversial whether tooth movement in adults is slower and more difficult than in adolescents. The same holds true for the risk for loss of periodontal support, for root resorption, for gnathologic problems and for relapse. As related to these variables there appears to be a large individual variation. Many adults show one or more problems in their dentition that may influence their orthodontic treatment. About 60% of the adult patients need a multidisciplinary approach. The development of implantology and of bone regeneration and bone grafting has lead to more combined treatments. The risks of such complex treatment plans are generally larger than those for more simple kinds of treatment. A very careful treatment planning and good communication between the different specialists is essential. Moreover the treatment plan with all its (dis)advantages has to be extensively discussed with the patient.
Wada, N; Kanda, Y; Takayama, R
Experiments were performed on 16 adult spinalized (L2) cats. Postsynaptic potentials (PSPs) produced by electrical stimulation of afferent nerves innervating foot pads were recorded from hindlimb motoneurons innervating the following hindlimb muscles: the posterior biceps and semitendinosus (PBSt), anterior biceps and semimembranosus (ABSm), lateral gastrocnemius and soleus (LGS), medial gastrocnemius (MG), plantaris (P1), tibialis anterior (TA), popliteus (Pop), flexor digitorum longus and flexor hallucis longus (FDHL) and peroneus longus (Per.l). The rate of occurrence of different types of PSPs (EPSPs, IPSPs and mixed PSPs), the size of the PSPs and their central latencies were analyzed for each group of motoneurons to identify the neural pathways from the afferents innervating foot pads to hindlimb motoneurons. The rates of occurrence of different types of PSPs did not depend on the foot pad stimulated in PBSt, ABSm and LGS motoneurons, but for other groups of motoneurons their rates of occurrence depended on the foot pad stimulated. It was often noted that the size of PSPs in the same motoneurons differed according to the foot pad stimulated. Measurements of the central latencies of the PSPs indicated that the shortest neural pathways for EPSPs and IPSPs were disynaptic (central latencies < 1.8 ms). The functional role of neuronal pathways from afferent nerves innervating foot pads to hindlimb motoneurons could be to maintain stability of the foot during different postural and motor activities.
Walker, Eric A.; Petscavage, Jonelle M.; Brian, Pamela L.; Logie, Chika Iloanusi; Montini, Kenneth M.; Murphey, Mark D.
The fibromatoses are a group of benign fibroblastic proliferations that vary from benign to intermediate in biological behavior. This article will discuss imaging characteristics and patient demographics of the adult type superficial (fascial) and deep (musculoaponeurotic) fibromatoses. The imaging appearance of these lesions can be characteristic (particularly when using magnetic resonance imaging). Palmar fibromatosis demonstrates multiple nodular or band-like soft tissue masses arising from the proximal palmar aponeurosis and extending along the subcutaneous tissues of the finger in parallel to the flexor tendons. T1 and T2-weighted signal intensity can vary from low (higher collagen) to intermediate (higher cellularity), similar to the other fibromatoses. Plantar fibromatosis manifests as superficial lesions along the deep plantar aponeurosis, which typically blend with the adjacent plantar musculature. Linear tails of extension (“fascial tail sign”) along the aponeurosis are frequent. Extraabdominal and abdominal wall fibromatosis often appear as a heterogeneous lesion with low signal intensity bands on all pulse sequences and linear fascial extensions (“fascial tail” sign) with MR imaging. Mesenteric fibromatosis usually demonstrates a soft tissue density on CT with radiating strands projecting into the adjacent mesenteric fat. When imaging is combined with patient demographics, a diagnosis can frequently be obtained. PMID:22966216
Walker, Eric A; Petscavage, Jonelle M; Brian, Pamela L; Logie, Chika Iloanusi; Montini, Kenneth M; Murphey, Mark D
The fibromatoses are a group of benign fibroblastic proliferations that vary from benign to intermediate in biological behavior. This article will discuss imaging characteristics and patient demographics of the adult type superficial (fascial) and deep (musculoaponeurotic) fibromatoses. The imaging appearance of these lesions can be characteristic (particularly when using magnetic resonance imaging). Palmar fibromatosis demonstrates multiple nodular or band-like soft tissue masses arising from the proximal palmar aponeurosis and extending along the subcutaneous tissues of the finger in parallel to the flexor tendons. T1 and T2-weighted signal intensity can vary from low (higher collagen) to intermediate (higher cellularity), similar to the other fibromatoses. Plantar fibromatosis manifests as superficial lesions along the deep plantar aponeurosis, which typically blend with the adjacent plantar musculature. Linear tails of extension ("fascial tail sign") along the aponeurosis are frequent. Extraabdominal and abdominal wall fibromatosis often appear as a heterogeneous lesion with low signal intensity bands on all pulse sequences and linear fascial extensions ("fascial tail" sign) with MR imaging. Mesenteric fibromatosis usually demonstrates a soft tissue density on CT with radiating strands projecting into the adjacent mesenteric fat. When imaging is combined with patient demographics, a diagnosis can frequently be obtained.
Khalil, Aya A.; Mohamed, Ghada A.; El Rahman, Soheir M. Abd; Elhafez, Salam M.; Nassif, Nagui S.
[Purpose] This study was conducted to investigate the effect of Wiihabilitation on the ankle dorsiflexion/plantar flexion strength ratio in adults. [Subjects and Methods] Thirty-two healthy male volunteers were randomly assigned to two equal groups (experimental and control). Participants in the experimental group received a Wiihabilitation training program for six weeks. Data were collected using a Biodex system 3 Isokinetic dynamometer. Peak torques of the dorsiflexors and plantar flexors were measured at an angular velocity of 60°/sec which in turn were used to derive the ankle dorsiflexion/plantar flexion strength ratio. [Results] The mean values of the ankle dorsiflexion/plantar flexion strength ratio decreased significantly between before and after the training in the experimental group, meanwhile there was no significant difference between before and after the training period in the control group . [Conclusion] Wiihabilitation has an impact on the ankle dorsiflexion/plantar flexion strength ratio, so it can be considered an effective training tool in terms of the ankle strength ratio. Thus, it could be recommended for both prevention and rehabilitation of ankle instability patients. PMID:27821951
In this paper, the author looks at the state of adult education in Ireland. He is suggesting that the state here means both the condition in which one now finds adult education and the role of the Irish State in adult education. He briefly outlines some recent developments in adult education, makes some critical comments on the state of adult…
According to the 2003 National Assessment of Adult Literacy, it is estimated that 93 million adults in the United States have basic or below basic literacy skills. Those individuals found most lacking in literacy skills were adults living in poverty, adults lacking a high school diploma, seniors and the elderly aged 65 and older, the more than one…
Intended for planners of adult education curriculums, this literature review explains the concepts involved in designing an adult education program, provides information about the roles of the people involved in the adult education process, cites some program planning models, and applies the program planning principles to an Adult Basic Education…
Lucas, John A., Ed.
Topics concerning the adult learner that are relevant to institutional researchers are addressed in four articles: marketing, predicting success for adult students, enrollment projection, and follow-up studies of adult learners. In "Institutional Research in Support of Marketing the Adult Student," Lydia Jurand notes the importance of…
Unaware of the messages a bare adult learning environment sends and its effect on adult learners, a trainer attends an intensive Reggio Emilia course and learns that the physical environment is the "third teacher"--for adults as well as for children. Using principles of Reggio, she offers suggestions for enhancing adult learning spaces and…
Moal, Bertrand; Bronsard, Nicolas; Raya, José G; Vital, Jean Marc; Schwab, Frank; Skalli, Wafa; Lafage, Virginie
AIM: To investigate fat infiltration and volume of spino-pelvic muscles in adults spinal deformity (ASD) with magnetic resonance imaging (MRI) and 3D reconstructions. METHODS: Nineteen female ASD patients (mean age 60 ± 13) were included prospectively and consecutively and had T1-weighted Turbo Spin Echo sequence MRIs with Dixon method from the proximal tibia up to T12 vertebra. The Dixon method permitted to evaluate the proportion of fat inside each muscle (fat-water ratio). In order to investigate the accuracy of the Dixon method for estimating fat vs water, the same MRI acquisition was performed on phantoms of four vials composed of different proportion of fat vs water. With Muscl’X software, 3D reconstructions of 17 muscles or group of muscles were obtained identifying the muscle’s contour on a limited number of axial images [Deformation of parametric specific objects (DPSO) Method]. Musclar volume (Vmuscle), infiltrated fat volume (Vfat) and percentage of fat infiltration [Pfat, calculated as follow: Pfat = 100 × (Vfat/Vmuscle)] were characterized by extensor or flexor function respectively for the spine, hip and knee and theirs relationship with demographic data were investigated. RESULTS: Phantom acquisition demonstrated a non linear relation between Dixon fat-water ratio and the real fat-water ratio. In order to correct the Dixon fat-water ratio, the non linear relation was approximated with a polynomial function of degree three using the phantom acquisition. On average, Pfat was 13.3% ± 5.3%. Muscles from the spinal extensor group had a Pfat significantly greater than the other muscles groups, and the largest variability (Pfat = 31.9% ± 13.8%, P < 0.001). Muscles from the hip extensor group ranked 2nd in terms of Pfat (14% ± 8%), and were significantly greater than those of the knee extensor (P = 0.030). Muscles from the knee extensor group demonstrated the least Pfat (12% ± 8%). They were also the only group with a significant correlation
Kanwar, Amrinder Jit
Adult-onset atopic dermatitis is still an under recognized condition as there are only few studies regarding this entity. As compared to childhood onset atopic dermatitis, clinical features of adult onset atopic dermatitis are still not categorized. Adult atopic dermatitis can present for the first time in adult age with atypical morphology or may progress from childhood onset. This article reviews the characteristic clinical features of adult atopic dermatitis, associated risk factors and management. PMID:27904186
Sengupta, Sabyasachi; Pan, Utsab; Khetan, Vikas
Retinoblastoma (RB) is the most common primary malignant intraocular tumor of childhood presenting usually before 5 years of age. RB in adults older than 20 years is extremely rare. A literature search using PubMed/PubMed Central, Scopus, Google Scholar, EMBASE, and Cochrane databases revealed only 45 cases till date. Over the past decade, there has been a significant increase in the number of such reports, indicating heightened level of suspicion among ophthalmologists. Compared to its pediatric counterpart, adult onset RB poses unique challenges in diagnosis and treatment. This article summarizes available literature on adult onset RB and its clinical and pathologic profile, genetics, association with retinocytoma, diagnostics, treatment, and outcomes. PMID:27609158
Seborrheic dermatitis is a common chronic-recurrent inflammatory disorder that most commonly affects adults; however, a more transient infantile form also occurs. The definitive cause of seborrheic dermatitis is unknown. However, proliferation of Malassezia species has been described as a contributing factor. The adult form of seborrheic dermatitis affects up to approximately five percent of the general population. The disorder commonly affects the scalp, face, and periauricular region, with the central chest, axillae, and genital region also involved in some cases. Pruritus is not always present and is relatively common, especially with scalp disease. A variety of treatments are available including topical corticosteroids, topical antifungal agents, topical calcineurin inhibitors, and more recently, a nonsteroidal “device ”cream. This article reviews the practical topical management of seborrheic dermatitis in the United States, focusing on the adult population. PMID:21607192
Rao, N Madhusudhana; Rambabu, K Murali; Rao, S Harinarayana
We generated transient transgenic zebrafish by applying electrical pulses subsequent to injection of DNA into muscle tissue of 3-6-month old adult zebrafish. Electroporation parameters, such as number of pulses, voltage, and amount of plasmid DNA, were optimized and found that 6 pulses of 40 V/cm at 15 mug/fish increased the luciferase expression by 10-fold compared with those in controls. By measuring the expression of luciferase, in vivo by electroporation in adult zebrafish and in vitro using fish cell line (Xiphophorus xiphidium A2 cells), the strength of three promoters (CMV, human EF-1alpha, and Xenopus EF-1alpha) was compared. Subsequent to electroporation after injecting DNA in the mid region of zebrafish, expression of green fluorescent protein was found far away from the site of injection in the head and the tail sections. Thus, electroporation in adult zebrafish provides a rapid way of testing the behavior of gene sequences in the whole organism.
Wilkinson, Katherine A; Kloefkorn, Heidi E; Hochman, Shawn
We utilized an in vitro adult mouse extensor digitorum longus (EDL) nerve-attached preparation to characterize the responses of muscle spindle afferents to ramp-and-hold stretch and sinusoidal vibratory stimuli. Responses were measured at both room (24°C) and muscle body temperature (34°C). Muscle spindle afferent static firing frequencies increased linearly in response to increasing stretch lengths to accurately encode the magnitude of muscle stretch (tested at 2.5%, 5% and 7.5% of resting length [Lo]). Peak firing frequency increased with ramp speeds (20% Lo/sec, 40% Lo/sec, and 60% Lo/sec). As a population, muscle spindle afferents could entrain 1:1 to sinusoidal vibrations throughout the frequency (10-100 Hz) and amplitude ranges tested (5-100 µm). Most units preferentially entrained to vibration frequencies close to their baseline steady-state firing frequencies. Cooling the muscle to 24°C decreased baseline firing frequency and units correspondingly entrained to slower frequency vibrations. The ramp component of stretch generated dynamic firing responses. These responses and related measures of dynamic sensitivity were not able to categorize units as primary (group Ia) or secondary (group II) even when tested with more extreme length changes (10% Lo). We conclude that the population of spindle afferents combines to encode stretch in a smoothly graded manner over the physiological range of lengths and speeds tested. Overall, spindle afferent response properties were comparable to those seen in other species, supporting subsequent use of the mouse genetic model system for studies on spindle function and dysfunction in an isolated muscle-nerve preparation.
Becker, Jonathan A; Stumbo, Jessica R
This article provides a summary of the many causes of back pain in adults. There is an overview of the history and physical examination with attention paid to red flags that alert the clinician to more worrisome causes of low back pain. An extensive differential diagnosis for back pain in adults is provided along with key historical and physical examination findings. The various therapeutic options are summarized with an emphasis on evidence-based findings. These reviewed treatments include medication, physical therapy, topical treatments, injections, and complementary and alternative medicine. The indications for surgery and specialty referral are also discussed.
Cabral Rodríguez, R; Arrieta Blanco, F J; Vicente Sánchez, F; Cordobés Martín, F J; Moreno Caballero, B
Coeliac disease is a chronic pathology of the small intestine. The pathogenic mechanism is caused by gluten intolerance. This disease present a characteristic and unspecific injury that causes nutrients and vitamins malabsorption. In adults is an underdiagnosed entity due to atypical forms. To make a premature diagnosis is basic because gluten-free diet prevent the complications after long-term like the intestinal T lymphoma and other digestives malignancies, and decrease the mortality of these patients. We present a case of adult oligosymptomatic coeliac disease in a patient with iron deficiency anaemia and vaginal bleeding. We study the clinic-nutrition and the alterations evolution of the patient.
Adults Learning, 2009
The Campaigning Alliance for Lifelong Learning is to lobby parliament for the restoration of the 1.5 million adult learning places lost over the past two years. The campaign has attracted supporters from an astonishingly wide range of backgrounds. In this article, Gordon Marsden, Caroline Biggins, Beth Walker, Mike Chaney, Peter Davies, Sian…
Taking an autobiographical approach, I tell the story of my experiences facilitating adult development, in a polytechnic and as a management consultant. I relate these to a developmental framework of Modes of Being and Learning that I created and elaborated with colleagues. I connect this picture with a number of related models, theories,…