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Sample records for plantar flexion torque

  1. Larger plantar flexion torque variability implies less stable balance in the young: an association affected by knee position.

    PubMed

    Mello, Emanuele Moraes; Magalhães, Fernando Henrique; Kohn, André Fabio

    2013-12-01

    The present study examined the association between plantar flexion torque variability during isolated isometric contractions and during quiet bipedal standing. For plantar flexion torque measurements in quiet stance (QS), subjects stood still over a force plate. The mean plantar flexion torque level exerted by each subject in QS (divided by 2 to give the torque due to a single leg) served as the target torque level for right leg force-matching tasks in extended knee (KE) and flexed knee (KF) conditions. Muscle activation levels (EMG amplitudes) of the triceps surae and mean, standard deviation and coefficient of variation of plantar flexion torque were computed from signals acquired during periods with and without visual feedback. No significant correlations were found between EMG amplitudes and torque variability, regardless of the condition and muscle being analyzed. A significant correlation was found between torque variability in QS and KE, whereas no significant correlation was found between torque variability in QS and KF, regardless of vision availability. Therefore, torque variability measured in a controlled extended knee plantar flexion contraction is a predictor of torque variability in the anterior-posterior direction when the subjects are in quiet standing. In other words, larger plantar flexion torque variability in KE (but not in KF) implies less stable balance. The mechanisms underlying the findings above are probably associated with the similar proprioceptive feedback from the triceps surae in QS and KE and poorer proprioceptive feedback from the triceps surae in KF due to the slackening of the gastrocnemii. An additional putative mechanism includes the different torque contributions of each component of the triceps surae in the two knee angles. From a clinical and research standpoint, it would be advantageous to be able to estimate changes in balance ability by means of simple measurements of torque variability in a force matching task.

  2. Mechanical power of ankle plantar flexion and subjective pain by monophasic electrical stimulation.

    PubMed

    Suzuki, Tatsuto; Watanabe, Takashi; Saura, Ryuichi; Uchiyama, Hironobu

    2011-01-01

    The aim of this study was to investigate the mechanical power of the ankle plantar flexion. The investigated power of the ankle plantar flexion would help to improve effectively the FES walking system using the ankle plantar flexion for patients and aged people in slow walking. The subjective pain by electrical stimulation sometimes becomes the burden to use the FES system. We also investigated the relationship between the mechanical power in ankle plantar flexion by electrical stimulation and the subjective pain. We developed the device to measure the ankle movement by electrical stimulation against load resistance torque. The device consisted of pads to support a single lower leg, a rotational footplate with a large pulley and a vertical weight to generate the load resistance torque, and a monophasic electrical stimulator via surface electrodes. Our results showed the proportional relationship between the mechanical power of the ankle plantar flexion and the subjective pain by electrical stimulation. To generate the same level in the ankle plantar flexor power 2.75 W under the maximum voluntary exertion, the subjective pain by electrical stimulation exceeded 70, which means the feeling of crying at the Face Pain Scale. This result would help the better design of the FES walking system using the ankle plantar flexion for patients and aged people.

  3. Calcaneal Plantar Flexion During the Stance Phase of Gait.

    PubMed

    Stamm, Stacy E; Chiu, Loren Z F

    2016-04-01

    When the rear- and forefoot are constrained, calcaneal plantar flexion may occur, deforming the longitudinal arch. Previous research has reported calcaneal motion relative to the tibia or forefoot; these joint rotations may not accurately describe rotation of the calcaneus alone. This investigation: (1) characterized the calcaneus and leg segment and ankle joint rotations during stance in gait, and (2) described the range of calcaneal plantar flexion in different structural arch types. Men (n = 14) and women (n = 16) performed gait in a motion analysis laboratory. From heel strike to heel off, the leg rotated forward while the calcaneus plantar flexed. Before foot flat, calcaneal plantar flexion was greater than forward leg rotation, resulting in ankle plantar flexion. After foot flat, forward leg rotation was greater than calcaneal plantar flexion, resulting in ankle dorsiflexion. Structural arch type was classified using the longitudinal arch angle. The range of calcaneal plantar flexion from foot flat to heel off was small in low (-2° to -8°), moderate in high (-3° to -12°), and large in normal (-2° to -20°) structural arches. Calcaneal plantar flexion in gait during midstance may reflect functional arch characteristics, which vary depending on structural arch type.

  4. Plantar flexor moment arm and muscle volume predict torque-generating capacity in young men.

    PubMed

    Baxter, Josh R; Piazza, Stephen J

    2014-03-01

    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.

  5. Imperceptible electrical noise attenuates isometric plantar flexion force fluctuations with correlated reductions in postural sway.

    PubMed

    Magalhães, Fernando Henrique; Kohn, André Fabio

    2012-03-01

    Optimal levels of noise stimulation have been shown to enhance the detection and transmission of neural signals thereby improving the performance of sensory and motor systems. The first series of experiments in the present study aimed to investigate whether subsensory electrical noise stimulation applied over the triceps surae (TS) in seated subjects decreases torque variability during a force-matching task of isometric plantar flexion and whether the same electrical noise stimulation decreases postural sway during quiet stance. Correlation tests were applied to investigate whether the noise-induced postural sway decrease is linearly predicted by the noise-induced torque variability decrease. A second series of experiments was conducted to investigate whether there are differences in torque variability between conditions in which the subsensory electrical noise is applied only to the TS, only to the tibialis anterior (TA) and to both TS and TA, during the force-matching task with seated subjects. Noise stimulation applied over the TS muscles caused a significant reduction in force variability during the maintained isometric force paradigm and also decreased postural oscillations during quiet stance. Moreover, there was a significant correlation between the reduction in force fluctuation and the decrease in postural sway with the electrical noise stimulation. This last result indicates that changes in plantar flexion force variability in response to a given subsensory random stimulation of the TS may provide an estimate of the variations in postural sway caused by the same subsensory stimulation of the TS. We suggest that the decreases in force variability and postural sway found here are due to stochastic resonance that causes an improved transmission of proprioceptive information. In the second series of experiments, the reduction in force variability found when noise was applied to the TA muscle alone did not reach statistical significance, suggesting that TS

  6. The medial gastrocnemius muscle attenuates force fluctuations during plantar flexion.

    PubMed

    Shinohara, Minoru; Yoshitake, Yasuhide; Kouzaki, Motoki; Fukunaga, Tetsuo

    2006-02-01

    Force fluctuations during steady contractions of multiple agonist muscles may be influenced by the relative contribution of force by each muscle. The purpose of the study was to compare force fluctuations during steady contractions performed with the plantar flexor muscles in different knee positions. Nine men (25.8+/-5.1 years) performed steady contractions of the plantar flexor muscles in the knee-flexed and knee-extended (greater involvement of the gastrocnemii muscles) positions. The maximal voluntary contraction (MVC) force was 32% greater in the knee-extended position compared with the knee-flexed position. The target forces were 2.5-10% MVC force in the respective position. The amplitude of electromyogram in the medial gastrocnemius muscle was greater in the knee-extended position (10.50+/-9.80%) compared with the knee-flexed position (1.26+/-1.15%, P<0.01). The amplitude of electromyogram in the soleus muscle was not influenced by the knee position. The amplitude of electromyogram in the lateral gastrocnemius and tibialis anterior muscles was marginal and unaltered with knee position. At the same force (in Newtons), the standard deviation of force was lower in the knee-extended position compared with the knee-flexed position. These results indicate that force fluctuations during plantar flexion are attenuated with greater involvement of the medial gastrocnemius muscle.

  7. Effects of 4 Weeks of Explosive-type Strength Training for the Plantar Flexors on the Rate of Torque Development and Postural Stability in Elderly Individuals.

    PubMed

    Kobayashi, Y; Ueyasu, Y; Yamashita, Y; Akagi, R

    2016-06-01

    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.

  8. A New Distal Arthrogryposis Syndrome Characterized by Plantar Flexion Contractures

    PubMed Central

    Stevenson, D.A.; Swoboda, K.J.; Sanders, R.K.; Bamshad, M.

    2011-01-01

    The distal arthrogryposis (DA) syndromes are a distinct group of disorders characterized by contractures of two or more different body areas. More than a decade ago, we revised the classification of DAs and distinguished several new syndromes. This revision has facilitated the identification of five genes (i.e., TNNI2, TNNT3, MYH3, MYH8, and TPM2) that encode components of the contractile apparatus of fast-twitch myofibers and cause DA syndromes. We now report the phenotypic features of a novel DA disorder characterized primarily by plantar flexion contractures in a large five-generation Utah family. Contractures of hips, elbows, wrists, and fingers were much milder though they varied in severity among affected individuals. All affected individuals had normal neurological examinations; electromyography and creatinine kinase levels were normal on selected individuals. We have tentatively labeled this condition distal arthrogryposis type 10 (DA10). PMID:17103435

  9. Relative sensitivity of depth discrimination for ankle inversion and plantar flexion movements.

    PubMed

    Black, Georgia; Waddington, Gordon; Adams, Roger

    2014-02-01

    25 participants (20 women, 5 men) were tested for sensitivity in discrimination between sets of six movements centered on 8 degrees, 11 degrees, and 14 degrees, and separated by 0.3 degrees. Both inversion and plantar flexion movements were tested. Discrimination of the extent of inversion movement was observed to decline linearly with increasing depth; however, for plantar flexion, the discrimination function for movement extent was found to be non-linear. The relatively better discrimination of plantar flexion movements than inversion movements at around 11 degrees from horizontal is interpreted as an effect arising from differential amounts of practice through use, because this position is associated with the plantar flexion movement made in normal walking. The fact that plantar flexion movements are discriminated better than inversion at one region but not others argues against accounts of superior proprioceptive sensitivity for plantar flexion compared to inversion that are based on general properties of plantar flexion such as the number of muscle fibres on stretch.

  10. Evaluation of plantar flexion contracture contribution during the gait of children with Duchenne muscular dystrophy.

    PubMed

    Gaudreault, Nathaly; Gravel, Denis; Nadeau, Sylvie

    2009-06-01

    Because of extensor weakness, children with Duchenne muscular dystrophy (DMD) maintain internal flexion moments at the joints of the lower extremities when they walk. We believe that at the ankle, the plantar flexion moments caused by contractures may contribute significantly to the production of the net ankle flexion moment during the gait in these children. The goal of the present study is to quantify ankle plantar flexion passive moments that may be associated with the presence of flexion contractures and to estimate their contribution to the net moment during the gait of children with DMD. Kinematic and kinetic parameters were collected during gait of eleven subjects with DMD. Ankle plantar flexion passive moments were also measured experimentally during the same session. Fourteen control children participated in the study in order to have normal reference values. The presence of ankle plantar flexion contractures in children with DMD was reflected by a rigidity coefficient obtained at a common moment of -7 Nm that was higher for these children (0.75 Nm/degrees vs. 0.48 Nm/degrees; p<0.05). The relative passive moment contribution to the net plantar flexion moments was higher for the children with DMD at the end of the lengthening phase of the plantar flexors (25% vs. 18%; p<0.05). We believe that the passive moments can compensate for the presence of progressive muscle weakness in the children with DMD and help these children with gait.

  11. Contributions of knee swing initiation and ankle plantar flexion to the walking mechanics of amputees using a powered prosthesis.

    PubMed

    Ingraham, Kimberly A; Fey, Nicholas P; Simon, Ann M; Hargrove, Levi J

    2014-01-01

    Recently developed powered prostheses are capable of producing near-physiological joint torque at the knee and/or ankle joints. Based on previous studies of biological joint impedance and the mechanics of able-bodied gait, an impedance-based controller has been developed for a powered knee and ankle prosthesis that integrates knee swing initiation and powered plantar flexion in late stance with increasing ankle stiffness throughout stance. In this study, five prosthesis configuration conditions were tested to investigate the individual contributions of each sub-strategy to the overall walking mechanics of four unilateral transfemoral amputees as they completed a clinical 10-m walk test using a powered knee and ankle prosthesis. The baseline condition featured constant ankle stiffness and no swing initiation or powered plantar flexion. The four remaining conditions featured knee swing initiation alone (SI) or in combination with powered plantar flexion (SI+PF), increasing ankle stiffness (SI+IK), or both (SI+PF+IK). Self-selected walking speed did not significantly change between conditions, although subjects tended to walk the slowest in the baseline condition compared to conditions with swing initiation. The addition of powered plantar flexion resulted in significantly higher ankle power generation in late stance irrespective of ankle stiffness. The inclusion of swing initiation resulted in a significantly more flexed knee at toe off and a significantly higher average extensor knee torque following toe off. Identifying individual contributions of intrinsic control strategies to prosthesis biomechanics could help inform the refinement of impedance-based prosthesis controllers and simplify future designs of prostheses and lower-limb assistive devices alike.

  12. Effect of the 6-minute walk test on plantar loading and capability to produce ankle plantar flexion forces.

    PubMed

    Vie, Bruno; Griffon, Patricia; Bijoux, Audrey; Cadiere, Julie; Weber, Jean Paul; Jammes, Yves

    2016-09-01

    The six-minute walk test (6MWT) is used to evaluate the ambulatory capacity of patients suffering from respiratory disorders, obesity or neuromuscular diseases. Our primary aim was to evaluate the effects of the 6MWT on the postural sway and the ankle plantar flexion forces in healthy subjects. We measured the ankle plantar flexion forces and the plantar contact area before and after a 6MWT in normal weight and overweight subjects with no history of respiratory, cardiac, and neuromuscular disorders. A post-6MWT sensation of bodily fatigue was evaluated by Multidimensional Fatigue Inventory (MFI) and Pichot fatigue scales. A computerized pedobarographic platform was used to collect the mean plantar contact area, the changes of the center of pressure (CoP) surface and its medial and lateral deviations. In a limited number of subjects, the reproducibility of all the measurements was explored. In both groups, the 6MWT elicited a sensation of bodily fatigue. It also significantly reduced the ankle plantar flexion forces, and increased both the mean plantar contact area and the CoP surface, the changes being not apparent after 10min. The post-6MWT lateral CoP deviations were accentuated in normal weight subjects, while an increase in medial CoP deviations occurred in overweight ones. The 6MWT-induced changes in the plantar flexion force and pedobarographic variables were reproducible. Because this study clearly showed some post-6MWT alterations of the subjects' posture sway of our subjects, we questioned the possible mechanisms occurring that could explain the altered muscle force and the transient destabilization of posture after the 6MWT.

  13. Blood pressure and calf muscle oxygen extraction during plantar flexion exercise in peripheral artery disease.

    PubMed

    Luck, J Carter; Miller, Amanda J; Aziz, Faisal; Radtka, John F; Proctor, David N; Leuenberger, Urs A; Sinoway, Lawrence I; Muller, Matthew D

    2017-04-06

    Peripheral artery disease (PAD) is an atherosclerotic vascular disease that affects 200 million worldwide. While PAD primarily affects large arteries, it is also associated with microvascular dysfunction, an exaggerated blood pressure (BP) response to exercise, and high cardiovascular mortality. We hypothesized that fatiguing plantar flexion exercise that evokes claudication elicits a greater reduction in skeletal muscle oxygenation (SmO2) and a higher rise in BP in PAD compared to age-matched healthy subjects, but low-intensity steady state plantar flexion elicits similar responses between groups. In the first experiment, eight PAD patients and eight healthy controls performed fatiguing plantar flexion exercise (from 0.5 to 7 kg for up to 14 min). In the second experiment, seven PAD patients and seven healthy controls performed low-intensity plantar flexion exercise (2.0 kg for 14 min). BP, heart rate (HR), and SmO2 from near-infrared spectroscopy (NIRS) were measured continuously. SmO2 is the ratio of oxygenated hemoglobin to total hemoglobin, expressed as a percent. At fatigue, PAD patients had a greater increase in mean arterial BP (18 ± 2 versus vs. 10 ± 2 mmHg, P = 0.029) and HR (14 ± 2 versus 6 ± 2 beats/min, P = 0.033) and a greater reduction in SmO2 (-54 ± 10 versus -12 ± 4 %, P = 0.001). However, both groups had similar physiological responses to low-intensity, non-painful plantar flexion exercise. These data suggest that PAD patients have altered oxygen uptake and/or utilization during fatiguing exercise coincident with an augmented BP response.

  14. Shortening behavior of the different components of muscle-tendon unit during isokinetic plantar flexions.

    PubMed

    Hauraix, Hugo; Nordez, Antoine; Dorel, Sylvain

    2013-10-01

    The torque-velocity relationship has been widely considered as reflecting the mechanical properties of the contractile apparatus, and the influence of tendinous tissues on this relationship obtained during in vivo experiments remains to be determined. This study describes the pattern of shortening of various muscle-tendon unit elements of the triceps surae at different constant angular velocities and quantifies the contributions of fascicles, tendon, and aponeurosis to the global muscle-tendon unit shortening. Ten subjects performed isokinetic plantar flexions at different preset angular velocities (i.e., 30, 90, 150, 210, 270, and 330°/s). Ultrafast ultrasound measurements were performed on the muscle belly and on the myotendinous junction of the medial and lateral gastrocnemius muscles. The contributions of fascicles, tendon, and aponeurosis to global muscle-tendon unit shortening velocity were calculated for velocity conditions for four parts of the total range of motion. For both muscles, the fascicles' contribution decreased throughout the motion (73.5 ± 21.5% for 100-90° angular range to 33.7 ± 20.2% for 80-70°), whereas the tendon contribution increased (25.8 ± 15.4 to 55.6 ± 16.8%). In conclusion, the tendon contribution to the global muscle-tendon unit shortening is significant even during a concentric contraction. However, this contribution depends on the range of motion analyzed. The intersubject variability found in the maximal fascicle shortening velocity, for a given angular velocity, suggests that some subjects might possess a more efficient musculoarticular complex to produce the movement velocity. These findings are of great interest for understanding the ability of muscle-tendon shortening velocity.

  15. Subthreshold electrical stimulation reduces motor unit discharge variability and decreases the force fluctuations of plantar flexion.

    PubMed

    Kouzaki, Motoki; Kimura, Tetsuya; Yoshitake, Yasuhide; Hayashi, Tatsuya; Moritani, Toshio

    2012-04-04

    The purpose of this study was to examine the influence of subthreshold electrical stimulation on the force fluctuations and motor-unit discharge variability during low-level, steady contraction of the plantar flexor muscles. Seven subjects performed a force-matching task of isometric plantar flexion at 5% of maximal voluntary contraction with and without random electrical stimulation applied to the tibial nerve. During the task, the motor unit action potential was continuously recorded with fine-wire electrodes, and the inter-spike intervals of a single motor unit were calculated. The coefficient of variation (CV) of the force fluctuations and the inter-spike intervals of the motor unit discharge were significantly decreased by the intervention of subthreshold electrical stimulation, although there were no changes in the mean values. These results suggest that subthreshold stimulation reduced the motor-unit discharge variability, which in turn, increased the steadiness of the force.

  16. Inhibition of cyclooxygenase attenuates the blood pressure response to plantar flexion exercise in peripheral arterial disease

    PubMed Central

    Drew, Rachel C.; Ross, Amanda J.; Blaha, Cheryl A.; Cauffman, Aimee E.; Kaufman, Marc P.; Sinoway, Lawrence I.

    2015-01-01

    Prostanoids are produced during skeletal muscle contraction and subsequently stimulate muscle afferent nerves, thereby contributing to the exercise pressor reflex. Humans with peripheral arterial disease (PAD) have an augmented exercise pressor reflex, but the metabolite(s) responsible for this augmented response is not known. We tested the hypothesis that intravenous injection of ketorolac, which blocks the activity of cyclooxygenase, would attenuate the rise in mean arterial blood pressure (MAP) and heart rate (HR) evoked by plantar flexion exercise. Seven PAD patients underwent 4 min of single-leg dynamic plantar flexion (30 contractions/min) in the supine posture (workload: 0.5–2.0 kg). MAP and HR were measured on a beat-by-beat basis; changes from baseline in response to exercise were determined. Ketorolac did not affect MAP or HR at rest. During the first 20 s of exercise with the most symptomatic leg, ΔMAP was significantly attenuated by ketorolac (2 ± 2 mmHg) compared with control (8 ± 2 mmHg, P = 0.005), but ΔHR was similar (6 ± 2 vs. 5 ± 1 beats/min). Importantly, patients rated the exercise bout as “very light” to “fairly light,” and average pain ratings were 1 of 10. Ketorolac had no effect on perceived exertion or pain ratings. Ketorolac also had no effect on MAP or HR in seven age- and sex-matched healthy subjects who performed a similar but longer plantar flexion protocol (workload: 0.5–7.0 kg). These data suggest that prostanoids contribute to the augmented exercise pressor reflex in patients with PAD. PMID:26055794

  17. Inhibition of cyclooxygenase attenuates the blood pressure response to plantar flexion exercise in peripheral arterial disease.

    PubMed

    Muller, Matthew D; Drew, Rachel C; Ross, Amanda J; Blaha, Cheryl A; Cauffman, Aimee E; Kaufman, Marc P; Sinoway, Lawrence I

    2015-08-01

    Prostanoids are produced during skeletal muscle contraction and subsequently stimulate muscle afferent nerves, thereby contributing to the exercise pressor reflex. Humans with peripheral arterial disease (PAD) have an augmented exercise pressor reflex, but the metabolite(s) responsible for this augmented response is not known. We tested the hypothesis that intravenous injection of ketorolac, which blocks the activity of cyclooxygenase, would attenuate the rise in mean arterial blood pressure (MAP) and heart rate (HR) evoked by plantar flexion exercise. Seven PAD patients underwent 4 min of single-leg dynamic plantar flexion (30 contractions/min) in the supine posture (workload: 0.5-2.0 kg). MAP and HR were measured on a beat-by-beat basis; changes from baseline in response to exercise were determined. Ketorolac did not affect MAP or HR at rest. During the first 20 s of exercise with the most symptomatic leg, ΔMAP was significantly attenuated by ketorolac (2 ± 2 mmHg) compared with control (8 ± 2 mmHg, P = 0.005), but ΔHR was similar (6 ± 2 vs. 5 ± 1 beats/min). Importantly, patients rated the exercise bout as "very light" to "fairly light," and average pain ratings were 1 of 10. Ketorolac had no effect on perceived exertion or pain ratings. Ketorolac also had no effect on MAP or HR in seven age- and sex-matched healthy subjects who performed a similar but longer plantar flexion protocol (workload: 0.5-7.0 kg). These data suggest that prostanoids contribute to the augmented exercise pressor reflex in patients with PAD.

  18. Dorsiflexion, Plantar-Flexion, and Neutral Ankle Positions During Passive Resistance Assessments of the Posterior Hip and Thigh Muscles

    PubMed Central

    Palmer, Ty B.; Akehi, Kazuma; Thiele, Ryan M.; Smith, Douglas B.; Warren, Aric J.; Thompson, Brennan J.

    2015-01-01

    Context: Passive straight-legged–raise (SLR) assessments have been performed with the ankle fixed in dorsiflexion (DF), plantar-flexion (PF), or neutral (NTRL) position. However, it is unclear whether ankle position contributes to differences in the passive resistance measured during an SLR assessment. Objective: To examine the influence of ankle position during an SLR on the passive torque, range of motion (ROM), and hamstrings electromyographic (EMG) responses to passive stretch of the posterior hip and thigh muscles. Design: Crossover study. Setting: Research laboratory. Patients or Other Participants: A total of 13 healthy volunteers (5 men: age = 24 ± 3 years, height = 178 ± 6 cm, mass = 85 ± 10 kg; 8 women: age = 21 ± 1 years, height = 163 ± 8 cm, mass = 60 ± 6 kg). Intervention(s): Participants performed 6 randomly ordered passive SLR assessments involving 2 assessments at each condition, which included the ankle positioned in DF, PF, and NTRL. All SLRs were performed using an isokinetic dynamometer programmed in passive mode to move the limb toward the head at 5°/s. Main Outcome Measure(s): During each SLR, maximal ROM was determined as the point of discomfort but not pain, as indicated by the participant. Passive torque and EMG amplitude were determined at 4 common joint angles (θ) separated by 5° during the final common 15° of ROM for each participant. Results: Passive torque was greater for the DF condition than the NTRL (P = .008) and PF (P = .03) conditions at θ3 and greater for the DF than NTRL condition (P = .02) at θ4. Maximal ROM was lower for the DF condition than the NTRL (P = .003) and PF (P < .001) conditions. However, we found no differences among conditions for EMG amplitude (P = .86). Conclusions: These findings suggest that performing SLRs with the ankle positioned in DF may elicit greater passive torque and lower ROM than SLRs with the ankle positioned in PF or NTRL. The greater passive torque and lower ROM induced by the DF

  19. Neck rotation modulates flexion synergy torques, indicating an ipsilateral reticulospinal source for impairment in stroke.

    PubMed

    Ellis, Michael D; Drogos, Justin; Carmona, Carolina; Keller, Thierry; Dewald, Julius P A

    2012-12-01

    The effect of reticular formation excitability on maximum voluntary torque (MVT) generation and associated muscle activation at the shoulder and elbow was investigated through natural elicitation (active head rotation) of the asymmetric tonic neck reflex (ATNR) in 26 individuals with stroke and 9 age-range-matched controls. Isometric MVT generation at the shoulder and elbow was quantified with the head rotated (face pointing) contralateral and ipsilateral to the paretic (stroke) and dominant (control) arm. Given the dominance of abnormal torque coupling of elbow flexion with shoulder abduction (flexion synergy) in stroke and well-developed animal models demonstrating a linkage between reticular formation and ipsilateral elbow flexors and shoulder abductors, we hypothesized that constituent torques of flexion synergy, specifically elbow flexion and shoulder abduction, would increase with contralateral head rotation. The findings of this investigation support this hypothesis. Increases in MVT for three of four flexion synergy constituents (elbow flexion, shoulder abduction, and shoulder external rotation) were observed during contralateral head rotation only in individuals with stroke. Electromyographic data of the associated muscle coactivations were nonsignificant but are presented for consideration in light of a likely underpowered statistical design for this specific variable. This study not only provides evidence for the reemergence of ATNR following stroke but also indicates a common neuroanatomical link, namely, an increased reliance on ipsilateral reticulospinal pathways, as the likely mechanism underlying the expression of both ATNR and flexion synergy that results in the loss of independent joint control.

  20. Foot claudication with plantar flexion as a result of dorsalis pedis artery impingement in an Irish dancer.

    PubMed

    Smith, Brigitte K; Engelbert, Travis; Turnipseed, William D

    2013-07-01

    Dorsalis pedis artery impingement is an extremely rare cause of foot claudication, with a single case reported in the literature. In this report, we describe the case of a 17-year-old female Irish dancer who presented with intermittent bilateral foot pain and discoloration during active plantar flexion.

  1. Hybrid diffuse optical techniques for continuous hemodynamic measurement in gastrocnemius during plantar flexion exercise

    NASA Astrophysics Data System (ADS)

    Henry, Brad; Zhao, Mingjun; Shang, Yu; Uhl, Timothy; Thomas, D. Travis; Xenos, Eleftherios S.; Saha, Sibu P.; Yu, Guoqiang

    2015-12-01

    Occlusion calibrations and gating techniques have been recently applied by our laboratory for continuous and absolute diffuse optical measurements of forearm muscle hemodynamics during handgrip exercises. The translation of these techniques from the forearm to the lower limb is the goal of this study as various diseases preferentially affect muscles in the lower extremity. This study adapted a hybrid near-infrared spectroscopy and diffuse correlation spectroscopy system with a gating algorithm to continuously quantify hemodynamic responses of medial gastrocnemius during plantar flexion exercises in 10 healthy subjects. The outcomes from optical measurement include oxy-, deoxy-, and total hemoglobin concentrations, blood oxygen saturation, and relative changes in blood flow (rBF) and oxygen consumption rate (rV˙O2). We calibrated rBF and rV˙O2 profiles with absolute baseline values of BF and V˙O2 obtained by venous and arterial occlusions, respectively. Results from this investigation were comparable to values from similar studies. Additionally, significant correlation was observed between resting local muscle BF measured by the optical technique and whole limb BF measured concurrently by a strain gauge venous plethysmography. The extensive hemodynamic and metabolic profiles during exercise will allow for future comparison studies to investigate the diagnostic value of hybrid technologies in muscles affected by disease.

  2. Volitional control of ankle plantar flexion in a powered transtibial prosthesis during stair-ambulation.

    PubMed

    Kannape, Oliver A; Herr, Hugh M

    2014-01-01

    Although great advances have been made in the design and control of lower extremity prostheses, walking on different terrains, such as ramps or stairs, and transitioning between these terrains remains a major challenge for the field. In order to generalize biomimetic behaviour of active lower-limb prostheses top-down volitional control is required but has until recently been deemed unfeasible due to the difficulties involved in acquiring an adequate electromyographic (EMG) signal. In this study, we hypothesize that a transtibial amputee can extend the functionality of a hybrid controller, designed for level ground walking, to stair ascent and descent by volitionally modulating powered plantar-flexion of the prosthesis. We here present data illustrating that the participant is able to reproduce ankle push-off behaviour of the intrinsic controller during stair ascent as well as prevent inadvertent push-off during stair descent. Our findings suggest that EMG signal from the residual limb muscles can be used to transition between level-ground walking and stair ascent/descent within a single step and significantly improve prosthesis performance during stair-ambulation.

  3. Hybrid diffuse optical techniques for continuous hemodynamic measurement in gastrocnemius during plantar flexion exercise

    PubMed Central

    Henry, Brad; Zhao, Mingjun; Shang, Yu; Uhl, Timothy; Thomas, D. Travis; Xenos, Eleftherios S.; Saha, Sibu P.; Yu, Guoqiang

    2015-01-01

    Abstract. Occlusion calibrations and gating techniques have been recently applied by our laboratory for continuous and absolute diffuse optical measurements of forearm muscle hemodynamics during handgrip exercises. The translation of these techniques from the forearm to the lower limb is the goal of this study as various diseases preferentially affect muscles in the lower extremity. This study adapted a hybrid near-infrared spectroscopy and diffuse correlation spectroscopy system with a gating algorithm to continuously quantify hemodynamic responses of medial gastrocnemius during plantar flexion exercises in 10 healthy subjects. The outcomes from optical measurement include oxy-, deoxy-, and total hemoglobin concentrations, blood oxygen saturation, and relative changes in blood flow (rBF) and oxygen consumption rate (rV˙O2). We calibrated rBF and rV˙O2 profiles with absolute baseline values of BF and V˙O2 obtained by venous and arterial occlusions, respectively. Results from this investigation were comparable to values from similar studies. Additionally, significant correlation was observed between resting local muscle BF measured by the optical technique and whole limb BF measured concurrently by a strain gauge venous plethysmography. The extensive hemodynamic and metabolic profiles during exercise will allow for future comparison studies to investigate the diagnostic value of hybrid technologies in muscles affected by disease. PMID:26720871

  4. Clarification of functional differences between the hallux and lesser toes during the single leg stance: immediate effects of conditioning contraction of the toe plantar flexion muscles.

    PubMed

    Saeki, Junya; Tojima, Michio; Torii, Suguru

    2015-09-01

    [Purpose] The purpose of this study was to determine the functional differences of the plantar flexion muscles of the hallux and lesser toes during the single leg stance by comparing postural sway in different conditioning contraction interventions. [Subjects] Thirty-four healthy, young males and females participated in this study. [Methods] The front-back and right-left direction components of maximal displacement and postural sway velocity during the single leg stance were measured in various conditioning contraction interventions for the plantar flexion muscles of the hallux or lessor toes. [Results] The main findings of this study were as follows: 1) the front-back direction component of maximal displacement was reduced by conditioning contraction of the plantar flexion muscles of the hallux, and 2) the front-back direction component of the postural sway velocity was reduced by conditioning contraction of the plantar flexion muscles of the lesser toes during the single leg stance. [Conclusion] The plantar flexion muscles of the lesser toes control the postural sway velocity. Furthermore, the plantar flexion muscles of the hallux appear to control the amplitude of postural sway.

  5. Change in the Mechanical Energy of the Body Center of Mass in Hemiplegic Gait after Continuous Use of a Plantar Flexion Resistive Ankle-foot Orthosis.

    PubMed

    Haruna, Hirokazu; Sugihara, Shunichi; Kon, Keisuke; Miyasaka, Tomoya; Hayakawa, Yasuyuki; Nosaka, Toshiya; Kimura, Kazuyuki

    2013-11-01

    [Purpose] The aim of this study was to investigate the changes in mechanical energy due to continuous use of a plantar flexion resistive ankle-foot orthosis (AFO) of subjects with chronic hemiplegia. [Subjects and Methods] The subjects were 5 hemiplegic patients using AFOs without a plantar flexion resistive function in their daily lives. We analyzed the gait of the subjects using a 3D motion capture system under three conditions: patients' use of their own AFOs; after being fitted with a plantar flexion resistive AFO; and after continuous use of the device. The gait efficiency was determined by calculating the mutual exchange of kinetic and potential energy of the center of mass. [Results] An increased exchange rate of the kinetic and potential energy was found for all subjects. A larger increase of energy exchange was shown on the non-paralyzed side, and after continuous use of the plantar flexion resistive AFO. [Conclusion] We found that continuous use of a plantar flexion resistive AFO increased the rate of mutual exchange between kinetic energy and potential energy. The change in the rate was closely related to the role of the non-paretic side, showing that the subjects needed a certain amount of time to adapt to the plantar flexion resistive AFO.

  6. Preserving plantar flexion strength after surgical treatment for contracture of the triceps surae: a computer simulation study.

    PubMed

    Delp, S L; Statler, K; Carroll, N C

    1995-01-01

    Contractures of the triceps surae commonly are treated by surgical lengthening of the gastrocnemius aponeurosis or the Achilles tendon. Although these procedures generally relieve contractures, patients sometimes are left with dramatically decreased plantar flexion strength (i.e., decreased capacity to generate plantar flexion moment). The purpose of this study was to examine the trade-off between restoring range of motion and maintaining plantar flexion strength after surgical treatment for contracture of the triceps surae. A computer model representing the normal moment-generating characteristics of the triceps surae was altered to represent two conditions: isolated contracture of the gastrocnemius and contracture of both the gastrocnemius and the soleus. The effects of lengthening the gastrocnemius aponeurosis and the Achilles tendon were simulated for each condition. The simulations showed that nearly normal moment-generating characteristics could be restored when isolated gastrocnemius contracture was treated with lengthening of the gastrocnemius aponeurosis. However, when isolated gastrocnemius contracture was treated with lengthening of the Achilles tendon, the moment-generating capacity of the plantar flexors decreased greatly. This suggests that lengthening of the Achilles tendon should be avoided in persons with isolated gastrocnemius contracture. Our simulations also suggest that neither lengthening of the gastrocnemius aponeurosis nor lengthening of the Achilles tendon by itself is an effective treatment for combined contracture of the gastrocnemius and soleus. Lengthening the gastrocnemius aponeurosis did not decrease the excessive passive moment developed by the contracted soleus. Lengthening the Achilles tendon restored the normal passive range of motion but substantially decreased the active force-generating capacity of the muscles.(ABSTRACT TRUNCATED AT 250 WORDS)

  7. In vivo maximal fascicle-shortening velocity during plantar flexion in humans.

    PubMed

    Hauraix, Hugo; Nordez, Antoine; Guilhem, Gaël; Rabita, Giuseppe; Dorel, Sylvain

    2015-12-01

    Interindividual variability in performance of fast movements is commonly explained by a difference in maximal muscle-shortening velocity due to differences in the proportion of fast-twitch fibers. To provide a better understanding of the capacity to generate fast motion, this study aimed to 1) measure for the first time in vivo the maximal fascicle-shortening velocity of human muscle; 2) evaluate the relationship between angular velocity and fascicle-shortening velocity from low to maximal angular velocities; and 3) investigate the influence of musculo-articular features (moment arm, tendinous tissues stiffness, and muscle architecture) on maximal angular velocity. Ultrafast ultrasound images of the gastrocnemius medialis were obtained from 31 participants during maximal isokinetic and light-loaded plantar flexions. A strong linear relationship between fascicle-shortening velocity and angular velocity was reported for all subjects (mean R(2) = 0.97). The maximal shortening velocity (V(Fmax)) obtained during the no-load condition (NLc) ranged between 18.8 and 43.3 cm/s. V(Fmax) values were very close to those of the maximal shortening velocity (V(max)), which was extrapolated from the F-V curve (the Hill model). Angular velocity reached during the NLc was significantly correlated with this V(Fmax) (r = 0.57; P < 0.001). This finding was in agreement with assumptions about the role of muscle fiber type, whereas interindividual comparisons clearly support the fact that other parameters may also contribute to performance during fast movements. Nevertheless, none of the biomechanical features considered in the present study were found to be directly related to the highest angular velocity, highlighting the complexity of the upstream mechanics that lead to maximal-velocity muscle contraction.

  8. Enhanced physiological tremor deteriorates plantar flexor torque steadiness after bed rest.

    PubMed

    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

    2011-04-01

    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.

  9. Simultaneous Knee Extensor Muscle Action Induces an Increase in Voluntary Force Generation of Plantar Flexor Muscles.

    PubMed

    Suzuki, Takahito; Shioda, Kohei; Kinugasa, Ryuta; Fukashiro, Senshi

    2017-02-01

    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.

  10. A restrained-torque-based motion instructor: forearm flexion/extension-driving exoskeleton

    NASA Astrophysics Data System (ADS)

    Nishimura, Takuya; Nomura, Yoshihiko; Sakamoto, Ryota

    2013-01-01

    When learning complicated movements by ourselves, we encounter such problems as a self-rightness. The self-rightness results in a lack of detail and objectivity, and it may cause to miss essences and even twist the essences. Thus, we sometimes fall into the habits of doing inappropriate motions. To solve these problems or to alleviate the problems as could as possible, we have been developed mechanical man-machine human interfaces to support us learning such motions as cultural gestures and sports form. One of the promising interfaces is a wearable exoskeleton mechanical system. As of the first try, we have made a prototype of a 2-link 1-DOF rotational elbow joint interface that is applied for teaching extension-flexion operations with forearms and have found its potential abilities for teaching the initiating and continuing flection motion of the elbow.

  11. Oral baclofen increases maximal voluntary neuromuscular activation of ankle plantar flexors in children with spasticity due to cerebral palsy.

    PubMed

    van Doornik, Johan; Kukke, Sahana; McGill, Kevin; Rose, Jessica; Sherman-Levine, Sara; Sanger, Terence D

    2008-06-01

    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.

  12. The role of interaction torque and muscle torque in the control of downward squatting.

    PubMed

    Fujisawa, Hiroyuki; Suzuki, Hiroto; Murakami, Kenichi; Kawakami, Shingo; Suzuki, Makoto

    2016-01-01

    [Purpose] The purposes of this study were first to analyze the multijoint dynamics of downward squatting, and to examine the contribution of interaction torque and muscle torque to net torque, and second, to examine mechanisms of movement control. [Subjects] The subjects were 31 healthy men with a mean age of 21.0 ± 1.2 years (range, 19-24 years). [Methods] Squatting tasks with the trunk in two positions, an erect and anterior tilt position, were performed by the subjects. Net, interaction, muscle, and gravity torque were calculated according to the Lagrange equation using 3D tracking data. [Results] The contribution ratio of interaction torque to net torque was approximately 90%, irrespective of the joint and task. In contrast, muscle torque showed complicated behavior to compensate for gravity torque. A combined muscle and gravity torque profile showed flexion or dorsiflexion immediately after the initiation of the movement, and it later changed to extension or plantar flexion. [Conclusion] The torque that contributes almost exclusively to the net torque was interaction torque. The combination of muscle and gravity torque at the knee joint and the hip joint is important for movement control, independent of the starting position.

  13. Dynamic 31P–MRSI using spiral spectroscopic imaging can map mitochondrial capacity in muscles of the human calf during plantar flexion exercise at 7 T

    PubMed Central

    Valkovič, Ladislav; Chmelík, Marek; Meyerspeer, Martin; Gagoski, Borjan; Rodgers, Christopher T.; Krššák, Martin; Andronesi, Ovidiu C.; Trattnig, Siegfried

    2016-01-01

    Abstract Phosphorus MRSI (31P–MRSI) using a spiral‐trajectory readout at 7 T was developed for high temporal resolution mapping of the mitochondrial capacity of exercising human skeletal muscle. The sensitivity and localization accuracy of the method was investigated in phantoms. In vivo performance was assessed in 12 volunteers, who performed a plantar flexion exercise inside a whole‐body 7 T MR scanner using an MR‐compatible ergometer and a surface coil. In five volunteers the knee was flexed (~60°) to shift the major workload from the gastrocnemii to the soleus muscle. Spiral‐encoded MRSI provided 16–25 times faster mapping with a better point spread function than elliptical phase‐encoded MRSI with the same matrix size. The inevitable trade‐off for the increased temporal resolution was a reduced signal‐to‐noise ratio, but this was acceptable. The phosphocreatine (PCr) depletion caused by exercise at 0° knee angulation was significantly higher in both gastrocnemii than in the soleus (i.e. 64.8 ± 19.6% and 65.9 ± 23.6% in gastrocnemius lateralis and medialis versus 15.3 ± 8.4% in the soleus). Spiral‐encoded 31P–MRSI is a powerful tool for dynamic mapping of exercising muscle oxidative metabolism, including localized assessment of PCr concentrations, pH and maximal oxidative flux with high temporal and spatial resolution. PMID:27862510

  14. Mapping of calf muscle oxygenation and haemoglobin content during dynamic plantar flexion exercise by multi-channel time-resolved near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Torricelli, Alessandro; Quaresima, Valentina; Pifferi, Antonio; Biscotti, Giovanni; Spinelli, Lorenzo; Taroni, Paola; Ferrari, Marco; Cubeddu, Rinaldo

    2004-03-01

    A compact and fast multi-channel time-resolved near-infrared spectroscopy system for tissue oximetry was developed. It employs semiconductor laser and fibre optics for delivery of optical signals. Photons are collected by eight 1 mm fibres and detected by a multianode photomultiplier. A time-correlated single photon counting board is used for the parallel acquisition of time-resolved reflectance curves. Estimate of the reduced scattering coefficient is achieved by fitting with a standard model of diffusion theory, while the modified Lambert-Beer law is used to assess the absorption coefficient. In vivo measurements were performed on five healthy volunteers to monitor spatial changes in calf muscle (medial and lateral gastrocnemius; MG, LG) oxygen saturation (SmO2) and total haemoglobin concentration (tHb) during dynamic plantar flexion exercise performed at 50% of the maximal voluntary contraction. At rest SmO2 was 73.0 ± 0.9 and 70.5 ± 1.7% in MG and LG, respectively (P = 0.045). At the end of the exercise, SmO2 decreased (69.1 ± 1.8 and 63.8 ± 2.1% in MG and LG, respectively; P < 0.01). The LG desaturation was greater than the MG desaturation (P < 0.02). These results strengthen the role of time-resolved near-infrared spectroscopy as a powerful tool for investigating the spatial and temporal features of muscle SmO2 and tHb.

  15. Relationship of EMG/SMG features and muscle strength level: an exploratory study on tibialis anterior muscles during plantar-flexion among hemiplegia patients

    PubMed Central

    2014-01-01

    Background Improvement in muscle strength is an important aim for the rehabilitation of hemiplegia patients. Presently, the rehabilitation prescription depends on the evaluation results of muscle strength, which are routinely estimated by experienced physicians and therefore not finely quantitative. Widely-used quantification methods for disability, such as Barthel Index (BI) and motor component of Functional Independent Measure (M-FIM), yet have limitations in their application, since both of them differentiated disability better in lower than higher disability, and they are subjective and recorded in wide scales. In this paper, to explore finely quantitative measures for evaluation of muscle strength level (MSL), we start with the study on quantified electromyography (EMG) and sonomyography (SMG) features of tibialis anterior (TA) muscles among hemiplegia patients. Methods 12 hemiplegia subjects volunteered to perform several sets of plantar-flexion movements in the study, and their EMG signals and SMG signals were recorded on TA independently to avoid interference. EMG data were filtered and then the root-mean-square (RMS) was computed. SMG signals, specifically speaking, the muscle thickness of TA, were manually measured by two experienced operators using ultrasonography. Reproducibility of the SMG assessment on TA between operators was evaluated by non-parametric test (independent sample T test). Possible relationship between muscle thickness changes (TC) of TA and muscle strength level of hemiplegia patients was estimated. Results Mean of EMG RMS between subjects is found linearly correlated with MSL (R2 = 0.903). And mean of TA muscle TC amplitudes is also linearly correlated with MSL among dysfunctional legs (R2 = 0.949). Moreover, rectified TC amplitudes (dysfunctional leg/ healthy leg, DLHL) and rectified EMG signals (DLHL) are found in linear correlation with MSL, with R2 = 0.756 and R2 = 0.676 respectively. Meanwhile, the preliminary

  16. Antagonist mechanical contribution to resultant maximal torque at the ankle joint in young and older men.

    PubMed

    Simoneau, Emilie M; Billot, Maxime; Martin, Alain; Van Hoecke, Jacques

    2009-04-01

    A recorded muscular torque at one joint is a resultant torque corresponding to the participation of both agonist and antagonist muscles. This study aimed to examine the effect of aging on the mechanical contributions of both plantar- and dorsi-flexors to the resultant maximal voluntary contraction (MVC) torques exerted at the ankle joint, in dorsi-flexion (DF) and plantar-flexion (PF). The estimation of isometric agonist and antagonist torques by means of an EMG biofeedback technique was made with nine young (mean age 24 years) and nine older (mean age 80 years) men. While there was a non-significant age-related decline in the measured resultant DF MVC torque (-15%; p=0.06), there was a clear decrease in the estimated agonist MVC torque exerted by the dorsi-flexors (-39%; p=0.001). The DF-to-PF resultant MVC torque ratio was significantly lower in young than in older men (0.25 vs. 0.31; p=0.006), whereas the DF-to-PF agonist MVC torque ratio was no longer different between the two populations (0.38 vs. 0.35; p>0.05). Thus, agonist MVC torques in PF and DF would be similarly affected by aging, which could not be deduced when only resultant torques were examined.

  17. The effects of fatigue of the plantar flexors on peak torque and voluntary activation in untrained and resistance-trained men.

    PubMed

    Hartman, Michael J; Ryan, Eric D; Cramer, Joel T; Bemben, Michael G

    2011-02-01

    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.

  18. Torque and Muscle Activation Impairment Along With Insulin Resistance Are Associated With Falls in Women With Fibromyalgia.

    PubMed

    Góes, Suelen M; Stefanello, Joice M F; Homann, Diogo; Lodovico, Angélica; Hubley-Kozey, Cheryl L; Rodacki, André L F

    2016-11-01

    Góes, SM, Stefanello, JMF, Homann, D, Lodovico, A, Hubley-Kozey, CL, and Rodacki, ALF. Torque and muscle activation impairment along with insulin resistance are associated with falls in women with fibromyalgia. J Strength Cond Res 30(11): 3155-3164, 2016-Fibromyalgia (FM) is a chronic pain condition associated with reduced muscle strength, which can lead to functional incapacity and higher risk of falls. The purpose of the study was to compare maximal ankle joint torque, muscle activation, and metabolic changes between women with and without FM. In addition, the relationship between those aspects and retrospectively reported falls in women with FM was determined. Twenty-nine middle-aged women with FM and 30 controls were recruited. Fall history, pain intensity, and pain threshold were assessed. Plasma glucose levels and insulin resistance (IR) were determined. Peak torque and rate of torque development (RTD) were calculated, and muscle activation was assessed from maximum isometric voluntary ankle dorsiflexion and plantar flexion contractions. In addition, voluntary muscle activation failure of the anterior tibialis muscle during maximal dorsiflexion was calculated. When compared to controls, women with FM reported higher number of retrospectively reported falls, exhibited higher IR, showed reduced plantar flexion and dorsiflexion RTD, had lower plantar flexion peak torque, and demonstrated more antagonist coactivation and higher muscle activation failure (p ≤ 0.05). Higher muscle activation failure was explained by glucose level and pain intensity (adj R = 0.28; p ≤ 0.05). Reduced plantar flexion and dorsiflexion peak torque explained 80% of retrospectively reported falls variance; also, high antagonist coactivation (odds ratio [OR] = 1.6; p ≤ 0.05) and high IR (OR = 1.8; p ≤ 0.05) increased the chance of falls in the FM group. A combination of metabolic factors and muscle function increased the odds of retrospectively reporting a fall in FM. Both aspects

  19. Plantar fasciitis

    MedlinePlus

    ... Concepts and Clinical Practice . 8th ed. Philadelphia, PA: Elsevier Saunders; 2014:chap 58. Ferri FF. Plantar fasciitis. ... FF ed. Ferri's Clinical Advisor 2016 . Philadelphia, PA: Elsevier; 2016:970. Kadakia AR. Heel pain and plantar ...

  20. Plantar fibromatosis.

    PubMed

    Zgonis, Thomas; Jolly, Gary Peter; Polyzois, Vasilios; Kanuck, David M; Stamatis, Emmanouil D

    2005-01-01

    Plantar fibromatosis is defined as a benign fibrous disorder involving the plantar aponeurosis. Although its incidence is well described on the hands, it is less commonly seen on the feet, and its etiology is unknown. A differential diagnosis for the heel pain along the medial arch could be a benign thickening of the plantar fascia associated with plantar fibromatosis. Its high recurrence after surgical excision and problematic scarring and wound presents a significant challenge to the reconstructive foot and ankle surgeon. This article reviews the history, clinical presentation, pathologic findings, and surgical approaches to the treatment of plantar fibromatosis.

  1. Resistance exercise prevents plantar flexor deconditioning during bed rest

    NASA Technical Reports Server (NTRS)

    Bamman, M. M.; Hunter, G. R.; Stevens, B. R.; Guilliams, M. E.; Greenisen, M. C.

    1997-01-01

    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

  2. Force Depression in Plantar Flexors Exists Equally in Plantar Flexed and Dorsiflexed Regions

    PubMed Central

    Fukutani, Atsuki; Misaki, Jun; Isaka, Tadao

    2017-01-01

    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

  3. Plantar fasciitis

    PubMed Central

    Tahririan, Mohammad Ali; Motififard, Mehdi; Tahmasebi, Mohammad Naghi; Siavashi, Babak

    2012-01-01

    Heel pain, mostly caused by plantar fasciitis (PF), is a common complaint of many patients who requiring professional orthopedic care and are mostly suffering from chronic pain beneath their heels. The present article reviews studies done by preeminent practitioners related to the anatomy of plantar fasciitis and their histo-pathological features, factors associated with PF, clinical features, imaging studies, differential diagnoses, and diverse treatment modalities for treatment of PF, with special emphasis on non-surgical treatment. Anti-inflammatory agents, plantar stretching, and orthosis proved to have highest priority; corticosteroid injection, night splints and extracorporeal shock wave therapy were of next priority, in patients with PF. In patients resistant to the mentioned treatments surgical intervention should be considered. PMID:23798950

  4. The effects of passive stretching plus vibration on strength and activation of the plantar flexors.

    PubMed

    Miller, Jonathan D; Herda, Trent J; Trevino, Michael A; Mosier, Eric M

    2016-09-01

    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.

  5. Maximum voluntary joint torque as a function of joint angle and angular velocity: model development and application to the lower limb.

    PubMed

    Anderson, Dennis E; Madigan, Michael L; Nussbaum, Maury A

    2007-01-01

    Measurements of human strength can be important during analyses of physical activities. Such measurements have often taken the form of the maximum voluntary torque at a single joint angle and angular velocity. However, the available strength varies substantially with joint position and velocity. When examining dynamic activities, strength measurements should account for these variations. A model is presented of maximum voluntary joint torque as a function of joint angle and angular velocity. The model is based on well-known physiological relationships between muscle force and length and between muscle force and velocity and was tested by fitting it to maximum voluntary joint torque data from six different exertions in the lower limb. Isometric, concentric and eccentric maximum voluntary contractions were collected during hip extension, hip flexion, knee extension, knee flexion, ankle plantar flexion and dorsiflexion. Model parameters are reported for each of these exertion directions by gender and age group. This model provides an efficient method by which strength variations with joint angle and angular velocity may be incorporated into comparisons between joint torques calculated by inverse dynamics and the maximum available joint torques.

  6. Association of force steadiness of plantar flexor muscles and postural sway during quiet standing by young adults.

    PubMed

    Oshita, Kazushige; Yano, Sumio

    2012-08-01

    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.

  7. Contributions of active and passive toe flexion to forefoot loading.

    PubMed

    Hamel, A J; Donahue, S W; Sharkey, N A

    2001-12-01

    Toe flexion during terminal stance has an active component contributed by the muscles that flex the toes and a passive component contributed by the plantar fascia. This study examined the relative importance of these two mechanisms in maintaining proper force sharing between the toes and forefoot. Thirteen nonpaired cadaver feet were tested in a dynamic gait stimulator, which reproduces the kinematics and kinetics of the foot, ankle, and tibia by applying physiologic muscle forces and proximal tibial kinematics. The distribution of plantar pressure beneath the foot was measured at the terminal stance phase of gait under normal extrinsic muscle activity with an intact plantar fascia, in the absence of extrinsic toe flexor activity (no flexor hallucis longus or flexor digitorum longus) with an intact plantar fascia, and after complete fasciotomy with normal extrinsic toe flexor activity. In the absence of the toe flexor muscles or after plantar fasciotomy the contact area decreased beneath the toes and contact force shifted from the toes to the metatarsal heads. In addition, pressure distribution beneath the metatarsal heads after fasciotomy shifted laterally and posteriorly, indicating that the plantar fascia enables more efficient force transmission through the high gear axis during locomotion. The plantar fascia enables the toes to provide plantar-directed force and bear high loads during push-off.

  8. Stretching-induced deficit of maximal isometric torque is restored within 10 minutes.

    PubMed

    Mizuno, Takamasa; Matsumoto, Minoru; Umemura, Yoshihisa

    2014-01-01

    The purpose of this study was to clarify the time course of the stretching-induced decrease in maximal isometric plantar flexion torque. Nineteen women participated in 2 randomly ordered experimental trials: static 5-minute stretching or control with no stretching. The participants performed isometric maximal voluntary contractions (MVCs) of the right plantar flexor muscles, whereas electromyographic (EMG) amplitude (root mean square) was calculated for the medial and lateral gastrocnemius muscles. Measurements were conducted preintervention; immediately after intervention; and 5, 10, 15, and 30 minutes postintervention. The static 5-minute stretching trial consisted of dorsiflexion to the end range of motion and holding that position for 1 minute, 5 times, whereas the control trial consisted of 5 minutes of resting. As a result, the MVC torque was significantly decreased immediately after, and 5 minutes after the static 5-minute stretching intervention compared with the preintervention value (p < 0.05), and this change recovered within 10 minutes. However, the EMG amplitude did not change from preintervention to postintervention under any conditions. These results suggest that the deficits of static stretching are disabled in a short time after static stretching.

  9. Intramuscular pressure and torque during isometric, concentric and eccentric muscular activity

    NASA Technical Reports Server (NTRS)

    Styf, J.; Ballard, R.; Aratow, M.; Crenshaw, A.; Watenpaugh, D.; Hargens, A. R.

    1995-01-01

    Intramuscular pressures, electromyography (EMG) and torque generation during isometric, concentric and eccentric maximal isokinetic muscle activity were recorded in 10 healthy volunteers. Pressure and EMG activity were continuously and simultaneously measured side by side in the tibialis anterior and soleus muscles. Ankle joint torque and position were monitored continuously by an isokinetic dynamometer during plantar flexion and dorsiflexion of the foot. The increased force generation during eccentric muscular activity, compared with other muscular activity, was not accompanied by higher intramuscular pressure. Thus, this study demonstrated that eccentric muscular activity generated higher torque values for each increment of intramuscular pressure. Intramuscular pressures during antagonistic co-activation were significantly higher in the tibilis anterior muscle (42-46% of maximal agonistic activity) compared with the soleus muscle (12-29% of maximal agonistic activity) and was largely due to active recruitment of muscle fibers. In summary, eccentric muscular activity creates higher torque values with no additional increase of the intramuscular pressure compared with concentric and isometric muscular activity.

  10. Impaired Foot Plantar Flexor Muscle Performance in Individuals With Plantar Heel Pain and Association With Foot Orthosis Use.

    PubMed

    McClinton, Shane; Collazo, Christopher; Vincent, Ebonie; Vardaxis, Vassilios

    2016-08-01

    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.

  11. Both the elongation of attached crossbridges and residual force enhancement contribute to joint torque enhancement by the stretch-shortening cycle

    PubMed Central

    Misaki, Jun; Isaka, Tadao

    2017-01-01

    This study examined the influence of the elongation of attached crossbridges and residual force enhancement on joint torque enhancement by the stretch-shortening cycle (SSC). Electrically evoked submaximal tetanic plantar flexions were adopted. Concentric contractions were evoked in the following three conditions: after 2 s isometric preactivation (ISO condition), after 1 s isometric then 1 s eccentric preactivation (ECC condition), and after 1 s eccentric then 1 s isometric preactivation (TRAN condition). Joint torque and fascicle length were measured during the concentric contraction phase. While no differences in fascicle length were observed among conditions at any time points, joint torque was significantly higher in the ECC than TRAN condition at the onset of concentric contraction. This difference would be caused by the dissipation of the elastic energy stored in the attached crossbridges induced by eccentric preactivation in TRAN condition due to 1 s transition phase. Furthermore, joint torques observed 0.3 and 0.6 s after concentric contraction were significantly larger in the ECC and TRAN conditions than in the ISO condition while no difference was observed between the ECC and TRAN conditions. Since the elastic energy stored in the attached crossbridges would have dissipated over this time frame, this result suggests that residual force enhancement induced by eccentric preactivation also contributes to joint torque enhancement by the SSC. PMID:28386453

  12. Plantar heel pain.

    PubMed

    Rosenbaum, Andrew J; DiPreta, John A; Misener, David

    2014-03-01

    Plantar heel pain is a common complaint encountered by orthopedic surgeons, internists, and family practitioners. Although it is most often caused by plantar fasciitis, this is a diagnosis of exclusion. Other mechanical, rheumatologic, and neurologic causes must be considered first. The history and physical examination are typically all that is needed to make the proper diagnosis, but diagnostic adjuncts are available to assist the clinician. When plantar fasciitis is diagnosed, conservative modalities must be tried first. Corticosteroid injections and extracorporeal shock-wave therapy may also be used. After 6 months of failed conservative treatments, surgical intervention should be considered.

  13. Spine lateral flexion strength development differences between exercises with pelvic stabilization and without pelvic stabilization

    NASA Astrophysics Data System (ADS)

    Straton, Alexandru; Gidu, Diana Victoria; Micu, Alexandru

    2015-02-01

    Poor lateral flexor muscle strength can be an important source of lumbar/thoracic back pain in women. The purpose of this study was to evaluate pelvic stabilization (PS) and no pelvic stabilization (NoPS) lateral flexion strength exercise training on the development of isolated right and left lateral flexion strength. Isometric torque of the isolated right and left lateral flexion muscles was measured at two positions (0° and 30° opposed angle range of motion) on 42 healthy women before and after 8 weeks of PS and NoPS lateral flexion strength exercise training. Subjects were assigned in three groups, the first (n=14) trained 3 times/week with PS lateral flexion strength exercise, the second (n=14) trained 3 times/week with NoPS lateral flexion strength exercise and the third (control, n=14) did not train. Post training isometric strength values describing PS and NoPS lateral flexion strength improved in greater extent for the PS lateral flexion strength exercise group and in lesser extent for the NoPS lateral flexion strength exercise group, in both angles (p<0.05) relative to controls. These data indicate that the most effective way of training the spine lateral flexion muscles is PS lateral flexion strength exercises; NoPS lateral flexion strength exercises can be an effective way of training for the spine lateral flexion muscles, if there is no access to PS lateral flexion strength training machines.

  14. Plantar fascia (image)

    MedlinePlus

    The plantar fascia is a very thick band of tissue that covers the bones on the bottom of the foot. It ... band of tissue causes a high arch. This fascia can become inflamed and painful in some people, ...

  15. [Plantar fibromatosis (Ledderhose's disease)].

    PubMed

    Koudela, K; Koudela, K; Kunešová, M; Koudelová, J

    2010-08-01

    The authors describe the concomitant presence of plantar fibromatosis and Dupuytren's disease in a 33-year-old man. A lesion located under the sesamoid bones of the first metatarsophalangeal joint on the right showed an aggressive tendency (rapid growth, pain, impossibility to put weight on the medial side of the foot). Another lesion located proximal to the first one was smaller and painless. Neither plain radiography nor computed tomography showed any structural changes of the skeleton. Contrast-enhancement on magnetic resonance imaging revealed two lesions on the sole of the foot. Since a concurrence of plantar fibromatosis and malignant tumour could not be ruled out, an excision of both lesions and the adjacent plantar aponeurosis was made for biopsy examination. The operative procedure was carried out from two incisions.The intra-operative findings included proliferative growth and bleeding in the lesion located under the first metatarsophalangeal joint, and delimited growth without noticeable bleeding in the other lesion. Based on histological examination, the diagnosis of plantar fibromatosis was made for both lesions.The differential diagnosis and therapy of plantar fibromatosis is discussed.

  16. Flexion strength of the toes in the normal foot. An evaluation using magnetic resonance imaging.

    PubMed

    Green, S M; Briggs, P J

    2013-12-01

    Flexion of the toes may be active from muscle contraction or passive from the reversed windlass function of the plantar aponeurosis. The aim of this study was to estimate the flexion moments the muscles of the foot and long digital flexors may be capable of generating and compare these calculations with published data. Magnetic resonance images were used to measure the maximal cross-sectional area of the foot muscles and long digital flexors, along with the radius of curvature of the metatarsal heads. Using known physiological data the maximal flexion moments the muscles may be able to generate at the metatarsophalangeal (MTP) joints were calculated. The methodology overestimates muscle strength and flexion moments at the metatarsophalangeal joints. The calculated maximal flexion moment at the 1st MTP joint is 4.27-6.84 Nm, for the 2nd, 3rd and 4th MTP joints 3.06-4.91 Nm, and the 5th MTP joint 0.47-0.75 Nm. The flexion moments the muscles may generate at the MTP joints do not account for the flexion forces seen in normal walking. Given that maximal strength is not used in normal walking, we conclude that the reversed windlass mechanism of the plantar aponeurosis must be important in normal function of the toes.

  17. Plantar fasciitis: a concise review.

    PubMed

    Schwartz, Emily N; Su, John

    2014-01-01

    One challenge in the treatment of plantar fasciitis is that very few high-quality studies exist comparing different treatment modalities to guide evidence-based management. Current literature suggests a change to the way that plantar fasciitis is managed. This article reviews the most current literature on plantar fasciitis and showcases recommended treatment guidelines. This serves to assist physicians in diagnosing and treating heel pain with plantar fasciitis.

  18. Rupture of the plantar fascia.

    PubMed

    Pai, V S

    1996-01-01

    Rupture of the plantar fascia in athletes engaged in sports that require running and jumping has been reported. However, spontaneous degenerative rupture of the plantar fascia is not well documented in the literature. This paper reports a patient with degenerative rupture of the plantar fascia.

  19. Talalgia: plantar fasciitis☆

    PubMed Central

    Cardenuto Ferreira, Ricardo

    2014-01-01

    Plantar fasciitis is a very common painful syndrome, but its exact etiology still remains obscure. The diagnosis is essentially clinical, based on history-taking and physical examination. Complementary laboratory tests and imaging examinations may be useful for differential diagnoses. The treatment is essentially conservative, with a high success rate (around 90%). The essence of the conservative treatment is the home-based program of exercises to stretch the plantar fascia. Indications for surgical treatment are only made when the symptoms persist without significant improvement, after at least six months of conservative treatment supervised directly by the doctor. PMID:26229803

  20. Analysis for Sit-to-Stand Performance According to the Angle of Knee Flexion in Individuals with Hemiparesis.

    PubMed

    Lee, Mi Young; Lee, Hae Yong

    2013-12-01

    [Purpose] Sit-to-stand (STS) is one of the important functional tasks people perform throughout the day. This study investigated whether varying angles of knee flexion affect STS patterns in individuals with hemiparesis by using a foot plantar pressure measurement system. [Methods] Fifteen stroke patients with hemiparesis participated for this study. They performed sit-to-stand with three angles of knee flexion (70°, 90°, and 110°). We measured the trajectory of the center of pressure, peak plantar pressure, and symmetry index using a Mat-scan system (Tekscan, South Boston, MA, USA). [Results] As a result, we found that there were significant differences among the three angle conditions (trajectory of center of pressure, peak plantar pressure on the affected side, and symmetry index). However, there was no significant difference in peak pressure according to the knee flexion on the unaffected side. [Conclusion] In the current study, we found that stroke patients with hemiparesis had a compensated STS pattern according to knee flexion angles. This indicates that the peak value of plantar pressure increased and that the trajectory of the center of pressure widened as the angle of knee flexion increased. We also suggest that hemiparesis patients should be more concerned about proper knee angle for symmetrical STS pattern.

  1. Strength training for plantar fasciitis and the intrinsic foot musculature: A systematic review.

    PubMed

    Huffer, Dean; Hing, Wayne; Newton, Richard; Clair, Mike

    2017-03-01

    The aim was to critically evaluate the literature investigating strength training interventions in the treatment of plantar fasciitis and improving intrinsic foot musculature strength. A search of PubMed, CINHAL, Web of Science, SPORTSDiscus, EBSCO Academic Search Complete and PEDRO using the search terms plantar fasciitis, strength, strengthening, resistance training, intrinsic flexor foot, resistance training. Seven articles met the eligibility criteria. Methodological quality was assessed using the modified Downs and Black checklist. All articles showed moderate to high quality, however external validity was low. A comparison of the interventions highlights significant differences in strength training approaches to treating plantar fasciitis and improving intrinsic strength. It was not possible to identify the extent to which strengthening interventions for intrinsic musculature may benefit symptomatic or at risk populations to plantar fasciitis. There is limited external validity that foot exercises, toe flexion against resistance and minimalist running shoes may contribute to improved intrinsic foot musculature function. Despite no plantar fascia thickness changes being observed through high-load plantar fascia resistance training there are indications that it may aid in a reduction of pain and improvements in function. Further research should use standardised outcome measures to assess intrinsic foot musculature strength and plantar fasciitis symptoms.

  2. Effect of antagonist muscle fatigue on knee extension torque.

    PubMed

    Beltman, J G M; Sargeant, A J; Ball, D; Maganaris, C N; de Haan, A

    2003-09-01

    The effect of hamstring fatigue on knee extension torque was examined at different knee angles for seven male subjects. Before and after a dynamic flexion fatigue protocol (180 degrees s(-1), until dynamic torque had declined by 50%), maximal voluntary contraction extension torque was measured at four knee flexion angles (90 degrees, 70 degrees, 50 degrees and 30 degrees ). Maximal torque generating capacity and voluntary activation of the quadriceps muscle were determined using electrical stimulation. Average rectified EMG of the biceps femoris was determined. Mean dynamic flexion torque declined by 48+/-11%. Extensor maximal voluntary contraction torque, maximal torque generating capacity, voluntary activation and average rectified EMG at the four knee angles were unaffected by the hamstring fatigue protocol. Only at 50 degrees knee angle was voluntary activation significantly lower (15.7%) after fatigue ( P<0.05). In addition, average rectified EMG before fatigue was not significantly influenced by knee angle. It was concluded that a fatigued hamstring muscle did not increase the maximal voluntary contraction extension torque and knee angle did not change coactivation. Three possible mechanisms may explain the results: a potential difference in recruited fibre populations in antagonist activity compared with the fibres which were fatigued in the protocol, a smaller loss in isometric torque generating capacity of the hamstring muscle than was expected from the dynamic measurements and/or a reduction in voluntary activation.

  3. Association of limited joint mobility and increased plantar hardness in diabetic foot ulceration in north Asian Indian: a preliminary study.

    PubMed

    Periyasamy, R; Anand, Sneh; Ammini, A C

    2012-04-01

    The aim of this article is to investigate the association of limited joint mobility and foot sole hardness in north Asian Indian type 2 diabetic patients. Limited joint mobility and hardness of the foot sole were measured for 39 subjects attending the AIIMS Endocrinology & Metabolism Clinic. The total subject divided into three groups: 13 control subjects (nondiabetic), 13 diabetic patients without neuropathy and 13 diabetic neuropathy patients. Neuropathy status was assessed using 10 gm Semen's Weinstein monofilament. Joint mobility parameters, such as ankle dorsiflexion/plantar flexion and metatarsophalangeal-1 dorsiflexion/plantar flexion, are measured using a goniometer. Foot sole hardness was measured using a durometer or shore meter. We found that diabetic patients with a neuropathic foot had significantly reduced joint mobility and increased foot sole hardness, placing them at risk for subsequent ulceration. Metatarsophalangeal-1 dorsiflexion/plantar flexion of both feet of diabetic patients had significant correlation (at p < 0.05, p < 0.001, p < 0.001 level) over age and body mass index. Also ankle plantar flexion/dorsiflexion and metatarsophalangeal-1 dorsiflexion/plantar flexion has a significant correlations (at p < 0.01, p < 0.05, p < 0.001, p < 0.001 level) with foot sole hardness in both feet of diabetic neuropathy subjects. Also linear regression analysis showed that duration of diabetes was significantly associated with the joint mobility parameters. In this study we conclude that joint mobility had reduced further if neuropathy and increased foot sole hardness coexisted owing to high plantar pressures. Hence, both limited joint mobility and increased foot sole hardness appears to be important determinants of foot sole ulceration in diabetic neuropathic subject.

  4. Treatment of Chronic Plantar Fasciitis With Percutaneous Latticed Plantar Fasciotomy.

    PubMed

    Yanbin, Xu; Haikun, Chu; Xiaofeng, Ji; Wanshan, Yang; Shuangping, Liu

    2015-01-01

    Plantar fasciitis, the most common cause of pain in the inferior heel, accounts for 11% to 15% of all foot symptoms requiring professional care among adults. The present study reports the results of a minimally invasive surgical treatment of chronic plantar fasciitis. All patients with plantar fasciitis who had undergone percutaneous latticed plantar fasciotomy at 3 clinical sites from March 2008 to March 2009 were included in the present study. The follow-up evaluations for this treatment were conducted using the Mayo clinical scoring system. We investigated 17 patients with recalcitrant chronic plantar fasciitis who had undergone this treatment within a follow-up period of ≥13 months. All procedures were performed in the clinic with the patient under local anesthesia. No wound infections or blood vessel or nerve damage occurred. At a mean follow-up period of 16.0 ± 2.29 (range 13 to 21) months, significant improvement was seen in the preoperative mean Mayo score (from 12.06 ± 2.54 to 89.76 ± 4.28, p < .001) and no patient had developed symptom recurrence. Also, none of the patients had developed complex regional pain syndrome. All patients were able to return to regular shoe wear by 3 weeks postoperatively. The technique of plantar fasciitis with percutaneous latticed plantar fasciotomy could be a promising treatment option for patients with recalcitrant chronic plantar fasciitis.

  5. Functional characteristics of the foot and plantar aponeurosis under tibiotalar loading.

    PubMed

    Sarrafian, S K

    1987-08-01

    Structurally the foot is equivalent to a twisted plate. The hindpart is located in the sagittal plane and the forepart in the transverse plane. The transition induced by the twist creates the transverse and the longitudinal arches. Under vertical loading of the foot plate by the tibiotalar column, compressive forces are created on the dorsum and tensile forces on the plantar aspect of the foot plate. The plantar aponeurosis acting as a tie-rod when under tension relieves the tensile forces from the plantar aspect of the foot plate. The increased tension in the plantar aponeurosis in the weightbearing position of the foot occurs with anterior flexion of the leg or with hyperextension of the toes. In the plantigrade position when vertical loading and external rotation are simultaneously applied by the tibiotalar column on the foot, the hindfoot and the midfoot are supinated, and the forefoot is pronated. The medial longitudinal arch is higher, the foot is shorter, and the plantar aponeurosis is relaxed. The foot is then more flexible. With vertical loading and simultaneous internal rotation, the hindfoot and the midfoot are pronated, and the forefoot is supinated. The medial longitudinal arch is lower, the foot is longer, and the plantar aponeurosis is tense. The foot is then more rigid and a better lever arm. Demonstrations are presented both in living and in anatomic dissections.

  6. Primary Care Management of Plantar Fasciitis.

    PubMed

    Melvin, Thomas J; Tankersley, Zach J; Qazi, Zain N; Jasko, John J; Odono, Russell; Shuler, Franklin D

    2015-01-01

    Plantar fasciitis (PF) is present in 10% of the population and is the most common cause of plantar heel pain. PF is painful, can alter daily activities and presents as a sharp pain localized to the plantar foot and medial heel. The underlying etiology involves microtrauma to the plantar fascia, specifically at its insertion point on the calcaneus. Successful management of plantar fasciitis is typically achieved with the conservative therapy approaches discussed.

  7. Plantar fasciitis: evaluation and treatment.

    PubMed

    Neufeld, Steven K; Cerrato, Rebecca

    2008-06-01

    Plantar fasciitis is the most common cause of plantar heel pain. Its characteristic features are pain and tenderness, predominately on the medial aspect of the calcaneus near the sole of the heel. Considering a complete differential diagnosis of plantar heel pain is important; a comprehensive history and physical examination guide accurate diagnosis. Many nonsurgical treatment modalities have been used in managing the disorder, including rest, massage, nonsteroidal anti-inflammatory drugs, night splints, heel cups/pads, custom and off-the-shelf orthoses, injections, casts, and physical therapy measures such as shock wave therapy. Most reported treatment outcomes rely on anecdotal experience or combinations of multiple modalities. Nevertheless, nonsurgical management of plantar fasciitis is successful in approximately 90% of patients. Surgical treatment is considered in only a small subset of patients with persistent, severe symptoms refractory to nonsurgical intervention for at least 6 to 12 months.

  8. Influence of joint angle on EMG-torque model during constant-posture, quasi-constant-torque contractions.

    PubMed

    Liu, Pu; Liu, Lukai; Martel, Francois; Rancourt, Denis; Clancy, Edward A

    2013-10-01

    Electromyogram (EMG)-torque modeling is of value to many different application areas, including ergonomics, clinical biomechanics and prosthesis control. One important aspect of EMG-torque modeling is the ability to account for the joint angle influence. This manuscript describes an experimental study which relates the biceps/triceps surface EMG of 12 subjects to elbow torque at seven joint angles (spanning 45-135°) during constant-posture, quasi-constant-torque contractions. Advanced EMG amplitude (EMGσ) estimation processors (i.e., whitened, multiple-channel) were investigated and three non-linear EMGσ-torque models were evaluated. When EMG-torque models were formed separately for each of the seven distinct joint angles, a minimum "gold standard" error of 4.23±2.2% MVCF90 resulted (i.e., error relative to maximum voluntary contraction at 90° flexion). This model structure, however, did not directly facilitate interpolation across angles. The best model which did so (i.e., parameterized the angle dependence), achieved an error of 4.17±1.7% MVCF90. Results demonstrated that advanced EMGσ processors lead to improved joint torque estimation. We also contrasted models that did vs. did not account for antagonist muscle co-contraction. Models that accounted for co-contraction estimated individual flexion muscle torques that were ∼29% higher and individual extension muscle torques that were ∼68% higher.

  9. Reliability of plantar pressure platforms.

    PubMed

    Hafer, Jocelyn F; Lenhoff, Mark W; Song, Jinsup; Jordan, Joanne M; Hannan, Marian T; Hillstrom, Howard J

    2013-07-01

    Plantar pressure measurement is common practice in many research and clinical protocols. While the accuracy of some plantar pressure measuring devices and methods for ensuring consistency in data collection on plantar pressure measuring devices have been reported, the reliability of different devices when testing the same individuals is not known. This study calculated intra-mat, intra-manufacturer, and inter-manufacturer reliability of plantar pressure parameters as well as the number of plantar pressure trials needed to reach a stable estimate of the mean for an individual. Twenty-two healthy adults completed ten walking trials across each of two Novel emed-x(®) and two Tekscan MatScan(®) plantar pressure measuring devices in a single visit. Intraclass correlation (ICC) was used to describe the agreement between values measured by different devices. All intra-platform reliability correlations were greater than 0.70. All inter-emed-x(®) reliability correlations were greater than 0.70. Inter-MatScan(®) reliability correlations were greater than 0.70 in 31 and 52 of 56 parameters when looking at a 10-trial average and a 5-trial average, respectively. Inter-manufacturer reliability including all four devices was greater than 0.70 for 52 and 56 of 56 parameters when looking at a 10-trial average and a 5-trial average, respectively. All parameters reached a value within 90% of an unbiased estimate of the mean within five trials. Overall, reliability results are encouraging for investigators and clinicians who may have plantar pressure data sets that include data collected on different devices.

  10. Topical cidofovir for plantar warts.

    PubMed

    Padilla España, Laura; Del Boz, Javier; Fernández Morano, Teresa; Arenas Villafranca, Javier; de Troya Martín, Magdalena

    2014-01-01

    Plantar warts are a common reason for dermatological consultations and their treatment can occasionally be a challenge. Plantar warts are benign lesions produced by the human papillomavirus (HPV) that often fail to respond to habitual treatment. Cidofovir is a potent antiviral drug that acts competitively, inhibiting viral DNA polymerase. Our aim was to assess the efficacy and safety of cidofovir cream for the treatment of viral plantar warts. We undertook a retrospective observational study of patients with plantar warts who received treatment with topical cidofovir between July 2008 and July 2011 at the Dermatology Service of the Hospital Costa del Sol, Marbella, Spain. Data about the rate of treatment response, the adverse effects, and recurrences, as well as the characteristics of the patient cohort, were recorded. We identified 35 patients who had received some previous treatment. The usual concentration was 3% (in 33 of 35 cases), applied twice a day (in 31 of 35 cases). A greater or lesser response was noted in 28 cases. There were two recurrences. Topical cidofovir seems to be a useful alternative for the therapeutic management of recalcitrant plantar common warts that fail to respond to usual treatment.

  11. Contribution of central vs. peripheral factors to the force loss induced by passive stretch of the human plantar flexors.

    PubMed

    Trajano, Gabriel S; Seitz, Laurent; Nosaka, Kasunori; Blazevich, Anthony J

    2013-07-15

    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.

  12. Knee Extensor and Flexor Torque Development with Concentric and Eccentric Isokinetic Training

    ERIC Educational Resources Information Center

    Miller, Larry E.; Pierson, Lee M.; Nickols-Richardson, Sharon M.; Wootten, David F.; Selmon, Serah E.; Ramp, Warren K.; Herbert, William G.

    2006-01-01

    This study assessed muscular torque and rate of torque development following concentric (CON) or eccentric (ECC) isokinetic training. Thirty-eight women were randomly assigned to either CON or ECC training groups. Training consisted of knee extension and flexion of the nondominant leg three times per week for 20 weeks (SD = 1). Eccentric training…

  13. Diagnosis and management of plantar fasciitis.

    PubMed

    Thompson, John V; Saini, Sundeep S; Reb, Christopher W; Daniel, Joseph N

    2014-12-01

    Plantar fasciitis, a chronic degenerative process that causes medial plantar heel pain, is responsible for approximately 1 million physician visits each year. Individuals with plantar fasciitis experience pain that is most intense during their first few steps of the day or after prolonged standing. The authors provide an overview of the diagnosis and management of a common problem encountered in the primary care setting. Routine imaging is not initially recommended for the evaluation of plantar fasciitis but may be required to rule out other pathologic conditions. Overall, plantar fasciitis carries a good prognosis when patients use a combination of several conservative treatment modalities. Occasionally, referral to a specialist may be necessary.

  14. Diagnosis and treatment of plantar fasciitis.

    PubMed

    Goff, James D; Crawford, Robert

    2011-09-15

    Plantar fasciitis, a self-limiting condition, is a common cause of heel pain in adults. It affects more than 1 million persons per year, and two-thirds of patients with plantar fasciitis will seek care from their family physician. Plantar fasciitis affects sedentary and athletic populations. Obesity, excessive foot pronation, excessive running, and prolonged standing are risk factors for developing plantar fasciitis. Diagnosis is primarily based on history and physical examination. Patients may present with heel pain with their first steps in the morning or after prolonged sitting, and sharp pain with palpation of the medial plantar calcaneal region. Discomfort in the proximal plantar fascia can be elicited by passive ankle/first toe dorsiflexion. Diagnostic imaging is rarely needed for the initial diagnosis of plantar fasciitis. Use of ultrasonography and magnetic resonance imaging is reserved for recalcitrant cases or to rule out other heel pathology; findings of increased plantar fascia thickness and abnormal tissue signal the diagnosis of plantar fasciitis. Conservative treatments help with the disabling pain. Initially, patient-directed treatments consisting of rest, activity modification, ice massage, oral analgesics, and stretching techniques can be tried for several weeks. If heel pain persists, then physician-prescribed treatments such as physical therapy modalities, foot orthotics, night splinting, and corticosteroid injections should be considered. Ninety percent of patients will improve with these conservative techniques. Patients with chronic recalcitrant plantar fasciitis lasting six months or longer can consider extracorporeal shock wave therapy or plantar fasciotomy.

  15. Plantar Fasciitis: Prescribing Effective Treatments.

    ERIC Educational Resources Information Center

    Shea, Michael; Fields, Karl B.

    2002-01-01

    Plantar fasciitis is an extremely common, painful injury seen among people in running and jumping sports. While prognosis for recovery with conservative care is excellent, prolonged duration of symptoms affects sports participation. Studies on treatment options show mixed results, so finding effective treatments can be challenging. A logical…

  16. Measured flexion following total knee arthroplasty.

    PubMed

    Mai, Kenny T; Verioti, Christopher A; Hardwick, Mary E; Ezzet, Kace A; Copp, Steven N; Colwell, Clifford W

    2012-10-01

    Postoperative flexion is an important factor in the outcome of total knee arthroplasty. Although normal activities of daily living require a minimum of 105° to 110° of flexion, patients from non-Western cultures often engage in activities such as kneeling and squatting that require higher flexion. The desire to achieve greater flexion serves as the driving force for prosthetic modifications, including high-flexion designs. Techniques used to measure knee flexion and knee position during measurement are not often described or are different depending on the examiner. The purpose of this study was to compare active (self) and passive (assisted) flexion after successful total knee arthroplasty for 5 prostheses (2 standard and 3 high-flexion) using clinical (goniometer) and radiographic (true lateral radiograph) measurement techniques by different independent examiners.At a mean follow-up of 2.7 years (range, 1-5.6 years), a total of 108 patients (144 total knee arthroplasties) had completed the study. Mean postoperative active flexion was 111° clinically and 109° radiographically for the standard designs and 114° clinically and 117° radiographically for the high-flexion designs. Adding passive flexion increased flexion to 115° clinically and 117° radiographically for the standard designs and 119° clinically and 124° radiographically for the high-flexion designs. Flexion differences between the 2 measurement techniques (active vs passive and clinically vs radiographically) were statistically significant (P<.05). These findings demonstrate the importance of describing how flexion is measured in studies and understanding how the method of measurement can affect the findings.

  17. Effect of implant design on knee flexion.

    PubMed

    Dennis, Douglas A; Heekin, R David; Clark, Charles R; Murphy, Jeffrey A; O'Dell, Tammy L; Dwyer, Kimberly A

    2013-03-01

    From March 2006 to August 2008, 93 subjects (186 knees) underwent simultaneous bilateral total knee arthroplasty performed by eight surgeons at North American centers. This randomized study was conducted to determine whether non-weight-bearing passive flexion was superior for knees receiving a posterior stabilized high flexion device compared to a posterior stabilized standard device in the contra-lateral knee. Weight-bearing single leg active flexion was one secondary endpoint. Follow-up compliance was 92.5%. Results show small, but significant superiority in the motion metrics for the high flexion device compared to the standard device 12 months after surgery, especially for a subgroup of patients with pre-operative flexion less than 120° in both knees. Thus, the ideal candidate for the high flexion device may be one with lesser pre-operative flexion.

  18. Plantar fibromatosis--topical review.

    PubMed

    Veith, Nils T; Tschernig, Thomas; Histing, Tina; Madry, Henning

    2013-12-01

    Morbus Ledderhose is a rare hyperproliferative disease of the plantar fascia, leading to the formation of nodules. Its origin is unknown. No causal therapy is available, and treatment remains symptomatic. Various therapeutic strategies to alleviate symptoms are available and are adapted to the severity of the disease. In early stages, conservative therapy including nonpharmacological, physical, and pharmacological treatments is applied. If the disease progresses, irradiation of the plantar surface, injections of steroids, shock wave therapy, and partial or complete fasciectomy as an ultimate therapy may be indicated. Novel experimental treatment options including application of fibrinolytic agents are currently being tested, but no controlled, randomized long-term studies are available. This review aims to provide a systematic overview of current established procedures and outlines novel experimental strategies for the treatment of morbus Ledderhose, including future avenues to treat this rare disease.

  19. A composite medial plantar flap for the repair of an achilles' tendon defect: a case report.

    PubMed

    Dumont, C E; Kessler, J

    2001-12-01

    The surgical management of infected necrosis of the Achilles' tendon and overlying skin is very demanding, and reconstruction with vascularized tendon and skin flaps is considered the benchmark procedure. The authors report a 65-year-old man who sustained a chronic wound after operative repair of a chronic rupture of the Achilles' tendon. A pedicled medial plantar flap including the surrounding vascularized plantar aponeurosis was elevated. The plantar aponeurosis was split and used to bridge the 4-cm-long tendon defect. The flap donor site was covered with a thin skin graft. The flap survived completely without recurrence of the infection. At the 7-month follow-up, the reconstructed Achilles' tendon showed a good functional result and a normal range of dorsi- and plantar flexion of the foot. This technique is of great interest in comparison with free flaps because it does not require vascular anastomosis in a septic environment or a secondary debulking operation, yet it still provides both vascularized tendon and skin graft.

  20. Plantar pressures in individuals with normal and pronated feet according to static squat depths.

    PubMed

    Koh, Da Hyun; Lee, Jong Dae; Kim, Kyoung

    2015-09-01

    [Purpose] The purpose of the present study was to investigate differences in plantar pressure between individuals with normal and pronated feet according to 3 static squat depths. [Subjects and Methods] Study subjects were 10 young adults with normal and pronated feet. Plantar pressures were measured in the standing position and static squat positions at 45° (semi-squat) and 90° (half-squat) knee flexion using the F-Mat. Subjects' plantar pressures were analyzed by dividing the foot into 4 areas: forefoot medial, forefoot lateral, midfoot, and heel. [Results] In the half-squat position, the pronated foot group showed a higher foot pressure in the forefoot medial than was seen in the normal group, whereas the normal group exhibited a higher foot pressure in the heel than was seen in the pronated foot group. [Conclusion] An increase in squat depth led to the transfer of plantar pressure to the heel in normal feet and to the forefoot medial in pronated feet.

  1. Plantar pressures in individuals with normal and pronated feet according to static squat depths

    PubMed Central

    Koh, Da Hyun; Lee, Jong Dae; Kim, Kyoung

    2015-01-01

    [Purpose] The purpose of the present study was to investigate differences in plantar pressure between individuals with normal and pronated feet according to 3 static squat depths. [Subjects and Methods] Study subjects were 10 young adults with normal and pronated feet. Plantar pressures were measured in the standing position and static squat positions at 45° (semi-squat) and 90° (half-squat) knee flexion using the F-Mat. Subjects’ plantar pressures were analyzed by dividing the foot into 4 areas: forefoot medial, forefoot lateral, midfoot, and heel. [Results] In the half-squat position, the pronated foot group showed a higher foot pressure in the forefoot medial than was seen in the normal group, whereas the normal group exhibited a higher foot pressure in the heel than was seen in the pronated foot group. [Conclusion] An increase in squat depth led to the transfer of plantar pressure to the heel in normal feet and to the forefoot medial in pronated feet. PMID:26504304

  2. Spontaneous rupture of the plantar fascia.

    PubMed

    Ahstrom, J P

    1988-01-01

    In this study, rupture of the plantar fascia was seen in five feet, of which four had had plantar fasciitis. At the time of the injury, which is an acceleration type of motion, there is severe pain in the heel followed by the development of ecchymosis in the sole and toward the heel of the foot. With conservative symptomatic care, the acute symptoms as well as the plantar fasciitis symptoms subside, generally allowing full activity in 3 to 4 weeks.

  3. Getting to the heel of the problem: plantar fascia lesions.

    PubMed

    Jeswani, T; Morlese, J; McNally, E G

    2009-09-01

    Heel pain is a frequent disabling symptom. Clinical diagnosis is often difficult with a large range of possible diagnoses. Lesions of the plantar fascia form an important group. We present a review describing the common lesions of the plantar fascia, including plantar fasciitis, plantar fascia rupture, plantar fibromatosis, and plantar xanthoma, and illustrate them with appropriate magnetic resonance imaging (MRI) and ultrasound imaging. We also address foreign-body reactions, enthesopathy, and diabetic fascial disease.

  4. Importance of correcting isokinetic peak torque for the effect of gravity when calculating knee flexor to extensor muscle ratios.

    PubMed

    Fillyaw, M; Bevins, T; Fernandez, L

    1986-01-01

    The purpose of our investigation was to compare, for the hamstring and quadriceps femoris muscles, peak torque values uncorrected for gravity with the peak torque values corrected for gravity and to determine the effect of making this correction on the hamstring to quadriceps femoris muscle peak torque ratio at slow and fast isokinetic speeds. We measured peak torques isokinetically at 60 degrees/sec (slow) and 240 degrees/sec (fast) in 25 female university soccer players. The gravity effect torque (GET) is the torque resulting from the effect of gravity on the combined weight of the leg and dynamometer arm at the precise angle of extension and flexion peak torque. The GET was added to the measured quadriceps femoris muscle peak torque and subtracted from the hamstring muscle peak torque to yield gravity corrected values. Failure to consider GET greatly underestimated quadriceps femoris muscle torque and overestimated hamstring muscle torque and the ratio between these torques at both speeds. Whereas the uncorrected hamstring to quadriceps femoris muscle peak torque ratio increased as speeds went from 60 degrees/sec to 240 degrees/sec, the gravity corrected ratio significantly decreased. Clinicians must remember the importance of making the gravity correction in patients with reduced torque output where the gravitational torque is a greater percentage of the measured torque to ascertain correctly the relative strength of antagonists inversely affected by gravity.

  5. Association of Achilles tendinopathy and plantar spurs.

    PubMed

    Vulcano, Ettore; Mani, Sriniwasan B; Mani, Sriniwasan; Do, Huong; Bohne, Walter H; Ellis, Scott J

    2014-10-01

    Plantar spurs and Achilles tendinopathy are common causes of heel pain. In the authors' practice, it was anecdotally noted that patients with Achilles tendinopathy often presented with plantar spurs. Nonetheless, there is a shortage of studies investigating whether Achilles tendinopathy and plantar spurs exist concomitantly. A better understanding of the association between the 2 pathologies might help physicians recognize and treat both conditions, educate patients about Achilles tendinopathy and plantar spurs, and ultimately investigate possible underlying causes of both pathologies that could be addressed together. The authors examined the prevalence of plantar spurs in patients diagnosed with Achilles tendinopathy as well as demographic differences within the unilateral and bilateral Achilles tendinopathy populations. A total of 785 patient records were retrospectively reviewed. Mean patient age was 56.2±15.5 years (46.9% men and 53.1% women). Seventy-two (9.2%) patients were affected bilaterally by Achilles tendinopathy. Lateral radiographs were reviewed by an orthopedic surgeon to identify the presence of plantar spurs. A total of 329 (41.9%) patients with Achilles tendinopathy were found to have a concomitant plantar spur. Patients with unilateral Achilles tendinopathy and a plantar spur were more likely to be women (58.7% vs 49.8%, P=.020) and older (62.7 vs 51.7 years, P<.001). In the bilateral Achilles tendinopathy group, there were 46 (63.9%) patients with at least one foot presenting with a plantar spur. The study's findings suggest a significant association between Achilles tendinopathy and plantar spurs. Older women with Achilles tendinopathy are at greater risk of being affected by plantar spurs.

  6. Mechanical and energetic consequences of reduced ankle plantar-flexion in human walking

    PubMed Central

    Huang, Tzu-wei P.; Shorter, Kenneth A.; Adamczyk, Peter G.; Kuo, Arthur D.

    2015-01-01

    ABSTRACT The human ankle produces a large burst of ‘push-off’ mechanical power late in the stance phase of walking, reduction of which leads to considerably poorer energy economy. It is, however, uncertain whether the energetic penalty results from poorer efficiency when the other leg joints substitute for the ankle's push-off work, or from a higher overall demand for work due to some fundamental feature of push-off. Here, we show that greater metabolic energy expenditure is indeed explained by a greater demand for work. This is predicted by a simple model of walking on pendulum-like legs, because proper push-off reduces collision losses from the leading leg. We tested this by experimentally restricting ankle push-off bilaterally in healthy adults (N=8) walking on a treadmill at 1.4 m s−1, using ankle–foot orthoses with steel cables limiting motion. These produced up to ∼50% reduction in ankle push-off power and work, resulting in up to ∼50% greater net metabolic power expenditure to walk at the same speed. For each 1 J reduction in ankle work, we observed 0.6 J more dissipative collision work by the other leg, 1.3 J more positive work from the leg joints overall, and 3.94 J more metabolic energy expended. Loss of ankle push-off required more positive work elsewhere to maintain walking speed; this additional work was performed by the knee, apparently at reasonably high efficiency. Ankle push-off may contribute to walking economy by reducing dissipative collision losses and thus overall work demand. PMID:26385330

  7. Finger-thumb coupling contributes to exaggerated thumb flexion in stroke survivors.

    PubMed

    Kamper, Derek G; Fischer, Heidi C; Conrad, Megan O; Towles, Joseph D; Rymer, William Z; Triandafilou, Kristen M

    2014-06-15

    The purpose of this study was to investigate altered finger-thumb coupling in individuals with chronic hemiparesis poststroke. First, an external device stretched finger flexor muscles by passively rotating the metacarpophalangeal (MCP) joints. Subjects then performed isometric finger or thumb force generation. Forces/torques and electromyographic signals were recorded for both the thumb and finger muscles. Stroke survivors with moderate (n = 9) and severe (n = 9) chronic hand impairment participated, along with neurologically intact individuals (n = 9). Stroke survivors exhibited strong interactions between finger and thumb flexors. The stretch reflex evoked by stretch of the finger flexors of stroke survivors led to heteronymous reflex activity in the thumb, while attempts to produce isolated voluntary finger MCP flexion torque/thumb flexion force led to increased and undesired thumb force/finger MCP torque production poststroke with a striking asymmetry between voluntary flexion and extension. Coherence between the long finger and thumb flexors estimated using intermuscular electromyographic correlations, however, was small. Coactivation of thumb and finger flexor muscles was common in stroke survivors, whether activation was evoked by passive stretch or voluntary activation. The coupling appears to arise from subcortical or spinal sources. Flexor coupling between the thumb and fingers seems to contribute to undesired thumb flexor activity after stroke and may impact rehabilitation outcomes.

  8. Post-traumatic unilateral plantar hyperhidrosis.

    PubMed

    Eren, Y; Yavasoglu, N G; Comoglu, S S

    2016-02-01

    Localized unilateral hyperhidrosis is rare and poorly understood, sometimes stemming from trauma. Feet, quite vulnerable to trauma are affected by disease-mediated plantar hyperhidrosis, usually bilaterally. This report describes partial hyperhidrosis developing post-traumatically on the left plantar region of a 52-year-old male.

  9. Targeting the Plantar Fascia for Corticosteroid Injection.

    PubMed

    Salvi, Andrea Emilio

    2015-01-01

    Plantar fasciitis is often a difficult condition to treat. It is related to repetitive strain of the fascia at its attachment to the heel bone. This condition quite often appears with the concomitant presence of a plantar calcaneal heel spur. Corticosteroid injection is a popular treatment choice for plantar fasciitis, and accurate localization of the injected medication is essential for successful resolution of symptoms after the injection. In the present brief technical communication, a method for targeting the attachment of the plantar fascia to the medial tubercle of the tuberosity of the calcaneus is described. The targeting method uses the lateral radiograph of the foot to aid in localization of the proximal attachment of the plantar fascia to the calcaneus.

  10. Acute effect of muscle stretching on the steadiness of sustained submaximal contractions of the plantar flexor muscles.

    PubMed

    Kato, Emika; Vieillevoye, Stéphanie; Balestra, Costantino; Guissard, Nathalie; Duchateau, Jacques

    2011-02-01

    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.

  11. Registration of plantar pressure images.

    PubMed

    Oliveira, Francisco P M; Tavares, João Manuel R S

    2012-01-01

    In this work, five computational methodologies to register plantar pressure images are compared: (1) the first methodology is based on matching the external contours of the feet; (2) the second uses the phase correlation technique; (3) the third addresses the direct maximization of cross-correlation using the Fourier transform; (4) the fourth minimizes the sum of squared differences using the Fourier transform; and (5) the fifth methodology iteratively optimizes an intensity (dis)similarity measure based on Powell's method. The accuracy and robustness of the five methodologies were assessed by using images from three common plantar pressure acquisition devices: a Footscan system, an EMED system, and a light reflection system. Using the residual error as a measure of accuracy, all methodologies revealed to be very accurate even in the presence of noise. The most accurate was the methodology based on the iterative optimization, when the mean squared error was minimized. It achieved a residual error inferior to 0.01 mm and 0.6 mm for non-noisy and noisy images, respectively. On the other hand, the methodology based on image contour matching was the fastest, but its accuracy was the lowest.

  12. Ballistic flexion movements of the human thumb.

    PubMed Central

    Hallett, M; Marsden, C D

    1979-01-01

    1. In response to an auditory stimulus normal subjects made ballistic flexion movements of the top joint of the thumb against a lever attached to the spindle of a low-inertia electric motor. 2. Electromyographic (e.m.g.) activity was recorded from pairs of fine wire electrodes inserted into flexor pollicis longus and extensor pollicis longus, respectively the sole flexor and extensor of the joint. 3. Movements of 5 degrees, 10 degrees and 20 degrees were made from initial angles of 10 degrees, 20 degrees and 30 degrees flexion against torques of 0.04, 0.08 and 0.16 Nm. 4. The e.m.g. activity initiating such movements was characterized by a 'triphasic' pattern of sequential bursts of activity in the agonist (flexor pollicis longus), then in the antagonist (extensor pollicis longus), and then in the agonist again. 5. The duration of the first agonist and first antagonist bursts ranged from about 50 to 90 ms and there was no significant change of burst length in the different mechanical conditions. 6. In movements of differing angular distance, the rectified and integrated e.m.g. activity of the first agonist burst could be correlated with the distance moved. The rectified and integrated e.m.g. activity of the first antagonist burst could not be correlated with the distance moved. 7. Responses of the muscles to perturbations either before or during the ballistic movements were studied. Current in the motor could be altered so to extend the thumb ('stretch'), to allow it to accelerate ('release'), or to prevent further movement ('halt'). 8. Suitably timed stretch increased the e.m.g. activity of the first agonist burst while release decreased it. 9. There was a small response of the agonist to stretch or halt timed to act during the interval between the first two agonist bursts; the major response was an augmentation of the second agonist burst. 10. Stretch, timed to act between the first two agonist bursts which released the antagonist, diminished the activity of the

  13. WEAK LENSING MASS RECONSTRUCTION: FLEXION VERSUS SHEAR

    SciTech Connect

    Pires, S.

    2010-11-10

    Weak gravitational lensing has proven to be a powerful tool to map directly the distribution of dark matter in the universe. The technique, currently used, relies on the accurate measurement of the gravitational shear that corresponds to the first-order distortion of the background galaxy images. More recently, a new technique has been introduced that relies on the accurate measurement of the gravitational flexion that corresponds to the second-order distortion of the background galaxy images. This technique should probe structures on smaller scales than that of shear analysis. The goal of this paper is to compare the ability of shear and flexion to reconstruct the dark matter distribution by taking into account the dispersion in shear and flexion measurements. Our results show that the flexion is less sensitive than shear for constructing the convergence maps on scales that are physically feasible for mapping, meaning that flexion alone should not be used to do convergence map reconstruction, even on small scales.

  14. Plantar fascia rupture associated with corticosteroid injection.

    PubMed

    Sellman, J R

    1994-07-01

    A series of 37 patients, all with a presumptive diagnosis of plantar fascia rupture, is presented. All had had prior heel pain diagnosed as plantar fasciitis, and all had been treated with corticosteroid injection into the calcaneal origin of the fascia. One third described a sudden tearing episode in the heel, while the rest had a gradual change in symptoms. Most of the patients had relief of the original heel pain, which had been replaced by a variety of new foot problems, including dorsal and lateral midfoot pain, swelling, foot weakness, metatarsal pain, and metatarsal fracture. In all 37 patients, there was a palpable diminution in the tension of the plantar fascia on the involved side, and footprints often showed a flattening of the involved arch. Magnetic resonance imaging done on one patient showed attenuation of the plantar fascia. From these observations and data, the author concluded that plantar fascia rupture had occurred. Treatment following rupture included supportive shoes, orthoses, and time. The majority had resolution of their new symptoms, but this often took 6 to 12 months to occur. In the remainder, there were persisting symptoms. Corticosteroid injections, although helpful in the treatment of plantar fasciitis, appear to predispose to plantar fascia rupture.

  15. Effect of ankle flexion on the quantification of MRS for intramyocellular lipids of the tibialis anterior and the medial gastrocnemius.

    PubMed

    Takashima, Hiroyuki; Shishido, Hiroki; Imamura, Rui; Akatsuka, Yoshihiro; Taniguchi, Keigo; Nakanishi, Mitsuhiro; Suzuki, Junpei; Nagahama, Hiroshi; Sakurai, Yuki; Sakata, Motomichi

    2015-07-01

    Muscle proton magnetic resonance spectroscopy (MRS) has been developed for non-invasive measurement of intramyocellular lipid (IMCL) levels. The majority of previous studies measuring IMCL with MRS have been performed on the calf muscle. The appearance of muscle MRS is influenced by bulk magnetic susceptibility and residual dipolar couplings, which depend on the angle between the muscle fibers and the main magnetic field. Our objective in this study was to evaluate the effect of ankle flexion and of the pennation angle on IMCL quantification in the calf muscle using proton MRS. The subjects comprised ten healthy male volunteers. In proton MRS, the ankle flexion angle was changed, and the pennation angle was measured from the tibialis anterior (TA) and the medial gastrocnemius (MG), respectively. We considered the relationship between the quantification of IMCL with (1)H MRS and the pennation angle by ankle flexion angle. The pennation angle of the TA and MG changed with the ankle flexion angle. The IMCL on the TA decreased significantly with plantar flexion (p < 0.05). However, the IMCL on the MG demonstrated no significant difference. The MR spectrum and IMCL quantitation changed with the pennation angle. Therefore, when spectra of individual subjects in longitudinal studies or between subjects are compared in cross-sectional studies, the foot position or calf muscle orientation must be considered.

  16. Pathologic conditions of the plantar fascia.

    PubMed

    La Porta, Guido A; La Fata, Paul C

    2005-01-01

    Plantar heel pain in adults is commonly seen in the office of the podiatric foot and ankle specialist. These symptoms may have developed acutely or over a period of time. Often the plantar fascia is the source of the pain, which is caused by a traumatic event or a biomechanical flaw. It is imperative that the podiatric physician understands the multiple causes of plantar foot pain and is able to differentiate the multiple causes of heel pain to confirm a specific diagnosis and formulate a proper treatment plan. A thorough history and physical examination are necessary to obtain this information, and diagnostic procedures are sometimes needed.

  17. Influence of Joint Angle on EMG-Torque Model During Constant-Posture, Torque-Varying Contractions.

    PubMed

    Liu, Pu; Liu, Lukai; Clancy, Edward A

    2015-11-01

    Relating the electromyogram (EMG) to joint torque is useful in various application areas, including prosthesis control, ergonomics and clinical biomechanics. Limited study has related EMG to torque across varied joint angles, particularly when subjects performed force-varying contractions or when optimized modeling methods were utilized. We related the biceps-triceps surface EMG of 22 subjects to elbow torque at six joint angles (spanning 60° to 135°) during constant-posture, torque-varying contractions. Three nonlinear EMG σ -torque models, advanced EMG amplitude (EMG σ ) estimation processors (i.e., whitened, multiple-channel) and the duration of data used to train models were investigated. When EMG-torque models were formed separately for each of the six distinct joint angles, a minimum "gold standard" error of 4.01±1.2% MVC(F90) resulted (i.e., error relative to maximum voluntary contraction at 90° flexion). This model structure, however, did not directly facilitate interpolation across angles. The best model which did so achieved a statistically equivalent error of 4.06±1.2% MVC(F90). Results demonstrated that advanced EMG σ processors lead to improved joint torque estimation as do longer model training durations.

  18. Isokinetic strength during knee flexion and extension in elite fencers.

    PubMed

    Poulis, I; Chatzis, S; Christopoulou, K; Tsolakis, Ch

    2009-06-01

    The relation of leg preference and muscular strength in elite fencers was examined. The dominant and nondominant extensor and flexor muscles of 30 elite fencers (M age = 18.2 yr., SD = 2.0 yr.; M height = 173 cm, SD=7.4 cm; M weight = 62.7 kg, SD=8.9 kg), who were members of the Greek national team, and 14 healthy, young, sedentary adults (8 men, 6 women; M age 23.4 yr., SD = 1.9; M height = 169 cm, SD = 10.5 cm; M weight = 66.3 kg, SD = 9.9) were tested for concentric isokinetic contraction at slow (30 to 60 degrees/sec.) and fast (240 degrees/sec.) angular velocities. Significant multivariate differences were found between groups for knee extension, angle of knee extension, knee flexion, and flexor/extensor peak torque ratio. In contrast, no significant difference was found between the dominant and nondominant legs. There was no significant difference in the flexor/extensor peak torque ratio among any of the concentric angular velocities tested. These findings suggest that long-term training in fencing influences the strength characteristics of the lower limbs.

  19. Torso flexion modulates stiffness and reflex response.

    PubMed

    Granata, K P; Rogers, E

    2007-08-01

    Neuromuscular factors that contribute to spinal stability include trunk stiffness from passive and active tissues as well as active feedback from reflex response in the paraspinal muscles. Trunk flexion postures are a recognized risk factor for occupational low-back pain and may influence these stabilizing control factors. Sixteen healthy adult subjects participated in an experiment to record trunk stiffness and paraspinal muscle reflex gain during voluntary isometric trunk extension exertions. The protocol was designed to achieve trunk flexion without concomitant influences of external gravitational moment, i.e., decouple the effects of trunk flexion posture from trunk moment. Systems identification analyses identified reflex gain by quantifying the relation between applied force disturbances and time-dependent EMG response in the lumbar paraspinal muscles. Trunk stiffness was characterized from a second order model describing the dynamic relation between the force disturbances versus the kinematic response of the torso. Trunk stiffness increased significantly with flexion angle and exertion level. This was attributed to passive tissue contributions to stiffness. Reflex gain declined significantly with trunk flexion angle but increased with exertion level. These trends were attributed to correlated changes in baseline EMG recruitment in the lumbar paraspinal muscles. Female subjects demonstrated greater reflex gain than males and the decline in reflex gain with flexion angle was greater in females than in males. Results reveal that torso flexion influences neuromuscular factors that control spinal stability and suggest that posture may contribute to the risk of instability injury.

  20. Head flexion angle while using a smartphone.

    PubMed

    Lee, Sojeong; Kang, Hwayeong; Shin, Gwanseob

    2015-01-01

    Repetitive or prolonged head flexion posture while using a smartphone is known as one of risk factors for pain symptoms in the neck. To quantitatively assess the amount and range of head flexion of smartphone users, head forward flexion angle was measured from 18 participants when they were conducing three common smartphone tasks (text messaging, web browsing, video watching) while sitting and standing in a laboratory setting. It was found that participants maintained head flexion of 33-45° (50th percentile angle) from vertical when using the smartphone. The head flexion angle was significantly larger (p < 0.05) for text messaging than for the other tasks, and significantly larger while sitting than while standing. Study results suggest that text messaging, which is one of the most frequently used app categories of smartphone, could be a main contributing factor to the occurrence of neck pain of heavy smartphone users. Practitioner Summary: In this laboratory study, the severity of head flexion of smartphone users was quantitatively evaluated when conducting text messaging, web browsing and video watching while sitting and standing. Study results indicate that text messaging while sitting caused the largest head flexion than that of other task conditions.

  1. Foot Plantar Pressure Measurement System: A Review

    PubMed Central

    Razak, Abdul Hadi Abdul; Zayegh, Aladin; Begg, Rezaul K.; Wahab, Yufridin

    2012-01-01

    Foot plantar pressure is the pressure field that acts between the foot and the support surface during everyday locomotor activities. Information derived from such pressure measures is important in gait and posture research for diagnosing lower limb problems, footwear design, sport biomechanics, injury prevention and other applications. This paper reviews foot plantar sensors characteristics as reported in the literature in addition to foot plantar pressure measurement systems applied to a variety of research problems. Strengths and limitations of current systems are discussed and a wireless foot plantar pressure system is proposed suitable for measuring high pressure distributions under the foot with high accuracy and reliability. The novel system is based on highly linear pressure sensors with no hysteresis. PMID:23012576

  2. Botulinum toxin effects on gasatrocnemius strength and plantar pressure in diabetics with peripheral neuropathy and forefoot ulceration

    PubMed Central

    Hastings, Mary K.; Mueller, Michael J.; Sinacore, David R.; Strube, Michael J.; Crowner, Beth; Johnson, Jeffrey E.; Racette, Brad A.

    2013-01-01

    Background High forefoot plantar pressure is associated with plantar ulcers in people with diabetes and peripheral neuropathy. The purpose of this pilot study is to determine safety and efficacy of botulinum toxin A injected into the gastrocnemius-soleus muscles to reduce muscle strength and plantar pressure. Materials and Methods This double blind, randomized clinical trial studied 17 people with diabetes mellitus, peripheral neuropathy and forefoot plantar ulcer. Subjects were randomized into one of three groups receiving gastrocnemius-soleus muscle injections on the involved side with; 1) Saline (n=5, weight = 99 ± 21 kg), 2) 200 units of Botox® (n=7, weight = 101 ± 5 kg), or 3) 300 units of Botox® (n=5, weight=129 ± 22 kg). Botox® dose was converted to units/kg, the majority received between 1.9 and 2.4 units/kg (n=11) and one 3.2 units/kg. Plantarflexor peak torque and forefoot peak plantar pressure were quantified prior and two weeks post injection. Results There were no complications from the injections. Plantarflexor peak torque on the involved side increased in the placebo and 300 groups (3 ± 4 Nm and 6 ± 10 Nm respectively) and decreased −8 ± 11 Nm in the 200 group. There was no relationship between units/kg of Botox® for each subject and change in plantarflexor peak torque. Forefoot peak plantar pressure did not change in the placebo and 300 groups (0 ± 11 and 0 ± 5 N/cm2 respectively) and decreased −4 ± 16 N/cm2 (4%) for the 200 group. Conclusions There were no adverse events associated with the Botox® injections. This study was unable to determine the dose to consistently reduce plantarflexor strength and forefoot plantar pressure. Additional research is needed to investigate diabetes mellitus specific physiological changes and their impact of BoNT-A effectiveness in order to guide appropriate dosing. PMID:22735277

  3. Angular Acceleration without Torque?

    ERIC Educational Resources Information Center

    Kaufman, Richard D.

    2012-01-01

    Hardly. Just as Robert Johns qualitatively describes angular acceleration by an internal force in his article "Acceleration Without Force?" here we will extend the discussion to consider angular acceleration by an internal torque. As we will see, this internal torque is due to an internal force acting at a distance from an instantaneous center.

  4. Different plantar interface effects on dynamics of the lower limb.

    PubMed

    Hao, Z H; Zhou, J B; Jin, D W; Zhou, D W; Li, X D

    2005-01-01

    The moments acting on the lower limb joints influence the life of the arthrosis. These loads may depend on the footwear and action style. The footwear factor was studied with three-dimensional gait measure system. Five young women in their 20s, wear 7 cm high-heeled shoes and sneakers, and walked in 10 m gait laboratory walkway. Inversed dynamics was used to analysis the torques at the ankle, knee and hip. Results showed that peak adduction moments at the knee and ankle increased and flexion/extension moments at hip increased with high-heel shoes compared with the sneakers. The high-heeled shoes result in greater load in lower limb joints especial to the knee and hip.

  5. van der Waals torque

    NASA Astrophysics Data System (ADS)

    Esquivel-Sirvent, Raul; Schatz, George

    2014-03-01

    The theory of generalized van der Waals forces by Lifshtz when applied to optically anisotropic media predicts the existence of a torque. In this work we present a theoretical calculation of the van der Waals torque for two systems. First we consider two isotropic parallel plates where the anisotropy is induced using an external magnetic field. The anisotropy will in turn induce a torque. As a case study we consider III-IV semiconductors such as InSb that can support magneto plasmons. The calculations of the torque are done in the Voigt configuration, that occurs when the magnetic field is parallel to the surface of the slabs. The change in the dielectric function as the magnetic field increases has the effect of decreasing the van der Waals force and increasing the torque. Thus, the external magnetic field is used to tune both the force and torque. The second example we present is the use of the torque in the non retarded regime to align arrays of nano particle slabs. The torque is calculated within Barash and Ginzburg formalism in the nonretarded limit, and is quantified by the introduction of a Hamaker torque constant. Calculations are conducted between anisotropic slabs of materials including BaTiO3 and arrays of Ag nano particles. Depending on the shape and arrangement of the Ag nano particles the effective dielectric function of the array can be tuned as to make it more or less anisotropic. We show how this torque can be used in self assembly of arrays of nano particles. ref. R. Esquivel-Sirvent, G. C. Schatz, Phys. Chem C, 117, 5492 (2013). partial support from DGAPA-UNAM.

  6. Absolute reliability of hamstring to quadriceps strength imbalance ratios calculated using peak torque, joint angle-specific torque and joint ROM-specific torque values.

    PubMed

    Ayala, F; De Ste Croix, M; Sainz de Baranda, P; Santonja, F

    2012-11-01

    The main purpose of this study was to determine the absolute reliability of conventional (H/Q(CONV)) and functional (H/Q(FUNC)) hamstring to quadriceps strength imbalance ratios calculated using peak torque values, 3 different joint angle-specific torque values (10°, 20° and 30° of knee flexion) and 4 different joint ROM-specific average torque values (0-10°, 11-20°, 21-30° and 0-30° of knee flexion) adopting a prone position in recreational athletes. A total of 50 recreational athletes completed the study. H/Q(CONV) and H/Q(FUNC) ratios were recorded at 3 different angular velocities (60, 180 and 240°/s) on 3 different occasions with a 72-96 h rest interval between consecutive testing sessions. Absolute reliability was examined through typical percentage error (CVTE), percentage change in the mean (CM) and intraclass correlations (ICC) as well as their respective confidence limits. H/Q(CONV) and H/Q(FUNC) ratios calculated using peak torque values showed moderate reliability values, with CM scores lower than 2.5%, CV(TE) values ranging from 16 to 20% and ICC values ranging from 0.3 to 0.7. However, poor absolute reliability scores were shown for H/Q(CONV) and H/Q(FUNC) ratios calculated using joint angle-specific torque values and joint ROM-specific average torque values, especially for H/Q(FUNC) ratios (CM: 1-23%; CV(TE): 22-94%; ICC: 0.1-0.7). Therefore, the present study suggests that the CV(TE) values reported for H/Q(CONV) and H/Q(FUNC) (≈18%) calculated using peak torque values may be sensitive enough to detect large changes usually observed after rehabilitation programmes but not acceptable to examine the effect of preventitive training programmes in healthy individuals. The clinical reliability of hamstring to quadriceps strength ratios calculated using joint angle-specific torque values and joint ROM-specific average torque values are questioned and should be re-evaluated in future research studies.

  7. Comparison of elasticity of human tendon and aponeurosis in knee extensors and ankle plantar flexors in vivo.

    PubMed

    Kubo, Keitaro; Kanehisa, Hiroaki; Fukunaga, Tetsuo

    2005-05-01

    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.

  8. Low-frequency force steadiness practice in plantar flexor muscle reduces postural sway during quiet standing.

    PubMed

    Oshita, Kazushige; Yano, Sumio

    2011-01-01

    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.

  9. Biomechanics of the Flexion of Spine.

    ERIC Educational Resources Information Center

    Hobbs, Harry K.; Aurora, T. S.

    1991-01-01

    The forces and torques experienced by the spine are examined to understand, and possibly avoid, low back pain. The structure, degrees of freedom, forces and torques when lifting objects, an experimental study, and other factors affecting the back are discussed. (KR)

  10. Torque-wrench extension

    NASA Technical Reports Server (NTRS)

    Peterson, D. H.

    1981-01-01

    Torque-wrench extension makes it easy to install and remove fasteners that are beyond reach of typical wrenches or are located in narrow spaces that prevent full travel of wrench handle. At same time, tool reads applied torque accurately. Wrench drive system, for torques up to 125 inch-pounds, uses 2 standard drive-socket extensions in aluminum frame. Extensions are connected to bevel gear that turns another bevel gear. Gears produce 1:1 turn ratio through 90 degree translation of axis of rotation. Output bevel has short extension that is used to attach 1/4-inch drive socket.

  11. Dynamic Torque Calibration Unit

    NASA Technical Reports Server (NTRS)

    Agronin, Michael L.; Marchetto, Carl A.

    1989-01-01

    Proposed dynamic torque calibration unit (DTCU) measures torque in rotary actuator components such as motors, bearings, gear trains, and flex couplings. Unique because designed specifically for testing components under low rates. Measures torque in device under test during controlled steady rotation or oscillation. Rotor oriented vertically, supported by upper angular-contact bearing and lower radial-contact bearing that floats axially to prevent thermal expansion from loading bearings. High-load capacity air bearing available to replace ball bearings when higher load capacity or reduction in rate noise required.

  12. Human papillomaviruses genotyping in plantar warts.

    PubMed

    de Planell-Mas, Elena; Martínez-Garriga, Blanca; Zalacain, Antonio Jesús; Vinuesa, Teresa; Viñas, Miguel

    2017-05-01

    Plantar warts are caused by human papillomaviruses (HPVs) and have been associated with several HPV genotypes. However, there are few studies focused exclusively on plantar warts. In this work, we aim to identify the HPV genotypes of plantar warts and explore their relation to demographic and clinical characteristics of patients. A total of 72 patients diagnosed with plantar warts were recruited at the Laser unit at Podiatric Hospital, University of Barcelona, Spain. Inner hyperkeratosis laminar sections of warts were collected and DNA of samples were extracted. Amplification of a conserved region of the HPV L1 gene was performed with the SK-Polymerase chain reaction method. DNA amplicons were sequenced and HPV types identified. The most prevalent genotypes detected among the 105 analyzed plantar warts were HPV-57 (37.1%), HPV-27 (23.8%), HPV-1a (20.9%), HPV-2 (15.2%), and HPV-65 (2.8%). The majority of patients (78%) presented one single plantar wart, whereas multiple warts were detected in 22.2% of patients. One patient with multiple warts presented HPV types from two different genera, suggesting the spread of warts by self-inoculation as well as by de novo infection. No significant differences between the number of warts in toes, midfoot and heel were found. The most prevalent HPV types detected in all areas belonged to the alpha genus. This work provides new insight on plantar warts and their associated HPV genotypes, and evidences the usefulness and reliability of both the sample collection procedure and the PCR method used for HPV detection and typing. J. Med. Virol. 89:902-907, 2017. © 2016 Wiley Periodicals, Inc.

  13. Pelvic rotation torque during fast-pitch softball hitting under three ball height conditions.

    PubMed

    Iino, Yoichi; Fukushima, Atsushi; Kojima, Takeji

    2014-08-01

    The purpose of this study was to investigate the relevance of hip joint angles to the production of the pelvic rotation torque in fast-pitch softball hitting and to examine the effect of ball height on this production. Thirteen advanced female softball players hit stationary balls at three different heights: high, middle, and low. The pelvic rotation torque, defined as the torque acting on the pelvis through the hip joints about the pelvic superior-inferior axis, was determined from the kinematic and force plate data using inverse dynamics. Irrespective of the ball heights, the rear hip extension, rear hip external rotation, front hip adduction, and front hip flexion torques contributed to the production of pelvic rotation torque. Although the contributions of the adduction and external rotation torques at each hip joint were significantly different among the ball heights, the contributions of the front and rear hip joint torques were similar among the three ball heights owing to cancelation of the two torque components. The timings of the peaks of the hip joint torque components were significantly different, suggesting that softball hitters may need to adjust the timings of the torque exertions fairly precisely to rotate the upper body effectively.

  14. Effects of hamstring stretching on passive muscle stiffness vary between hip flexion and knee extension maneuvers.

    PubMed

    Miyamoto, N; Hirata, K; Kanehisa, H

    2017-01-01

    The purpose of this study was to examine whether the effects of hamstring stretching on the passive stiffness of each of the long head of the biceps femoris (BFl), semitendinosus (ST), and semimembranosus (SM) vary between passive knee extension and hip flexion stretching maneuvers. In 12 male subjects, before and after five sets of 90 s static stretching, passive lengthening measurements where knee or hip joint was passively rotated to the maximal range of motion (ROM) were performed. During the passive lengthening, shear modulus of each muscle was measured by ultrasound shear wave elastography. Both stretching maneuvers significantly increased maximal ROM and decreased passive torque at a given joint angle. Passive knee extension stretching maneuver significantly reduced shear modulus at a given knee joint angle in all of BFl, ST, and SM. In contrast, the stretching effect by passive hip flexion maneuver was significant only in ST and SM. The present findings indicate that the effects of hamstring stretching on individual passive muscles' stiffness vary between passive knee extension and hip flexion stretching maneuvers. In terms of reducing the muscle stiffness of BFl, stretching of the hamstring should be performed by passive knee extension rather than hip flexion.

  15. Platelet-rich plasma and plantar fasciitis.

    PubMed

    Monto, Raymond R

    2013-12-01

    Plantar fasciitis is the most common cause of heel pain and can prove difficult to treat in its most chronic and severe forms. Advanced cases of plantar fasciitis are often associated with ankle stiffness, heel spurs, and other conditions and can lead to extensive physical disability and financial loss. Most available traditional treatments, including orthoses, nonsteroidal anti-inflammatory drugs, and steroid injections have a paucity of supportive clinical evidence. More invasive treatments, ranging from corticosteroid and botulinum-A toxin injections to shockwave therapy and plantar fasciotomy, have demonstrated varying clinical success in severe cases but carry the potential for serious complication and permanent disability. Platelet-rich plasma has recently been demonstrated to be helpful in managing chronic severe tendinopathies when other techniques have failed. This review examines the pathophysiology, diagnostic options, nonoperative treatment modalities, and surgical options currently used for plantar fasciitis. It also focuses on the clinical rationale and available evidence for using autologous platelet-rich plasma to treat severe refractory chronic plantar fasciitis.

  16. Surgery for Patients With Recalcitrant Plantar Fasciitis

    PubMed Central

    Wheeler, Patrick; Boyd, Kevin; Shipton, Mary

    2014-01-01

    Background: Plantar fasciitis is a common cause of foot pain, and although many episodes are self-limiting with short duration, 10% leave chronic symptoms. Recalcitrant cases can be managed surgically, with studies demonstrating good results in the short term but uncertainties over longer term outcomes. Purpose: To assess the outcome following surgical intervention for patients with plantar fasciitis. Study Design: Case series; Level of evidence, 4. Methods: Seventy-nine patients were identified from operative diaries undergoing plantar fasciotomy surgery between 1993 and 2009. They were contacted to investigate long-term results using self-reported outcome measures. Results: Sixty-eight responses were received (86% response rate), with an average of 7 years (range, 1-15 years) of follow-up. Patients reported an average reduction in pain by visual analog scale of 79%, and 84% of patients were happy with the surgical results. Greater success was achieved in patients with shorter duration of symptoms preoperatively. No deterioration in success was seen over time. Conclusion: Plantar fasciotomy surgery for plantar fasciitis remains controversial, with biomechanical arguments against surgery; however, this article reports good success following surgery over a long follow-up period. The results of current operative techniques need to be fully investigated for longer term success, as do the outcomes of newer nonoperative management strategies. PMID:26535314

  17. Fabricated torque shaft

    SciTech Connect

    Mashey, Thomas Charles

    2002-01-01

    A fabricated torque shaft is provided that features a bolt-together design to allow vane schedule revisions with minimal hardware cost. The bolt-together design further facilitates on-site vane schedule revisions with parts that are comparatively small. The fabricated torque shaft also accommodates stage schedules that are different one from another in non-linear inter-relationships as well as non-linear schedules for a particular stage of vanes.

  18. Improving lensing cluster mass estimate with flexion

    NASA Astrophysics Data System (ADS)

    Cardone, V. F.; Vicinanza, M.; Er, X.; Maoli, R.; Scaramella, R.

    2016-11-01

    Gravitational lensing has long been considered as a valuable tool to determine the total mass of galaxy clusters. The shear profile, as inferred from the statistics of ellipticity of background galaxies, allows us to probe the cluster intermediate and outer regions, thus determining the virial mass estimate. However, the mass sheet degeneracy and the need for a large number of background galaxies motivate the search for alternative tracers which can break the degeneracy among model parameters and hence improve the accuracy of the mass estimate. Lensing flexion, i.e. the third derivative of the lensing potential, has been suggested as a good answer to the above quest since it probes the details of the mass profile. We investigate here whether this is indeed the case considering jointly using weak lensing, magnification and flexion. We use a Fisher matrix analysis to forecast the relative improvement in the mass accuracy for different assumptions on the shear and flexion signal-to- noise (S/N) ratio also varying the cluster mass, redshift, and ellipticity. It turns out that the error on the cluster mass may be reduced up to a factor of ˜2 for reasonable values of the flexion S/N ratio. As a general result, we get that the improvement in mass accuracy is larger for more flattened haloes, but it extracting general trends is difficult because of the many parameters at play. We nevertheless find that flexion is as efficient as magnification to increase the accuracy in both mass and concentration determination.

  19. Human torque velocity adaptations to sprint, endurance, or combined modes of training

    NASA Technical Reports Server (NTRS)

    Shealy, M. J.; Callister, R.; Dudley, G. A.; Fleck, S. J.

    1992-01-01

    We had groups of athletes perform sprint and endurance run training independently or concurrently for 8 weeks to examine the voluntary in vivo mechanical responses to each type of training. Pre- and posttraining angle-specific peak torque during knee extension and flexion were determined at 0, 0.84, 1.65, 2.51, 3.35, 4.19, and 5.03 radian.sec-1 and normalized for lean body mass. Knee extension torque in the sprint-trained group increased across all test velocities, the endurance-trained group increased at 2.51, 3.34, 4.19, and 5.03 radian.sec-1, and the group performing the combined training showed no change at any velocity. Knee flexion torque of the sprint and combined groups decreased at 0.84, 1.65, and 2.51 radian.sec-1. Knee flexion torque in the sprint-trained group also decreased at 0 radian.sec-1 and in the combined group at 3.34 radian.sec-1. Knee flexion torque in the endurance-trained group showed no change at any velocity of contraction. Mean knee flexion:extension ratios across the test velocities significantly decreased in the sprint-trained group. Knee extension endurance during 30 seconds of maximal contractions significantly increased in all groups. Only the sprint-trained group showed a significant increase in endurance of the knee flexors. These data suggest that changes in the voluntary in vivo mechanical characteristics of knee extensor and flexor skeletal muscles are specific to the type of run training performed.

  20. Absolute reliability of isokinetic knee flexion and extension measurements adopting a prone position.

    PubMed

    Ayala, F; De Ste Croix, M; Sainz de Baranda, P; Santonja, F

    2013-01-01

    The main purpose of this study was to determine the absolute and relative reliability of isokinetic peak torque (PT), angle of peak torque (APT), average power (PW) and total work (TW) for knee flexion and extension during concentric and eccentric actions measured in a prone position at 60, 180 and 240° s(-1). A total of 50 recreational athletes completed the study. PT, APT, PW and TW for concentric and eccentric knee extension and flexion were recorded at three different angular velocities (60, 180 and 240° s(-1)) on three different occasions with a 72- to 96-h rest interval between consecutive testing sessions. Absolute reliability was examined through typical percentage error (CV(TE)), percentage change in the mean (ChM) and relative reliability with intraclass correlations (ICC(3,1)). For both the knee extensor and flexor muscle groups, all strength data (except APT during knee flexion movements) demonstrated moderate absolute reliability (ChM < 3%; ICCs > 0·70; and CV(TE) < 20%) independent of the knee movement (flexion and extension), type of muscle action (concentric and eccentric) and angular velocity (60, 180 and 240° s(-1)). Therefore, the current study suggests that the CV(TE) values reported for PT (8-20%), APT (8-18%) (only during knee extension movements), PW (14-20%) and TW (12-28%) may be acceptable to detect the large changes usually observed after rehabilitation programmes, but not acceptable to examine the effect of preventative training programmes in healthy individuals.

  1. Biomechanical consequences of adding plantar fascia release to metatarsal osteotomies: Changes in forefoot plantar pressures.

    PubMed

    Aydogan, Umur; Roush, Evan P; Moore, Blake E; Andrews, Seth H; Lewis, Gregory S

    2016-06-09

    Destruction of the normal metatarsal arch by a long metatarsal is often a cause for metatarsalgia. When surgery is warranted, distal oblique or proximal dorsiflexion osteotomies of the long metatarsal bones are commonly used. The plantar fascia has anatomical connection to all metatarsal heads. There is controversial scientific evidence on the effect of plantar fascia release on forefoot biomechanics. In this cadaveric biomechanical study, we hypothesized that plantar fascia release would augment the plantar metatarsal pressure decreasing effects of two common second metatarsal osteotomy techniques. Six matched pairs of foot and ankle specimens were mounted on a pressure mat loading platform. Two randomly assigned surgery groups, which had received either distal oblique or proximal dorsiflexion osteotomy of the second metatarsal, were evaluated before and after plantar fasciectomy. Specimens were loaded up to a ground reaction force of 400 N at varying Achilles tendon forces. Average pressures, peak pressures, and contact areas were analyzed. Supporting our hypothesis, average pressures under the second metatarsal during 600 N Achilles load were decreased by plantar fascia release following proximal osteotomy (p <.05). However contrary to our hypothesis, peak pressures under the second metatarsal were significantly increased by plantar fascia release following modified distal osteotomy, under multiple Achilles loading conditions (p <.05). This article is protected by copyright. All rights reserved.

  2. Displaceable Gear Torque Controlled Driver

    NASA Technical Reports Server (NTRS)

    Cook, Joseph S., Jr. (Inventor)

    1997-01-01

    Methods and apparatus are provided for a torque driver including a displaceable gear to limit torque transfer to a fastener at a precisely controlled torque limit. A biasing assembly biases a first gear into engagement with a second gear for torque transfer between the first and second gear. The biasing assembly includes a pressurized cylinder controlled at a constant pressure that corresponds to a torque limit. A calibrated gage and valve is used to set the desired torque limit. One or more coiled output linkages connect the first gear with the fastener adaptor which may be a socket for a nut. A gear tooth profile provides a separation force that overcomes the bias to limit torque at the desired torque limit. Multiple fasteners may be rotated simultaneously to a desired torque limit if additional output spur gears are provided. The torque limit is adjustable and may be different for fasteners within the same fastener configuration.

  3. Human upper-limb force capacities evaluation with robotic models for ergonomic applications: effect of elbow flexion.

    PubMed

    Hernandez, Vincent; Rezzoug, Nasser; Jacquier-Bret, Julien; Gorce, Philippe

    2016-01-01

    The aim of this study was to apply models derived from the robotics field to evaluate the human upper-limb force generation capacity. Four models were compared: the force ellipsoid (FE) and force polytope (FP) based on unit joint torques and the scaled FE (SFE) and scaled FP (SFP) based on maximum isometric joint torques. The four models were assessed from four upper-limb postures with varying elbow flexion (40°, 60°, 80° and 100°) measured by an optoelectronic system and their corresponding isometric joint torques. Ten subjects were recruited. Three specific ellipsoids and polytopes parameters were compared: isotropy, principal force orientation and volume. Isotropy showed that the ellipsoids and polytopes were elongated. The angle between the two ellipsoids main axis and the two polytopes remained low but increased with the elbow flexion. The FE and FP volumes increased and those of SFE and SFP decreased with the elbow flexion. The interest and limits of such models are discussed in the framework of ergonomics and rehabilitation.

  4. [Plantar fibromatosis: therapy by total plantarfasciectomy].

    PubMed

    Beckmann, J; Kalteis, T; Baer, W; Grifka, J; Lerch, K

    2004-01-01

    Morbus Ledderhose is a rare fibromatous disease of the plantar fascia. Clinical features include palpable solitary or multiple nodules and cords, mainly affecting the medial part of the plantar fascia. When clinical symptoms occur, conservative options include stretching, orthotics, nonsteroidal antirheumatic drugs, local cortisone-injections and physiotherapy. Operative treatment is indicated in case of persistent pain or if conservative measures fail. The standard procedure includes a partial fasciectomy of the plantar aponeurosis. There is a high recurrence rate with an increased risk of complications and more aggressive ingrowth into anatomical structures after partial resection. Therefore we recommend a complete fasciectomy not only in recurrent disease, but also as the primary procedure of choice.

  5. Plantar fibromatosis: an immunohistochemical and ultrastructural study.

    PubMed

    de Palma, L; Santucci, A; Gigante, A; Di Giulio, A; Carloni, S

    1999-04-01

    The analogies between plantar fibromatosis and Dupuytren's disease (palmar fibromatosis) are well known. The latter is clinically more frequent and has been the object of extensive immunohistochemical and ultrastructural studies, with a view to investigating its pathogenesis. By contrast, such data on plantar fibromatosis are quite scarce. A histochemical, immunohistochemical, and ultrastructural study was performed on nodule tissue from six patients who were subjected to total fasciectomy for plantar fibromatosis. The study of myofibroblasts revealed features suggestive of their fibroblastic origin and evidenced a cytoskeleton and an extracellular filamentous system that could enable myofibroblasts to generate and exert the intracellular forces that contribute to the contraction of the aponeurosis. These aspects are similar to those observed in Dupuytren's disease and seem to lend support to the theory that the two diseases are expressions of the same disorder.

  6. A novel treatment for refractory plantar fasciitis.

    PubMed

    Patel, Mihir M

    2015-03-01

    Chronic plantar fasciitis is a major health care problem worldwide and affects nearly 10% of the US population. Although most cases resolve with conservative care, the numerous treatments for refractory plantar fasciitis attest to the lack of consensus regarding these cases. The emerging goals for this condition are a minimally invasive percutaneous intervention that is safe, effective, and well-tolerated and has minimal morbidity and a low complication rate. We conducted a prospective study in which patients were allowed either to continue with noninvasive treatment or to undergo focal aspiration and partial fasciotomy with an ultrasonic probe. This is the first report of a plantar fascia partial release guided by ultrasonic energy delivered by a percutaneously inserted probe under local anesthesia. The procedure appears to be a safe, effective, well-tolerated treatment for a condition that is refractory to other options.

  7. Plantar fasciitis: diagnosis and therapeutic considerations.

    PubMed

    Roxas, Mario

    2005-06-01

    Plantar fasciitis is the most common cause of inferior heel pain. The pain and discomfort associated with this condition can have a dramatic impact on physical mobility. The etiology of this condition is not clearly understood and is probably multi-factorial in nature. Weight gain, occupation-related activity, anatomical variations, poor biomechanics, overexertion, and inadequate footwear are contributing factors. Although plantar fasciitis is generally regarded as a self-limited condition, it can take months to years to resolve, presenting a challenge for clinicians. Many treatment options are available that demonstrate variable levels of efficacy. Conservative therapies include rest and avoidance of potentially aggravating activities, stretching and strengthening exercises, orthotics, arch supports, and night splinting. Other considerations include use of anti-inflammatory agents, ultrasonic shockwave therapy, and, in the most extreme cases, surgery. This article reviews plantar fasciitis, presents the most effective treatment options currently available, and proposes nutritional considerations that may be beneficial in the management of this condition.

  8. Primary afferent depolarization and flexion reflexes produced by radiant heat stimulation of the skin.

    PubMed

    Burke, R E; Rudomin, P; Vyklický, L; Zajac, F E

    1971-02-01

    1. The reflex effects of pulses of intense radiant heat applied to the skin of the central plantar pad have been studied in unanaesthetized (decerebrate) spinal cats.2. Pad heat pulses produced flexion of the ipsilateral hind limb and increased ipsilateral flexor monosynaptic reflexes, due to post-synaptic excitation of flexor alpha motoneurones. These effects were accompanied by reduction of extensor monosynaptic reflexes and post-synaptic inhibition of extensor motoneurones.3. Ipsilateral (and contralateral) pad heat pulses consistently evoked negative dorsal root potentials (DRPs) as well as increased excitability of both cutaneous and group Ib muscle afferent terminals. The excitability of group Ia afferents was sometimes also increased during pad heat pulses, but to a lesser extent.4. Pad heat pulses produced negative DRPs in preparations in which positive DRP components could be demonstrated following electrical stimulation of both skin and muscle nerves.5. The motor and primary afferent effects of heat pulses always accompanied one another, beginning after the pad surface temperature had reached rather high levels (usually 48-55 degrees C).6. Negative DRPs increased excitability of cutaneous and group Ib afferents, and motoneurone activation produced by pad heat pulses was essentially unmodified when conduction in large myelinated afferents from the central plantar pad was blocked by cooling the posterior tibial nerve trunk.7. It is concluded that adequate noxious activation of cutaneous afferents of small diameter produces primary afferent depolarization in a variety of large diameter afferent fibres, as well as post-synaptic effects in alpha motoneurones.

  9. Primary afferent depolarization and flexion reflexes produced by radiant heat stimulation of the skin

    PubMed Central

    Burke, R. E.; Rudomin, P.; Vyklický, L.; Zajac, F. E.

    1971-01-01

    1. The reflex effects of pulses of intense radiant heat applied to the skin of the central plantar pad have been studied in unanaesthetized (decerebrate) spinal cats. 2. Pad heat pulses produced flexion of the ipsilateral hind limb and increased ipsilateral flexor monosynaptic reflexes, due to post-synaptic excitation of flexor alpha motoneurones. These effects were accompanied by reduction of extensor monosynaptic reflexes and post-synaptic inhibition of extensor motoneurones. 3. Ipsilateral (and contralateral) pad heat pulses consistently evoked negative dorsal root potentials (DRPs) as well as increased excitability of both cutaneous and group Ib muscle afferent terminals. The excitability of group Ia afferents was sometimes also increased during pad heat pulses, but to a lesser extent. 4. Pad heat pulses produced negative DRPs in preparations in which positive DRP components could be demonstrated following electrical stimulation of both skin and muscle nerves. 5. The motor and primary afferent effects of heat pulses always accompanied one another, beginning after the pad surface temperature had reached rather high levels (usually 48-55° C). 6. Negative DRPs increased excitability of cutaneous and group Ib afferents, and motoneurone activation produced by pad heat pulses was essentially unmodified when conduction in large myelinated afferents from the central plantar pad was blocked by cooling the posterior tibial nerve trunk. 7. It is concluded that adequate noxious activation of cutaneous afferents of small diameter produces primary afferent depolarization in a variety of large diameter afferent fibres, as well as post-synaptic effects in alpha motoneurones. PMID:5575337

  10. Active Flexion in Weight Bearing Better Correlates with Functional Outcomes of Total Knee Arthroplasty than Passive Flexion

    PubMed Central

    Song, Young Dong; Jain, Nimash; Kang, Yeon Gwi; Kim, Tae Yune

    2016-01-01

    Purpose Correlations between maximum flexion and functional outcomes in total knee arthroplasty (TKA) patients are reportedly weak. We investigated whether there are differences between passive maximum flexion in nonweight bearing and other types of maximum flexion and whether the type of maximum flexion correlates with functional outcomes. Materials and Methods A total of 210 patients (359 knees) underwent preoperative evaluation and postoperative follow-up evaluations (6, 12, and 24 months) for the assessment of clinical outcomes including maximum knee flexion. Maximum flexion was measured under five conditions: passive nonweight bearing, passive weight bearing, active nonweight bearing, and active weight bearing with or without arm support. Data were analyzed for relationships between passive maximum flexion in nonweight bearing by Pearson correlation analyses, and a variance comparison between measurement techniques via paired t test. Results We observed substantial differences between passive maximum flexion in nonweight bearing and the other four maximum flexion types. At all time points, passive maximum flexion in nonweight bearing correlated poorly with active maximum flexion in weight bearing with or without arm support. Active maximum flexion in weight bearing better correlated with functional outcomes than the other maximum flexion types. Conclusions Our study suggests active maximum flexion in weight bearing should be reported together with passive maximum flexion in nonweight bearing in research on the knee motion arc after TKA. PMID:27274468

  11. Rupture of the plantar fascia in athletes.

    PubMed

    Leach, R; Jones, R; Silva, T

    1978-06-01

    Symptoms resembling those of plantar fasciitis were seen in six athletes who were thought to have a partial rupture of the plantar fascia. Treatment, which included the use of crutches, anti-inflammatory agents, strapping of the arch, and ice packs, was successful in all but one patient who had a painful mass in the area of the previous rupture. After surgical excision of the painful mass and release of the fascia, he recovered. Five of the six athletes had been previously treated with repeated local injections of steroid.

  12. Plantar fascia rupture: diagnosis and treatment.

    PubMed

    Rolf, C; Guntner, P; Ericsäter, J; Turan, I

    1997-01-01

    Two patients with spontaneous medial plantar fascia rupture due to a definite injury with no prior symptoms, were referred to our institution. Clinically, there was a tender lump in the sole, and magnetic resonance imaging confirmed the diagnosis. Nonoperative treatment was sufficient in curing the acute total rupture. Endoscopic release was used on the partially ruptured plantar fascia, but it is probably more optimal in the acute phase. The literature provides no comparative data on operative or nonoperative treatment efficacy for this rare condition.

  13. Biomechanics of the flexion of spine

    NASA Astrophysics Data System (ADS)

    Hobbs, H. K.; Aurora, T. S.

    1991-03-01

    Low back pain is a common problem and it involves different kinds of injury to the spine. In this article the forces and torques experienced by the spine are examined in order to understand, and possibly avoid, low back pain.

  14. Plantar fasciitis: a degenerative process (fasciosis) without inflammation.

    PubMed

    Lemont, Harvey; Ammirati, Krista M; Usen, Nsima

    2003-01-01

    The authors review histologic findings from 50 cases of heel spur surgery for chronic plantar fasciitis. Findings include myxoid degeneration with fragmentation and degeneration of the plantar fascia and bone marrow vascular ectasia. Histologic findings are presented to support the thesis that "plantar fasciitis" is a degenerative fasciosis without inflammation, not a fasciitis. These findings suggest that treatment regimens such as serial corticosteroid injections into the plantar fascia should be reevaluated in the absence of inflammation and in light of their potential to induce plantar fascial rupture.

  15. Torque multiplier subsea tool

    SciTech Connect

    Leicht, F. M.; Baugh, B. F.; Palany, H. C.

    1985-10-22

    A torque multiplier subsea tool for setting a seal between a casing hanger and a subsea wellhead includes a mandrel having a sun gear with axial elongate teeth. An outer barrel is disposed around the mandrel forming an annulus therebetween. A planetary gear assembly is disposed in the annulus between the barrel and the sun gear to transmit to the barrel a torque which is higher in magnitude than that applied to the mandrel. A connector body disposed around the mandrel, below the planetary gear assembly, includes radially movable dogs for engaging the casing hanger. The barrel engages the sealing assembly and transmits the increased torque thereto to advance the sealing assembly downwards and to set the seal. The mandrel advances downwards with the sealing assembly and releases the dogs from the casing hanger. An emergency release mechanism is provided to advance the mandrel downwards to release the dogs in the event such downward movement is prevented during normal seal setting operation.

  16. Negative Optical Torque

    NASA Astrophysics Data System (ADS)

    Chen, Jun; Ng, Jack; Ding, Kun; Fung, Kin Hung; Lin, Zhifang; Chan, C. T.

    2014-09-01

    Light carries angular momentum, and as such it can exert torques on material objects. Applications of these opto-mechanical effects were limited initially due to their smallness in magnitude, but later becomes powerful and versatile after the invention of laser. Novel and practical approaches for harvesting light for particle rotation have since been demonstrated, where the structure is always subjected to a positive optical torque along a certain axis if the incident angular momentum has a positive projection on the same axis. We report here an interesting phenomenon of ``negative optical torque'', meaning that incoming photons carrying angular momentum rotate an object in the opposite sense. Surprisingly this can be realized quite straightforwardly in simple planar structures. Field retardation is a necessary condition and discrete rotational symmetry of material object plays an important role. The optimal conditions are explored and explained.

  17. Negative optical torque.

    PubMed

    Chen, Jun; Ng, Jack; Ding, Kun; Fung, Kin Hung; Lin, Zhifang; Chan, C T

    2014-09-17

    Light carries angular momentum, and as such it can exert torques on material objects. Applications of these opto-mechanical effects were limited initially due to their smallness in magnitude, but later becomes powerful and versatile after the invention of laser. Novel and practical approaches for harvesting light for particle rotation have since been demonstrated, where the structure is always subjected to a positive optical torque along a certain axis if the incident angular momentum has a positive projection on the same axis. We report here an interesting phenomenon of "negative optical torque", meaning that incoming photons carrying angular momentum rotate an object in the opposite sense. Surprisingly this can be realized quite straightforwardly in simple planar structures. Field retardation is a necessary condition and discrete rotational symmetry of material object plays an important role. The optimal conditions are explored and explained.

  18. Ironless armature torque motor

    NASA Technical Reports Server (NTRS)

    Fisher, R. L.

    1972-01-01

    Four iron-less armature torque motors, four Hall device position sensor assemblies, and two test fixtures were fabricated. The design approach utilized samarium cobalt permanent magnets, a large airgap, and a three-phase winding in a stationary ironless armature. Hall devices were employed to sense rotor position. An ironless armature torque motor having an outer diameter of 4.25 inches was developed to produce a torque constant of 65 ounce-inches per ampere with a resistance of 20.5 ohms. The total weight, including structural elements, was 1.58 pounds. Test results indicated that all specifications were met except for generated voltage waveform. It is recommended that investigations be made concerning the generated voltage waveform to determine if it may be improved.

  19. Reduce torques and stick the landing: limb posture during landing in toads.

    PubMed

    Azizi, Emanuel; Larson, Neil P; Abbott, Emily M; Danos, Nicole

    2014-10-15

    A controlled landing, where an animal does not crash or topple, requires enough stability to allow muscles to effectively dissipate mechanical energy. Toads (Rhinella marina) are exemplary models for understanding the mechanics and motor control of landing given their ability to land consistently during bouts of continuous hopping. Previous studies in anurans have shown that ground reaction forces (GRFs) during landing are significantly higher compared with takeoff and can potentially impart large torques about the center of mass (COM), destabilizing the body at impact. We predict that in order to minimize such torques, toads will align their COM with the GRF vector during the aerial phase in anticipation of impact. We combined high-speed videography and force-plate ergometry to quantify torques at the COM and relate the magnitude of torques to limb posture at impact. We show that modulation of hindlimb posture can shift the position of the COM by about 20% of snout-vent length. Rapid hindlimb flexion during the aerial phase of a hop moved the COM anteriorly and reduced torque by aligning the COM with the GRF vector. We found that the addition of extrinsic loads did not significantly alter landing behavior but did change the torques experienced at impact. We conclude that anticipatory hindlimb flexion during the aerial phase of a hop is a critical feature of a mechanically stable landing that allows toads to quickly string together multiple, continuous hops.

  20. Plantar fasciitis: what is the diagnosis and treatment?

    PubMed

    Johnson, Rachel E; Haas, Kim; Lindow, Kyle; Shields, Robert

    2014-01-01

    Foot pain, specifically plantar heel pain, is a common complaint among patients in a podiatric or orthopaedic office setting but may be seen in primary care offices, urgent care centers, or emergency departments as well. There are numerous causes for heel pain, but plantar fasciitis is the most frequent cause. The diagnosis of plantar fasciitis is generally made clinically, but there are many diagnostic modalities that may be used to confirm the diagnosis. Treatment of plantar fasciitis ranges from conservative measures to surgical interventions, but most cases of plantar fasciitis can be managed conservatively. There is no definitive treatment proven to be the best option for plantar fasciitis. Treatment is patient dependent and commonly requires a combination of different modalities to successfully alleviate the symptoms. In this article, plantar fasciitis from defining the disorder, diagnosis, and treatment are discussed.

  1. Incidence of plantar fascia ruptures following corticosteroid injection.

    PubMed

    Kim, Chul; Cashdollar, Michael R; Mendicino, Robert W; Catanzariti, Alan R; Fuge, LaDonna

    2010-12-01

    Plantar fasciitis is commonly treated with corticosteroid injections to decrease pain and inflammation. Therapeutic benefits often vary in terms of efficacy and duration. Rupture of the plantar fascia has been reported as a possible complication following corticosteroid injection. A retrospective chart review of 120 patients who received corticosteroid injection for plantar fasciitis was performed at the authors' institution to determine the incidence of plantar fascia rupture. The plantar fascia rupture was diagnosed clinically and confirmed with magnetic resonance imaging. Various factors were analyzed, including the number of injections, interval between injections, body mass index (BMI), and activity level. Four patients (2.4%) consequently experienced plantar fascia rupture following an average of 2.67 injections. The average BMI of these patients was 38.6 kg/m². The authors conclude that corticosteroid injection therapy appears to be a safe and effective form of nonoperative treatment with minimal complications and a relatively low incident of plantar fascia rupture.

  2. Plantar fascia coronal length: a new parameter for plantar fascia assessment.

    PubMed

    Sari, Ahmet Sinan; Demircay, Emre; Cakmak, Gokhan; Sahin, M Sukru; Tuncay, I Cengiz; Altun, Suleyman

    2015-01-01

    The effects of gender and various anthropometric variables were previously reported as significant predictors of plantar fascia thickness. Although a strong correlation between either the body weight or body mass index (BMI) and plantar fascia thickness were not demonstrated, a moderate relation was stated. We retrospectively investigated the role of gender, height, weight, and body mass index on plantar fascia thickness at the calcaneal origin (PFCO) and 1 cm distal from the calcaneal origin (PF1cm) and the coronal length of the plantar fascia at the calcaneal origin (CLPF) in healthy subjects. The PFCO, PF1cm, and CLPF were retrospectively measured from magnetic resonance images of 100 healthy subjects. The gender, height, weight, and body mass index of the participants were also noted. Gender was a predictive factor for the length of the CLPF. The subjects with a BMI >25 kg/m(2) had a significantly greater PFCO, PF1cm, and CLPF. Height was mildly and BMI and weight were moderately related to the PFCO. However the CLPF showed a better correlation with height, BMI, and weight than that of plantar fascia thickness. CLPF better reflected the role of weight, BMI, and height than its thickness. It is a new parameter that could be valuable in the evaluation of plantar fascia disorders.

  3. Plantar fasciitis: current diagnostic modalities and treatments.

    PubMed

    Healey, Kevin; Chen, Katherine

    2010-07-01

    Plantar fasciitis is a common cause of heel pain. The diagnosis is made clinically and validated with different diagnostic modalities ranging from ultrasound to magnetic resonance imaging. Treatments vary from stretching exercises to different surgical options. No single treatment is guaranteed to alleviate the heel pain.

  4. Peak triceps surae muscle activity is not specific to knee flexion angles during MVIC.

    PubMed

    Hébert-Losier, Kim; Schneiders, Anthony G; García, José A; Sullivan, S John; Simoneau, Guy G

    2011-10-01

    There is limited research on peak activity of the separate triceps surae muscles in select knee flexion (KF) positions during a maximum voluntary isometric contraction (MVIC) used to normalize EMG signals. The aim of this study was to determine how frequent peak activity occurred during an MVIC for soleus (SOL), gastrocnemius medialis (GM), and gastrocnemius lateralis (GL) in select KF positions, and if these peaks were recorded in similar KF positions. Forty-eight healthy individuals performed unilateral plantar-flexion MVIC in standing with 0°KF and 45°KF, and in sitting with 90°KF. Surface EMG of SOL, GM, and GL were collected and processed in 250 ms epochs to determine peak root-mean-square amplitude. Peak activity was most frequently captured in standing and rarely in sitting, with no position selective to SOL, GM or GL activity. Peak GM and GL activity was more frequent in 0°KF than 45°KF, and more often in similar KF positions than not. Peak SOL activity was just as likely in 45°KF as 0°KF, and more in positions similar to GM, but not GL. The EMG amplitudes were at least 20% greater in positions that captured peak activity over those that did not. The overall findings support performing an MVIC in more than one KF position to normalize triceps surae EMG. It is emphasized that no KF position is selective to SOL, GM, or GL alone.

  5. Square, Random Fasciocutaneous Plantar Flaps for Treating Noninfected Diabetic Plantar Ulcers: A Patient Series.

    PubMed

    Caravaggi, Carlo Maria Ferdinando; Sganzaroli, Adriana Barbara; Bona, Fosca; Galenda, Paolo; Ferraresi, Roberto; Gherardi, Piero; Reho, Andrea

    2016-01-01

    In patients with diabetes, the off-loading cast has not been widely used to treat plantar ulcers because of its poor acceptance by patients and the high risk of side effects. We evaluated the safety and efficacy of an alternative surgical treatment: a square, fasciocutaneous random plantar flap to cover plantar ulcers. From December 2012 to February 2013, we enrolled 23 consecutive diabetic patients with deep neuropathic or neuroischemic plantar ulcers. Of these 23 patients, 9 underwent percutaneous transluminal angioplasty, 10 had the metatarsal removed, 3 underwent dorsiflexory, distal metatarsal osteotomies, 2 underwent first metatarsophalangeal joint resection and ray stabilization with Kirschner wires, and 1 each underwent midfoot exostectomy, sesamoidectomy, and partial calcanectomy. A square random fasciocutaneous plantar flap was created for all 23 patients. Two patients were excluded from the analysis for weightbearing on the involved foot within 24 hours of surgery. The healing rate was 100% for the remaining 21 patients, with healing by first intention in 15 (mean ± standard deviation time to healing 30 ± 13 days), by second intention in 5 (86 ± 40 days), and by surgical revision in 1. The overall mean healing time was 44 ± 31 days. During a mean follow-up of 724 ± 275 days, no ulcer recurred; however, 1 transfer ulcer appeared on an adjacent metatarsal head. The use of a square random fasciocutaneous plantar flap is a safe and effective surgical option for treating neuropathic plantar ulcers, offering a high healing rate, a short healing time, and a low rate of recurrence.

  6. Transtibial amputation with plantar flap for congenital deficiency of the tibia.

    PubMed

    Fujii, Hiroshi; Doi, Kazuteru; Baliarsing, Amresh S

    2002-10-01

    Disarticulation of the knee has been the preferred treatment for the severe type (Type Ia and Type Ib classification of Jones et al) of congenital deficiency of the tibia because of marked flexion contracture of the knee and loss of quadriceps function. In such cases, the disarticulated stump is often small and poorly covered by soft tissues because of dysplastic femoral condyles and calf muscles. Therefore, stump complications after disarticulation may prevent early aggressive walking exercises and delay independent ambulation. To overcome this problem, a greater weightbearing surface was created by a transtibial amputation with a short stump of the fibula using the flexed knee. By this method, the distal femoral condyle and the anterior surface of the fibula were used for weightbearing. In addition, coverage of the new weightbearing area by a neurovascular pedicled sensate plantar flap provided a more tolerable weightbearing site. The purpose of the current study was to report a 5-year-old boy with bilateral congenital total deficiency of both tibias, who was treated using this technique. The patient was ambulating independently 15 weeks after surgery. A transtibial amputation with a plantar flap is an alternative procedure to knee disarticulation for the severe type of congenital deficiency of the tibia.

  7. Torque, Cognitive Ability, and Schooling.

    ERIC Educational Resources Information Center

    Csapo, Marg

    1985-01-01

    West African Hausan Children (N=110) aged 5-6 were administered a torque test and relationshps between the torque task and visual spatial tasks were analyzed. Findings supported the assumption that educational experience related to circling accounts for decrease in torque, or that the educational experiences have potential influence on cortical…

  8. Floating-Pinion Torque Splitter

    NASA Technical Reports Server (NTRS)

    Melles, Harold W.

    1994-01-01

    Designed-in looseness at right locations helps to distribute torques more evenly. Gear-drive mechanism helps to apportion torques nearly equally along two parallel drive paths from input bevel gear to output bull gear. Mechanism of this type used as part of redundant drive train between engine and rotor of helicopter. Weighs less than comparably rated prior torque-splitting mechanisms.

  9. Torque-Splitting Gear Drive

    NASA Technical Reports Server (NTRS)

    Kish, J.

    1991-01-01

    Geared drive train transmits torque from input shaft in equal parts along two paths in parallel, then combines torques in single output shaft. Scheme reduces load on teeth of meshing gears while furnishing redundancy to protect against failures. Such splitting and recombination of torques common in design of turbine engines.

  10. The bending stiffness of shoes is beneficial to running energetics if it does not disturb the natural MTP joint flexion.

    PubMed

    Oh, Keonyoung; Park, Sukyung

    2017-02-28

    A local minimum for running energetics has been reported for a specific bending stiffness, implying that shoe stiffness assists in running propulsion. However, the determinant of the metabolic optimum remains unknown. Highly stiff shoes significantly increase the moment arm of the ground reaction force (GRF) and reduce the leverage effect of joint torque at ground push-off. Inspired by previous findings, we hypothesized that the restriction of the natural metatarsophalangeal (MTP) flexion caused by stiffened shoes and the corresponding joint torque changes may reduce the benefit of shoe bending stiffness to running energetics. We proposed the critical stiffness, kcr, which is defined as the ratio of the MTP joint (MTPJ) torque to the maximal MTPJ flexion angle, as a possible threshold of the elastic benefit of shoe stiffness. 19 subjects participated in a running test while wearing insoles with five different bending stiffness levels. Joint angles, GRFs, and metabolic costs were measured and analyzed as functions of the shoe stiffness. No significant changes were found in the take-off velocity of the center of mass (CoM), but the horizontal ground push-offs were significantly reduced at different shoe stiffness levels, indicating that complementary changes in the lower-limb joint torques were introduced to maintain steady running. Slight increases in the ankle, knee, and hip joint angular impulses were observed at stiffness levels exceeding the critical stiffness, whereas the angular impulse at the MTPJ was significantly reduced. These results indicate that the shoe bending stiffness is beneficial to running energetics if it does not disturb the natural MTPJ flexion.

  11. Trunk Muscle Activation at the Initiation and Braking of Bilateral Shoulder Flexion Movements of Different Amplitudes.

    PubMed

    Eriksson Crommert, M; Halvorsen, K; Ekblom, M M

    2015-01-01

    The aim of this study was to investigate if trunk muscle activation patterns during rapid bilateral shoulder flexions are affected by movement amplitude. Eleven healthy males performed shoulder flexion movements starting from a position with arms along sides (0°) to either 45°, 90° or 180°. EMG was measured bilaterally from transversus abdominis (TrA), obliquus internus (OI) with intra-muscular electrodes, and from rectus abdominis (RA), erector spinae (ES) and deltoideus with surface electrodes. 3D kinematics was recorded and inverse dynamics was used to calculate the reactive linear forces and torque about the shoulders and the linear and angular impulses. The sequencing of trunk muscle onsets at the initiation of arm movements was the same across movement amplitudes with ES as the first muscle activated, followed by TrA, RA and OI. All arm movements induced a flexion angular impulse about the shoulders during acceleration that was reversed during deceleration. Increased movement amplitude led to shortened onset latencies of the abdominal muscles and increased level of activation in TrA and ES. The activation magnitude of TrA was similar in acceleration and deceleration where the other muscles were specific to acceleration or deceleration. The findings show that arm movements need to be standardized when used as a method to evaluate trunk muscle activation patterns and that inclusion of the deceleration of the arms in the analysis allow the study of the relationship between trunk muscle activation and direction of perturbing torque during one and the same arm movement.

  12. Trunk Muscle Activation at the Initiation and Braking of Bilateral Shoulder Flexion Movements of Different Amplitudes

    PubMed Central

    Eriksson Crommert, M.; Halvorsen, K.; Ekblom, M. M.

    2015-01-01

    The aim of this study was to investigate if trunk muscle activation patterns during rapid bilateral shoulder flexions are affected by movement amplitude. Eleven healthy males performed shoulder flexion movements starting from a position with arms along sides (0°) to either 45°, 90° or 180°. EMG was measured bilaterally from transversus abdominis (TrA), obliquus internus (OI) with intra-muscular electrodes, and from rectus abdominis (RA), erector spinae (ES) and deltoideus with surface electrodes. 3D kinematics was recorded and inverse dynamics was used to calculate the reactive linear forces and torque about the shoulders and the linear and angular impulses. The sequencing of trunk muscle onsets at the initiation of arm movements was the same across movement amplitudes with ES as the first muscle activated, followed by TrA, RA and OI. All arm movements induced a flexion angular impulse about the shoulders during acceleration that was reversed during deceleration. Increased movement amplitude led to shortened onset latencies of the abdominal muscles and increased level of activation in TrA and ES. The activation magnitude of TrA was similar in acceleration and deceleration where the other muscles were specific to acceleration or deceleration. The findings show that arm movements need to be standardized when used as a method to evaluate trunk muscle activation patterns and that inclusion of the deceleration of the arms in the analysis allow the study of the relationship between trunk muscle activation and direction of perturbing torque during one and the same arm movement. PMID:26562017

  13. Differential displacement of the human soleus and medial gastrocnemius aponeuroses during isometric plantar flexor contractions in vivo.

    PubMed

    Bojsen-Møller, Jens; Hansen, Philip; Aagaard, Per; Svantesson, Ulla; Kjaer, Michael; Magnusson, S Peter

    2004-11-01

    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.

  14. Management of plantar fasciitis in the outpatient setting.

    PubMed

    Lim, Ang Tee; How, Choon How; Tan, Benedict

    2016-04-01

    Plantar fasciitis is a very common cause of inferior heel pain that can be triggered and aggravated by prolonged standing, walking, running and obesity, among other factors. Treatments are largely noninvasive and efficacious. Supportive treatments, including the plantar fascia-specific stretch, calf stretching, appropriate orthotics and night dorsiflexion splinting, can alleviate plantar fascia pain. While local injections of corticosteroids can help with pain relief, the effects are short-lived and must be weighed against the risk of fat pad atrophy and plantar fascia rupture. Ultrasonography-guided focal extracorporeal shock wave therapy is useful for patients with chronic plantar fasciitis and referrals for this treatment can be made in recalcitrant cases. Activity modification to decrease cyclical repetitive loading of the plantar fascia should be advised during the treatment phase regardless of the chosen treatment modality.

  15. Mechanical Information of Plantar Fascia during Normal Gait

    NASA Astrophysics Data System (ADS)

    Gu, Yaodong; Li, Zhiyong

    The plantar fascia is an important foot tissue in stabilizing the longitudinal arch of human foot. Direct measurement to monitor the mechanical situation of plantar fascia at human locomotion is difficult. The purpose of this study was to construct a three-dimensional finite element model of the foot to calculate the internal stress/strain value of plantar fascia during different stage of gait. The simulated stress distribution of plantar fascia was the lowest at heel-strike, which concentrated on the medial side of calcaneal tubercle. The peak stress of plantar fascia was appeared at push-off, and the value is more than 5 times of the heel-strike position. Current FE model was able to explore the plantar fascia tension trend at the main sub-phases of foot. More detailed fascia model and intrinsic muscle forces could be developed in the further study.

  16. Management of plantar fasciitis in the outpatient setting

    PubMed Central

    Lim, Ang Tee; How, Choon How; Tan, Benedict

    2016-01-01

    Plantar fasciitis is a very common cause of inferior heel pain that can be triggered and aggravated by prolonged standing, walking, running and obesity, among other factors. Treatments are largely noninvasive and efficacious. Supportive treatments, including the plantar fascia-specific stretch, calf stretching, appropriate orthotics and night dorsiflexion splinting, can alleviate plantar fascia pain. While local injections of corticosteroids can help with pain relief, the effects are short-lived and must be weighed against the risk of fat pad atrophy and plantar fascia rupture. Ultrasonography-guided focal extracorporeal shock wave therapy is useful for patients with chronic plantar fasciitis and referrals for this treatment can be made in recalcitrant cases. Activity modification to decrease cyclical repetitive loading of the plantar fascia should be advised during the treatment phase regardless of the chosen treatment modality. PMID:27075037

  17. Angle- and gender-specific quadriceps femoris muscle recruitment and knee extensor torque.

    PubMed

    Pincivero, Danny M; Salfetnikov, Yuliya; Campy, Robert M; Coelho, Alan J

    2004-11-01

    The objectives were to examine knee angle-, and gender-specific knee extensor torque output and quadriceps femoris (QF) muscle recruitment during maximal effort, voluntary contractions. Fourteen young adult men and 15 young adult women performed three isometric maximal voluntary contractions (MVC), in a random order, with the knee at 0 degrees (terminal extension), 10 degrees, 30 degrees, 50 degrees, 70 degrees, and 90 degrees flexion. Knee extensor peak torque (PT), and average torque (AT) were expressed in absolute (N m), relative (N m kg(-1)) and allometric-modeled (N m kg(-n)) units. Vastus medialis (VM), vastus lateralis (VL), and rectus femoris (RF) muscle EMG signals were full-wave rectified and integrated over the middle 3 s of each contraction, averaged over the three trials at each knee angle, and normalized to the activity recorded at 0 degrees. Muscle recruitment efficiency was calculated as the ratio of the normalized EMG of each muscle to the allometric-modeled average torque (normalized to the values at 0 degrees flexion), and expressed as a percent. Men generated significantly greater knee extensor PT and AT than women in absolute, relative and allometric-modeled units. Absolute and relative PT and AT were significantly highest at 70 degrees, while allometric-modeled values were observed to increase significantly across knee joint angles 10-90 degrees. VM EMG was significantly greater than the VL and RF muscles across all angles, and followed a similar pattern to absolute knee extensor torque. Recruitment efficiency improved across knee joint angles 10-90 degrees and was highest for the VL muscle. VM recruitment efficiency improved more than the VL and RF muscles across 70-90 degrees flexion. The findings demonstrate angle-, and gender-specific responses of knee extensor torque to maximal-effort contractions, while superficial QF muscle recruitment was most efficient at 90 degrees, and less dependent on gender.

  18. Effects of Cervical Flexion on the Flexion-relaxation Ratio during Smartphone Use.

    PubMed

    Shin, HyeonHui; Kim, KyeongMi

    2014-12-01

    [Purpose] The purpose of this study was to measure the cervical flexion-relaxation ratio (FRR) and intensity of neck pain and identify the differences according to postures adopted while using smartphones. [Subjects] Fifteen healthy adults with no neck pain, spinal trauma, or history cervical surgery participated in this study. [Methods] The activity of the cervical erector spinae muscle was recorded while performing a standardized cervical flexion-extension movement in three phases (flexion, sustained full flexion, extension). And neck pain intensity was recorded using a visual analog scale (VAS) with values between 0 and 10. Postures held while using a smartphone are distinguished between desk postures and lap postures. The FRR was calculated by dividing the maximal muscle activation during the extension phase by average activation during the complete flexion phase. [Results] No significant differences were found in the FRR between desk posture, lap posture, and baseline, though the intensity of the neck pain increased in the lap posture. [Conclusion] The FRR could be a significant criterion of neuromuscular impairment in chronic neck pain or lumbar pain patients, but it is impossible to distinguish neck pain that is caused by performing task for a short time. Prolonged lap posture might cause neck pain, so the use of smartphones for a long time in this posture should be avoided.

  19. Knee extension torque variability after exercise in ACL reconstructed knees.

    PubMed

    Goetschius, John; Kuenze, Christopher M; Hart, Joseph M

    2015-08-01

    The purpose of this study was to compare knee extension torque variability in patients with ACL reconstructed knees before and after exercise. Thirty two patients with an ACL reconstructed knee (ACL-R group) and 32 healthy controls (control group) completed measures of maximal isometric knee extension torque (90° flexion) at baseline and following a 30-min exercise protocol (post-exercise). Exercise included 30-min of repeated cycles of inclined treadmill walking and hopping tasks. Dependent variables were the coefficient of variation (CV) and raw-change in CV (ΔCV): CV = (torque standard deviation/torque mean x 100), ΔCV = (post-exercise - baseline). There was a group-by-time interaction (p = 0.03) on CV. The ACL-R group demonstrated greater CV than the control group at baseline (ACL-R = 1.07 ± 0.55, control = 0.79 ± 0.42, p = 0.03) and post-exercise (ACL-R = 1.60 ± 0.91, control = 0.94 ± 0.41, p = 0.001). ΔCV was greater (p = 0.03) in the ACL-R group (0.52 ± 0.82) than control group (0.15 ± 0.46). CV significantly increased from baseline to post-exercise (p = 0.001) in the ACL-R group, while the control group did not (p = 0.06). The ACL-R group demonstrated greater knee extension torque variability than the control group. Exercise increased torque variability more in the ACL-R group than control group.

  20. Hex ball torque test

    NASA Technical Reports Server (NTRS)

    Robinson, B. A.; Foster, C. L.

    1986-01-01

    A series of torque tests were performed on four flight-type hex ball universal joints in order to characterize and determine the actual load-carrying capability of this device. The universal joint is a part of manual actuation rods for scientific instruments within the Hubble Space Telescope. It was found that the hex ball will bind slightly during the initial load application. This binding did not affect the function of the universal joint, and the units would wear-in after a few additional loading cycles. The torsional yield load was approximately 50 ft-lb, and was consistent among the four test specimens. Also, the torque required to cause complete failure exceeded 80 ft-lb. It is concluded that the hex ball universal joint is suitable for its intended applications.

  1. In vivo healthy knee kinematics during dynamic full flexion.

    PubMed

    Hamai, Satoshi; Moro-oka, Taka-aki; Dunbar, Nicholas J; Miura, Hiromasa; Iwamoto, Yukihide; Banks, Scott A

    2013-01-01

    Healthy knee kinematics during dynamic full flexion were evaluated using 3D-to-2D model registration techniques. Continuous knee motions were recorded during full flexion in a lunge from 85° to 150°. Medial and lateral tibiofemoral contacts and femoral internal-external and varus-valgus rotations were analyzed as a function of knee flexion angle. The medial tibiofemoral contact translated anteroposteriorly, but remained on the center of the medial compartment. On the other hand, the lateral tibiofemoral contact translated posteriorly to the edge of the tibial surface at 150° flexion. The femur exhibited external and valgus rotation relative to the tibia over the entire activity and reached 30° external and 5° valgus rotations at 150° flexion. Kinematics' data during dynamic full flexion may provide important insight as to the designing of high-flexion total knee prostheses.

  2. Transarterial Coil Embolization of a Symptomatic Posttraumatic Plantar Pseudoaneurysm

    PubMed Central

    Beyer, Lukas Philipp; Wohlgemuth, Walter A.; Müller-Wille, René

    2015-01-01

    Posttraumatic pseudoaneurysms of the lateral plantar artery are rare. We report the case of a 31-year-old woman with a painful pseudoaneurysm of the lateral plantar artery resulting from a deep plantar cut injury. The pseudoaneurysm was successfully treated by performing a transarterial “frontdoor-backdoor” coil embolization technique, which is a minimally invasive alternative to conventional ligature of the artery. PMID:25874151

  3. The effect of the gastrocnemius on the plantar fascia.

    PubMed

    Pascual Huerta, Javier

    2014-12-01

    Although anatomic and functional relationship has been established between the gastrocnemius muscle, via the Achilles tendon, and the plantar fascia, the exact role of gastrocnemius tightness in foot and plantar fascia problems is not completely understood. This article summarizes past and current literature linking these 2 structures and gives a mechanical explanation based on functional models of the relationship between gastrocnemius tightness and plantar fascia. The effect of gastrocnemius tightness on the sagittal behavior of the foot is also discussed.

  4. Accuracy of dental torque wrenches.

    PubMed

    Wood, James S; Marlow, Nicole M; Cayouette, Monica J

    2015-01-01

    The aim of this in vitro study was to compare the actual torque of 2 manual wrench systems to their stated (target) torque. New spring- (Nobel Biocare USA, LLC) and friction-style (Zimmer Dental, Inc.) manual dental torque wrenches, as well as spring torque wrenches that had undergone sterilization and clinical use, were tested. A calibrated torque gauge was used to compare actual torque to target torque values of 15 and 35 N/cm. Data were statistically analyzed via mixed-effects regression model with Bonferroni correction. At a target torque of 15 N/cm, the mean torque of new spring wrenches (13.97 N/cm; SE, 0.07 N/cm) was significantly different from that of used spring wrenches (14.94 N/cm; SE, 0.06 N/cm; P < 0.0001). However, the mean torques of new spring and new friction wrenches (14.10 N/cm; SE, 0.07 N/cm; P = 0.21) were not significantly different. For torque measurements calibrated at 35 N/cm, the mean torque of new spring wrenches (35.29 N/cm; SE, 0.10 N/cm) was significantly different (P < 0.0001) from the means of new friction wrenches (36.20 N/cm; SE, 0.08 N/cm) and used spring wrenches (36.45 N/cm; SE, 0.08 N/cm). Discrepancies in torque could impact the clinical success of screw-retained dental implants. It is recommended that torque wrenches be checked regularly to ensure that they are performing to target values.

  5. Endoscopic plantar fasciotomy versus injection of platelet-rich plasma for resistant plantar fasciopathy

    PubMed Central

    Othman, Ahmed Mohamed Ahmed; Hegazy, Islam Hassan Ali

    2015-01-01

    Background Resistant plantar fasciopathy is a common orthopedic problem. Aim Comparing two different methods of treatment. Methods Fifty patients with chronic resistant plantar fasciopathy were divided into two groups. The first included 23 patients treated by endoscopic release of plantar fascia (EPF) and the second included 27 patients treated by injection of platelet-rich plasma (PRP). Results In the EPF group, the average VAS improved from 8.28 to 2.35. The average AOFAS improved from 65 to 94. In the PRP group, average VAS improved from 8.22 to 2.9 and the average AOFAS improved from 66 to 92. Conclusion Both methods gave comparable results at late follow-up. PMID:27047220

  6. Reduction of digital plantar pressure by debridement and silicone orthosis.

    PubMed

    Slater, R A; Hershkowitz, I; Ramot, Y; Buchs, A; Rapoport, M J

    2006-12-01

    The lesser digits are frequent sites of elevated plantar pressure and ulceration in the diabetic foot. We sought to determine whether debridement of callus and the wearing of a custom molded digital orthosis could significantly reduce digital plantar pressure. Fourteen patients with distal digital callus were studied. For each patient, the toe with the highest plantar pressure was selected. A computerized pressure mat was used to record the plantar pressure before and after debridement with and without a moldable silicone digital orthosis. Mean peak plantar digital pressures before treatment were 2.80+/-0.7 kg/cm2 for the entire group. The digital orthosis alone reduced plantar pressure to a mean of 1.95+/-0.65 kg/cm2 p < 0.05. Treatment by debridement similarly reduced pressure to 1.99+/-0.76 kg/cm2 p < 0.05. The most effective reduction of pressure for all patients, as well as the most statistically significant, occurred when both treatments were given, with mean peak plantar pressure falling to 1.28+/-0.61 kg/cm2 p < 0.01. Debridement and custom molded digital orthoses alleviate distal digital plantar pressure. Since elevated plantar pressure increases the risk of neuropathic ulceration, these treatments should be considered in the prophylactic care of appropriate patients.

  7. Influence of predominant patterns of coordination on the exploitation of interaction torques in a two-joint rhythmic arm movement.

    PubMed

    de Rugy, Aymar; Riek, Stephan; Carson, Richard G

    2006-11-01

    In this study we investigate the coordination between rhythmic flexion-extension (FE) and supination-pronation (SP) movements at the elbow joint-complex, while manipulating the intersegmental dynamics by means of a 2-degrees of freedom (df) robot arm. We hypothesized that constraints imposed by the structure of the neuromuscular-skeletal system would (1) result in predominant pattern(s) of coordination in the absence of interaction torques and (2) influence the capabilities of participants to exploit artificially induced interaction torques. Two experiments were conducted in which different conditions of interaction torques were applied on the SP-axis as a function of FE movements. These conditions promoted different patterns of coordination between the 2-df. Control trials conducted in the absence of interaction torques revealed that both the in-phase (supination synchronized with flexion) and the anti-phase (pronation synchronized with flexion) patterns were spontaneously established by participants. The predominance of these patterns of coordination is explained in terms of the mechanical action of bi-articular muscles acting at the elbow joint-complex, and in terms of the reflexes that link the activity of the muscles involved. Results obtained in the different conditions of interaction torques revealed that those neuromuscular-skeletal constraints either impede or favor the exploitation of intersegmental dynamics depending on the context. Interaction torques were indeed found to be exploited to a greater extent in conditions in which the profiles of interaction torques favored one of the two predominant patterns of coordination (i.e., in-phase or anti-phase) as opposed to other patterns of coordination (e.g., 90 degrees or 270 degrees). Those results are discussed in relation to recent studies reporting exploitation of interaction torques in the context of rhythmic movements.

  8. Is high flexion following total knee arthroplasty safe?: evaluation of knee joint loads in the patients during maximal flexion.

    PubMed

    Nagura, Takeo; Otani, Toshiro; Suda, Yasunori; Matsumoto, Hideo; Toyama, Yoshiaki

    2005-08-01

    The purpose of this study was to indicate the mechanical loads and the flexion angle at the knee during rise from maximal flexion following total knee arthroplasty (TKA). Twenty three knees were evaluated using skin marker-based motion analysis system during four different activities of daily living. The average maximum flexion was 90 degrees (34 degrees less than passive flexion) and all subjects required support for their weight to rise from maximal flexion. The external moments and the external forces at the knee during the maximal flexion were smaller than those during the stair descending activity. The results indicate that capable flexion angle for the patients following TKA is approximately 90 degrees which has smaller mechanical loads at the knee than the stair descending activity.

  9. Plantar fasciitis (fasciosis) treatment outcome study: plantar fascia thickness measured by ultrasound and correlated with patient self-reported improvement.

    PubMed

    Fabrikant, Jerry M; Park, Tae Soon

    2011-06-01

    Ultrasound, well recognized as an effective diagnostic tool, reveals a thickening of the plantar fascia in patients with plantar fasciitis/fasciosis disease. The authors hypothesized that ultrasound would also reveal a decrease in the plantar fascia thickness for patients undergoing treatment for the disease, a hypothesis that, heretofore, had been only tested on a limited number of subjects. They conducted a more statistically significant study that found that clinical treatment with injection and biomechanical correction does indeed diminish plantar fascia thickness as shown on ultrasound. The study also revealed that patients experience the most heightened plantar fascia tenderness toward the end of the day, and improvement in their symptomatic complaints were associated with a reduction in plantar fascia thickness. As a result, the authors conclude that office-based ultrasound can help diagnose and confirm plantar fasciitis/fasciosis through the measurement of the plantar fascia thickness. Because of the advantages of ultrasound--that it is non-invasive with greater patient acceptance, cost effective and radiation-free--the imaging tool should be considered and implemented early in the diagnosis and treatment of plantar fasciitis/fasciosis.

  10. Maximal dynamic grip force and wrist torque: the effects of gender, exertion direction, angular velocity, and wrist angle.

    PubMed

    Morse, Jonathan L; Jung, Myung-Chul; Bashford, Gregory R; Hallbeck, M Susan

    2006-11-01

    The objective of this study was to examine the effects of gender, exertion direction, angular velocity and wrist angle on simultaneous grip force and wrist torque under the isokinetic condition. The study used 20 participants (10 males and 10 females) and included 6 angular velocities (15, 30, 45, 60, 75, and 90 degrees /s) and 2 wrist exertion directions (flexion and extension) over the wrist range of motion of 70 degrees flexion to 60 degrees extension in 5 degrees increments. Similar to other studies, males and flexion exertion produced larger forces than females and extension exertion, respectively. However, the largest forces were generated at near extreme flexion of the wrist and the dependent variable of angular velocity was not practically significant. These results can contribute to the evaluation of cumulative trauma syndromes, but there is a need for more research on the dynamic measures of the hand and wrist complex and for standard development for dynamic force measurement.

  11. Investigating the Effects of Knee Flexion during the Eccentric Heel-Drop Exercise

    PubMed Central

    Weinert-Aplin, Robert A.; Bull, Anthony M.J.; McGregor, Alison H.

    2015-01-01

    This study aimed to characterise the biomechanics of the widely practiced eccentric heel-drop exercises used in the management of Achilles tendinosis. Specifically, the aim was to quantify changes in lower limb kinematics, muscle lengths and Achilles tendon force, when performing the exercise with a flexed knee instead of an extended knee. A musculoskeletal modelling approach was used to quantify any differences between these versions of the eccentric heel drop exercises used to treat Achilles tendinosis. 19 healthy volunteers provided a group from which optical motion, forceplate and plantar pressure data were recorded while performing both the extended and flexed knee eccentric heel-drop exercises over a wooden step when barefoot or wearing running shoes. This data was used as inputs into a scaled musculoskeletal model of the lower limb. Range of ankle motion was unaffected by knee flexion. However, knee flexion was found to significantly affect lower limb kinematics, inter-segmental loads and triceps muscle lengths. Peak Achilles load was not influenced despite significantly reduced peak ankle plantarflexion moments (p < 0.001). The combination of reduced triceps lengths and greater ankle dorsiflexion, coupled with reduced ankle plantarflexion moments were used to provide a basis for previously unexplained observations regarding the effect of knee flexion on the relative loading of the triceps muscles during the eccentric heel drop exercises. This finding questions the role of the flexed knee heel drop exercise when specifically treating Achilles tendinosis. Key points A more dorsiflexed ankle and a flexing knee are characteristics of performing the flexed knee heel-drop eccentric exercise. Peak ankle plantarflexion moments were reduced with knee flexion, but did not reduce peak Achilles tendon force. Kinematic changes at the knee and ankle affected the triceps muscle length and resulted in a reduction in the amount of Achilles tendon work performed. A version

  12. Specific modulation of spinal and cortical excitabilities during lengthening and shortening submaximal and maximal contractions in plantar flexor muscles.

    PubMed

    Duclay, Julien; Pasquet, Benjamin; Martin, Alain; Duchateau, Jacques

    2014-12-15

    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.

  13. Effect of socks structures on plantar dynamic pressure distribution.

    PubMed

    Soltanzadeh, Zeynab; Shaikhzadeh Najar, Saeed; Haghpanahi, M; Mohajeri-Tehrani, M R

    2016-11-01

    A major purpose of investigating the plantar pressure in patients with pain or those at risk for skin injury is to reduce the pressure below metatarsal heads, specially first and second metatarsal heads. The aim of this article is to evaluate the effects of the socks structures on the changes in plantar dynamic pressure. In this study, seven socks types with different structures for the sole area were produced. The Gaitview(®) AFA-50 system, a force plate, was used to measure the plantar dynamic pressure of 10 participants. The barefoot plantar dynamic pressure distribution was compared with the plantar dynamic pressure distribution with socks by two independent samples test on various zones of the foot and on different genders using SPSS software. Mann-Whitney tests were used to determine specific significant differences. The obtained results showed that the main trend was to redistribute the plantar dynamic pressure from the higher plantar pressure zones (toe and first through forth metatarsal bone regions) were decreased and as a result the plantar pressure toward the relatively lower pressure zones (fifth metatarsal bone and midfoot regions). In comparison with the barefoot condition, the cross miss structure reduced the mean pressure in the critical region of the foot (first metatarsal) for male and female subjects ( p < 0.05) and also the mock rib structure reduced the mean pressure for female subjects ( p < 0.05). In general, the results suggested wearing the socks because the socks make the plantar pressure redistributed from high to low plantar pressure zones. The results of this research indicated that wearing socks with cross miss and mock rib structures will reduce the mean plantar pressure values in forefoot area in comparison with the barefoot condition.

  14. Plantar fascia calcification a sequelae of corticosteroid injection in the treatment of recalcitrant plantar fasciitis

    PubMed Central

    Fox, Thomas Peter; Oliver, Govind; Wek, Caesar; Hester, Thomas

    2013-01-01

    We report the case of a 72-year-old woman suffering with severe plantar fasciitis who received a therapeutic corticosteroid injection. Two-and-a-half years after the injection she developed a small calcified lump under the skin which subsequently caused ulceration and infection. She went on to develop a diabetic foot infection requiring an extended course of intravenous antibiotics. PMID:23955985

  15. Single-interface Casimir torque

    NASA Astrophysics Data System (ADS)

    Morgado, Tiago A.; Silveirinha, Mário G.

    2016-10-01

    A different type of Casimir-type interaction is theoretically predicted: a single-interface torque at a junction of an anisotropic material and a vacuum or another material system. The torque acts to reorient the polarizable microscopic units of the involved materials near the interface, and thus to change the internal structure of the materials. The single-interface torque depends on the zero-point energy of the interface localized and extended modes. Our theory demonstrates that the single-interface torque is essential to understand the Casimir physics of material systems with anisotropic elements and may influence the orientation of the director of nematic liquid crystals.

  16. Tibiofemoral contact areas and pressures in six high flexion knees

    PubMed Central

    Vizesi, Frank; Bruce, Warwick; Herrmann, Sebastian; Walsh, William R

    2007-01-01

    The tibiofemoral articulating interfaces of six high flexion knee designs were examined using a standard testing protocol developed by Harris et al. [J Biomech 32:951–958 (1999)] to investigate the polyethylene insert contact areas and pressures. A load of 3600 N was applied for 10 s at 0, 30, 60, 90, 110, 135 and 155° of flexion. Contact areas and pressures at the femoral–polyethylene insert interface were measured with a I-scan 4000 system. Up to 110°of flexion, the VANGUARD RP HI-FLEX showed the highest contact area and lowest pressure. At the deep flexion angles, contact area decreased and contact pressure increased significantly in all knees. The NexGen series showed a constant contact area throughout the various flexion angles. In general, all high flexion knees could result in almost point contact in an extremely high range of motion. PMID:18034243

  17. The role of hamstring tightness in plantar fasciitis.

    PubMed

    Labovitz, Jonathan M; Yu, Jenny; Kim, Chul

    2011-06-01

    The purpose of this prospective cohort study was to determine if hamstring tightness was an increased risk in plantar fasciitis. It was thought that there is an increased risk of plantar fasciitis when hamstring tightness is present. A total of 105 patients (68 women, 37 men) were included in the study, 79 of whom were diagnosed with plantar fasciitis. Body mass index (BMI) was calculated and the presence of plantar fasciitis, equinus, and calcaneal spurs were assessed. The popliteal angle was measured using standard diagnostic techniques. Without controlling for covariates, BMI, the presence of a calcaneal spur, tightness in the gastrocnemius, gastrocnemius-soleus, and hamstring all had statistically significant association with plantar fasciitis. After controlling for covariates, patients with hamstring tightness were about 8.7 times as likely to experience plantar fasciitis (P < .0001). Patients with BMI >35 were approximately 2.4 times as likely to experience plantar fasciitis compared with those with BMI <35 (P = .04). This study demonstrates that hamstring tightness plays a significant role in the presence of plantar fasciitis and should be addressed along with equinus and obesity when providing treatment to patients with this diagnosis.

  18. Torque feedback transmission

    SciTech Connect

    Whalen, B.L.

    1987-01-20

    This patent describes an infinitely variable transmission of inline configuration for interconnecting a primer mover with a load for clutch free operation in a range of speed including hydraulic neutral comprising: a. planetary gear train means having a ring gear, planetary gears supported by a planetary gear carrier, and a sun gear, the sun gear being connected mechanically to the load, output shaft means for joining the sun gear to the load; b. variable torque feedback means comprising (i) a variable displacement hydraulic motor whose rotor shaft is in line with the output shaft means and drivingly connected to the prime mover and the planetary gear carrier during the full range of operation of the transmission, and (ii) a fixed displacement hydraulic pump connected hydraulically to the motor, the rotor shaft of the pump being connected mechanically to the ring gear and being axially displaced from the output shaft means; c. means for adjusting the displacement volume within the hydraulic motor for controlling the torque feedback in the transmission to provide infinitely variable coupling between the prime mover and the load over the full range of the transmission including hydraulic neutral; d. a speed reducer between the primer mover and the motor rotor shaft and a speed multiplier between the sun gear and the load; and e. mechanical transmission assembly means between the speed multiplier and the load in line with the motor rotor shaft and the output shaft means for providing selection of drive, reverse, park, and neutral.

  19. Iontophoresis for palmar and plantar hyperhidrosis.

    PubMed

    Pariser, David M; Ballard, Angela

    2014-10-01

    Iontophoresis is a safe, efficacious, and cost-effective primary treatment of palmar and plantar hyperhidrosis. Decades of clinical experience and research show significant reduction in palmoplantar excessive sweating with minimal side effects. To get the best results from iontophoresis, health care professionals need to provide education on the mechanism of action and benefits, evidence of its use, and creation of a future patient-specific plan of care for continued treatments at home or in the physician's office. Iontophoresis may be combined with other hyperhidrosis treatments, such as topical antiperspirants and botulinum toxin injections.

  20. Plantar pressure cartography reconstruction from 3 sensors.

    PubMed

    Abou Ghaida, Hussein; Mottet, Serge; Goujon, Jean-Marc

    2014-01-01

    Foot problem diagnosis is often made by using pressure mapping systems, unfortunately located and used in the laboratories. In the context of e-health and telemedicine for home monitoring of patients having foot problems, our focus is to present an acceptable system for daily use. We developed an ambulatory instrumented insole using 3 pressures sensors to visualize plantar pressure cartographies. We show that a standard insole with fixed sensor position could be used for different foot sizes. The results show an average error measured at each pixel of 0.01 daN, with a standard deviation of 0.005 daN.

  1. Material properties of the plantar aponeurosis.

    PubMed

    Kitaoka, H B; Luo, Z P; Growney, E S; Berglund, L J; An, K N

    1994-10-01

    Material properties of the plantar aponeurosis were determined by a two-dimensional video tracking method to simultaneously measure the aponeurosis deformation. Failure loads averaged 1189 +/- 244 N and were higher in men. Average stiffness of the intact fascia was 203.7 +/- 50.5 N/mm at a loading rate of 11.12 N/sec and it did not vary significantly for the loading rates of 11.12 to 1112 N/sec. The high tensile loads required for failure were consistent with clinical and biomechanical studies and indicated the importance of the aponeurosis in foot function and arch stability.

  2. Ultrasound-Assisted Endoscopic Partial Plantar Fascia Release

    PubMed Central

    Ohuchi, Hiroshi; Ichikawa, Ken; Shinga, Kotaro; Hattori, Soichi; Yamada, Shin; Takahashi, Kazuhisa

    2013-01-01

    Various surgical treatment procedures for plantar fasciitis, such as open surgery, percutaneous release, and endoscopic surgery, exist. Skin trouble, nerve disturbance, infection, and persistent pain associated with prolonged recovery time are complications of open surgery. Endoscopic partial plantar fascia release offers the surgeon clear visualization of the anatomy at the surgical site. However, the primary medial portal and portal tract used for this technique have been shown to be in close proximity to the posterior tibial nerves and their branches, and there is always the risk of nerve damage by introducing the endoscope deep to the plantar fascia. By performing endoscopic partial plantar fascia release under ultrasound assistance, we could dynamically visualize the direction of the endoscope and instrument introduction, thus preventing nerve damage from inadvertent insertion deep to the fascia. Full-thickness release of the plantar fascia at the ideal position could also be confirmed under ultrasound imaging. We discuss the technique for this new procedure. PMID:24265989

  3. Provocative mechanical tests of the peripheral nervous system affect the joint torque-angle during passive knee motion.

    PubMed

    Andrade, R J; Freitas, S R; Vaz, J R; Bruno, P M; Pezarat-Correia, P

    2015-06-01

    This study aimed to determine the influence of the head, upper trunk, and foot position on the passive knee extension (PKE) torque-angle response. PKE tests were performed in 10 healthy subjects using an isokinetic dynamometer at 2°/s. Subjects lay in the supine position with their hips flexed to 90°. The knee angle, passive torque, surface electromyography (EMG) of the semitendinosus and quadriceps vastus medialis, and stretch discomfort were recorded in six body positions during PKE. The different maximal active positions of the cervical spine (neutral; flexion; extension), thoracic spine (neutral; flexion), and ankle (neutral; dorsiflexion) were passively combined for the tests. Visual analog scale scores and EMG were unaffected by body segment positioning. An effect of the ankle joint was verified on the peak torque and knee maximum angle when the ankle was in the dorsiflexion position (P < 0.05). Upper trunk positioning had an effect on the knee submaximal torque (P < 0.05), observed as an increase in the knee passive submaximal torque when the cervical and thoracic spines were flexed (P < 0.05). In conclusion, other apparently mechanical unrelated body segments influence torque-angle response since different positions of head, upper trunk, and foot induce dissimilar knee mechanical responses during passive extension.

  4. Scapular winging as a symptom of cervical flexion myelopathy.

    PubMed

    Yaguchi, Hiroaki; Takahashi, Ikuko; Tashiro, Jun; Tsuji, Sachiko; Yabe, Ichiro; Sasaki, Hidenao

    2007-01-01

    A 23-year-old man complained of weakness of the right arm that he first noted six years prior to his visit. Neurological examination revealed atrophy and weakness of the triceps and serratus anterior muscle on the right side, which resulted in scapular winging on that side. MRI with neck flexion revealed compression of the cervical cord enabling a diagnosis of flexion myelopathy. Proximal muscle weakness and atrophy in flexion myelopathies including Hirayama disease are extremely rare. Here, we report a case of unilateral, proximal upper limb atrophy with scapular winging, attributed to middle cervical flexion myelopathy.

  5. Effects of Static Flexion-relaxation on Paraspinal Reflex Behavior

    PubMed Central

    Granata, Kevin P.; Rogers, Ellen; Moorhouse, Kevin

    2006-01-01

    Background. Static trunk flexion working postures and disturbed trunk muscle reflexes are related to increased risk of low-back pain. Animal studies conclude that these factors may be related; passive tissue strain in spinal ligaments causes subsequent short-term changes in reflex. Although studies have documented changes in the myoelectric onset angle of flexion-relaxation following prolonged static flexion and cyclic flexion we could find no published evidence related to the human reflex response of the trunk extensor muscles following a period of static flexion-relaxation loading. Methods. Eighteen subjects maintained static lumbar flexion for 15 min. Paraspinal muscle reflexes were elicited both before and after the flexion-relaxation protocol using pseudorandom stochastic force disturbances while recording EMG. Reflex gain was computed from the peak value of the impulse response function relating input force perturbation to EMG response using time-domain deconvolution analyses. Findings. Reflexes showed a trend toward increased gain after the period of flexion-relaxation (P < 0.055) and were increased with trunk extension exertion (P < 0.021). Significant gender differences in reflex gain were observed (P < 0.01). Interpretations. Occupational activities requiring extended periods of trunk flexion contribute to changes in reflex behavior of the paraspinal muscles. Results suggest potential mechanisms by which flexed posture work may contribute to low-back pain. Significant gender differences indicate risk analyses should consider personal factors when considering neuromuscular behavior. PMID:15567532

  6. Temperature as a predictive tool for plantar triaxial loading.

    PubMed

    Yavuz, Metin; Brem, Ryan W; Davis, Brian L; Patel, Jalpa; Osbourne, Abe; Matassini, Megan R; Wood, David A; Nwokolo, Irene O

    2014-11-28

    Diabetic foot ulcers are caused by moderate repetitive plantar stresses in the presence of peripheral neuropathy. In severe cases, the development of these foot ulcers can lead to lower extremity amputations. Plantar pressure measurements have been considered a capable predictor of ulceration sites in the past, but some investigations have pointed out inconsistencies when solely relying on this method. The other component of ground reaction forces/stresses, shear, has been understudied due to a lack of adequate equipment. Recent articles reported the potential clinical significance of shear in diabetic ulcer etiology. With the lack of adequate tools, plantar temperature has been used as an alternative method for determining plantar triaxial loading and/or shear. However, this method has not been previously validated. The purpose of this study was to analyze the potential association between exercise-induced plantar temperature increase and plantar stresses. Thirteen healthy individuals walked on a treadmill for 10 minutes at 3.2km/h. Pre and post-exercise temperature profiles were obtained with a thermal camera. Plantar triaxial stresses were quantified with a custom-built stress plate. A statistically significant correlation was observed between peak shear stress (PSS) and temperature increase (r=0.78), but not between peak resultant stress (PRS) and temperature increase (r=0.46). Plantar temperature increase could predict the location of PSS and PRS in 23% and 39% of the subjects, respectively. Only a moderate linear relationship was established between triaxial plantar stresses and walking-induced temperature increase. Future research will investigate the value of nonlinear models in predicting plantar loading through foot temperature.

  7. Comparison of upper cervical flexion and cervical flexion angle of computer workers with upper trapezius and levator scapular pain.

    PubMed

    Yoo, Won-Gyu

    2014-02-01

    [Purpose] In this study, we compared upper cervical flexion and cervical flexion angle of computer workers with upper trapezius and levator scapular pain. [Subject] Eight male computer workers with upper trapezius muscle pain and eight others with levator scapular muscle pain participated. [Methods] Each subject was assessed in terms of upper cervical flexion angle and total cervical flexion angles using a cervical range of motion instrument after one hour of computer work. [Results] The upper cervical flexion angle of the group with levator scapular pain was significantly lower than that of the group with upper trapezius pain after computer work. The total cervical flexion angle of the group with upper trapezius pain was significantly lower than that of the group with levator scapular pain after computer work. [Conclusion] For selective and effective intervention for neck pain, therapists should evaluate upper and lower cervical motion individually.

  8. Torque control for electric motors

    NASA Technical Reports Server (NTRS)

    Bernard, C. A.

    1980-01-01

    Method for adjusting electric-motor torque output to accomodate various loads utilizes phase-lock loop to control relay connected to starting circuit. As load is imposed, motor slows down, and phase lock is lost. Phase-lock signal triggers relay to power starting coil and generate additional torque. Once phase lock is recoverd, relay restores starting circuit to its normal operating mode.

  9. Spatial resolution in plantar pressure measurement revisited.

    PubMed

    Pataky, Todd C

    2012-08-09

    Plantar pressures are typically measured using sensors of finite area, so the accuracy with which one can measure true maximum pressure is dependent on sensor size. Measurement accuracy has been modeled previously for one patient's metatarsals (Lord, 1997), but has not been modeled either for general subjects or for other parts of the foot. The purposes of this study were (i) to determine whether Lord's (1997) model is also valid for heel and hallux pressures, and (ii) to examine how sensor size relates to measurement accuracy in the context of four factors common to many measurement settings: pressure pulse size, foot positioning, pressure change quantification, and gross pressure redistribution. Lord's (1997) model was first generalized and was then validated using 10 healthy walking subjects, with relatively low RMSE values on the order of 20 kPa. Next, postural data were used to show that gross pressure redistributions can be accurately quantified (p<0.002), even with rather gross sensor sizes of 30 mm. Finally, numerical analyses revealed that the relation between sensor size and measurement accuracy is highly complex, with deep dependency on the measurement context. In particular, the critical sensor widths required to achieve 90% accuracy ranged from 1.7 mm to 17.4 mm amongst the presently investigated scenarios. Since measurement accuracy varies so extensively with so many factors, the current results cannot yield specific recommendations regarding spatial resolution. It is concluded simply that no particular spatial resolution can yield a constant measurement accuracy across common plantar pressure measurement tasks.

  10. Bimanual shoulder flexion system with surface electromyography for hemiplegic patients after stroke: A preliminary study.

    PubMed

    Park, Kihan; Kwon, Suncheol; Kim, Jung; Rim, Byeongcheol

    2011-01-01

    A robot-assisted bimanual shoulder flexion rehabilitation system with surface electromyography (sEMG) for hemiplegic patients after stroke is presented as a preliminary study before clinical test. The assistive system driven by combination of bimanual mirror imaging motion and sEMG in order to induce continuous voluntary stimulation to muscle and nerve of the patients. In this paper, hardware design, controller with impedance compensation of actuator using disturbance observer (DOB) for back-drivable operation, and sEMG signal processing to obtain desired assistive torque are also reported. The performance of impedance compensation and assistive operation of the system with sEMG were verified by experiments with a healthy participant. This system is expected to help to recover functionality of neural/musculoskeletal system to hemiplegic patients.

  11. Isokinetic Identification of Knee Joint Torques before and after Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Czaplicki, Adam; Jarocka, Marta; Walawski, Jacek

    2015-01-01

    The aim of this study was to evaluate the serial change of isokinetic muscle strength of the knees before and after anterior cruciate ligament reconstruction (ACLR) in physically active males and to estimate the time of return to full physical fitness. Extension and flexion torques were measured for the injured and healthy limbs at two angular velocities approximately 1.5 months before the surgery and 3, 6, and 12 months after ACLR. Significant differences (p ≤ 0.05) in peak knee extension and flexion torques, hamstring/quadriceps (H/Q) strength ratios, uninvolved/involved limb peak torque ratios, and the normalized work of these muscles between the four stages of rehabilitation were identified. Significant differences between extension peak torques for the injured and healthy limbs were also detected at all stages. The obtained results showed that 12 months of rehabilitation were insufficient for the involved knee joint to recover its strength to the level of strength of the uninvolved knee joint. The results helped to evaluate the progress of the rehabilitation and to implement necessary modifications optimizing the rehabilitation training program. The results of the study may also be used as referential data for physically active males of similar age. PMID:26646385

  12. Identification of Foot Pathologies Based on Plantar Pressure Asymmetry.

    PubMed

    Wafai, Linah; Zayegh, Aladin; Woulfe, John; Aziz, Syed Mahfuzul; Begg, Rezaul

    2015-08-18

    Foot pathologies can negatively influence foot function, consequently impairing gait during daily activity, and severely impacting an individual's quality of life. These pathologies are often painful and correspond with high or abnormal plantar pressure, which can result in asymmetry in the pressure distribution between the two feet. There is currently no general consensus on the presence of asymmetry in able-bodied gait, and plantar pressure analysis during gait is in dire need of a standardized method to quantify asymmetry. This paper investigates the use of plantar pressure asymmetry for pathological gait diagnosis. The results of this study involving plantar pressure analysis in fifty one participants (31 healthy and 20 with foot pathologies) support the presence of plantar pressure asymmetry in normal gait. A higher level of asymmetry was detected at the majority of the regions in the feet of the pathological population, including statistically significant differences in the plantar pressure asymmetry in two regions of the foot, metatarsophalangeal joint 3 (MPJ3) and the lateral heel. Quantification of plantar pressure asymmetry may prove to be useful for the identification and diagnosis of various foot pathologies.

  13. Ultrasound evaluation of a spontaneous plantar fascia rupture.

    PubMed

    Louwers, Michael J; Sabb, Brian; Pangilinan, Percival H

    2010-11-01

    Plantar fascia rupture is an occasional complication in patients with chronic plantar fasciitis or in patients with plantar fasciitis treated with steroid injection. Very few cases of spontaneous plantar fascia rupture have been reported in the literature (Herrick and Herrick, Am J Sports Med 1983;11:95; Lun et al, Clin J Sports Med 1999;9:48-9; Rolf et al, J Foot Ankle Surg 1997;36:112-4; Saxena and Fullem, Am J Sports Med 2004;32:662-5). Spontaneous medial plantar fascia rupture in a 37-yr-old man with no preceding symptoms or steroid injections was confirmed with diagnostic ultrasound, which revealed severe fasciitis at the calcaneal insertion with partial tearing. After conservative treatment, the patient returned to full activities. We discuss the anatomy, risk factors, examination findings, and treatment for this condition, as well as the unique benefits that ultrasound offers over magnetic resonance imaging. It is important to consider plantar fascia rupture in patients with hindfoot pain and medioplantar ecchymosis, particularly if an injury occurred during acceleration maneuvers. Ultrasound in these cases can be used to diagnose a plantar fascia tear quickly, accurately, and cost-effectively.

  14. Subcalcaneal bursitis with plantar fasciitis treated by arthroscopy.

    PubMed

    Yamakado, Kotaro

    2013-05-01

    We report the successful arthroscopic treatment of a case of subcalcaneal bursitis with plantar fasciitis. To our knowledge, this is the first report on arthroscopic excision of a subcalcaneal bursa. Right heel pain developed in a 50-year-old woman, without any obvious cause. She reported that the heel pain occurred immediately after waking and that the heel ached when she walked. Magnetic resonance imaging showed an extra-articular, homogeneous, high-intensity lesion in the fat pad adjacent to the calcaneal tubercle on T2-weighted sagittal and coronal images and thickening of the plantar fascia on T2-weighted sagittal images. A diagnosis of a recalcitrant subcalcaneal bursitis with plantar fasciitis was made, and surgery was performed. The arthroscope was placed between the calcaneus and the plantar fascia. With the surgeon viewing from the lateral portal and working from the medial portal, the dorsal surface of the degenerative plantar fascia was debrided and the medial half of the plantar fascia was released, followed by debridement of the subcalcaneal bursal cavity through the incised plantar fascia. Full weight bearing and gait were allowed immediately after the operation. At the latest follow-up, the patient had achieved complete resolution of heel pain without a recurrence of the mass, confirmed by magnetic resonance imaging.

  15. Subcalcaneal Bursitis With Plantar Fasciitis Treated by Arthroscopy

    PubMed Central

    Yamakado, Kotaro

    2013-01-01

    We report the successful arthroscopic treatment of a case of subcalcaneal bursitis with plantar fasciitis. To our knowledge, this is the first report on arthroscopic excision of a subcalcaneal bursa. Right heel pain developed in a 50-year-old woman, without any obvious cause. She reported that the heel pain occurred immediately after waking and that the heel ached when she walked. Magnetic resonance imaging showed an extra-articular, homogeneous, high-intensity lesion in the fat pad adjacent to the calcaneal tubercle on T2-weighted sagittal and coronal images and thickening of the plantar fascia on T2-weighted sagittal images. A diagnosis of a recalcitrant subcalcaneal bursitis with plantar fasciitis was made, and surgery was performed. The arthroscope was placed between the calcaneus and the plantar fascia. With the surgeon viewing from the lateral portal and working from the medial portal, the dorsal surface of the degenerative plantar fascia was debrided and the medial half of the plantar fascia was released, followed by debridement of the subcalcaneal bursal cavity through the incised plantar fascia. Full weight bearing and gait were allowed immediately after the operation. At the latest follow-up, the patient had achieved complete resolution of heel pain without a recurrence of the mass, confirmed by magnetic resonance imaging. PMID:23875139

  16. Classification of Calcaneal Spurs and Their Relationship With Plantar Fasciitis.

    PubMed

    Zhou, Binghua; Zhou, You; Tao, Xu; Yuan, Chengsong; Tang, Kanglai

    2015-01-01

    Calcaneal spurs, as a cause of plantar fasciitis, are currently debatable. A prospective study was performed to classify calcaneal spurs according to the findings from an investigation of the relationship between calcaneal spurs and plantar fasciitis. Thirty patients with calcaneal spurs and plantar heel pain underwent calcaneal spur removal and endoscopic plantar fasciotomy. The relationship between the classification of calcaneal spurs and plantar fasciitis was evaluated by endoscopic findings, clinical symptoms, radiographic images, and biopsy findings. The visual analog scale for pain and the American Orthopedic Foot and Ankle Society ankle-hindfoot scores for functional evaluation were used preoperatively and postoperatively, respectively. The mean follow-up period was 24 months. Two separate types of calcaneal spurs were recognized. Type A calcaneal spurs were located superior to the plantar fascia insertion, and type B calcaneal spurs were located within the plantar fascia. Magnetic resonance imaging results showed a more severe plantar fasciitis grade in type B calcaneal spurs preoperatively. Histologic examination showed that the numbers of granulocytes per image in type B spurs were significantly increased compared with those in type A spurs. Statistically significant improvements were found in the mean visual analog scale and American Orthopedic Foot and Ankle Society scores and magnetic resonance imaging results in both groups. The amount of change in the visual analog scale score and American Orthopedic Foot and Ankle Society score, the number of granulocytes per image, and calcaneal spur length showed a high association with the classification of the calcaneal spurs. Calcaneal spurs were completely removed and did not recur in any of the patients on radiographic assessment during the follow-up period. Calcaneal spurs can be classified into 2 distinct types that are indicative of the severity of plantar fasciitis.

  17. [Management of Flexion Contracture in Primary Total Knee Arthroplasty].

    PubMed

    Hube, R; Mayr, H O; Pfitzner, T; von Roth, P

    2015-06-01

    Flexion contracture is a common deformity of the arthritic knee. The present publication describes causes, clinical relevance and surgical technique in the presence of flexion contractures in total knee arthroplasty. Flexion contracture can be attributed to different causes. Basically it is a mismatch between flexion and extension gaps. Moderate and severe deformities have to be corrected by additional surgical interventions. In most cases soft tissue techniques with release of contracted structures, the removal of osteophytes and additional distal femoral bone resection are necessary. The goal of these interventions is to achieve full extension of the knee. During rehabilitation attention has to be paid to maintain it with intensive physical therapy. A remaining flexion contracture is associated with inferior functional outcome and persistent pain.

  18. Evidence of Preserved Oxidative Capacity and Oxygen Delivery in the Plantar Flexor Muscles With Age.

    PubMed

    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

    2015-09-01

    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.

  19. Influence of shoes increasing dorsiflexion and decreasing metatarsus flexion on lower limb muscular activity during fitness exercises, walking, and running.

    PubMed

    Bourgit, David; Millet, Guillaume Y; Fuchslocher, Jörg

    2008-05-01

    The aim of the present study was to compare electromyographic activity during fitness exercises, walking, and running among 3 different dorsiflexion shoes (+2 degrees , +4 degrees , and +10 degrees ) and standard shoes (-4 degrees ). The 3 different dorsiflexion shoes tested in this study have a curvature placed in the middle of the sole. This design was specially projected to decrease the metatarsus flexion. Electromyographic activity of 9 lower limb muscles was measured on 12 healthy female subjects during 5 fitness exercises (unload squat, side and front step, submaximal ballistic plantar flexion, and lunge exercise), and during running (10 km x h(-1)) and walking (4.5 km x h(-1)) on a treadmill. EMG signal was analyzed with the root mean square (RMS) and integrated EMG. All RMS data measured during these exercises were expressed as percentages of maximum voluntary isometric contraction. The results show that dorsiflexion affects muscle recruitment and reorganizes the motor pattern. The general tendency was that the tibialis anterior activity increased with dorsiflexion. However, an optimal dorsiflexion existed for various exercises. It is concluded that shoes with moderate dorsiflexion can activate lower limb muscles differently compared with both standard shoes and shoes with large dorsiflexion during submaximal exercises and locomotion.

  20. Weak lensing goes bananas: what flexion really measures

    NASA Astrophysics Data System (ADS)

    Schneider, P.; Er, X.

    2008-07-01

    In weak gravitational lensing, the image distortion caused by shear measures the projected tidal gravitational field of the deflecting mass distribution. To lowest order, the shear is proportional to the mean image ellipticity. If the image sizes are not small compared to the scale over which the shear varies, higher-order distortions occur, called flexion. For ordinary weak lensing, the observable quantity is not the shear, but the reduced shear, owing to the mass-sheet degeneracy. Likewise, the flexion itself is unobservable. Instead, higher-order image distortions measure the reduced flexion, i.e., derivatives of the reduced shear. We derive the corresponding lens equation in terms of the reduced flexion and calculate the resulting relation between brightness moments of source and image. Assuming an isotropic distribution of source orientations, estimates for the reduced shear and flexion are obtained and then tested with simulations. In particular, the presence of flexion affects the determination of the reduced shear. The results of these simulations yield the amount of bias of the estimators as a function of the shear and flexion. We point out and quantify a fundamental limitation of the flexion formalism in terms of the product of reduced flexion and source size. If this product increases above the derived threshold, multiple images of the source are formed locally, and the formalism breaks down. Finally, we show how a general (reduced) flexion field can be decomposed into its four components. Two of them are due to a shear field, carrying an E- and B-mode in general. The other two components do not correspond to a shear field, and they can also be split up into corresponding E- and B-modes.

  1. Medial and Lateral Plantar Artery Angiosome Rotational Flaps for Transmetatarsal and Lisfranc Amputation in Patients With Compromised Plantar Tissue.

    PubMed

    Boffeli, Troy J; Waverly, Brett J

    2016-01-01

    Traditional incision techniques for midfoot amputation might not provide immediate soft tissue coverage of the underlying metatarsal and tarsal bones in the presence of a large plantar soft tissue defect. Patients undergoing transmetatarsal and Lisfranc amputation frequently have compromised plantar tissue in association with neuropathic ulcers, forefoot gangrene, and infection, necessitating wide resection as a part of the amputation procedure. Open amputation will routinely be performed under these circumstances, although secondary healing could be compromised owing to residual bone exposure. Alternatively, the surgeon might elect to perform a more proximal lower extremity amputation, which will allow better soft tissue coverage but compromises function of the lower extremity. A third option for this challenging situation is to modify the plantar flap incision design to incorporate a medial or lateral plantar artery angiosome-based rotational flap, which will provide immediate coverage of the forefoot and midfoot soft tissue defects without excessive shortening of the bone structure. A plantar medial soft tissue defect is treated with the lateral plantar artery angiosome flap, and a plantar lateral defect is treated with the medial plantar artery angiosome flap. Medial and lateral flaps can be combined to cover a central plantar wound defect. Incorporating large rotational flaps requires knowledge of the applicable angiosome anatomy and specific modifications to incision planning and dissection techniques to ensure adequate soft tissue coverage and preservation of the blood supply to the flap. A series of 4 cases with an average follow-up duration of 5.75 years is presented to demonstrate our patient selection criteria, flap design principles, dissection pearls, and surgical staging protocol.

  2. Arthrofibrosis after TKA - Influence factors on the absolute flexion and gain in flexion after manipulation under anaesthesia

    PubMed Central

    2011-01-01

    Background Stiffness with decreased range of motion (ROM) has been described as a frustrating complication after TKA. If all methods of physiotherapeutic treatment have been exhausted trying to develop ROM, manipulation under anaesthesia (MUA) can be discussed. The aim of the present study was to show the effect of MUA and to determine the influence of BMI, number of previous surgical procedures, pre-MUA ROM and timing of MUA for the results after MUA in regard to absolute flexion and gain in flexion. Methods 858 patients underwent TKA at our institution between 2004 and 2009. 39 of these patients underwent MUA because of postoperative knee stiffness. The data were retrospective analysed for the influence of BMI, pre-MUA flexion (/≤ 30 days after TKA) and number of previous surgery on the results after MUA (absolute Flexion/gain in flexion). Results The prevalence for stiffness after TKA was 4.54%. There was a statistically significant improvement in flexion not only directly after MUA but also 6 weeks after MUA. Patients with two or more previous operations before TKA showed statistically significant worse results six weeks after MUA in absolute flexion and gain in flexion (p = 0.039) than patients with one or two previous operations. No statistical significance in absolute flexion (p = 0.655) and gain in flexion (p = 0.328) after MUA between "early" and "late" was detected. The stiffer knees with a flexion below 70° showed significantly worse results (p = 0.044) in absolute flexion six weeks after MUA, but they also had statistical statistically better results with regard to gain in flexion (p ≤ 0.001). Conclusion MUA is a good instrument for improving ROM after TKA. The time between TKA and MUA seems less important, so different types of physiotherapeutic treatment could be tried before the procedure is started. MUA in patients with many previous operations and a flexion of less than 70° before MUA is not as effective as in

  3. Fiber optic plantar pressure/shear sensor

    NASA Astrophysics Data System (ADS)

    Soetanto, William; Nguyen, Ngoc T.; Wang, Wei-Chih

    2011-04-01

    A full-scale foot pressure/shear sensor that has been developed to help diagnose the cause of ulcer formation in diabetic patients is presented. The design involves a tactile sensor array using intersecting optical fibers embedded in soft elastomer. The basic configuration incorporates a mesh that is comprised of two sets of parallel optical fiber plane; the planes are configured so the parallel rows of fiber of the top and bottom planes are perpendicular to each other. Threedimensional information is determined by measuring the loss of light from each of the waveguide to map the overall pressure distribution and the shifting of the layers relative to each other. In this paper we will present the latest development on the fiber optic plantar pressure/shear sensor which can measure normal force up from 19.09 kPa to 1000 kPa.

  4. Quick torque coupling

    DOEpatents

    Luft, Peter A.

    2009-05-12

    A coupling for mechanically connecting modular tubular struts of a positioning apparatus or space frame, comprising a pair of toothed rings (10, 12) attached to separate strut members (16), the teeth (18, 20) of the primary rings (10, 12) mechanically interlocking in both an axial and circumferential manner, and a third part comprising a sliding, toothed collar (14) the teeth (22) of which interlock the teeth (18, 20) of the primary rings (10, 12), preventing them from disengaging, and completely locking the assembly together. A secondary mechanism provides a nesting force for the collar, and/or retains it. The coupling is self-contained and requires no external tools for installation, and can be assembled with gloved hands in demanding environments. No gauging or measured torque is required for assembly. The assembly can easily be visually inspected to determine a "go" or "no-go" status. The coupling is compact and relatively light-weight. Because of it's triply interlocking teeth, the connection is rigid. The connection does not primarily rely on clamps, springs or friction based fasteners, and is therefore reliable in fail-safe applications.

  5. Deformable micro torque swimmer

    NASA Astrophysics Data System (ADS)

    Ishikawa, Takuji; Tanaka, Tomoyuki; Omori, Toshihiro; Imai, Yohsuke

    2015-11-01

    We investigated the deformation of a ciliate swimming freely in a fluid otherwise at rest. The cell body was modeled as a capsule with a hyper elastic membrane enclosing Newtonian fluid. Thrust forces due to the ciliary beat were modeled as torques distributed above the cell body. Effects of the membrane elasticity, the aspect ratio of cell's reference shape and the density difference between the cell and the surrounding fluid were investigated. The results showed that the cell deformed like heart shape when Capillary number (Ca) was sufficiently large, and the swimming velocity decreased as Ca was increased. The gravity effect on the membrane tension suggested that the upwards and downwards swimming velocities of Paramecium might be reglated by the calcium ion channels distributed locally around the anterior end. Moreover, the gravity induced deformation made a cell directed vertically downwards, which resulted in a positive geotaxis like behavior with physical origin. These results are important to understand physiology of ciliate's biological responses to mechanical stimuli.

  6. Influence of different safety shoes on gait and plantar pressure: a standardized examination of workers in the automotive industry

    PubMed Central

    Ochsmann, Elke; Noll, Ulrike; Ellegast, Rolf; Hermanns, Ingo; Kraus, Thomas

    2016-01-01

    Objective: Working conditions, such as walking and standing on hard surfaces, can increase the development of musculoskeletal complaints. At the interface between flooring and musculoskeletal system, safety shoes may play an important role in the well-being of employees. The aim of this study was to evaluate the effects of different safety shoes on gait and plantar pressure distributions on industrial flooring. Methods: Twenty automotive workers were individually fitted out with three different pairs of safety shoes ( "normal" shoes, cushioned shoes, and midfoot bearing shoes). They walked at a given speed of 1.5 m/s. The CUELA measuring system and shoe insoles were used for gait analysis and plantar pressure measurements, respectively. Statistical analysis was conducted by ANOVA analysis for repeated measures. Results: Walking with cushioned safety shoes or a midfoot bearing safety shoe led to a significant decrease of the average trunk inclination (p<0.005). Furthermore, the average hip flexion angle decreased for cushioned shoes as well as midfoot bearing shoes (p<0.002). The range of motion of the knee joint increased for cushioned shoes. As expected, plantar pressure distributions varied significantly between cushioned or midfoot bearing shoes and shoes without ergonomic components. Conclusion: The overall function of safety shoes is the avoidance of injury in case of an industrial accident, but in addition, safety shoes could be a long-term preventive instrument for maintaining health of the employees' musculoskeletal system, as they are able to affect gait parameters. Further research needs to focus on safety shoes in working situations. PMID:27488038

  7. Zero torque gear head wrench

    NASA Technical Reports Server (NTRS)

    Mcdougal, A. R.; Norman, R. M. (Inventor)

    1976-01-01

    A gear head wrench particularly suited for use in applying torque to bolts without transferring torsional stress to bolt-receiving structures is introduced. The wrench is characterized by a coupling including a socket, for connecting a bolt head with a torque multiplying gear train, provided within a housing having an annulus concentrically related to the socket and adapted to be coupled with a spacer interposed between the bolt head and the juxtaposed surface of the bolt-receiving structure for applying a balancing counter-torque to the spacer as torque is applied to the bolt head whereby the bolt-receiving structure is substantially isolated from torsional stress. As a result of the foregoing, the operator of the wrench is substantially isolated from any forces which may be imposed.

  8. Plantar pressures in rheumatoid arthritis using prefabricated metatarsal padding.

    PubMed

    Jackson, Lorraine; Binning, Jodi; Potter, Julia

    2004-01-01

    We sought to determine whether one of two prefabricated insole designs could better manage high forefoot plantar pressures in patients with rheumatoid arthritis. Ten subjects with rheumatoid arthritis who experienced pain with shod weightbearing were studied by using a plantar pressure measurement system. Two insole designs and a shoe-only control condition were randomly tested in repeated trials. Dome- and bar-shaped metatarsal pads made of latex foam were incorporated into full-length insoles made of urethane. Significant reductions in mean peak plantar pressures over the central metatarsals were noted when using the insole and dome pad design (12% [33 kPa]) and the insole and bar pad design (21% [58 kPa]) compared with the shoe-only condition. A prefabricated insole design incorporating a bar metatarsal pad is recommended to manage high forefoot plantar pressures in patients with rheumatoid arthritis.

  9. A comparison of shoe insole materials in plantar pressure relief.

    PubMed

    Leber, C; Evanski, P M

    1986-12-01

    A clinical study was performed to evaluate the effectiveness of seven shoe insole materials and their ability to relieve areas of high plantar pressure. The following materials were tested: Latex foam, Plastazote, Dynafoam, Ortho felt, PPTR, Spenco, and Molo. Twenty-six patients with areas of high plantar pressure were tested using each of these materials. The Harris and Beath footprinting technique was used to measure plantar pressure. It was found that the average pressure of a clinically painful plantar area was 398.15kN/m2. All insole materials tested decreased this pressure, with averages ranging from 186.33kN/m2 to 286.35kN/m2. PPT, Plastazote and Spenco were the most effective products tested.

  10. [Magnetic resonance imaging in lesions of the plantar aponeurosis].

    PubMed

    Roger, B; Christel, P; Poux, D; Saillant, G; Cabanis, E A

    1987-12-01

    Exploration of sporting injures to plantar aponeurosis (PA) has up to now been based mainly on clinical examination, from which the diagnosis was established. Imaging technics such as standard radiography and ultrasound scanning have limitations allowing diagnosis to be made usually only by elimination, the lesion being very rarely visualized directly. Ten patients with hyperalgic lesion of plantar arch and functional impotence were explored by MR imaging, and in all cases this examination provided superior data confirmed at operation. The examination is painless and little invasive and can be carried out during the acute phase. The plantar aponeurosis is visualized directly between the muscle mass of the plantar arch and the fatty cushion. All three spatial planes can be investigated, most interesting data being obtained from the sagittal (in the PA axis) and frontal (comparative) planes.

  11. Plantar fasciitis: evidence-based review of diagnosis and therapy.

    PubMed

    Cole, Charles; Seto, Craig; Gazewood, John

    2005-12-01

    Plantar fasciitis causes heel pain in active as well as sedentary adults of all ages. The condition is more likely to occur in persons who are obese or in those who are on their feet most of the day. A diagnosis of plantar fasciitis is based on the patient's history and physical findings. The accuracy of radiologic studies in diagnosing plantar heel pain is unknown. Most interventions used to manage plantar fasciitis have not been studied adequately; however, shoe inserts, stretching exercises, steroid injection, and custom-made night splints may be beneficial. Extracorporeal shock wave therapy may effectively treat runners with chronic heel pain but is ineffective in other patients. Limited evidence suggests that casting or surgery may be beneficial when conservative measures fail.

  12. Acitretin for the treatment of recalcitrant plantar warts.

    PubMed

    Joshipura, Deep; Goldminz, Ari; Greb, Jacqueline; Gottlieb, Alice

    2017-03-15

    Plantar warts caused by human papilloma virus (HPV)may be challenging to treat when conventionalmodalities fail. We report a case of severely recalcitrantplantar warts, successfully treated with oral acitretinand topical 40% urea cream.

  13. Torque Simulator for Rotating Systems

    NASA Technical Reports Server (NTRS)

    Davis, W. T.

    1982-01-01

    New torque brake simulates varying levels of friction in bearings of rotating body. Rolling-tail torque brake uses magnetic force to produce friction between rotating part and stationary part. Simulator electronics produce positive or negative feedback signal, depending on direction of rotation. New system allows for first time in-depth study of effects of tail-fin spin rates on pitch-, yaw-, and roll-control characteristics.

  14. Torque-Summing Brushless Motor

    NASA Technical Reports Server (NTRS)

    Vaidya, J. G.

    1986-01-01

    Torque channels function cooperatively but electrically independent for reliability. Brushless, electronically-commutated dc motor sums electromagnetic torques on four channels and applies them to single shaft. Motor operates with any combination of channels and continues if one or more of channels fail electrically. Motor employs single stator and rotor and mechanically simple; however, each of channels electrically isolated from other so that failure of one does not adversely affect others.

  15. 14 CFR 27.361 - Engine torque.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Engine torque. 27.361 Section 27.361... STANDARDS: NORMAL CATEGORY ROTORCRAFT Strength Requirements Flight Loads § 27.361 Engine torque. (a) For turbine engines, the limit torque may not be less than the highest of— (1) The mean torque for...

  16. 14 CFR 27.361 - Engine torque.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Engine torque. 27.361 Section 27.361... STANDARDS: NORMAL CATEGORY ROTORCRAFT Strength Requirements Flight Loads § 27.361 Engine torque. (a) For turbine engines, the limit torque may not be less than the highest of— (1) The mean torque for...

  17. 14 CFR 27.361 - Engine torque.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Engine torque. 27.361 Section 27.361... STANDARDS: NORMAL CATEGORY ROTORCRAFT Strength Requirements Flight Loads § 27.361 Engine torque. (a) For turbine engines, the limit torque may not be less than the highest of— (1) The mean torque for...

  18. 14 CFR 27.361 - Engine torque.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Engine torque. 27.361 Section 27.361... STANDARDS: NORMAL CATEGORY ROTORCRAFT Strength Requirements Flight Loads § 27.361 Engine torque. (a) For turbine engines, the limit torque may not be less than the highest of— (1) The mean torque for...

  19. 14 CFR 27.361 - Engine torque.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Engine torque. 27.361 Section 27.361... STANDARDS: NORMAL CATEGORY ROTORCRAFT Strength Requirements Flight Loads § 27.361 Engine torque. (a) For turbine engines, the limit torque may not be less than the highest of— (1) The mean torque for...

  20. Heel lipoma mimicking plantar fasciitis in a ballroom dancer.

    PubMed

    Taweel, Nicholas R; Raikin, Steven M

    2015-01-01

    The present case illustrates a lipoma as an unusual cause of heel pain. A 64-year-old female ballroom dancer presented with 8 months of pain that was unresponsive to previous treatment of plantar fasciitis. Magnetic resonance imaging revealed a heel lipoma. Her pain was fully resolved after surgical excision. Soft tissue tumors should be included in the differential diagnosis of heel pain, especially when symptoms and treatment response do not follow the typical course of plantar fasciitis.

  1. Differential effects of plantar desensitization on locomotion dynamics.

    PubMed

    Manor, Brad; Wolenski, Peter; Guevaro, Alvaro; Li, Li

    2009-10-01

    Reduced plantar sensation secondary to chronic diffuse polyneuropathy (PN) is believed to reduce locomotor stability, especially when walking at non-preferred speeds. However, the contribution of plantar sensation to the maintenance of locomotor stability is not entirely clear. The purpose of this study was to examine the effects of acute loss of plantar sensation on the stability-related kinematic properties of walking at different speeds. Lower-extremity joint kinematics were acquired as healthy young adults walked on a treadmill at their preferred walking speed (PWS) and three predetermined speeds (0.8, 1.0, and 1.2m/s) under both normal and desensitized conditions. Desensitization of the foot soles was induced by ice-exposure, and plantar pressure sensation was assessed by a 5.07 monofilament. The average magnitude of stride duration variability (SDvar) and lower-extremity joint angle variability (JTvar), as well as short- and long-term "finite-time" Lyapunov exponents (lambda(ST)(*), lambda(LT)(*)) associated with lower-extremity joint angles were computed. Ice-induced plantar desensitization led to increased lambda(ST)(*) ( approximately 40%) and lambda(LT)(*) (approximately 8%) values but did not affect SDvar or JTvar. Higher treadmill speed led to greater lambda(ST)(*) and lambda(LT)(*) values, but the speed effects were not influenced by plantar desensitization.While acute loss of plantar sensation does not appear to influence the magnitude of spatial or temporal variability, it did attenuate the state-space trajectory divergence caused by stride-to-stride variability (i.e., lambda(ST)( *) and lambda(LT)(*)). However, as opposed to walking at PWS, otherwise healthy locomotor systems do not appear to place increased reliance on plantar sensation when walking at non-preferred treadmill speeds.

  2. Variation of plantar pressure in Chinese diabetes mellitus.

    PubMed

    Yang, Chuan; Xiao, Huisheng; Wang, Chuan; Mai, LiFang; Liu, Dan; Qi, Yiqing; Ren, Meng; Yan, Li

    2015-01-01

    To investigate dynamic changes in plantar pressure in Chinese diabetes mellitus patients and to provide a basis for further preventing diabetic foot. This is a cross-sectional investigation including 649 Chinese diabetes mellitus patients (diabetes group) and 808 "normal" Chinese persons (nondiabetes group) with normal blood glucose levels. All the subjects provided a complete medical history and underwent a physical examination and a 75-g oral glucose tolerance test. All subjects walked barefoot with their usual gait, and their dynamic plantar forces were measured using the one-step method with a plantar pressure measurement instrument; 5 measurements were performed for each foot. No significant differences were found in age, height, body weight, or body mass index between the two groups. The fasting blood glucose levels, plantar contact time, maximum force, pressure-time integrals and force-time integrals in the diabetes group were significantly higher than those in the nondiabetes group (p < 0.05). However, the maximum pressure was significantly higher in the nondiabetes group than in the diabetes group (p < 0.05). No difference was found in the contact areas between the two groups (p > 0.05). The maximum plantar force distributions were essentially the same, with the highest force found for the medial heel, followed by the medial forefoot and the first toe. The peak plantar pressure was located at the medial forefoot for the nondiabetes group and at the hallucis for the diabetes group. In the diabetes group, the momentum in each plantar region was higher than that in the nondiabetes group; this difference was especially apparent in the heel, the lateral forefoot and the hallucis. The dynamic plantar pressures in diabetic patients differ from those in nondiabetic people with increased maximum force and pressure, a different distribution pattern and significantly increased momentum, which may lead to the formation of foot ulcers.

  3. Variable magnetic circuit torque sensor

    NASA Astrophysics Data System (ADS)

    Lemarquand, G.; Lemarquand, V.

    1991-11-01

    This paper presents an original torque sensor structure using the properties of magnetic circuits, including permanent magnets. The torque is measured through the torsion of the transmitting shaft. The torsion is proportional to the torque. Considering two points of the shaft on the same line in absence of torque, the information is given by the twisting angle in the presence of a torque. A rotating magnetic circuit yields an angle representative signal. This circuit is deformed by the shaft torsion. The reluctance varies and so does the magnet operating point. The induction is measured in an airgap by a statoric galvanomagnetic device. The magnetic field source is an axial permanent magnet ring. Two iron-toothed rings, fixed to the driving and driven part of the shaft, respectively, and separated by an airgap make up the variable part of the magnetic circuit. The teeth get out of line whenever a torque is applied. The galvanomagnetic device measures an uniform induction and so delivers a modulation free signal, i.e., rotation independent. Because of the periodic toothed structure, the induction varies periodically with the twisting angle. The sense of the variation is the same over half a period or half a pitch. The variation form depends on the teeth design. Operating interval is to be chosen equal to or smaller than the half pitch.

  4. Eccentric Torque-Producing Capacity is Influenced by Muscle Length in Older Healthy Adults.

    PubMed

    Melo, Ruth C; Takahashi, Anielle C M; Quitério, Robison J; Salvini, Tânia F; Catai, Aparecida M

    2016-01-01

    Considering the importance of muscle strength to functional capacity in the elderly, the study investigated the effects of age on isokinetic performance and torque production as a function of muscle length. Eleven younger (24.2 ± 2.9 years) and 16 older men (62.7 ± 2.5 years) were subjected to concentric and eccentric isokinetic knee extension/flexion at 60 and 120° · s(-1) through a functional range of motion. The older group presented lower peak torque (in newton-meters) than the young group for both isokinetic contraction types (age effect, p < 0.001). Peak torque deficits in the older group were near 30 and 29% for concentric and eccentric contraction, respectively. Concentric peak torque was lower at 120° · s(-1) than at 60° · s(-1) for both groups (angular velocity effect, p < 0.001). Eccentric knee extension torque was the only exercise tested that showed an interaction effect between age and muscle length (p < 0.001), which suggested different torque responses to the muscle length between groups. Compared with the young group, the eccentric knee extension torque was 22-56% lower in the older group, with the deficits being lower in the shortened muscle length (22-27%) and higher (33-56%) in the stretched muscle length. In older men, the production of eccentric knee strength seems to be dependent on the muscle length. At more stretched positions, older subjects lose the capacity to generate eccentric knee extension torque. More studies are needed to assess the mechanisms involved in eccentric strength preservation with aging and its relationship with muscle length.

  5. Control of torque direction by spinal pathways at the cat ankle joint.

    PubMed

    Nichols, T R; Lawrence, J H; Bonasera, S J

    1993-01-01

    To study the biomechanics of the calcaneal tendon's complex insertion onto the calcaneus, we measured torque-time trajectories exerted by the triceps surae and tibialis anterior muscles in eight unanesthetized decerebrate cats using a multi-axis force-moment sensor placed at the ankle joint. The ankle was constrained to an angle of 110 degrees plantarflexion. Muscles were activated using crossed-extension (XER), flexion (FWR), and caudal cutaneous sural nerve (SNR) reflexes. Torque contributions of other muscles activated by these reflexes were eliminated by denervation or tenotomy. In two animals, miniature pressure transducers were implanted among tendon fibers from the lateral gastrocnemius (LG) muscle that insert straight into the calcaneus or among tendon fibers from the medial gastrocnemius (MG) that cross over and insert on the lateral aspect of calcaneus. Reflexively evoked torques had the following directions: FWR, dorsiflexion and adduction; SNR, plantarflexion and abduction; and XER, plantarflexion and modest abduction or adduction. The proportion of abduction torque to plantarflexion torque was always greater for SNR than XER; this difference was about 50% of the magnitude of abduction torque generated by tetanic stimulation of the peronei. During SNR, pressures were higher in regions of the calcaneal tendon originating from MG than regions originating from LG. Similarly, pressures within the MG portion of the calcaneal tendon were higher during SNR than during XER, although these two reflexes produced matched ankle plantarflexion forces. Selective tenotomies and electromyographic recordings further demonstrated that MG generated most of the torque in response to SNR, while soleus, LG, and MG all generated torques in response to XER.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. Plantar Pressure Detection with Fiber Bragg Gratings Sensing System.

    PubMed

    Liang, Tsair-Chun; Lin, Jhe-Jhun; Guo, Lan-Yuen

    2016-10-22

    In this paper, a novel fiber-optic sensing system based on fiber Bragg gratings (FBGs) to measure foot plantar pressure is proposed. This study first explores the Pedar-X insole foot pressure types of the adult-size chart and then defines six measurement areas to effectively identify four foot types: neutral foot, cavus foot, supinated foot and flat foot. The plantar pressure signals are detected by only six FBGs, which are embedded in silicone rubber. The performance of the fiber optic sensing is examined and compared with a digital pressure plate of i-Step P1000 with 1024 barometric sensors. In the experiment, there are 11 participants with different foot types to participate in the test. The Pearson correlation coefficient, which is determined from the measured results of the homemade fiber-optic plantar pressure system and i-Step P1000 plantar pressure plate, reaches up to 0.671 (p < 0.01). According to the measured results from the plantar pressure data, the proposed fiber optic sensing system can successfully identify the four different foot types. Measurements of this study have demonstrated the feasibility of the proposed system so that it can be an alternative for plantar pressure detection systems.

  7. Discrete sensors distribution for accurate plantar pressure analyses.

    PubMed

    Claverie, Laetitia; Ille, Anne; Moretto, Pierre

    2016-12-01

    The aim of this study was to determine the distribution of discrete sensors under the footprint for accurate plantar pressure analyses. For this purpose, two different sensor layouts have been tested and compared, to determine which was the most accurate to monitor plantar pressure with wireless devices in research and/or clinical practice. Ten healthy volunteers participated in the study (age range: 23-58 years). The barycenter of pressures (BoP) determined from the plantar pressure system (W-inshoe®) was compared to the center of pressures (CoP) determined from a force platform (AMTI) in the medial-lateral (ML) and anterior-posterior (AP) directions. Then, the vertical ground reaction force (vGRF) obtained from both W-inshoe® and force platform was compared for both layouts for each subject. The BoP and vGRF determined from the plantar pressure system data showed good correlation (SCC) with those determined from the force platform data, notably for the second sensor organization (ML SCC= 0.95; AP SCC=0.99; vGRF SCC=0.91). The study demonstrates that an adjusted placement of removable sensors is key to accurate plantar pressure analyses. These results are promising for a plantar pressure recording outside clinical or laboratory settings, for long time monitoring, real time feedback or for whatever activity requiring a low-cost system.

  8. [Experimental research of gaits based on young plantar pressure test].

    PubMed

    Meng, Qingyun; Tan, Shili; Yu, Hongliu; Shen, Lixing; Zhuang, Jianhai; Wang, Jinwu

    2014-10-01

    The present paper is to study the center line of the plantar pressure of normal young people, and to find the relation between center line of the plantar pressure and gait stability and balance. The paper gives the testing principle and calculating methods for geometric center of plantar pressure distribution and the center of pressure due to the techniques of footprint frame. The calculating formulas in both x direction and y direction are also deduced in the paper. In the experiments carried out in our laboratory, the gait parameters of 131 young subjects walking as usual speed were acquired, and 14 young subjects of the total were specially analyzed. We then provided reference data for the walking gait database of young people, including time parameters, space parameters and plantar pressure parameters. We also obtained the line of geometry center and pressure center under the foot. We found that the differences existed in normal people's geometric center line and the pressure center line. The center of pressure trajectory revealed foot movement stability. The length and lateral changes of the center line of the plantar pressure could be applied to analysis of the plantar pressure of all kinds of people. The results in this paper are useful in clinical foot disease diagnosis and evaluation of surgical effect.

  9. Plantar Pressure Detection with Fiber Bragg Gratings Sensing System

    PubMed Central

    Liang, Tsair-Chun; Lin, Jhe-Jhun; Guo, Lan-Yuen

    2016-01-01

    In this paper, a novel fiber-optic sensing system based on fiber Bragg gratings (FBGs) to measure foot plantar pressure is proposed. This study first explores the Pedar-X insole foot pressure types of the adult-size chart and then defines six measurement areas to effectively identify four foot types: neutral foot, cavus foot, supinated foot and flat foot. The plantar pressure signals are detected by only six FBGs, which are embedded in silicone rubber. The performance of the fiber optic sensing is examined and compared with a digital pressure plate of i-Step P1000 with 1024 barometric sensors. In the experiment, there are 11 participants with different foot types to participate in the test. The Pearson correlation coefficient, which is determined from the measured results of the homemade fiber-optic plantar pressure system and i-Step P1000 plantar pressure plate, reaches up to 0.671 (p < 0.01). According to the measured results from the plantar pressure data, the proposed fiber optic sensing system can successfully identify the four different foot types. Measurements of this study have demonstrated the feasibility of the proposed system so that it can be an alternative for plantar pressure detection systems. PMID:27782089

  10. Assessment of plantar pressure and balance in patients with diabetes

    PubMed Central

    Anjos, Daniela M.C.; Gomes, Luciana P.O.; Sampaio, Luciana M.M.; Correa, João C.F.

    2010-01-01

    Introduction Patients with diabetes for more than 10 years may have an increase in peak plantar pressure, considerable postural oscillation, balance deficit, alterations in gait pattern and an increased risk of falls. The aim of the present study was to assess the correlation between plantar pressure distribution and balance in patients with diabetes using a pressure platform (Footwork). Material and methods The study was carried out at the Human Movement Clinic of the Centro Universitário de Belo Horizonte (Brazil). The sample was made up of 18 right-handed individuals with type 2 diabetes – 14 females and 4 males – with an average age of 58.72 ±9.54 and an average of 18.56 ±6.61 years since diagnosis. Result Data analysis revealed that greater peak plantar pressure on the right hindfoot led to greater radial displacement (Rd) (r = 0.2022) and greater displacement velocity (r = 0.2240). Greater peak plantar pressure on the left hindfoot also led to greater displacement velocity (P) (r = 0.5728) and radial displacement (RD) (r = 0.1972). A positive correlation was found between time elapsed since diagnosis and peak midfoot pressure (r = 0.3752) on the right and left side as well as between BMI and plantar pressure on all regions of the foot. Conclusions The data reveal a correlation between postural oscillation and peak plantar pressure on the hindfoot. PMID:22371719

  11. Pressurized fluid torque driver control and method

    NASA Astrophysics Data System (ADS)

    Cook, Joseph S., Jr.

    1994-08-01

    Methods and apparatus are provided for a torque driver including a displaceable gear to limit torque transfer to a fastener at a precisely controlled torque limit. A biasing assembly biases a first gear into engagement with a second gear for torque transfer between the first and second gear. The biasing assembly includes a pressurized cylinder controlled at a constant pressure that corresponds to a torque limit. A calibrated gage and valve is used to set the desired torque limit. One or more coiled output linkages connect the first gear with the fastener adaptor which may be a socket for a nut. A gear tooth profile provides a separation force that overcomes the bias to limit torque at the desired torque limit. Multiple fasteners may be rotated simultaneously to a desired torque limit if additional output spur gears are provided. The torque limit is adjustable and may be different for fasteners within the same fastener configuration.

  12. Pressurized fluid torque driver control and method

    NASA Technical Reports Server (NTRS)

    Cook, Joseph S., Jr. (Inventor)

    1994-01-01

    Methods and apparatus are provided for a torque driver including a displaceable gear to limit torque transfer to a fastener at a precisely controlled torque limit. A biasing assembly biases a first gear into engagement with a second gear for torque transfer between the first and second gear. The biasing assembly includes a pressurized cylinder controlled at a constant pressure that corresponds to a torque limit. A calibrated gage and valve is used to set the desired torque limit. One or more coiled output linkages connect the first gear with the fastener adaptor which may be a socket for a nut. A gear tooth profile provides a separation force that overcomes the bias to limit torque at the desired torque limit. Multiple fasteners may be rotated simultaneously to a desired torque limit if additional output spur gears are provided. The torque limit is adjustable and may be different for fasteners within the same fastener configuration.

  13. The effects of the application of low-dye taping on paretic side plantar pressure among patients with plantar fasciitis.

    PubMed

    Park, Chan; Lee, Sangyong; Kim, Shingyun; Hwangbo, Gak

    2015-11-01

    [Purpose] This study aimed to examine the effects of low-dye taping on paretic side plantar pressure in patients with plantar fasciitis. [Subjects] The 30 patients in this study were randomly allocated to a low-dye taping group (n = 15) or a conservative treatment group (n =15). [Methods] Both groups received treatment thrice a week for six weeks. BioRescue was used to measure the weight distribution of the patients' paretic side. [Results] Within-group comparison showed that the posterior weight distribution significantly increased among patients in both groups. However, comparison between the two groups showed that the low-dye taping group's posterior weight distribution was significantly higher than that of the conservative treatment group. [Conclusion] These findings show that the application of low-dye taping is an effective intervention for paretic-side plantar pressure among patients with plantar fasciitis.

  14. The effects of the application of low-dye taping on paretic side plantar pressure among patients with plantar fasciitis

    PubMed Central

    Park, Chan; Lee, Sangyong; Kim, Shingyun; Hwangbo, Gak

    2015-01-01

    [Purpose] This study aimed to examine the effects of low-dye taping on paretic side plantar pressure in patients with plantar fasciitis. [Subjects] The 30 patients in this study were randomly allocated to a low-dye taping group (n = 15) or a conservative treatment group (n =15). [Methods] Both groups received treatment thrice a week for six weeks. BioRescue was used to measure the weight distribution of the patients’ paretic side. [Results] Within-group comparison showed that the posterior weight distribution significantly increased among patients in both groups. However, comparison between the two groups showed that the low-dye taping group’s posterior weight distribution was significantly higher than that of the conservative treatment group. [Conclusion] These findings show that the application of low-dye taping is an effective intervention for paretic-side plantar pressure among patients with plantar fasciitis. PMID:26696737

  15. Joint torques in a freely walking insect reveal distinct functions of leg joints in propulsion and posture control.

    PubMed

    Dallmann, Chris J; Dürr, Volker; Schmitz, Josef

    2016-01-27

    Determining the mechanical output of limb joints is critical for understanding the control of complex motor behaviours such as walking. In the case of insect walking, the neural infrastructure for single-joint control is well described. However, a detailed description of the motor output in form of time-varying joint torques is lacking. Here, we determine joint torques in the stick insect to identify leg joint function in the control of body height and propulsion. Torques were determined by measuring whole-body kinematics and ground reaction forces in freely walking animals. We demonstrate that despite strong differences in morphology and posture, stick insects show a functional division of joints similar to other insect model systems. Propulsion was generated by strong depression torques about the coxa-trochanter joint, not by retraction or flexion/extension torques. Torques about the respective thorax-coxa and femur-tibia joints were often directed opposite to fore-aft forces and joint movements. This suggests a posture-dependent mechanism that counteracts collapse of the leg under body load and directs the resultant force vector such that strong depression torques can control both body height and propulsion. Our findings parallel propulsive mechanisms described in other walking, jumping and flying insects, and challenge current control models of insect walking.

  16. Joint torques in a freely walking insect reveal distinct functions of leg joints in propulsion and posture control

    PubMed Central

    2016-01-01

    Determining the mechanical output of limb joints is critical for understanding the control of complex motor behaviours such as walking. In the case of insect walking, the neural infrastructure for single-joint control is well described. However, a detailed description of the motor output in form of time-varying joint torques is lacking. Here, we determine joint torques in the stick insect to identify leg joint function in the control of body height and propulsion. Torques were determined by measuring whole-body kinematics and ground reaction forces in freely walking animals. We demonstrate that despite strong differences in morphology and posture, stick insects show a functional division of joints similar to other insect model systems. Propulsion was generated by strong depression torques about the coxa–trochanter joint, not by retraction or flexion/extension torques. Torques about the respective thorax–coxa and femur–tibia joints were often directed opposite to fore–aft forces and joint movements. This suggests a posture-dependent mechanism that counteracts collapse of the leg under body load and directs the resultant force vector such that strong depression torques can control both body height and propulsion. Our findings parallel propulsive mechanisms described in other walking, jumping and flying insects, and challenge current control models of insect walking. PMID:26791608

  17. Does dragonfly's abdomen flexion help with fast turning maneuvers?

    NASA Astrophysics Data System (ADS)

    Liu, Geng; Li, Chengyu; Dong, Haibo; Flow Simulation Research Group Team

    2013-11-01

    Dragonflies are able to achieve fast turning maneuvers during take-off flights. Both asymmetric wing flapping and abdomen flexion have been observed during the fast turning. It's widely thought that the asymmetric wing beats are responsible of producing the aerodynamic moment needed for the body rotation. However, the dynamic effect of the abdomen flexion is not clear yet. In this study, an integrated experimental and computational approach is used to study the underlying dynamic effect of dragonfly abdomen flexion. It's found that dragonfly abdomen tended to bend towards the same side as the body reorienting to. Quantitative analysis have shown that during take-off turning maneuver the abdomen flexion can modulate the arm of force by changing the position of the center of mass relative to the thorax. As a result, roll and yaw moments produced by the wing flapping can be enhanced. This work is supported by NSF CBET-1313217. This work is supported by NSF CBET-1313217.

  18. Endoscopic Decompression of the First Branch of the Lateral Plantar Nerve and Release of the Plantar Aponeurosis for Chronic Heel Pain.

    PubMed

    Lui, Tun Hing

    2016-06-01

    Entrapment of the first branch of the lateral plantar nerve is a commonly missed cause of recalcitrant plantar heel pain. The diagnosis is made on a clinical ground with maximal tenderness at the site of nerve entrapment. Treatment of the nerve entrapment is similar to that for plantar fasciitis, with rest, activity modification, nonsteroidal anti-inflammatory drugs, stretching exercise, and local steroid injection. Surgical release of the deep abductor hallucis fascia is indicated when conservative treatment failed. Endoscopic release of the nerve through the dorsal and plantar portals, as well as endoscopic plantar aponeurosis release, is a feasible approach.

  19. In-shoe plantar tri-axial stress profiles during maximum-effort cutting maneuvers.

    PubMed

    Cong, Yan; Lam, Wing Kai; Cheung, Jason Tak-Man; Zhang, Ming

    2014-12-18

    Soft tissue injuries, such as anterior cruciate ligament rupture, ankle sprain and foot skin problems, frequently occur during cutting maneuvers. These injuries are often regarded as associated with abnormal joint torque and interfacial friction caused by excessive external and in-shoe shear forces. This study simultaneously investigated the dynamic in-shoe localized plantar pressure and shear stress during lateral shuffling and 45° sidestep cutting maneuvers. Tri-axial force transducers were affixed at the first and second metatarsal heads, lateral forefoot, and heel regions in the midsole of a basketball shoe. Seventeen basketball players executed both cutting maneuvers with maximum efforts. Lateral shuffling cutting had a larger mediolateral braking force than 45° sidestep cutting. This large braking force was concentrated at the first metatarsal head, as indicated by its maximum medial shear stress (312.2 ± 157.0 kPa). During propulsion phase, peak shear stress occurred at the second metatarsal head (271.3 ± 124.3 kPa). Compared with lateral shuffling cutting, 45° sidestep cutting produced larger peak propulsion shear stress (463.0 ± 272.6 kPa) but smaller peak braking shear stress (184.8 ± 181.7 kPa), of which both were found at the first metatarsal head. During both cutting maneuvers, maximum medial and posterior shear stress occurred at the first metatarsal head, whereas maximum pressure occurred at the second metatarsal head. The first and second metatarsal heads sustained relatively high pressure and shear stress and were expected to be susceptible to plantar tissue discomfort or injury. Due to different stress distribution, distinct pressure and shear cushioning mechanisms in basketball footwear might be considered over different foot regions.

  20. High resolution weak lensing mass mapping combining shear and flexion

    NASA Astrophysics Data System (ADS)

    Lanusse, F.; Starck, J.-L.; Leonard, A.; Pires, S.

    2016-06-01

    Aims: We propose a new mass mapping algorithm, specifically designed to recover small-scale information from a combination of gravitational shear and flexion. Including flexion allows us to supplement the shear on small scales in order to increase the sensitivity to substructures and the overall resolution of the convergence map without relying on strong lensing constraints. Methods: To preserve all available small scale information, we avoid any binning of the irregularly sampled input shear and flexion fields and treat the mass mapping problem as a general ill-posed inverse problem, which is regularised using a robust multi-scale wavelet sparsity prior. The resulting algorithm incorporates redshift, reduced shear, and reduced flexion measurements for individual galaxies and is made highly efficient by the use of fast Fourier estimators. Results: We tested our reconstruction method on a set of realistic weak lensing simulations corresponding to typical HST/ACS cluster observations and demonstrate our ability to recover substructures with the inclusion of flexion, which are otherwise lost if only shear information is used. In particular, we can detect substructures on the 15'' scale well outside of the critical region of the clusters. In addition, flexion also helps to constrain the shape of the central regions of the main dark matter halos. Our mass mapping software, called Glimpse2D, is made freely available at http://www.cosmostat.org/software/glimpse

  1. Free sensate medial plantar flap for contralateral plantar forefoot reconstruction with flap reinnervation using end-to-side neurorrhaphy: a case report and literature review.

    PubMed

    Lykoudis, Efstathios G; Seretis, Konstantinos; Lykissas, Marios G

    2013-03-01

    Reconstruction of weight-bearing plantar defects remains a challenge due to the unique characteristics of the plantar skin and thus the limited available options. The medial plantar flap, either pedicled or free, represents an ideal option, but its use as sensate flap for forefoot defects has been scarcely reported. We present a case of plantar forefoot reconstruction with a free sensate medial plantar flap, with end-to-side coaptation of the cutaneous sensory fascicles of the flap to the medial plantar nerve of the recipient. Last follow-up, at 2 years post-op, verified a very good functional and aesthetic outcome, indicating that the suggested approach may prove the treatment of choice in selected cases of plantar forefoot reconstruction.

  2. Split torque transmission load sharing

    NASA Technical Reports Server (NTRS)

    Krantz, T. L.; Rashidi, M.; Kish, J. G.

    1992-01-01

    Split torque transmissions are attractive alternatives to conventional planetary designs for helicopter transmissions. The split torque designs can offer lighter weight and fewer parts but have not been used extensively for lack of experience, especially with obtaining proper load sharing. Two split torque designs that use different load sharing methods have been studied. Precise indexing and alignment of the geartrain to produce acceptable load sharing has been demonstrated. An elastomeric torque splitter that has large torsional compliance and damping produces even better load sharing while reducing dynamic transmission error and noise. However, the elastomeric torque splitter as now configured is not capable over the full range of operating conditions of a fielded system. A thrust balancing load sharing device was evaluated. Friction forces that oppose the motion of the balance mechanism are significant. A static analysis suggests increasing the helix angle of the input pinion of the thrust balancing design. Also, dynamic analysis of this design predicts good load sharing and significant torsional response to accumulative pitch errors of the gears.

  3. The Artificial Gravity Bed Rest Pilot Project: Effects on Knee Extensor and Plantar Flexor Muscle Groups

    NASA Technical Reports Server (NTRS)

    Caiozzo, V. J.; Haddad, F.; Lee, S.; Baker, M.; Baldwin, K. M.

    2007-01-01

    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

  4. High torque miniature rotary actuator

    NASA Astrophysics Data System (ADS)

    Nalbandian, Ruben

    2005-07-01

    This paper summarizes the design and the development of a miniature rotary actuator (36 mm diameter by 100 mm length) used in spacecraft mechanisms requiring high torques and/or ultra-fine step resolution. This actuator lends itself to applications requiring high torque but with strict volume limitations which challenge the use of conventional rotary actuators. The design challenge was to develop a lightweight (less than 500 grams), very compact, high bandwidth, low power, thermally stable rotary actuator capable of producing torques in excess of 50 N.m and step resolutions as fine as 0.003 degrees. To achieve a relatively high torsional stiffness in excess of 1000 Nm/radian, the design utilizes a combination of harmonic drive and multistage planetary gearing. The unique design feature of this actuator that contributes to its light weight and extremely precise motion capability is a redundant stepper motor driving the output through a multistage reducing gearbox. The rotary actuator is powered by a high reliability space-rated stepper motor designed and constructed by Moog, Inc. The motor is a three-phase stepper motor of 15 degree step angle, producing twenty-four full steps per revolution. Since micro-stepping is not used in the design, and un-powered holding torque is exhibited at every commanded step, the rotary actuator is capable of reacting to torques as high as 35 Nm by holding position with the power off. The output is driven through a gear transmission having a total train ratio of 5120:1, resulting in a resolution of 0.003 degrees output rotation per motor step. The modular design of the multi-stage output transmission makes possible the addition of designs having different output parameters, such as lower torque and higher output speed capability. Some examples of an actuator family based on this growth capability will be presented in the paper.

  5. The torque-velocity relationship in large human muscles: maximum voluntary versus electrically stimulated behaviour.

    PubMed

    Pain, Matthew T G; Young, Fraser; Kim, Jinwoo; Forrester, Stephanie E

    2013-02-22

    The in vivo maximum voluntary torque-velocity profile for large muscle groups differs from the in vitro tetanic profile with lower than expected eccentric torques. Using sub-maximal transcutaneous electrical stimulation has given torque-velocity profiles with an eccentric torque plateau ∼1.4 times the isometric value. This is closer to, but still less than, the in vitro tetanic profiles with plateaus between 1.5 and 1.9 times isometric. This study investigated the maximum voluntary and sub-maximum transcutaneous electrical stimulated torque-angle-angular velocity profiles for the knee extensors and flexors in a group of healthy males. Fifteen male subjects performed maximum voluntary and sub-maximum electrically stimulated (∼40% for extensors and ∼20% for flexors) eccentric and concentric knee extension and flexions on an isovelocity dynamometer at velocities ranging from ±50°s(-1) to ±400°s(-1). The ratio of peak eccentric to peak isometric torque (T(ecc)/T(0)) was compared between the maximum voluntary and electrically stimulated conditions for both extensors and flexors, and between muscle groups. Under maximum voluntary conditions the peak torque ratio, T(ecc)/T(0), remained close to 1 (0.9-1.2) while for the electrically stimulated conditions it was significantly higher (1.4-1.7; p<0.001) and within the range of tetanic values reported from in vitro studies. In all but one case there was no significant difference in ratios between the extensors and flexors. The results showed that even the largest muscle groups have an intrinsic T(ecc)/T(0) comparable with in vitro muscle tests, and it can be ascertained from appropriate in vivo testing.

  6. A review of plantar heel pain of neural origin: differential diagnosis and management.

    PubMed

    Alshami, Ali M; Souvlis, Tina; Coppieters, Michel W

    2008-05-01

    Plantar heel pain is a symptom commonly encountered by clinicians. Several conditions such as plantar fasciitis, calcaneal fracture, rupture of the plantar fascia and atrophy of the heel fat pad may lead to plantar heel pain. Injury to the tibial nerve and its branches in the tarsal tunnel and in the foot is also a common cause. Entrapment of these nerves may play a role in both the early phases of plantar heel pain and recalcitrant cases. Although the contribution of nerve entrapment to plantar heel pain has been well documented in the literature, its pathophysiology, diagnosis and management are still controversial. Therefore, the purpose of this article was to critically review the available literature on plantar heel pain of neural origin. Possible sites of nerve entrapment, effectiveness of diagnostic clinical tests and electrodiagnostic tests, differential diagnoses for plantar heel pain, and conservative and surgical treatment will be discussed.

  7. Differences in calcium accumulation between human plantar and palmar aponeuroses.

    PubMed

    Azuma, Cho; Tohno, Yoshiyuki; Morimoto, Mamoru; Tohno, Setsuko; Minami, Takeshi; Takano, Yasuo; Utsumi, Masako; Moriwake, Yumi; Nishiwaki, Fumio; Yamada, Masa-oki

    2002-01-01

    To elucidate the characteristics of calcium accumulation of human plantar and palmar aponeuroses, the authors determined the calcium content of human plantar and palmar aponeuroses by atomic absorption flame emission spectrophotometry. The subjects consisted of 9 men and 14 women, ranging in age from 61 to 93 yr. In the plantar aponeurosis, the calcium content was significantly higher in the anterior and posterior parts than in the middle part. It is known that pressure distribution under the sole of a foot is higher in the anterior and posterior parts than in the middle part. The present study suggests that the accumulation of calcium in the plantar aponeurosis is related with the pressure distribution under the sole of a foot. The calcium content increased progressively with aging in the anterior part of the plantar aponeurosis, but not in the middle and posterior parts. Regarding the palmar aponeurosis, the calcium content was significantly higher in the anterior and posterior parts in comparison with the middle part. It was found that the calcium content increased progressively with aging in the posterior part of the palmar aponeurosis, whereas it did not increase significantly with aging in the anterior and middle parts. Regarding the relationship between the calcium content of the aponeuroses and the bone mineral density, a significant correlation was found between the calcium content in the anterior part of the palmar aponeurosis and the bone mineral density of the scaphoid bone.

  8. Role of the plantar fascia in digital stabilization. A case report.

    PubMed

    Pontious, J; Flanigan, K P; Hillstrom, H J

    1996-01-01

    The plantar aponeurosis is a ligamentous structure that extends from the calcaneus to the proximal phalanges. Under tension, it functions to support the longitudinal arch, supinate the rearfoot, and stabilize the digits against the ground. The anatomy and biomechanics of the plantar fascia and plantar aponeurosis, particularly their role in digital stabilization, are reviewed. A case is presented showing a patient who developed hammer toes as a postoperative complication after having a portion of the plantar aponeurosis removed.

  9. Influence of musculo-tendinous stiffness of the plantar ankle flexor muscles upon maximal power output on a cycle ergometre.

    PubMed

    Driss, Tarak; Lambertz, Daniel; Rouis, Majdi; Vandewalle, Henry

    2012-11-01

    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.

  10. Endoscopic Plantar Fasciotomy Improves Early Postoperative Results: A Retrospective Comparison of Outcomes After Endoscopic Versus Open Plantar Fasciotomy.

    PubMed

    Chou, Andrew Chia Chen; Ng, Sean Yung Chuan; Koo, Kevin Oon Thien

    2016-01-01

    Plantar fasciotomy is offered to patients with recalcitrant plantar fasciitis. Few studies have characterized the functional outcomes over time for the endoscopic approach compared with the open approach. We hypothesized that patients undergoing endoscopic surgery will have better postoperative functional outcomes early in the postoperative period but equivalent long-term outcomes compared with patients undergoing open surgery. We analyzed the prospectively collected data of all patients undergoing plantar fasciotomy at our institution from December 2007 to August 2014. A total of 42 feet of 38 patients were included in the analysis. The clinical data were collected preoperatively and at 3 and 6 months and 1 year. The functional outcomes analyzed included the American Orthopaedic Foot and Ankle Society Ankle-Hindfoot scale, the Medical Outcomes Study, Short-Form, 36-item Health Survey, and patient satisfaction and expectations. Patients undergoing endoscopic surgery had significantly greater American Orthopaedic Foot and Ankle Society Ankle-Hindfoot and SF-36 Health Survey scores and lower pain scores at the 3-month period. They were also significantly more likely to be satisfied with and have had their expectations met by surgery. Compared with the open approach, the patients who had undergone endoscopic plantar fasciotomy experienced significantly greater improvements in the subjective and objective functional outcomes, with less pain and greater satisfaction, and had had their expectations met earlier in the recovery period, with equivalent long-term outcomes, compared with the patients who had undergone open plantar fasciotomy.

  11. Distally Based Abductor Hallucis Adipomuscular Flap for Forefoot Plantar Reconstruction.

    PubMed

    Lee, Sanglim; Kim, Min Bom; Lee, Young Ho; Baek, Jeong Kook; Baek, Goo Hyun

    2015-09-01

    Soft tissue and bone defects of the lower leg, ankle, and heel region often require coverage by local or distant flaps. The authors successfully used the distally based adipomuscular abductor hallucis flap for the treatment of 7 patients with soft tissue defect on the plantar forefoot after diabetic ulcer (n = 2), excision of melanoma at the medial forefoot (n = 3), and posttraumatic defects of the plantar forefoot (n = 2). The size of the defects ranged from 6 to 36 cm. All defects were covered successfully without major complications. The distally based adipomuscular flap from the abductor hallucis muscle provides a reliable coverage for small and moderate defects of the plantar and medial forefoot. This flap is often preferable to the use of free flaps because the surgery is rapidly performed and does not require microsurgical expertise.

  12. Complications of plantar fascia rupture associated with corticosteroid injection.

    PubMed

    Acevedo, J I; Beskin, J L

    1998-02-01

    From 1992 to 1995, 765 patients with a clinical diagnosis of plantar fasciitis were evaluated by one of the authors. Fifty-one patients were diagnosed with plantar fascia rupture, and 44 of these ruptures were associated with corticosteroid injection. The authors injected 122 of the 765 patients, resulting in 12 of the 44 plantar fascia ruptures. Subjective and objective evaluations were conducted through chart and radiographic review. Thirty-nine of these patients were evaluated at an average 27-month follow-up. Thirty patients (68%) reported a sudden onset of tearing at the heel, and 14 (32%) had a gradual onset of symptoms. In most cases the original heel pain was relieved by rupture. However, these patients subsequently developed new problems including longitudinal arch strain, lateral and dorsal midfoot strain, lateral plantar nerve dysfunction, stress fracture, hammertoe deformity, swelling, and/or antalgia. All patients exhibited diminished tension of the plantar fascia upon examination by the stretch test. Comparison of calcaneal pitch angles in the affected and uninvolved foot showed a statistically significant difference of 3.7 degrees (P = 0.0001). Treatment included NSAIDs, rest or cross-training, stretching, orthotics, and boot-brace immobilization. At an average 27-month follow-up, 50% had good/excellent scores and 50% had fair/poor scores. Recovery time was varied. Ten feet were asymptomatic by 6 months post rupture, four feet by 12 months post rupture, and 26 feet remained symptomatic 1 year post rupture. Our findings demonstrate that plantar fascia rupture after corticosteroid injection may result in long-term sequelae that are difficult to resolve.

  13. In vivo evidence of an age-related increase in ATP cost of contraction in the plantar flexor muscles.

    PubMed

    Layec, Gwenael; Trinity, Joel D; Hart, Corey R; Kim, Seong-Eun; Groot, Henderik Jonathan; Le Fur, Yann; Sorensen, Jacob R; Jeong, Eun-Kee; Richardson, Russell S

    2014-04-01

    Impaired skeletal muscle efficiency potentially contributes to the age-related decline in exercise capacity and may explain the altered haemodynamic response to exercise in the elderly. Thus we examined whether (i) the ATP cost of contraction increases with age, and (ii) this results in altered convective O(2) delivery to maintain microvascular oxygenation in the calf muscle. To this aim, we used an integrative experimental approach combining (31)P-MRS (magnetic resonance spectroscopy), Doppler ultrasound imaging and NIRS (near-IR spectroscopy) during dynamic plantar flexion exercise at 40% of WR(max) (maximal power output) in 20 healthy young and 20 older subjects matched for physical activity. The ATP cost of contraction was significantly higher in the old (7.2±4.1 mM/min per W) compared with the young (2.4±1.9 mM/min per W; P<0.05) and this was only significantly correlated with the plantar flexion WR(max) value in the old subjects (r=-0.52; P<0.05). Even when differences in power output were taken into account, end-exercise blood flow (old, 259±168 ml/min per W and young, 134±40 ml/min per W; P<0.05) and convective O(2) delivery (old, 0.048±0.031 l/min per W and young, 0.026±0.008 l/min per W; P<0.05) were greater in the old in comparison with the young subjects. In contrast, the NIRS oxyhaemoglobin, deoxyhaemoglobin and microvascular oxygenation indices were not significantly different between the groups (P>0.05). Therefore the present study reveals that, although the peripheral haemodynamic responses to plantar flexion exercise appear to be appropriate, the elevated energy cost of contraction and associated reduction in the WR(max) value in this muscle group may play a role in limiting exercise capacity with age.

  14. Management of Plantar Hyperhidrosis with Endoscopic Lumbar Sympathectomy.

    PubMed

    Rieger, Roman

    2016-11-01

    Primary plantar hyperhidrosis is defined as excessive secretion of the sweat glands of the feet and may lead to significant limitations in private and professional lifestyle and reduction of health-related quality of life. Conservative therapy measures usually fail to provide sufficient relieve of symptoms and do not allow long-lasting elimination of hyperhidrosis. Endoscopic lumbar sympathectomy appears to be a safe and effective procedure for eliminating excessive sweating of the feet and improves quality of life of patients with severe plantar hyperhidrosis.

  15. The use of skeletal extension torque in reversing Dupuytren contractures of the proximal interphalangeal joint.

    PubMed

    Agee, John M; Goss, Ben C

    2012-07-01

    Dupuytren contracture of the proximal interphalangeal (PIP) joint can be reversed by an extension torque transmitted from an external device, the Digit Widget, by skeletal pins to the middle phalanx. This extension torque, generated by the same elastic bands dentists use to align teeth, gradually restores length to soft tissues palmar to the PIP joint's axis of rotation. Simultaneously, tissues dorsal to the joint's axis will shorten toward normal length as the PIP progressively straightens. Although the contractile nodules and bands of Dupuytren disease may be excised either before or after reversal of the joint's contracture, a 2-staged approach is preferred: (1) reverse the PIP flexion contracture, and (2) excise the diseased tissue from the straightened finger. We believe this 2-staged approach yields better results. In addition, it is technically easier to avoid injury to nerves and arteries while excising the nodules and bands, when one operates through palmar skin of more nearly normal length.

  16. 14 CFR 29.361 - Engine torque.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Engine torque. 29.361 Section 29.361... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Strength Requirements Flight Loads § 29.361 Engine torque. The limit engine torque may not be less than the following: (a) For turbine engines, the highest of— (1)...

  17. 14 CFR 29.361 - Engine torque.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Engine torque. 29.361 Section 29.361... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Strength Requirements Flight Loads § 29.361 Engine torque. The limit engine torque may not be less than the following: (a) For turbine engines, the highest of— (1)...

  18. 14 CFR 29.361 - Engine torque.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Engine torque. 29.361 Section 29.361... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Strength Requirements Flight Loads § 29.361 Engine torque. The limit engine torque may not be less than the following: (a) For turbine engines, the highest of— (1)...

  19. 14 CFR 29.361 - Engine torque.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Engine torque. 29.361 Section 29.361... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Strength Requirements Flight Loads § 29.361 Engine torque. The limit engine torque may not be less than the following: (a) For turbine engines, the highest of— (1)...

  20. 14 CFR 29.361 - Engine torque.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Engine torque. 29.361 Section 29.361... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Strength Requirements Flight Loads § 29.361 Engine torque. The limit engine torque may not be less than the following: (a) For turbine engines, the highest of— (1)...

  1. Computerized Torque Control for Large dc Motors

    NASA Technical Reports Server (NTRS)

    Willett, Richard M.; Carroll, Michael J.; Geiger, Ronald V.

    1987-01-01

    Speed and torque ranges in generator mode extended. System of shunt resistors, electronic switches, and pulse-width modulation controls torque exerted by large, three-phase, electronically commutated dc motor. Particularly useful for motor operating in generator mode because it extends operating range to low torque and high speed.

  2. Paraplegic flexion contracture of hip joints: An unsolvable problem

    PubMed Central

    Bhattacharyya, Sailendra

    2016-01-01

    Paraplegic flexion contracture of hip joints beyond 90° is a difficult condition to treat for any orthopedic surgeon. There is no fixed protocol of treatment described, by and large it is individualized. A 20 year old female presented with paraplegia for last 15 years due to irrecoverable spinal cord disease with complete sensory and motor loss of both lower extremities and was admitted with acute flexion contracture of both hip joints with trunk resting on thighs. She underwent bilateral proximal femoral resection. Both hip joints were straight immediately after surgery and patient could lie on her back. In a course of time, she started sitting on her buttocks, led a comfortable wheelchair life with a sitting balance. Proximal femoral resection is an effective method to treat long standing irrecoverable paraplegic acute flexion deformity of the hip joint. PMID:27904226

  3. Paraplegic flexion contracture of hip joints: An unsolvable problem.

    PubMed

    Bhattacharyya, Sailendra

    2016-01-01

    Paraplegic flexion contracture of hip joints beyond 90° is a difficult condition to treat for any orthopedic surgeon. There is no fixed protocol of treatment described, by and large it is individualized. A 20 year old female presented with paraplegia for last 15 years due to irrecoverable spinal cord disease with complete sensory and motor loss of both lower extremities and was admitted with acute flexion contracture of both hip joints with trunk resting on thighs. She underwent bilateral proximal femoral resection. Both hip joints were straight immediately after surgery and patient could lie on her back. In a course of time, she started sitting on her buttocks, led a comfortable wheelchair life with a sitting balance. Proximal femoral resection is an effective method to treat long standing irrecoverable paraplegic acute flexion deformity of the hip joint.

  4. Reduced plantarflexor specific torque in the elderly is associated with a lower activation capacity.

    PubMed

    Morse, Christopher I; Thom, Jeanette M; Davis, Mark G; Fox, Ken R; Birch, Karen M; Narici, Marco V

    2004-06-01

    Previous studies have reported a decrease in muscle torque per cross-sectional area in old age. This investigation aimed at determining the influence of agonists muscle activation and antagonists co-activation on the specific torque of the plantarflexors (PF) in recreationally active elderly males (EM) and, for comparison, in young men (YM). Twenty-one EM, aged 70-82 years, and 14 YM, aged 19-35 years, performed isometric maximum voluntary contractions (MVC). Activation was assessed by comparing the amplitude of interpolated supramaximal twitch doublets at MVC, with post-tetanic doublet peak torque. Co-activation of the tibialis anterior (TA) was evaluated as the ratio of TA-integrated EMG (IEMG) activity during PF MVC compared to TA IEMG during maximal voluntary dorsiflexion. Triceps surae muscle volume (VOL) was assessed using magnetic resonance imaging (MRI), and PF peak torque was normalised to VOL (PT/VOL) since the later approximates physiological cross-sectional area (CSA) more closely than anatomical CSA. Also, physical activity level, assessed by accelerometry, was significantly lower (21%) in the elderly males. In comparison to the YM group, a greater difference in PT (39%) than VOL (19%) was found in the EM group. PT/VOL and activation capacity were respectively lower by 25% and 21% in EM compared to YM, whereas co-activation was not significantly different. In EM PT/VOL correlated with activation (R(2)=0.31, P<0.01). In conclusion, a reduction in activation capacity may contribute significantly to the decline in specific torque in the plantar flexors of elderly males. The hypothesis is put forward that reduced physical activity is partialy responsible for the reduced activation capacity in the elderly.

  5. Intraoperative Manipulation for Flexion Contracture During Total Knee Arthroplasty.

    PubMed

    Matsui, Yoshio; Minoda, Yukihide; Fumiaki, Inori; Nakagawa, Sigeru; Okajima, Yoshiaki; Kobayashi, Akio

    2016-11-01

    Joint gap balancing during total knee arthroplasty (TKA) is important for ensuring postoperative joint stability and range of motion. Although the joint gap should be balanced to ensure joint stability, it is not easy to achieve perfect balancing during TKA. In particular, relative extension gap shortening can induce flexion contracture. Intraoperative manipulation is often empirically performed. This study evaluated the tension required for this manipulation and investigated the influence of intraoperative manipulation on the joint gap in cadaveric knees. Total knee arthroplasty was performed in 6 cadaveric knees from whole body cadavers. Flexion contracture was induced using an insert that was 4 mm thicker than the extension gap, and intraoperative manipulation was performed. Study measurements included the changes in the joint gap after manipulation at 6 positions, with the knee bending from extension to 120° flexion, and the manipulation tension that was required to create a 4-mm increase in the gap. The manipulation tension needed to create a 4-mm increase in the extension gap was 303±17 N. The changes in the joint gap after manipulation were 0.4 mm, 0.6 mm, 0.2 mm, -0.2 mm, -0.4 mm, and -0.6 mm at 0°, 30°, 45°, 60°, 90°, and 120° flexion, respectively. Therefore, the joint gap was not significantly changed by the manipulation. Intraoperative manipulation does not resolve flexion contracture. Therefore, if flexion contracture occurs during TKA, treatment with additional bone cutting and soft tissue release is likely more appropriate than manipulation. [Orthopedics. 2016; 39(6):e1070-e1074.].

  6. EMG-torque Relation in Chronic Stroke: A Novel EMG Complexity Representation with A Linear Electrode Array.

    PubMed

    Zhang, Xu; Wang, Dongqing; Yu, Zaiyang; Chen, Xiang; Li, Sheng; Zhou, Ping

    2016-11-08

    This study examines the electromyogram (EMG) - torque relation for chronic stroke survivors using a novel EMG complexity representation. Ten stroke subjects performed a series of submaximal isometric elbow flexion tasks using their affected and contralateral arms, respectively, while a 20-channel linear electrode array was used to record surface EMG from the biceps brachii muscles. The sample entropy (SampEn) of surface EMG signals was calculated with both global and local tolerance schemes. A regression analysis was performed between SampEn of each channel's surface EMG and elbow flexion torque. It was found that a linear regression can be used to well describe the relation between surface EMG SampEn and the torque. Each channel's root mean square (RMS) amplitude of surface EMG signal in the different torque level was computed to determine the channel with the highest EMG amplitude. The slope of the regression (observed from the channel with the highest EMG amplitude) was smaller on the impaired side than on the non-impaired side in 8 of the 10 subjects, regardless of the tolerance scheme (global or local) and the range of torques (full or matched range) used for comparison. The surface EMG signals from the channels above the estimated muscle innervation zones demonstrated significantly lower levels of complexity compared with other channels between innervation zones and muscle tendons. The study provides a novel point of view of the EMG-torque relation in the complexity domain, and reveals its alterations post stroke, which are associated with complex neural and muscular changes post stroke. The slope difference between channels with regard to innervation zones also confirms the relevance of electrode position in surface EMG analysis.

  7. Clinical and radiological profile of Hirayama disease: A flexion myelopathy due to tight cervical dural canal amenable to collar therapy

    PubMed Central

    Hassan, K. M.; Sahni, Hirdesh; Jha, Atul

    2012-01-01

    Background: Hirayama disease (HD) is benign focal amyotrophy of the distal upper limbs, often misdiagnosed as motor neuron disease. Routine magnetic resonance imaging (MRI) is often reported normal. Objective: To study the clinicoradiological profile of hand wasting in young males. Materials and Methods: Patients presenting with insidious-onset hand wasting from March 2008 to May 2011 were evaluated electrophysiologically. Cervical MRI in neutral position was done in 11 patients and flexion contrast imaging was done in 10 patients. Results: All patients were males less than 25 years of age, with median age 23 years, except one patient who was 50 years old. Duration of illness was 3 months to 3 years. All (100%) had oblique amyotrophy, four (36%) cold paresis, 10 (91%) minipolymyoclonus and three (27%) had fasciculations. Regional reflexes were variably absent. Two patients (18%) had brisk reflexes of lower limbs with flexor plantars. Electromyography (EMG) showed chronic denervation in the C7-T1 myotomes. Neutral position MRI showed loss of cervical lordosis in 10/11 (91%), localized lower cervical cord atrophy in 9/11 (82%), asymmetric cord flattening in 11/11 (100%) and intramedullary hyperintensity in 2/11 (18%); flexion study showed loss of dural attachment, anterior displacement of dorsal dura, epidural flow voids in 9/10 (90%) and enhancing epidural crescent in 10/10 (100%). Clinical profile, imaging and electrophysiological findings of the patient aged 50 years will be described in detail as presentation at this age is exceptional. Collar therapy slowed progression in most cases. Conclusion: Clinical features of HD corroborated well with electrophysiological diagnosis of anterior horn cell disease of lower cervical cord. While dynamic contrast MRI is characteristic, routine studies have a high predictive value for diagnosis. Prompt diagnosis is important to institute early collar therapy. PMID:22566723

  8. An Electromyographic-driven Musculoskeletal Torque Model using Neuro-Fuzzy System Identification: A Case Study.

    PubMed

    Jafari, Zohreh; Edrisi, Mehdi; Marateb, Hamid Reza

    2014-10-01

    The purpose of this study was to estimate the torque from high-density surface electromyography signals of biceps brachii, brachioradialis, and the medial and lateral heads of triceps brachii muscles during moderate-to-high isometric elbow flexion-extension. The elbow torque was estimated in two following steps: First, surface electromyography (EMG) amplitudes were estimated using principal component analysis, and then a fuzzy model was proposed to illustrate the relationship between the EMG amplitudes and the measured torque signal. A neuro-fuzzy method, with which the optimum number of rules could be estimated, was used to identify the model with suitable complexity. Utilizing the proposed neuro-fuzzy model, the clinical interpretability was introduced; contrary to the previous linear and nonlinear black-box system identification models. It also reduced the estimation error compared with that of the most recent and accurate nonlinear dynamic model introduced in the literature. The optimum number of the rules for all trials was 4 ± 1, that might be related to motor control strategies and the % variance accounted for criterion was 96.40 ± 3.38 which in fact showed considerable improvement compared with the previous methods. The proposed method is thus a promising new tool for EMG-Torque modeling in clinical applications.

  9. Effect of sex on torque, recovery, EMG, and MMG responses to fatigue

    PubMed Central

    Hill, E.C.; Housh, T.J.; Smith, C.M.; Cochrane, K.C.; Jenkins, N.D.M.; Cramer, J.T.; Schmidt, R.J.; Johnson, G.O.

    2016-01-01

    Objective: The purpose of the present investigation was to examine the effect of sex on maximal voluntary isometric contraction (MVIC) torque and the EMG and MMG responses as a result of fatiguing, intermittent, submaximal (65% of MVIC), isometric elbow flexion muscle contractions. Methods: Eighteen men and women performed MVIC trials before (pretest), after (posttest), and 5-min after (5-min recovery) performing 50 intermittent, submaximal isometric muscle contractions. Surface electromyographic (EMG) and mechanomyographic (MMG) signals were simultaneously recorded from the biceps brachii muscle. Results: As a result of the fatiguing workbout torque decreased similarly from pretest to posttest for both the men (24.0%) and women (23.3%). After 5-min of recovery, torque had partially recovered for the men, while torque had returned to pretest levels for the women. For both sexes, from pretest to posttest EMG mean power frequency and MMG amplitude decreased, but returned to pretest levels after 5-min of recovery. Conclusions: In the present study, there were sex-related differences in muscle fatigue that were not associated with the EMG or MMG responses. PMID:27973383

  10. Within- and between-session reliability of the maximal voluntary knee extension torque and activation.

    PubMed

    Park, Jihong; Hopkins, J Ty

    2013-01-01

    A ratio between the torque generated by maximal voluntary isometric contraction (MVIC) and exogenous electrical stimulus, central activation ratio (CAR), has been widely used to assess quadriceps function. To date, no data exist regarding between-session reliability of this measurement. Thirteen neurologically sound volunteers underwent three testing sessions (three trials per session) with 48 hours between-session. Subjects performed MVICs of the quadriceps with the knee locked at 90° flexion and the hip at 85°. Once the MVIC reached a plateau, an electrical stimulation from superimposed burst technique (SIB: 125 V with peak output current 450 mA) was manually delivered and transmitted directly to the quadriceps via stimulating electrodes. CAR was calculated by using the following equation: CAR = MVIC torque/MVIC + SIB torque. Intraclass correlation coefficients (ICC) were calculated within- (ICC((2,1))) and between-session (ICC((2,k))) for MVIC torques and CAR values. Our data show that quadriceps MVIC and CAR are very reliable both within- (ICC((2,1)) = 0.99 for MVIC; 0.94 for CAR) and between-measurement sessions (ICC((2,k)) = 0.92 for MVIC; 0.86 for CAR) in healthy young adults. For clinical research, more data of the patients with pathological conditions are required to ensure reproducibility of calculation of CAR.

  11. Event-related differences in the cross-sectional areas and torque generation capabilities of quadriceps femoris and hamstrings in male high school athletes.

    PubMed

    Hoshikawa, Yoshihiro; Muramatsu, Masataka; Iida, Tomomi; Uchiyama, Akiko; Nakajima, Yoshiharu; Kanehisa, Hiroaki

    2010-01-01

    This study investigated the event-related differences in the cross-sectional areas (CSAs) and torque generation capabilities of the quadriceps femoris (QF) and hamstrings (HAM) in male high school athletes. Subjects were soccer players (n=32), volleyball players (21), rowers (29), karate athletes (18), sumo wrestlers (15), sprinters (22), throwers (16), and nonathletes (20). The CSAs of QF and HAM at the mid-thigh were determined using magnetic resonance imaging. In addition, isokinetic torques during knee extension and flexion were determined at a pre-set velocity of 1.05 rad/s. The CSAs of the two muscle groups and torques developed in the two motions were significantly related to the two-third power of lean body mass (LBM(2/3)) and the product of CSA and femur length (CSA*fl), calculated as an index of muscle volume, respectively. CSA relative to LBM(2/3) for QF did not differ among the groups, but that for HAM was higher in sprinters, soccer players, throwers, and karate athletes than in sumo wrestlers, rowers, volleyball players, and nonathletes. Knee extension torque relative to the CSA*fl of QF was higher in karate athletes, soccer players, and rowers than in nonathletes, but the corresponding value for knee flexion did not differ among groups. Thus, the present study indicated that, at least in male high school athletes, the event-related differences in LBM and the muscularity of QF and HAM produced the corresponding differences in the CSAs of the reciprocal muscle groups and knee extension and flexion torques, respectively. However, specific profiles related to competitive and/or training styles exist in HAM CSA and knee extension torque, which cannot be explained by the magnitude of LBM and QF CSA, respectively.

  12. The duration of the inhibitory effects with static stretching on quadriceps peak torque production.

    PubMed

    Siatras, Theophanis A; Mittas, Vasilios P; Mameletzi, Dimitra N; Vamvakoudis, Eystratios A

    2008-01-01

    Although several studies have investigated the acute effect of static stretching exercises, the duration of exercises that negatively affects performance has not been ascertained. This study was conducted to determine the acute effect of different static stretching durations on quadriceps isometric and isokinetic peak torque production. The 50 participants were randomly allocated into five equivalent sized groups and were asked to perform a stretching exercise of different duration (no stretch, 10-second stretch, 20-second stretch, 30-second stretch, and 60-second stretch). The knee flexion range of motion and the isometric and concentric isokinetic peak torques of the quadriceps were measured before and after a static stretching exercise in the four experimental groups. The same parameters were examined in the control group (no stretch) without stretching, before and after a 5-minute passive rest. There were no significant differences among groups before the experimentation regarding their physical characteristics and performances (P > 0.05). These results reflect the different groups' homogeneity. Significant knee joint flexibility increases (P < 0.001) and significant isometric and isokinetic peak torque reductions (P < 0.05-0.001) have been shown to occur only after 30 and 60 seconds of quadriceps static stretching. Stretching reduced isometric peak torque by 8.5% and 16.0%, respectively. Concerning isokinetic peak torque after 30 and 60 seconds of stretching, it was reduced by 5.5% vs. 11.6% at 60 degrees/s and by 5.8% vs. 10.0% at 180 degrees/s. We suggest that torque decrements are related to changes of muscle neuromechanical properties. It is recommended that static stretching exercises of a muscle group for more than 30 seconds of duration be avoided before performances requiring maximal strength.

  13. Effects of body mass index on plantar pressure and balance

    PubMed Central

    Yoon, Se-Won; Park, Woong-Sik; Lee, Jeong-Woo

    2016-01-01

    [Purpose] To suggest physiotherapy programs and to determine foot stability based on the results of plantar pressure and spontaneity balance in the normal group and in the obesity group according to the body mass index (BMI). [Subjects and Methods] The plantar pressure and balance of 20 females college students in their 20s were measured according to their BMI. BMI was measured by using BMS 330. The peak plantar pressure was measured in a static position in the forefoot and hind-foot areas. To study balance, the spontaneity balance of each foot was measured on both stable and unstable surfaces. [Results] In terms of plantar pressure, no significant change was observed in the forefoot and hind-foot peak pressure. In terms of spontaneity balance, no significant difference in foot position interaction was observed on both stable and unstable surfaces, while a significant difference was observed in the foot position between the groups. [Conclusion] The index of hind-foot spontaneity balance was low, particularly in the obesity group. This meant significant hind-foot swaying. The forefoot body weight support percentage increased to reinforce the reduced spontaneity balance index. PMID:27942127

  14. How We Manage Plantar Fasciitis (With Memory Jogger).

    ERIC Educational Resources Information Center

    Tanner, Suzanne M.; Harvey, Jack S.

    1988-01-01

    Common among runners and athletes who participate in jumping sports, plantar fasciitis is an overuse injury that is potentially incapacitating, causes heel and arch pain, and usually occurs after sudden increases in running mileage, frequency, or speed. Therapy is described. (Author/CB)

  15. Nordic Walking Practice Might Improve Plantar Pressure Distribution

    ERIC Educational Resources Information Center

    Perez-Soriano, Pedro; Llana-Belloch, Salvador; Martinez-Nova, Alfonso; Morey-Klapsing, G.; Encarnacion-Martinez, Alberto

    2011-01-01

    Nordic walking (NW), characterized by the use of two walking poles, is becoming increasingly popular (Morgulec-Adamowicz, Marszalek, & Jagustyn, 2011). We studied walking pressure patterns of 20 experienced and 30 beginner Nordic walkers. Plantar pressures from nine foot zones were measured during trials performed at two walking speeds (preferred…

  16. Effects of body mass index on plantar pressure and balance.

    PubMed

    Yoon, Se-Won; Park, Woong-Sik; Lee, Jeong-Woo

    2016-11-01

    [Purpose] To suggest physiotherapy programs and to determine foot stability based on the results of plantar pressure and spontaneity balance in the normal group and in the obesity group according to the body mass index (BMI). [Subjects and Methods] The plantar pressure and balance of 20 females college students in their 20s were measured according to their BMI. BMI was measured by using BMS 330. The peak plantar pressure was measured in a static position in the forefoot and hind-foot areas. To study balance, the spontaneity balance of each foot was measured on both stable and unstable surfaces. [Results] In terms of plantar pressure, no significant change was observed in the forefoot and hind-foot peak pressure. In terms of spontaneity balance, no significant difference in foot position interaction was observed on both stable and unstable surfaces, while a significant difference was observed in the foot position between the groups. [Conclusion] The index of hind-foot spontaneity balance was low, particularly in the obesity group. This meant significant hind-foot swaying. The forefoot body weight support percentage increased to reinforce the reduced spontaneity balance index.

  17. Comparison of plantar loads during running on different overground surfaces.

    PubMed

    Wang, Lin; Hong, Youlian; Li, Jing-Xian; Zhou, Ji-He

    2012-04-01

    The objective of this study is to compare plantar loads during running on different overground surfaces. Fifteen heel-to-toe runners participated in the study. Plantar load data were collected and analyzed using an insole sensor system during running on concrete, synthetic rubber, and grass surfaces at a running speed of 3.8 m/s. Compared with running on concrete surface, running on natural grass showed a lower magnitude of maximum plantar pressure at the total foot (451.8 kPa vs. 401.7 kPa, p = 0.016), lateral midfoot (175.3 kPa vs. 148.0 kPa, p = 0.004), central forefoot (366.3 kPa vs. 336.8 kPa, p = 0.003), and lateral forefoot (290.2 kPa vs. 257.9 kPa, p = 0.004). Moreover, running on natural grass showed a longer relative contact time compared with running on a concrete surface at the central forefoot (81.9% vs. 78.8%, p = 0.017) and lateral forefoot (75.2% vs. 73.1%, p = 0.007). No significant difference was observed in other multiple comparisons. Different surfaces affected the plantar loads while running. The differences may help us to understand potential injury mechanisms.

  18. Calculation of plantar pressure time integral, an alternative approach.

    PubMed

    Melai, Tom; IJzerman, T Herman; Schaper, Nicolaas C; de Lange, Ton L H; Willems, Paul J B; Meijer, Kenneth; Lieverse, Aloysius G; Savelberg, Hans H C M

    2011-07-01

    In plantar pressure measurement, both peak pressure and pressure time integral are used as variables to assess plantar loading. However, pressure time integral shows a high concordance with peak pressure. Many researchers and clinicians use Novel software (Novel GmbH Inc., Munich, Germany) that calculates this variable as the summation of the products of peak pressure and duration per time sample, which is not a genuine integral of pressure over time. Therefore, an alternative calculation method was introduced. The aim of this study was to explore the relevance of this alternative method, in different populations. Plantar pressure variables were measured in 76 people with diabetic polyneuropathy, 33 diabetic controls without polyneuropathy and 19 healthy subjects. Peak pressure and pressure time integral were obtained using Novel software. The quotient of the genuine force time integral over contact area was obtained as the alternative pressure time integral calculation. This new alternative method correlated less with peak pressure than the pressure time integral as calculated by Novel. The two methods differed significantly and these differences varied between the foot sole areas and between groups. The largest differences were found under the metatarsal heads in the group with diabetic polyneuropathy. From a theoretical perspective, the alternative approach provides a more valid calculation of the pressure time integral. In addition, this study showed that the alternative calculation is of added value, along peak pressure calculation, to interpret adapted plantar pressures patterns in particular in patients at risk for foot ulceration.

  19. Low-Torque Seal Development

    NASA Technical Reports Server (NTRS)

    Lattime, Scott B.; Borowski, Richard

    2009-01-01

    The EcoTurn Class K production prototypes have passed all AAR qualification tests and received conditional approval. The accelerated life test on the second set of seals is in progress. Due to the performance of the first set, no problems are expected.The seal has demonstrated superior performance over the HDL seal in the test lab with virtually zero torque and excellent contamination exclusion and grease retention.

  20. Torque and Twist against Superlubricity

    NASA Astrophysics Data System (ADS)

    Filippov, Alexander E.; Dienwiebel, Martin; Frenken, Joost W. M.; Klafter, Joseph; Urbakh, Michael

    2008-02-01

    Superlubricity between incommensurate surfaces provides a desired low-friction state essential for the function of small-scale machines. Here we demonstrate experimentally and theoretically that superlubricity in contacts lubricated by lamellar solids might be eliminated due to torque-induced reorientation coupled to lateral motion. We find that the possibility of reorientation always leads to stabilization of a high frictional state which corresponds to a commensurate configuration.

  1. Torque and twist against superlubricity.

    PubMed

    Filippov, Alexander E; Dienwiebel, Martin; Frenken, Joost W M; Klafter, Joseph; Urbakh, Michael

    2008-02-01

    Superlubricity between incommensurate surfaces provides a desired low-friction state essential for the function of small-scale machines. Here we demonstrate experimentally and theoretically that superlubricity in contacts lubricated by lamellar solids might be eliminated due to torque-induced reorientation coupled to lateral motion. We find that the possibility of reorientation always leads to stabilization of a high frictional state which corresponds to a commensurate configuration.

  2. Space Suit Joint Torque Testing

    NASA Technical Reports Server (NTRS)

    Valish, Dana J.

    2011-01-01

    In 2009 and early 2010, a test was performed to quantify the torque required to manipulate joints in several existing operational and prototype space suits in an effort to develop joint torque requirements appropriate for a new Constellation Program space suit system. The same test method was levied on the Constellation space suit contractors to verify that their suit design meets the requirements. However, because the original test was set up and conducted by a single test operator there was some question as to whether this method was repeatable enough to be considered a standard verification method for Constellation or other future space suits. In order to validate the method itself, a representative subset of the previous test was repeated, using the same information that would be available to space suit contractors, but set up and conducted by someone not familiar with the previous test. The resultant data was compared using graphical and statistical analysis and a variance in torque values for some of the tested joints was apparent. Potential variables that could have affected the data were identified and re-testing was conducted in an attempt to eliminate these variables. The results of the retest will be used to determine if further testing and modification is necessary before the method can be validated.

  3. Prior Knowledge Improves Decoding of Finger Flexion from Electrocorticographic Signals

    PubMed Central

    Wang, Z.; Ji, Q.; Miller, K. J.; Schalk, Gerwin

    2011-01-01

    Brain–computer interfaces (BCIs) use brain signals to convey a user’s intent. Some BCI approaches begin by decoding kinematic parameters of movements from brain signals, and then proceed to using these signals, in absence of movements, to allow a user to control an output. Recent results have shown that electrocorticographic (ECoG) recordings from the surface of the brain in humans can give information about kinematic parameters (e.g., hand velocity or finger flexion). The decoding approaches in these studies usually employed classical classification/regression algorithms that derive a linear mapping between brain signals and outputs. However, they typically only incorporate little prior information about the target movement parameter. In this paper, we incorporate prior knowledge using a Bayesian decoding method, and use it to decode finger flexion from ECoG signals. Specifically, we exploit the constraints that govern finger flexion and incorporate these constraints in the construction, structure, and the probabilistic functions of the prior model of a switched non-parametric dynamic system (SNDS). Given a measurement model resulting from a traditional linear regression method, we decoded finger flexion using posterior estimation that combined the prior and measurement models. Our results show that the application of the Bayesian decoding model, which incorporates prior knowledge, improves decoding performance compared to the application of a linear regression model, which does not incorporate prior knowledge. Thus, the results presented in this paper may ultimately lead to neurally controlled hand prostheses with full fine-grained finger articulation. PMID:22144944

  4. New Torque Estimation Method Considering Spatial Harmonics and Torque Ripple Reduction in Permanent Magnet Synchronous Motors

    NASA Astrophysics Data System (ADS)

    Hida, Hajime; Tomigashi, Yoshio; Ueyama, Kenji; Inoue, Yukinori; Morimoto, Shigeo

    This paper proposes a new torque estimation method that takes into account the spatial harmonics of permanent magnet synchronous motors and that is capable of real-time estimation. First, the torque estimation equation of the proposed method is derived. In the method, the torque ripple of a motor can be estimated from the average of the torque calculated by the conventional method (cross product of the fluxlinkage and motor current) and the torque calculated from the electric input power to the motor. Next, the effectiveness of the proposed method is verified by simulations in which two kinds of motors with different components of torque ripple are considered. The simulation results show that the proposed method estimates the torque ripple more accurately than the conventional method. Further, the effectiveness of the proposed method is verified by performing on experiment. It is shown that the torque ripple is decreased by using the proposed method to the torque control.

  5. Artificial gravity as a countermeasure to microgravity: a pilot study examining the effects on knee extensor and plantar flexor muscle groups.

    PubMed

    Caiozzo, V J; Haddad, F; Lee, S; Baker, M; Paloski, William; Baldwin, K M

    2009-07-01

    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.

  6. Application of ultrasound in the assessment of plantar fascia in patients with plantar fasciitis: a systematic review.

    PubMed

    Mohseni-Bandpei, Mohammad Ali; Nakhaee, Masoomeh; Mousavi, Mohammad Ebrahim; Shakourirad, Ali; Safari, Mohammad Reza; Vahab Kashani, Reza

    2014-08-01

    Plantar fasciitis (PFS) is one of the most common causes of heel pain, estimated to affect 10% of the general population during their lifetime. Ultrasound (US) imaging technique is increasingly being used to assess plantar fascia (PF) thickness, monitor the effect of different interventions and guide therapeutic interventions in patients with PFS. The purpose of the present study was to systematically review previously published studies concerning the application of US in the assessment of PF in patients with PFS. A literature search was performed for the period 2000-2012 using the Science Direct, Scopus, PubMed, CINAHL, Medline, Embase and Springer databases. The key words used were: ultrasound, sonography, imaging techniques, ultrasonography, interventional ultrasonography, plantar fascia and plantar fasciitis. The literature search yielded 34 relevant studies. Sixteen studies evaluated the effect of different interventions on PF thickness in patients with PFS using US; 12 studies compared PF thickness between patients with and without PFS using US; 6 studies investigated the application of US as a guide for therapeutic intervention in patients with PFS. There were variations among studies in terms of methodology used. The results indicated that US can be considered a reliable imaging technique for assessing PF thickness, monitoring the effect of different interventions and guiding therapeutic interventions in patients with PFS.

  7. Casting methods and plantar pressure: effects of custom-made foot orthoses on dynamic plantar pressure distribution.

    PubMed

    Guldemond, Nick A; Leffers, Pieter; Sanders, Antal P; Emmen, Hans; Schaper, Nicolaas C; Walenkamp, Geert H I M

    2006-01-01

    Foot orthoses are widely used to treat various foot problems. A literature search revealed no publications on differences in plantar pressure distribution resulting from casting methods for foot orthoses. Four casting methods were used for construction of orthoses. Two foam box techniques were used: accommodative full weightbearing method (A) and functional semiweightbearing method (B). Also, two suspension plaster casting techniques were used: accommodative casting (C) and functional subtalar joint neutral position (Root) method (D). Their effects on contact area, plantar pressure, and walking convenience were evaluated. All orthoses increased the total contact area (mean, 17.4%) compared with shoes without orthoses. Differences in contact areas between orthoses for total plantar surface were statistically significant. Peak pressures for the total plantar surface were lower with orthoses than without orthoses (mean, 22.8%). Among orthoses, only the difference between orthoses A and B was statistically significant. Differences between orthoses for the forefoot were small and not statistically significant. The gait lines of the shoe without an insole and of the accommodative orthoses are more medially located than those of functional orthoses. Walking convenience in the shoe was better rated than that with orthoses. There were no differences in perception of walking convenience between orthoses A, B, and C. Orthosis D had the lowest convenience rating. The four casting methods resulted in differences between orthoses with respect to contact areas and walking convenience but only slight differences in peak pressures.

  8. Torque magnetometry in unconventional superconductors

    NASA Astrophysics Data System (ADS)

    Li, Lu

    This thesis describes torque magnetometry studies on unconventional superconductors. Torque magnetometry measures the anisotropic magnetization of samples by recording their torque signals in a tilted magnetic field. Applied to superconductors, this method provides a reliable way to measure the field dependence of magnetization with high resolution under extreme conditions: DC magnetic fields from zero to 45.2 T, and temperature from 300 mK to 300K. The results can be used to determine many important parameters, such as the upper critical field H c2, the superconducting condensation energy, the onset temperature of diamagnetic signals, and so on. We carried out the torque magnetometry measurements on unconventional superconductors---high Tc superconductors and the p-wave superconductor Sr2RuO4---and uncovered new features that do not exist in conventional BCS superconductors. In high Tc superconductors, our torque magnetometry studies focus on the properties of the vortex liquid state. First, by comparing the observed magnetization curves with the Nernst effect results in Bi 2Sr2CaCu2O8+delta, we confirm that the unusually large Nernst effect signals originate from the surviving vortex liquid state above Tc. Second, the M-H curves near the critical temperature Tc suggest that the nature of the transition is the Kosterlitz-Thouless transition. Near Tc, the magnetization response at low field is strongly nonlinear, and the T dependence of the magnetic susceptibility in the low-field limit approaches the predicted curve from the Kosterlitz-Thouless transition. Third, the measurements in intense magnetic field up to 45 T reveal the unusual, weak T-dependence of Hc2. These observations strongly support the existence of the vortex liquid state above Tc. The superconducting state is destroyed by the phase fluctuation of the pair condensate, while the pair condensate keeps its amplitude above T c. Further studies in single-layered high Tc superconductors reveal more

  9. Spin-orbit torque opposing the Oersted torque in ultrathin Co/Pt bilayers

    SciTech Connect

    Skinner, T. D. Irvine, A. C.; Heiss, D.; Kurebayashi, H.; Ferguson, A. J.; Wang, M.; Hindmarch, A. T.; Rushforth, A. W.

    2014-02-10

    Current-induced torques in ultrathin Co/Pt bilayers were investigated using an electrically driven ferromagnetic resonance technique. The angle dependence of the resonances, detected by a rectification effect as a voltage, was analysed to determine the symmetries and relative magnitudes of the spin-orbit torques. Both anti-damping (Slonczewski) and field-like torques were observed. As the ferromagnet thickness was reduced from 3 to 1 nm, the sign of the sum of the field-like torque and Oersted torque reversed. This observation is consistent with the emergence of a Rashba spin orbit torque in ultra-thin bilayers.

  10. Three Point Extension Splint To Treat Flexion Contractures About Limb Synovial Hinge Joints.

    DTIC Science & Technology

    rehabilitating flexion contractures caused by soft tissue injury. More particularly, the invention relates to a three point extension splint to treat flexion contractures about the knee, elbow and/or finger.

  11. Effects of the sustained computer work on upper cervical flexion motion.

    PubMed

    Park, Se-Yeon; Yoo, Won-Gyu

    2014-03-01

    [Purpose] The purpose of this study was to evaluate the effect of sustained computer work on cervical flexion, especially the upper cervical region. [Subjects] We recruited 11 sedentary workers who used a computer for at least 4 hours a day. [Methods] Total range of cervical flexion, upper cervical flexion, and their ratio were measured before and after 1 hour of computer work. [Results] The total range of cervical flexion was not significantly different between pre-and post-measurement. However, upper cervical flexion, and the ratio between the upper cervical flexion and total cervical flexion significantly decreased after 1 hour of computer work, compared to pre-measurement. [Conclusion] Sustained computer work affects the range of cervical flexion, especially in the upper cervical region.

  12. Landau-Lifshitz theory of thermomagnonic torque

    NASA Astrophysics Data System (ADS)

    Kim, Se Kwon; Tserkovnyak, Yaroslav

    2015-07-01

    We derive the thermomagnonic torque associated with smooth magnetic textures subjected to a temperature gradient in the framework of the stochastic Landau-Lifshitz-Gilbert equation. Our approach captures on equal footing two distinct contributions: (i) a local entropic torque that is caused by a temperature dependence of the effective exchange field, the existence of which had been previously suggested based on numerics, and (ii) the well-known spin-transfer torque induced by thermally induced magnon flow. The dissipative components of two torques have the same structure, following a common phenomenology, but opposite signs, with the twice as large entropic torque leading to a domain-wall motion toward the hotter region. We compare the efficiency of the torque-driven domain-wall motion with the recently proposed Brownian thermophoresis.

  13. Effects of hip and head position on ankle range of motion, ankle passive torque, and passive gastrocnemius tension.

    PubMed

    Andrade, R J; Lacourpaille, L; Freitas, S R; McNair, P J; Nordez, A

    2016-01-01

    Ankle joint range of motion (ROM) is notably influenced by the position of the hip joint. However, this result remains unexplained. Thus, the aim of this study was to test if the ankle passive torque and gastrocnemius muscle tension are affected by the hip and the head positions. The torque and the muscle shear elastic modulus (measured by elastography to estimate muscle tension) were collected in nine participants during passive ankle dorsiflexions performed in four conditions (by combining hip flexion at 90 or 150°, and head flexed or neutral). Ankle maximum dorsiflexion angle significantly decreased by flexing the hip from 150 to 90° (P < 0.001; mean difference 17.7 ± 2.5°), but no effect of the head position was observed (P > 0.05). Maximal passive torque and shear elastic modulus were higher with the hip flexed at 90° (P < 0.001). During submaximal ROM, no effects of the head and hip positioning (P > 0.05) were found for both torque and shear elastic modulus at a given common ankle angle among conditions. Shifts in maximal ankle angle due to hip angle manipulation are not related neither to changes in passive torque nor tension of the gastrocnemius. Further studies should be addressed to better understand the functional role of peripheral nerves and fasciae in the ankle ROM limits.

  14. Design of a new torque standard machine based on a torque generation method using electromagnetic force

    NASA Astrophysics Data System (ADS)

    Nishino, Atsuhiro; Ueda, Kazunaga; Fujii, Kenichi

    2017-02-01

    To allow the application of torque standards in various industries, we have been developing torque standard machines based on a lever deadweight system, i.e. a torque generation method using gravity. However, this method is not suitable for expanding the low end of the torque range, because of the limitations to the sizes of the weights and moment arms. In this study, the working principle of the torque generation method using an electromagnetic force was investigated by referring to watt balance experiments used for the redefinition of the kilogram. Applying this principle to a rotating coordinate system, an electromagnetic force type torque standard machine was designed and prototyped. It was experimentally demonstrated that SI-traceable torque could be generated by converting electrical power to mechanical power. Thus, for the first time, SI-traceable torque was successfully realized using a method other than that based on the force of gravity.

  15. Torque converter and assembly utilizing same

    SciTech Connect

    Pitassi, V.E.; Fernandez, A.

    1989-12-26

    This patent describes a torque converter for converting a first torque to a second torque. It comprises: a housing; an input shaft having the first torque; a driving sun gear rotatable about a first axis, the input shaft being coupled to the sun gear; a driven carrier including a shaft portion rotatable about the first axis; a first planetary shaft mounted on the driven carrier coaxillay with a second axis parallel to the first axis; a first planetary gear meshing with and driven by the sun gear and mounted on the first planetary shaft so that the first planetary gear is rotatable about the second axis; a first mass eccentric to the second axis and coupled to the first planetary gear for rotation together about the second axis; first and second unidirectional clutches connected to the shaft portion of the driven carrier and operating in opposite directions; an output torque shaft, one if the first and second unidirectional clutches being coupled to the output torque shaft to transmit the second torque thereto in a pulsating fashion and to permit continuous rotation of the output torque shaft and the other one of the first and second unidirectional clutches being connected to the housing to transmit an algebraic addition of the first and second torques together.

  16. 40 CFR 1065.310 - Torque calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... range. Oscillate or rotate the dynamometer during calibration to reduce frictional static hysteresis... during calibration to reduce frictional static hysteresis. In this case, the reference torque...

  17. 40 CFR 1065.310 - Torque calibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... range. Oscillate or rotate the dynamometer during calibration to reduce frictional static hysteresis... during calibration to reduce frictional static hysteresis. In this case, the reference torque...

  18. Torque limited drive for manual valves

    DOEpatents

    Elliott, Philip G.; Underwood, Daniel E.

    1989-06-06

    The present invention is directed to a torque-limiting handwheel device for preventing manual valves from being damaged due to the application of excessive torque during the opening or closing operation of the valves. Torque can only be applied when ridges in the handwheel assembly engage in channels machined in the face of the baseplate. The amount of torque required for disengagement of the ridges from the channels is determined by the force exerted by various Bellville springs and the inclination of the side faces of the channels.

  19. Torque limited drive for manual valves

    DOEpatents

    Elliott, Philip G.; Underwood, Daniel E.

    1989-01-01

    The present invention is directed to a torque-limiting handwheel device for preventing manual valves from being damaged due to the application of excessive torque during the opening or closing operation of the valves. Torque can only be applied when ridges in the handwheel assembly engage in channels machined in the face of the baseplate. The amount of torque required for disengagement of the ridges from the channels is determined by the force exerted by various Bellville springs and the inclination of the side faces of the channels.

  20. Neuromuscular disorders associated with static lumbar flexion: a feline model.

    PubMed

    Solomonow, M; Zhou, B; Baratta, R V; Zhu, M; Lu, Y

    2002-04-01

    Static flexion of the lumbar spine with constant load applied to the viscoelastic structures for 20 minutes and for 50 minutes resulted in development of spasms and inhibition in the multifidus muscles (e.g., deep erector spinae) and in creep of the supraspinous ligament in the feline model. The development of spasms and inhibition was not dependent on load magnitude. It is suggested that occupational and sports activities which require prolonged static lumbar flexion within the physiological range can cause a "sprain"-like injury to the ligaments, which in turn reflexively induce spasms and inhibition in some erector spinae muscles. Such disorder may take a long time to recover, in the order of days to weeks, depending on the level of creep developed in the tissues.

  1. Peak knee flexion angles during stair descent in TKA patients.

    PubMed

    Bjerke, Joakim; Öhberg, Fredrik; Nilsson, Kjell G; Foss, Olav A; Stensdotter, Ann K

    2014-04-01

    Reduced peak knee flexion during stair descent (PKSD) is demonstrated in subjects with total knee arthroplasty (TKA), but the underlying factors are not well studied. 3D gait patterns during stair descent, peak passive knee flexion (PPKF), quadriceps strength, pain, proprioception, demographics, and anthropometrics were assessed in 23 unilateral TKA-subjects ~19 months post-operatively, and in 23 controls. PKSD, PPKF and quadriceps strength were reduced in the TKA-side, but also in the contralateral side. A multiple regression analysis identified PPKF as the only predictor (57%) to explain the relationship with PKSD. PPKF was, however sufficient for normal PKSD. Deficits in quadriceps strength in TKA-group suggest that strength is also contributing to smaller PKSD. Increased hip adduction at PKSD may indicate both compensatory strategy and reduced hip strength.

  2. High-torque quiet gear

    NASA Astrophysics Data System (ADS)

    Moody, Paul E.

    1995-07-01

    A high-torque quiet gear construction consists of an inner hub having a plurality of circumferentially spaced arms extending radially outwardly therefrom, and an outer ring member having a plurality of circumferentially spaced-teeth extending radially inwardly therefrom. The ring member further includes a plurality of gear formations on an outer surface thereof for intermeshing with other gears. The teeth of the ring member are received in spaced relation in corresponding spaces formed between adjacent arms of the hub. An elastomeric member is received in the space formed between the hub and the ring member to form a resilient correction between the arms of the hub and the teeth of the ring member. The side surfaces of the arms and the teeth extend generally parallel to each other and at least partially overlap in a longitudinal direction. The purpose of this configuration is to place the elastomeric member in compression when torque is applied to the hub. Since elastomeric material is relatively incompressible, the result is low shear loads on the adhesive bonds which hold the elastomeric member to both the hub and outer ring member.

  3. Ultrasound-guided injection for plantar fasciitis: A brief review

    PubMed Central

    Nair, AS; Sahoo, RK

    2016-01-01

    Plantar fasciitis (PF) is a distressing condition experienced by many patients. Although self-limiting, it tends to become a chronic ailment if the precipitating factors are not addressed. One of the modality of treating PF is intra-lesional corticosteroid injection. This was done using palpation technique earlier but nowadays many specialists use ultrasound (US) imaging as a guide to give injection accurately instead of inadvertently damaging the plantar fascia or injecting into surrounding soft tissue, both of which can have serious implications. We did a literature search in Medline, Scopus, and Embase databases to find out articles describing US-guided corticosteroid injection for treating PF and whether guided injection was effective than injection given by palpation. PMID:27833490

  4. Continuous phenobarbital treatment leads to recurrent plantar fibromatosis.

    PubMed

    Strzelczyk, Adam; Vogt, Heinrich; Hamer, Hajo M; Krämer, Günter

    2008-11-01

    Despite contrary recommendations by expert opinion and international guidelines phenobarbital remains the most widely prescribed anticonvulsant worldwide. Although associated connective tissue disorders were described in a timely way after its introduction, the association between plantar fibromatosis--also called Ledderhose syndrome--and phenobarbital seems not to be well known in general. Our case series uniquely demonstrates that continuous phenobarbital treatment leads to recurrent plantar fibromatosis and may result in long-term disability and numerous unnecessary operations. In general, the association between connective tissue disorders and phenobarbital most prominently appears in adult patients of northern European descent. However, our case series and data from the literature suggest that patient groups less susceptible to connective tissue disorders may as well develop Ledderhose syndrome or other associated syndromes as Dupuytren's contractures, frozen shoulder, Peyronie's disease or complex regional pain syndrome in the course of phenobarbital treatment.

  5. [Anatomical quantification of the tibial part of the plantar aponeurosis].

    PubMed

    Hiramoto, Y

    1983-03-01

    The metrical analysis of the anatomical characteristics is important because of its objectiveness. As it is concerned with the organs belonging to the locomotor system, the metrical method of the bones has already been systematized by Martin (1928), whereas the same kind of method for use on other organs remains undeveloped. The author aims to establish the metrical method of the plantar aponeurosis. The method for measuring the tibial part of the aponeurosis developed in this paper is sufficiently applicable for obtaining its principal anatomical characteristics. The results show that the tibial portion of the plantar aponeurosis becomes statistically significantly wider and thinner in its anterior part, and that the thickness of the tibial portion of the aponeurosis in the anterior part is larger on the right side than on the left side.

  6. Plantar fascia rupture in a professional soccer player.

    PubMed

    Suzue, Naoto; Iwame, Toshiyuki; Kato, Kenji; Takao, Shoichiro; Tateishi, Tomohiko; Takeda, Yoshitsugu; Hamada, Daisuke; Goto, Tomohiro; Takata, Yoichiro; Matsuura, Tetsuya; Sairyo, Koichi

    2014-01-01

    We report the case of a 29-year-old male professional soccer player who presented with symptoms of plantar fasciitis. His symptoms occurred with no remarkable triggers and gradually worsened despite conservative treatments including taping, use of insoles, and physical therapy. Local corticosteroid injection was given twice as a further intervention, but his plantar fascia partially ruptured 49 days after the second injection. He was treated conservatively with platelet-rich plasma, and magnetic resonance imaging showed regenerative change of the ruptured fascia. Five months after the rupture, he returned to his original level of training. If professional athletes find it difficult to refrain from athletic activity, as in the present case, the risk of rupture due to corticosteroid injection should not be overlooked.

  7. Heel pain-plantar fasciitis and Achilles enthesopathy.

    PubMed

    Williams, Seth K; Brage, Michael

    2004-01-01

    Plantar fasciitis and Achilles enthesopathy are two of the most common causes of posterior heel pain. In the vast majority of cases, nonsurgical treatment methods are effective. In recalcitrant cases, surgery has been shown to be generally effective. There are a variety of described techniques for both conditions. Endoscopic treatment of plantar fasciitis leads to slightly enhanced recovery times compared with the traditional open release, but in the long term the results seem to be equivalent. Open debridement of the retrocalcaneal bursa, calcaneal osteophyte, and diseased tendon is the underlying principle behind surgical treatment of Achilles enthesopathy. This can be performed through a variety of approaches, and augmentation with suture anchors, tendon transfers, or allograft may be necessary when more than 50% of the tendon is excised.

  8. Extracorporeal shockwave therapy for chronic proximal plantar fasciitis.

    PubMed

    Strash, Walter W; Perez, Richard R

    2002-10-01

    Although much enthusiasm surrounds applying extracorporeal shock wave therapy for various musculoskeletal conditions, its effects are not well understood and warrant continued study. Certain body tissues or organs may be damaged either acutely or chronically by ESWT; however, it is unequivocal that lung tissue may be damaged. It is theorized that neovascularization is responsible for improvement in symptoms of plantar fasciitis. Neovascularization is the direct effect of macrophage stimulation through cytokines. ESWT has effects at the cellular level--does it interfere with metabolic activity or enhance it? The noninvasive nature and minimal complications of appropriately applied ESWT are its primary advantages. Symptoms may continue to improve for three weeks to six months after treatment; the effects of shock wave therapy seem to be time dependent. ESWT is an effective form of treatment for proximal insertional plantar fasciitis after exhaustive, conservative forms of treatment have failed.

  9. The effect of trunk flexion on able-bodied gait.

    PubMed

    Saha, Devjani; Gard, Steven; Fatone, Stefania

    2008-05-01

    This study examined the effect of sagittal trunk posture on the gait of able-bodied subjects. Understanding the effect of trunk posture on gait is of clinical interest since alterations in trunk posture often occur with age or in the presence of spinal pathologies, such as lumbar flatback. Gait analysis was conducted on 14 adults walking at self-selected slow, normal, and fast walking speeds while maintaining three trunk postures: upright, and with 25+/-7 degrees and 50+/-7 degrees of trunk flexion from the vertical. During trunk-flexed gait, subjects adopted a crouch posture characterized by sustained knee flexion during stance and an increase in ankle dorsiflexion and hip flexion angles. During stance, these kinematic adaptations produced a posterior shift in the positions of the trunk and pelvis, which helped to offset the anterior shift in the trunk mass that occurred with trunk flexion. In this way, kinematic adaptations may have been used to maintain balance by shifting the body's center of mass to a position similar to that of upright walking. These changes in lower limb joint kinematics created a phase lag in the position of the hip joint center relative to that of the ankle joint center in the sagittal plane. Alterations in the sagittal alignment of the hip and ankle joint positions were associated with a phase lag in the vertical position, velocity, and acceleration of the body's center of mass (BCOM) relative to upright walking. Since the vertical ground reaction force (GRF(v)) is proportional to the vertical acceleration of the BCOM, significant changes were also seen in the GRF(v) during trunk-flexed gait. In summary, kinematic adaptations necessary to maintain dynamic balance altered the trajectory and acceleration of the BCOM in the vertical direction, which was reflected in the GRF(v). The results of this study may help clinicians better understand the nature and impact of compensatory mechanisms in patients who exhibit trunk-flexed postures during

  10. Endoscopic Debridement for Treatment of Chronic Plantar Fasciitis: An Innovative Surgical Technique.

    PubMed

    Cottom, James M; Maker, Jared M

    2016-01-01

    Plantar fasciitis is one the most common pathologies seen by foot and ankle surgeons. When nonoperative therapy fails, surgical intervention is warranted. Various surgical procedures are available for the treatment of recalcitrant plantar fasciitis. The most common surgical management typically consists of open versus endoscopic plantar fascia release. The documented comorbidities associated with the release of the plantar fascia include lateral column overload and metatarsalgia. We present a new technique for this painful condition that is minimally invasive, allows visualization of the plantar fascia, and maintains the integrity of this fascia. Our hypothesis was that the use of endoscopic debridement of the plantar fascia would provide a minimally invasive technique with acceptable patient outcomes.

  11. Pathologic and post-operative conditions of the plantar fascia: review of MR imaging appearances.

    PubMed

    Yu, J S

    2000-09-01

    Magnetic resonance (MR) imaging has emerged as an important noninvasive diagnostic imaging technique for assessment of foot pathology. This modality, owing to its multiplanar imaging capability and inherent superiority in contrast, has been shown to be more accurate and sensitive for detection of plantar fascia pathology than any other imaging method. One of the most important and recognizable causes of heel pain is plantar fasciitis. With the exception of plantar fasciitis, there has been little emphasis on imaging other conditions that affect this important structure. The objective of this review is to demonstrate, from a perspective of MR imaging, the many different pathologic conditions that affect the plantar fascia. Included in this review will be a discussion of normal anatomy as well as entities such as acute plantar fasciitis, chronic plantar fasciitis, traumatic rupture, normal post-surgical changes, pathologic post-fasciotomy conditions, infection, and fibromatosis.

  12. Obesity is not associated with increased knee joint torque and power during level walking.

    PubMed

    DeVita, Paul; Hortobágyi, Tibor

    2003-09-01

    While it is widely speculated that obesity causes increased loads on the knee leading to joint degeneration, this concept is untested. The purpose of the study was to identify the effects of obesity on lower extremity joint kinetics and energetics during walking. Twenty-one obese adults were tested at self-selected (1.29m/s) and standard speeds (1.50m/s) and 18 lean adults were tested at the standard speed. Motion analysis and force platform data were combined to calculate joint torques and powers during the stance phase of walking. Obese participants were more erect with 12% less knee flexion and 11% more ankle plantarflexion in self-selected compared to standard speeds (both p<0.02). Obese participants were still more erect than lean adults with approximately 6 degrees more extension at all joints (p<0.05, for each joint) at the standard speed. Knee and ankle torques were 17% and 11% higher (p<0.034 and p<0.041) and negative knee work and positive ankle work were 68% and 11% higher (p<0.000 and p<0.048) in obese participants at the standard speed compared to the slower speed. Joint torques and powers were statistically identical at the hip and knee but were 88% and 61% higher (both p<0.000) at the ankle in obese compared to lean participants at the standard speed. Obese participants used altered gait biomechanics and despite their greater weight, they had less knee torque and power at their self-selected walking speed and equal knee torque and power while walking at the same speed as lean individuals. We propose that the ability to reorganize neuromuscular function during gait may enable some obese individuals to maintain skeletal health of the knee joint and this ability may also be a more accurate risk indicator for knee osteoarthritis than body weight.

  13. Lumbopelvic flexibility modulates neuromuscular responses during trunk flexion-extension.

    PubMed

    Sánchez-Zuriaga, Daniel; Artacho-Pérez, Carla; Biviá-Roig, Gemma

    2016-06-01

    Various stimuli such as the flexibility of lumbopelvic structures influence the neuromuscular responses of the trunk musculature, leading to different load sharing strategies and reflex muscle responses from the afferents of lumbopelvic mechanoreceptors. This link between flexibility and neuromuscular response has been poorly studied. The aim of this study was to investigate the relationship between lumbopelvic flexibility and neuromuscular responses of the erector spinae, hamstring and abdominal muscles during trunk flexion-extension. Lumbopelvic movement patterns were measured in 29 healthy women, who were separated into two groups according to their flexibility during trunk flexion-extension. The electromyographic responses of erector spinae, rectus abdominis and biceps femoris were also recorded. Subjects with greater lumbar flexibility had significantly less pelvic flexibility and vice versa. Subjects with greater pelvic flexibility had a higher rate of relaxation and lower levels of hamstring activation during maximal trunk flexion. The neuromuscular response patterns of the hamstrings seem partially modulated by pelvic flexibility. Not so with the lumbar erector spinae and lumbar flexibility, despite the assertions of some previous studies. The results of this study improve our knowledge of the relationships between trunk joint flexibility and neuromuscular responses, a relationship which may play a role in low back pain.

  14. Weak gravitational shear and flexion with polar shapelets

    NASA Astrophysics Data System (ADS)

    Massey, Richard; Rowe, Barnaby; Refregier, Alexandre; Bacon, David J.; Bergé, Joel

    2007-09-01

    We derive expressions, in terms of `polar shapelets', for the image distortion operations associated with weak gravitational lensing. Shear causes galaxy shapes to become elongated, and is sensitive to the second derivative of the projected gravitational potential along their line of sight; flexion bends galaxy shapes into arcs, and is sensitive to the third derivative. Polar shapelets provide a natural representation, in which both shear and flexion transformations are compact. Through this tool, we understand progress in several weak lensing methods. We then exploit various symmetries of shapelets to construct a range of shear estimators with useful properties. Through an analogous investigation, we also explore several flexion estimators. In particular, some of the estimators can be measured simultaneously and independently for every galaxy, and will provide unique checks for systematics in future weak lensing analyses. Using simulated images from the Shear TEsting Programme, we show that we can recover input shears with no significant bias. A complete software package to parametrize astronomical images in terms of polar shapelets, and to perform a full weak lensing analysis, is available on the Internet.

  15. In-vivo spinal cord deformation in flexion

    NASA Astrophysics Data System (ADS)

    Yuan, Qing; Dougherty, Lawrence; Margulies, Susan S.

    1997-05-01

    Traumatic mechanical loading of the head-neck complex results cervical spinal cord injury when the distortion of the cord is sufficient to produce functional or structural failure of the cord's neural and/or vascular components. Characterizing cervical spinal cord deformation during physiological loading conditions is an important step to defining a comprehensive injury threshold associated with acute spinal cord injury. In this study, in vivo quasi- static deformation of the cervical spinal cord during flexion of the neck in human volunteers was measured using magnetic resonance (MR) imaging of motion with spatial modulation of magnetization (SPAMM). A custom-designed device was built to guide the motion of the neck and enhance more reproducibility. the SPAMM pulse sequence labeled the tissue with a series of parallel tagging lines. A single- shot gradient-recalled-echo sequence was used to acquire the mid-sagittal image of the cervical spine. A comparison of the tagged line pattern in each MR reference and deformed image pair revealed the distortion of the spinal cord. The results showed the cervical spinal cord elongates during head flexion. The elongation experienced by the spinal cord varies linearly with head flexion, with the posterior surface of the cord stretching more than the anterior surface. The maximal elongation of the cord is about 12 percent of its original length.

  16. Surgical Release of Severe Flexion Contracture for Oncologic Knee Arthroplasty

    PubMed Central

    Ng, Vincent Y.

    2017-01-01

    Background: Severe postoperative knee contractures after arthroplasty or megaprosthesis reconstruction occur rarely, but are devastating complications. Management of preoperative flexion contractures is well-described, but there is a paucity of literature for surgical treatment of postoperative contractures. A retrospective chart review was performed for a single surgeon of cases between 1996 and 2014. Results: Nine patients (5 of 66 for pediatrics; 4 of 95 for adults) underwent surgical release for severe stiffness after implantation of knee megaprosthesis. The total arc of motion was improved from a preoperative mean of 34° (range, 10° to 70°) to a postoperative mean 89° (63° to 125°). The amount of extension improved by a mean of 27° (range, -3° to +70°) and the amount of flexion improved by a mean of 28° (range, -10° to +75°). Conclusion: Surgical release of severe postoperative knee contracture is a challenging procedure, but in most cases, the amount of extension and flexion can be improved, yielding a greater total arc of motion.

  17. [Surgical treatment of rupture of the plantar fascia].

    PubMed

    Christel, P; Rigal, S; Poux, D; Roger, B; Witvoët, J

    1993-01-01

    Among the various lesions of the hindfoot in athletes, plantar fascia ruptures are not well documented and their surgical treatment is not often reported in the literature. The purpose of the current work was to more precisely define therapeutic indications and to evaluate the results of the surgical treatment based on the excision-release of the plantar fascia. Between 1986 and 1991, 19 patients (5 females, 14 males, average age 32 years) were operated on by one surgeon. All patients were either recreational or competitive athletes. The plantar fascia rupture occurred 18 times during sports activity. Surgical treatment was indicated when pain persisted despite a well conducted conservative treatment. In 17 cases, MRI allowed to plan the operative strategy by showing the fascia lesion. The patients were operated after an average of 8 months following the initial injury (6-16 months). One patient was lost for follow-up, 2 had a follow-up below 6 months, thus 16 patients were available for analysis. The clinical outcome was evaluated through persistence of pain, return to sports, and functional activity. With a 16-month average follow-up (6-51 months) it was observed that pain constantly disappeared and that 11 patients over 16 returned to the same level of sports activity after 6 months with a time-stable result. After failure of a well conducted conservative treatment, surgical treatment of plantar fascia rupture must be proposed. Surgical technique is based not only on fascia release but also on the excision of the pathological scar tissue in order to avoid the restoration of the continuity of the fascia with the calcaneus.

  18. Shock wave therapy for chronic proximal plantar fasciitis.

    PubMed

    Ogden, J A; Alvarez, R; Levitt, R; Cross, G L; Marlow, M

    2001-06-01

    Three hundred two patients with chronic heel pain caused by proximal plantar fasciitis were enrolled in a study to assess the treatment effects consequent to administration of electrohydraulicall-generated extracorporeal shock waves. Symptoms had been present from 6 months to 18 years. Each treated patient satisfied numerous inclusion and exclusion criteria before he or she was accepted into this study, which was approved by the Food and Drug Administration as a randomized, double-blind evaluation of the efficacy of shock wave therapy for this disorder. Overall, at the predetermined evaluation period 3 months after one treatment, 56% more of the treated patients had a successful result by all four of the evaluation criteria when compared with the patients treated with a placebo. This difference was significant and corroborated the fact that this difference in the results was specifically attributable to the shock wave treatment, rather than any natural improvement caused by the natural history of the condition. The current study showed that the directed application of electrohydraulic-generated shock waves to the insertion of the plantar fascia onto the calcaneus is a safe and effective nonsurgical method for treating chronic, recalcitrant heel pain syndrome that has been present for at least 6 months and has been refractory to other commonly used nonoperative therapies. This technology, when delivered using the OssaTron (High Medical Technology, Kreuz-lingen, Switzerland), has been approved by the Food and Drug Administration specifically for the treatment of chronic proximal plantar fasciitis. The results suggest that this therapeutic modality should be considered before any surgical options, and even may be preferable to cortisone injection, which has a recognized risk of rupture of the plantar fascia and recurrence of symptoms.

  19. Novel and Conservative Approaches Towards Effective Management of Plantar Fasciitis

    PubMed Central

    Ahmad, Awaiz; Kiani, Immad; Ghani, Usman; Wadhera, Vikram; Tom, Todd N

    2016-01-01

    We assessed the effectiveness of the different treatments for plantar fasciitis (PF) based on the changes in functional outcomes. A systematic literature search was carried out and studies from 2010 to 2016 were included in this review. The databases from Google Scholar, PubMed and Cochrane were used for the various treatment modalities of plantar fasciitis. The objectives measured included visual analog scale (VAS), Roles and Maudsley scale, foot function index (FFI), plantar fascia thickness and American Orthopedic Foot and Ankle Society (AOFAS) ankle-hind foot scale as the tools to predict the improvement in symptoms of pain and discomfort. Eight randomized controlled trails that met the selection criteria were included in this review. Extracorporeal shock wave lithotripsy (ESWL) with botulinum toxin type A, corticosteroid injections, autologous whole blood and plasma treatment, novel treatments like cryopreserved human amniotic membrane, effect of placebo, platelet rich plasma injections and corticosteroid injections, physiotherapy and high strength training were analyzed. All the treatment modalities applied did lead to the reduction in pain scores, but for long term management autologous condition plasma and platelet rich plasma are the preferred treatment options. Impact of physiotherapy and high strength training is equivalent to corticosteroid injections and hence is suited for patients avoiding invasive forms of treatment.  PMID:28083457

  20. Novel and Conservative Approaches Towards Effective Management of Plantar Fasciitis.

    PubMed

    Assad, Salman; Ahmad, Awaiz; Kiani, Immad; Ghani, Usman; Wadhera, Vikram; Tom, Todd N

    2016-12-05

    We assessed the effectiveness of the different treatments for plantar fasciitis (PF) based on the changes in functional outcomes. A systematic literature search was carried out and studies from 2010 to 2016 were included in this review. The databases from Google Scholar, PubMed and Cochrane were used for the various treatment modalities of plantar fasciitis. The objectives measured included visual analog scale (VAS), Roles and Maudsley scale, foot function index (FFI), plantar fascia thickness and American Orthopedic Foot and Ankle Society (AOFAS) ankle-hind foot scale as the tools to predict the improvement in symptoms of pain and discomfort. Eight randomized controlled trails that met the selection criteria were included in this review. Extracorporeal shock wave lithotripsy (ESWL) with botulinum toxin type A, corticosteroid injections, autologous whole blood and plasma treatment, novel treatments like cryopreserved human amniotic membrane, effect of placebo, platelet rich plasma injections and corticosteroid injections, physiotherapy and high strength training were analyzed. All the treatment modalities applied did lead to the reduction in pain scores, but for long term management autologous condition plasma and platelet rich plasma are the preferred treatment options. Impact of physiotherapy and high strength training is equivalent to corticosteroid injections and hence is suited for patients avoiding invasive forms of treatment.

  1. Insertion torque, resonance frequency, and removal torque analysis of microimplants.

    PubMed

    Tseng, Yu-Chuan; Ting, Chun-Chan; Du, Je-Kang; Chen, Chun-Ming; Wu, Ju-Hui; Chen, Hong-Sen

    2016-09-01

    This study aimed to compare the insertion torque (IT), resonance frequency (RF), and removal torque (RT) among three microimplant brands. Thirty microimplants of the three brands were used as follows: Type A (titanium alloy, 1.5-mm × 8-mm), Type B (stainless steel, 1.5-mm × 8-mm), and Type C (titanium alloy, 1.5-mm × 9-mm). A synthetic bone with a 2-mm cortical bone and bone marrow was used. Each microimplant was inserted into the synthetic bone, without predrilling, to a 7 mm depth. The IT, RF, and RT were measured in both vertical and horizontal directions. One-way analysis of variance and Spearman's rank correlation coefficient tests were used for intergroup and intragroup comparisons, respectively. In the vertical test, the ITs of Type C (7.8 Ncm) and Type B (7.5 Ncm) were significantly higher than that of Type A (4.4 Ncm). The RFs of Type C (11.5 kHz) and Type A (10.2 kHz) were significantly higher than that of Type B (7.5 kHz). Type C (7.4 Ncm) and Type B (7.3 Ncm) had significantly higher RTs than did Type A (4.1 Ncm). In the horizontal test, both the ITs and RTs were significantly higher for Type C, compared with Type A. No significant differences were found among the groups, and the study hypothesis was accepted. Type A had the lowest inner/outer diameter ratio and widest apical facing angle, engendering the lowest IT and highest RF values. However, no significant correlations in the IT, RF, and RT were observed among the three groups.

  2. Effects of stretching on peak torque and the H:Q ratio.

    PubMed

    Costa, P B; Ryan, E D; Herda, T J; DeFreitas, J M; Beck, T W; Cramer, J T

    2009-01-01

    The purpose of the present study was to examine the acute effects of hamstring and calf stretching on leg extension and flexion peak torque (PT) and the hamstrings-to-quadriceps (H : Q) ratio during maximal, concentric isokinetic muscle actions at 60, 180, and 300 degrees . s (-1) in women. Thirteen women (mean age +/- SD = 20.8 +/- 1.8 yrs; height = 163.0 +/- 5.7 cm; mass = 64.0 +/- 8.3 kg) performed 3 maximal concentric isokinetic leg extension and flexion muscle actions at 3 randomly ordered angular velocities (60, 180, and 300 degrees . s (-1)) before and after a bout of static stretching. The stretching protocol consisted of 1 unassisted and 3 assisted static stretching exercises designed to stretch the posterior muscles of the thigh and leg. Four repetitions of each stretch were held for 30 s with 20 s rest between repetitions. The results indicated that leg flexion PT decreased from pre- to post-stretching (34.9 +/- 3.5 and 32.4 +/- 3.2 Nm, respectively) collapsed across velocity. However, no other changes were observed from pre- to post-stretching for leg extension PT (78.5 +/- 5.9 and 77.8 +/- 5.5 Nm, respectively) and the H : Q ratio (0.47 +/- 0.04 and 0.44 +/- 0.03, respectively). Our findings suggested that despite the stretching-induced decreases in leg flexion PT, leg extension PT and the H : Q ratios were unaltered by the stretching.

  3. First Tarsometatarsal Arthrodesis: An Anatomic Evaluation of Dorsomedial Versus Plantar Plating.

    PubMed

    Simons, Paul; Fröber, Rosemarie; Loracher, Clemens; Knobe, Matthias; Gras, Florian; Hofmann, Gunther O; Klos, Kajetan

    2015-01-01

    Fusion of the first tarsometatarsal joint is a widely used procedure for the correction of hallux valgus deformity. Although dorsomedial H-shaped plating systems are being increasingly used, fusion can also be achieved by plantar plating. The goal of the present study was to compare these 2 operative techniques based on the anatomic considerations and show the potential pitfalls of both procedures. Six pairs of deep-frozen human lower legs were used in the present cadaveric study. In a randomized manner, either dorsomedial arthrodesis or plantar plating through a medial incision was performed. With regard to arterial injury, the plantar technique resulted in fewer lesions (plantar, 4 injuries [66.7%] to the terminal branches of the first digital branch of the medial plantar artery; dorsomedial, 3 injuries [50%] to the main trunks of the plantar metatarsal arteries and the first dorsal metatarsal artery). With respect to injury to the veins, the plantar procedure affected significantly fewer high-caliber subcutaneous trunk veins. The nerves coursing through the operative field, such as the saphenous and superficial fibular nerves, were compromised more often by the dorsal approach. Neither the plantar plating nor the dorsomedial plating technique was associated with injury to the insertion of the tibialis anterior muscle. Both studied techniques are safe, well-established procedures. Arthrodesis with plantar plating, however, offers additional advantages and is a reliable tool in the foot and ankle surgeon's repertoire.

  4. Impaired plantar sensitivity among the obese is associated with increased postural sway.

    PubMed

    Wu, Xuefang; Madigan, Michael L

    2014-11-07

    Impaired foot plantar sensitivity has been hypothesized among individuals who are obese, and may contribute to their impaired balanced during quiet standing. The objective of this study was to investigate the effects of obesity on plantar sensitivity, and explore the relationship between plantar sensitivity and balance during quiet standing. Thirty-nine young adults from the university population participated in the study including 19 obese and 20 non-obese adults. Plantar sensitivity was measured as the force threshold at which an increasing force applied to the plantar surface of the foot was first perceived, and the force threshold at which a decreasing force was last perceived. Measurements were obtained while standing, and at two locations on the plantar surface of the dominant foot. Postural sway during quiet standing was then measured under three different sensory conditions. Results indicated less sensitive plantar sensitivity and increased postural sway among the obese, and statistically significant correlations between plantar sensitivity and postural sway that were characterized as weak to moderate in strength. As such, impaired plantar sensitivity among individuals who are obese may be a mechanism by which obesity degrades standing balance among these individuals.

  5. Applicability of contrast-enhanced ultrasound in the diagnosis of plantar fasciitis.

    PubMed

    Broholm, Rikke; Pingel, Jessica; Simonsen, Lene; Bülow, Jens; Johannsen, Finn

    2017-02-27

    Contrast-enhanced ultrasound (CEUS) is used to visualize the microvascularisation in various tissues. The purpose of this study was to investigate whether CEUS could be used to visualize the microvascular volume (MV) in the plantar fascia, and to compare the method to clinical symptoms and B-mode ultrasound (US) in patients with plantar fasciitis (PF). 20 patients with unilateral PF were included and were divided by US in insertional thickening (10), midsubstance thickening (5) and no US changes (5). The MV was measured simultaneously in both heels. Four areas in the plantar fascia and plantar fat pad were measured independently by two observers. Inter- and intra-observer correlation analyses were performed. The asymptomatic heels showed a constantly low MV, and for the whole group of patients a significantly higher MV was found in the symptomatic plantar fascia and plantar fat pad. Inter-observer correlation as well as intra-observer agreement was excellent. The MV in the plantar fascia and plantar fat pad can be measured reliably using CEUS, suggesting that it is a reproducible method to examine patients with plantar fasciitis. This article is protected by copyright. All rights reserved.

  6. The Human Papillomavirus and Its Role in Plantar Warts: A Comprehensive Review of Diagnosis and Management.

    PubMed

    Vlahovic, Tracey C; Khan, M Tariq

    2016-07-01

    Viral warts or verruca pedis (plantar warts) are common skin conditions seen in both children and adults. Human papilloma virus (HPV), a DNA virus, is responsible for plantar verrucae. It needs an epidermal abrasion and a transiently impaired immune system to inoculate a keratinocyte. These entities are a therapeutic conundrum for many practitioners. This article discusses HPV infiltration and its subtypes involved in plantar warts; the evaluation of patients with plantar warts; and subsequent treatment options, such as laser, Candida albicans immunotherapy, topical therapy such as phytotherapy, and surgical excision.

  7. [The use of magnetic resonance imaging in the diagnosis of plantar fibromatosis: a case report].

    PubMed

    Halefoğlu, Ahmet Mesrur

    2005-01-01

    Plantar fibromatosis is a benign but infiltrative neoplasm, presenting as a slow-growing nodular thickening most often within the central band of the plantar aponeurosis. In this case report, we presented a 43-year-old male patient who had a tender nodule in the sole of the right foot for two years. On magnetic resonance images, the location and signal intensity characteristics of the lesion were suggestive of plantar fibromatosis, which was histologically confirmed following an incisional biopsy. Magnetic resonance imaging is a noninvasive method for confirmation of the clinical diagnosis of plantar fibromatosis and also has an important role in planning surgical treatment by delineating the extent of the lesion.

  8. Fibromatosis of the plantar fascia: diagnosis and indications for surgical treatment.

    PubMed

    Dürr, H R; Krödel, A; Trouillier, H; Lienemann, A; Refior, H J

    1999-01-01

    Plantar fibromatosis is a rare, benign lesion involving the plantar aponeurosis. Eleven patients (13 feet) underwent 24 operations, including local excision, wide excision, or complete plantar fasciectomy. Clinical results were evaluated retrospectively. There were no differences among the subgroups in postoperative complications. Two primary fasciectomies did not recur. Three of six revised fasciectomies, seven of nine wide excisions, and six of seven local excisions recurred. Our results indicate that recurrence of plantar fibromatosis after surgical resection can be reduced by aggressive initial surgical resection.

  9. Biomechanical consequences of plantar fascial release or rupture during gait. Part II: alterations in forefoot loading.

    PubMed

    Sharkey, N A; Donahue, S W; Ferris, L

    1999-02-01

    With a model using feet from cadavers, we tested the hypothesis that plantar fascial release or rupture alters the loading environment of the forefoot during the latter half of the stance phase of gait. The model simulated the position and loading environment of the foot at two instants: early in terminal stance immediately after heel-off and late in terminal stance just preceding contralateral heel strike. Eight feet were loaded at both positions by simulated plantar flexor contraction, and the distribution of plantar pressure was measured before and after progressive release of the plantar fascia. Strain in the diaphysis of the second metatarsal was also measured, from which the bending moments and axial force imposed on the metatarsal were calculated. Cutting the medial half of the central plantar fascial band significantly increased peak pressure under the metatarsal heads but had little effect on pressures in other regions of the forefoot or on second metatarsal strain and loading. Dividing the entire central band or completely releasing the plantar fascia from the calcaneus had a much greater effect and caused significant shifts in plantar pressure and force from the toes to beneath the metatarsal heads. These shifts were accompanied by significantly increased strain and bending in the second metatarsal. Complete fasciotomy increased the magnitude of strain in the dorsal aspect of the second metatarsal by more than 80%, suggesting that plantar fascial release or rupture accelerates the accumulation of fatigue damage in these bones. Altered forefoot loading may be a potential complication of plantar fasciotomy.

  10. Percutaneous Ultrasonic Fasciotomy for Refractory Plantar Fasciopathy After Failure of a Partial Endoscopic Release Procedure.

    PubMed

    Pourcho, Adam M; Hall, Mederic M

    2015-11-01

    Plantar fasciopathy is a painful, degenerative condition of the plantar fascia that affects 2 million people annually and has an estimated 10% lifetime prevalence. When both nonoperative and operative management fails, patients have limited therapeutic options. We present a case of an active 47-year-old male runner who was successfully treated with songraphically guided percutaneous ultrasonic fasciotomy after undergoing a prolonged course of nonoperative management and an endoscopic plantar fascia release procedure. Percutaneous ultrasonic fasciotomy may be considered in patients with chronic, refractory plantar fasciopathy, including those for whom a prior operative release procedure has failed.

  11. Radiation Forces and Torques without Stress (Tensors)

    ERIC Educational Resources Information Center

    Bohren, Craig F.

    2011-01-01

    To understand radiation forces and torques or to calculate them does not require invoking photon or electromagnetic field momentum transfer or stress tensors. According to continuum electromagnetic theory, forces and torques exerted by radiation are a consequence of electric and magnetic fields acting on charges and currents that the fields induce…

  12. Casimir torque on a cylindrical gear

    NASA Astrophysics Data System (ADS)

    Vaidya, Varun

    2014-08-01

    I utilize effective field theory(EFT) techniques to calculate the Casimir torque on a cylindrical gear in the presence of a polarizable but neutral object and present results for the energy and torque as a function of angle for a gear with multiple cogs, as well as for the case of a concentric cylindrical gear.

  13. 14 CFR 25.361 - Engine torque.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Supplementary Conditions § 25.361 Engine torque. (a) Each engine mount and its supporting structure must be designed for the effects of— (1) A limit engine torque.... (b) For turbine engine installations, the engine mounts and supporting structure must be designed...

  14. 14 CFR 25.361 - Engine torque.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Supplementary Conditions § 25.361 Engine torque. (a) Each engine mount and its supporting structure must be designed for the effects of— (1) A limit engine torque.... (b) For turbine engine installations, the engine mounts and supporting structure must be designed...

  15. 14 CFR 25.361 - Engine torque.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Supplementary Conditions § 25.361 Engine torque. (a) Each engine mount and its supporting structure must be designed for the effects of— (1) A limit engine torque.... (b) For turbine engine installations, the engine mounts and supporting structure must be designed...

  16. 14 CFR 25.361 - Engine torque.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Supplementary Conditions § 25.361 Engine torque. (a) Each engine mount and its supporting structure must be designed for the effects of— (1) A limit engine torque.... (b) For turbine engine installations, the engine mounts and supporting structure must be designed...

  17. 14 CFR 25.361 - Engine torque.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Supplementary Conditions § 25.361 Engine torque. (a) Each engine mount and its supporting structure must be designed for the effects of— (1) A limit engine torque.... (b) For turbine engine installations, the engine mounts and supporting structure must be designed...

  18. A review of 105 consecutive uniport endoscopic plantar fascial release procedures for the treatment of chronic plantar fasciitis.

    PubMed

    Morton, Troy N; Zimmerman, Jeffrey P; Lee, Michael; Schaber, John D

    2013-01-01

    Plantar fasciitis is a common cause of heel pain in the U.S. Army soldier, resulting in a significant loss of man hours. Given the heavy operations tempo of the U.S. military, successful treatment options need to be considered and used as quickly as possible. Plantar fasciitis can be successfully treated in up to 90% of patients using conservative measures. Operative intervention might need to be considered for those in whom conservative measures have failed. The present report is a review of 105 consecutive uniport endoscopic plantar fascial release procedures performed by the principal investigator during a 9-year period. The following data were collected and analyzed: gender, age, weight, height, body mass index, medical treatment facility, procedure laterality, preoperative pain levels, postoperative pain levels at 3 months, first ambulatory day in the controlled ankle motion boot, return to activity as tolerated, and complications. Three major points were of interest: evidence of improvement in chronic plantar fasciitis when treated with uniport endoscopic procedures; the patient attributes associated with self-reported pain levels 90 days postoperatively; and the patient attributes associated with the average time until patients were able to return to activities as tolerated in a controlled ankle motion boot. It was noted that 44.5% of those with a body mass index of 29.80 kg/m(2) or greater reported a postoperative pain level of 0; and 96.3% of those with a body mass index of 25.53 kg/m(2) or less reported postoperative pain levels of 0. The analyzed data were used to characterize the clinical outcomes of the procedure, identify changes in outcome with surgeon experience, and identify whether certain patient subgroups have better outcomes, allowing surgeons to identify which patient might be the best candidates for an endoscopic release procedure.

  19. Estimating Torque Imparted on Spacecraft Using Telemetry

    NASA Technical Reports Server (NTRS)

    Lee, Allan Y.; Wang, Eric K.; Macala, Glenn A.

    2013-01-01

    There have been a number of missions with spacecraft flying by planetary moons with atmospheres; there will be future missions with similar flybys. When a spacecraft such as Cassini flies by a moon with an atmosphere, the spacecraft will experience an atmospheric torque. This torque could be used to determine the density of the atmosphere. This is because the relation between the atmospheric torque vector and the atmosphere density could be established analytically using the mass properties of the spacecraft, known drag coefficient of objects in free-molecular flow, and the spacecraft velocity relative to the moon. The density estimated in this way could be used to check results measured by science instruments. Since the proposed methodology could estimate disturbance torque as small as 0.02 N-m, it could also be used to estimate disturbance torque imparted on the spacecraft during high-altitude flybys.

  20. In-line rotating capacitive torque sensor

    DOEpatents

    Kronberg, J.W.

    1991-09-10

    Disclosed are a method and apparatus for measuring torques developed along a rotating mechanical assembly comprising a rotating inner portion and a stationary outer portion. The rotating portion has an electrically-conductive flexing section fitted between two coaxial shafts in a configuration which varies radially in accordance with applied torque. The stationary portion comprises a plurality of conductive plates forming a surface concentric with and having a diameter slightly larger than the diameter of the rotating portion. The capacitance between the outer, nonrotating and inner, rotating portion varies with changes in the radial configuration of the rotating portion. Signal output varies approximately linearly with torque for small torques, nonlinearly for larger torques. The sensor is preferably surrounded by a conductive shell to minimize electrical interference from external sources. 18 figures.

  1. Torque requirement of rotating rods in airflow

    NASA Technical Reports Server (NTRS)

    Barna, P. S.; Crossman, G. R.

    1979-01-01

    Experiments were performed to determine the torque required for rotating a rotor disk fitted with a number of radially arranged rods placed into a ducted airflow. An array of stationary rods, also radially arranged, was placed upstream close to the rotor with a small gap between the rods to cause wake interference. The results show that torque generally increased with airflow and the rate of increase varied considerably. At lower values of airflow, the rate of increase was larger than at higher airflow, and definite torque peaks occurred at certain airflow rates, where the torque attained a maximum within the test airflow range. During the test, a maximum blade passage frequency of 2037 Hz was attained. The results also show that the torque peaks occurred at the same Strouhal number for all speeds.

  2. Torque transducer based on fiber Bragg grating

    NASA Astrophysics Data System (ADS)

    Li, Tao; Jiang, Shu; Li, Jiang; Lin, Jiejun; Qi, Hongli

    2016-11-01

    In order to obtain the accurate torque measurements in harsh condition, such as marine environment, a torque transducer based on fiber Bragg grating is proposed in this paper. According to its optimized elastomer design and fiber Bragg grati ng patching tactics, the new proposed torque transducer realizes automatic compensations of temperature and bending moment which avoids influences from environment. The accuracy and stability of the torquetransducer, as well as its under water performance are tested by loading tests both in air and in underwater environment, which indicate the designed tor que transducer is not only able to realize highaccurate and robust measurements, but also can be applied in torque sensing in harsh environment. We believe the proposed design detailed illustrated in this paper provides important reference for studies and applications on torque measurements in marine environment.

  3. In-line rotating capacitive torque sensor

    DOEpatents

    Kronberg, James W.

    1991-01-01

    A method and apparatus for measuring torques developed along a rotating mechanical assembly comprising a rotating inner portion and a stationary outer portion. The rotating portion has an electrically-conductive flexing section fitted between two coaxial shafts in a configuration which varies radially in accordance with applied torque. The stationary portion comprises a plurality of conductive plates forming a surface concentric with and having a diameter slightly larger than the diameter of the rotating portion. The capacitance between the outer, nonrotating and inner, rotating portion varies with changes in the radial configuration of the rotating portion. Signal output varies approximately linearly with torque for small torques, nonlinearly for larger torques. The sensor is preferably surrounded by a conductive shell to minimize electrical interference from external sources.

  4. RADIOACTIVE MATERIAL PACKAGING TORQUE REQUIREMENTS COMPLIANCE

    SciTech Connect

    Watkins, R.; Leduc, D.

    2011-03-24

    Shipping containers used to transport radioactive material (RAM) in commerce employ a variety of closure mechanisms. Often, these closure mechanisms require a specific amount of torque be applied to a bolt, nut or other threaded fastener. It is important that the required preload is achieved so that the package testing and analysis is not invalidated for the purpose of protecting the public. Torque compliance is a means of ensuring closure preload, is a major factor in accomplishing the package functions of confinement/containment, sub-criticality, and shielding. This paper will address the importance of applying proper torque to package closures, discuss torque value nomenclature, and present one methodology to ensure torque compliance is achieved.

  5. Removal Tools are Faster and Produce Less Force and Torque on the Helmet Than Cutting Tools During Face-Mask Retraction.

    PubMed

    Jenkins, Heather L; Valovich, Tamara C; Arnold, Brent L; Gansneder, Bruce M

    2002-09-01

    OBJECTIVE: To investigate the retraction time, forces, and torques applied to the football helmet during removal of the face mask with different face-mask removal tools. DESIGN AND SETTING: Subjects retracted the face mask of a football helmet mounted to a force platform in a laboratory setting. They removed a standard face mask by cutting or removing (or both) the lateral plastic loop straps using 4 different tools: the Trainer's Angel (TA), FM Extractor (FM), power screwdriver (SD), and Quick Release System (QR) in a counterbalanced fashion. SUBJECTS: Eighteen certified athletic trainers participated in this study. MEASUREMENTS: We started measuring time when the subject picked up the tool and ended when the face mask was in a fully retracted position. Maximum forces and torques were measured from the force platform during the retraction process. RESULTS: The SD and QR retracted the face mask significantly faster than the TA and FM. Forces producing superior-inferior translation were least with the SD. The SD and QR produced less lateral translation and rotation and lateral flexion moment than the TA and FM. The FM produced less torque in the lateral flexion moment than the TA. CONCLUSIONS: Tools that removed the loop straps (SD, QR) were faster and produced less force and torque on the helmet than the tools that cut through the loop straps (TA, FM).

  6. Distribution and correlates of plantar hyperkeratotic lesions in older people

    PubMed Central

    Spink, Martin J; Menz, Hylton B; Lord, Stephen R

    2009-01-01

    Background Plantar hyperkeratotic lesions are common in older people and are associated with pain, mobility impairment and functional limitations. However, little has been documented in relation to the frequency or distribution of these lesions. The aim of this study was to document the occurrence of plantar hyperkeratotic lesions and the patterns in which they occur in a random sample of older people. Methods A medical history questionnaire was administered to a random sample of 301 people living independently in the community (117 men, 184 women) aged between 70 and 95 years (mean 77.2, SD 4.9), who also underwent a clinical assessment of foot problems, including the documentation of plantar lesion locations, toe deformities and the presence and severity of hallux valgus. Results Of the 301 participants, 180 (60%) had at least one plantar hyperkeratotic lesion. Those with plantar lesions were more likely to be female (χ2 = 18.75, p < 0.01; OR = 2.86), have moderate to severe hallux valgus (χ2 = 6.15, p < 0.02; OR = 2.95), a larger dorsiflexion range of motion at the ankle (39.4 ± 9.3 vs 36.3 ± 8.4°; t = 2.68, df = 286, p < 0.01), and spent more time on their feet at home (5.1 ± 1.0 vs 4.8 ± 1.3 hours, t = -2.46, df = 299, p = 0.01). No associations were found between the presence of plantar lesions and body mass index, obesity, foot posture, dominant foot or forefoot pain. A total of 53 different lesions patterns were observed, with the most common lesion pattern being "roll-off" hyperkeratosis on the medial aspect of the 1st metatarsophalangeal joint (MPJ), accounting for 12% of all lesion patterns. "Roll-off" lesions under the 1st MPJ and interphalangeal joint were significantly associated with moderate to severe hallux valgus (p < 0.05), whereas lesions under the central MPJs were significantly associated with deformity of the corresponding lesser toe (p < 0.05). Factor analysis indicated that 62% of lesion patterns could be grouped under three broad

  7. Direction-Specific Impairments in Cervical Range of Motion in Women with Chronic Neck Pain: Influence of Head Posture and Gravitationally Induced Torque

    PubMed Central

    Björklund, Martin; Svedmark, Åsa; Srinivasan, Divya; Djupsjöbacka, Mats

    2017-01-01

    Background Cervical range of motion (ROM) is commonly assessed in clinical practice and research. In a previous study we decomposed active cervical sagittal ROM into contributions from lower and upper levels of the cervical spine and found level- and direction-specific impairments in women with chronic non-specific neck pain. The present study aimed to validate these results and investigate if the specific impairments can be explained by the neutral posture (defining zero flexion/extension) or a movement strategy to avoid large gravitationally induced torques on the cervical spine. Methods Kinematics of the head and thorax was assessed in sitting during maximal sagittal cervical flexion/extension (high torque condition) and maximal protraction (low torque condition) in 120 women with chronic non-specific neck pain and 40 controls. We derived the lower and upper cervical angles, and the head centre of mass (HCM), from a 3-segment kinematic model. Neutral head posture was assessed using a standardized procedure. Findings Previous findings of level- and direction-specific impairments in neck pain were confirmed. Neutral head posture was equal between groups and did not explain the direction-specific impairments. The relative magnitude of group difference in HCM migration did not differ between high and low torques conditions, lending no support for our hypothesis that impairments in sagittal ROM are due to torque avoidance behaviour. Interpretation The direction- and level-specific impairments in cervical sagittal ROM can be generalised to the population of women with non-specific neck pain. Further research is necessary to clarify if torque avoidance behaviour can explain the impairments. PMID:28099504

  8. Absence of distal interphalangeal creases of fingers with flexion limitation.

    PubMed Central

    Fried, K; Mundel, G

    1976-01-01

    An Ashkenazi Jewish family is described, in which absence of distal interphalangeal creases of fingers with flexion limitation is transmitted through 4 generations with 8 affected individuals. The malformation is caused by an autosomal dominant gene with full penetrance and variable expressivity, and causes only little inconvenience. In one case the joints were normal on radiological examination. The malformation was not associated with any other anomaly except in the propositus who was referred becaused of profound mental retardation and cerebral palsy. This association is probably fortuitous as the other affected members were of above average intelligence. We were unable to find any report on this anomaly without associated malformations. Images PMID:933109

  9. Absence of distal interphalangeal creases of fingers with flexion limitation.

    PubMed

    Fried, K; Mundel, G

    1976-04-01

    An Ashkenazi Jewish family is described, in which absence of distal interphalangeal creases of fingers with flexion limitation is transmitted through 4 generations with 8 affected individuals. The malformation is caused by an autosomal dominant gene with full penetrance and variable expressivity, and causes only little inconvenience. In one case the joints were normal on radiological examination. The malformation was not associated with any other anomaly except in the propositus who was referred becaused of profound mental retardation and cerebral palsy. This association is probably fortuitous as the other affected members were of above average intelligence. We were unable to find any report on this anomaly without associated malformations.

  10. Research on new dynamic torque calibration system

    NASA Astrophysics Data System (ADS)

    Zhang, Li; Wang, Zhong Yu; Yin, Xiao

    2016-06-01

    Dynamic torque calibration method based on rotating table and interferometric system is studied in this paper. A load mass with certain moment of inertia are screwed on the top of torque transducer, the dynamic torque is realized by load object are traceable to angular acceleration and moment of inertia of the object by M (t)=I θ ¨(t) , where I is the total moment of inertia acting on the sensing element of the torque transducer and θ ¨ is the time and spatial-dependent angular acceleration of the load object which is directly measured by a laser interferometer. This paper will introduce a dynamic torque calibration system developed at Changcheng Institute of Metrology and Measurement (CIMM). It uses servomotor to generate dynamic torque in the range from 0.1Nm to 200Nm, and heterodyne laser interferometers cooperated with column grating are used for angular acceleration measurement. An airbearing system is developed to increase the performance of the dynamic turque calibration system. This paper introduce the setup of the dynamic torque calibration system.

  11. Switching Torque Converter: Concept and Preliminary Implementation

    NASA Astrophysics Data System (ADS)

    Hirota, Koichi; Ikei, Yasushi

    It is preferable to refrain from switching the torque in mechanical systems because the abrupt change tends to cause vibration and noise. However, such vibration can be beneficial if it is used to store mechanical energy. Moreover, torque switching operations at higher frequencies are becoming possible because of the recent advances in clutch devices. This paper describes a novel torque conversion mechanism based on torque switching operations. The fundamental principle of the mechanism is the reciprocal translation between the work to and from axles and the rotational energy of a flywheel. Clutches are used to intermittently connect or disconnect the axles with the flywheel; the output torque is controlled by changing the time ratio of the connection. By performing switching operations at a higher frequency, almost continuous torque conversion can be realized. A prototype was created using electrorheological fluid clutches, and it showed the potential for torque conversion. The performance of the prototype was also analyzed by numerical simulation; this showed that the prototype worked in accordance with the principle. Moreover, the potential capability of the principle was investigated using a numerical model and the results suggest that by improving the mechanical design, a considerable improvement in performance is possible.

  12. Torque Ripple Reduction of Reluctance Torque Assisted Motors Using Asymmetric Flux Barriers

    NASA Astrophysics Data System (ADS)

    Hiramoto, Kenji; Takeda, Yoji; Sanada, Masayuki; Morimoto, Shigeo

    Interior permanent magnet synchronous motor (IPMSM) is efficient and can be operated in wide speed region; therefore it is used widely. However, torque ripple of reluctance torque assisted motors, for example IPMSM and synchronous reluctance motor (SynRM), is very large. The skew is known in the prior art as a torque ripple reduction method of AC motors. Although the skew is effective for torque ripple reduction, structure is complicated and it has the disadvantage that average torque will decrease. The discontinuous variation of magnetic resistance between flux barriers and teeth cause the torque ripple. In this paper, in order to ease the discontinuous variation of magnetic resistance, flux barriers are asymmetrically designed so that the relative position relation between flux barriers and teeth may not be in agreement as much as possible. As a result, the torque ripple can be reduced dramatically without the average torque decrease. The experimental motor has been fabricated and the results of measuring torque ripple prove the validity of the torque ripple reduction using asymmetric flux barriers.

  13. BIOMECHANICAL INVESTIGATION OF STATIC PULL WITH CONSTANT SHOULDER TORQUES.

    DTIC Science & Technology

    of elbow flexion and the height of the shoulder below the lever arm were varied. It was concluded that the best elbow flexion angle for static lever...further concluded that 100 degrees of elbow flexion allows almost steady state of ventilation rate over the entire work period for all loads. These

  14. Imaging of Lesser Metatarsophalangeal Joint Plantar Plate Degeneration, Tear, and Repair.

    PubMed

    Linklater, James M; Bird, Stephen J

    2016-04-01

    Plantar plate degeneration and tear is a common cause of forefoot pain, typically involving the second metatarsophalangeal joint at the proximal phalangeal insertion laterally, frequently confused with the second web space Morton neuroma. The condition has received increased attention with the development of surgical techniques that can result in successful repair of the plantar plate and substantial improvement in patient symptoms. High-resolution MRI or ultrasound can confirm a diagnosis of plantar plate degeneration and tear and exclude other pathologies, particularly Morton neuroma. The normal plantar plate is a mildly hyperechoic structure on ultrasound and is hypointense on all conventional MR sequences. Plantar plate degeneration manifests on ultrasound as hypoechoic echotextural change and on MRI as mild signal hyperintensity on short TE sequences, becoming less conspicuous on long TE sequences. Adjacent entheseal bony irregularity is commonly present. Plantar plate tears on ultrasound may be seen as an anechoic cleft defect or area of heterogeneous echotexture, sometimes more conspicuous with dorsiflexion stress. Plantar plate tears demonstrate greater signal hyperintensity on proton-density sequences, becoming more conspicuous on fat-suppressed proton density and T2-weighted sequences. Edema and fibrotic change in the pericapsular fat plane is commonly seen in the setting of an adjacent plantar plate tear and should not be misinterpreted as reflecting a Morton neuroma.

  15. Flat Feet and a Diagnosis of Plantar Fasciitis in a Marine Corps Recruit.

    PubMed

    Lurati, Ann R

    2015-04-01

    A 22-year-old man sought care at an orthopedic clinic for acute plantar fasciitis. He reported that he had begun an intensive exercise program to prepare himself for Marine Corps Officer Candidate School. Pes Planus, or flat feet, was noted on physical examination. This article reviews the diagnoses of pes planus and plantar fasciitis as well as current intervention strategies.

  16. The effect of heel elevation on strain within the plantar aponeurosis: in vitro study.

    PubMed

    Kogler, G F; Veer, F B; Verhulst, S J; Solomonidis, S E; Paul, J P

    2001-05-01

    Mild, temporary reduction of symptoms from plantar fasciitis have been reported with the use of high heeled shoes (i.e. cowboy boots, ladies pumps). However, little is known on how heel elevation may contribute to a decrease in the pain and inflammation. The aim of this study was to quantify strain in the plantar aponeurosis in cadaveric feet with the use of various heel elevation configurations. An in vitro method that simulated "static" stance was used to determine the loading characteristics of the plantar aponeurosis (n = 12). Heel elevation was evaluated with blocks placed beneath the heel and with a contoured platform that simulated the arch profile of a shoe at three different heel heights (2.0, 4.0, 6.0 cm) with a level plane serving as the control. Strain in the plantar aponeurosis decreased with elevations of the heel that simulated the arch profile of a shoe at load levels (337, 450 N) (P < 0.05). Elevations of the heel with blocks did not significantly affect strain in the plantar aponeurosis (P < 0.05). Contrasting results of some specimen limbs compared with the overall means suggests that the influence of heel elevation on loading of the plantar aponeurosis may be dependent on individual variation and foot structure differences. Therefore, clinicians should be cautious in recommending heel elevation as a treatment for plantar fasciitis since some subjects may not achieve the desired decrease in plantar aponeurosis strain.

  17. Plantar pressures and relative lesser metatarsal lengths in older people with and without forefoot pain.

    PubMed

    Menz, Hylton B; Fotoohabadi, Mohammad R; Munteanu, Shannon E; Zammit, Gerard V; Gilheany, Mark F

    2013-03-01

    Forefoot pain is a common problem in older people. We determined whether plantar pressures during gait and the relative lengths of the lesser metatarsals differ between older people with and without plantar forefoot pain. Dynamic plantar pressure assessment during walking was undertaken using the Tekscan MatScan® system in 118 community-dwelling older people (44 males and 74 females), mean age 74 (standard deviation=5.9) years, 43 (36%) of whom reported current or previous plantar forefoot pain. The relative lengths of metatarsals 1-5 were determined from weightbearing X-rays. Participants with current or previous plantar forefoot pain exhibited significantly (p=0.032) greater peak plantar pressure under metatarsal heads 3-5 (1.93 ± 0.41 kg/cm(2) vs. 1.74 ± 0.48 kg/cm(2) ). However, no differences were found in relative metatarsal lengths between the groups. These findings indicate that older people with forefoot pain generate higher peak plantar pressures under the lateral metatarsal heads when walking, but do not exhibit relatively longer lesser metatarsals. Other factors may be responsible for the observed pressure increase, such as reduced range of motion of the metatarsophalangeal joints and increased stiffness of plantar soft tissues.

  18. Magnetic torque on a rotating superconducting sphere

    NASA Technical Reports Server (NTRS)

    Holdeman, L. B.

    1975-01-01

    The London theory of superconductivity is used to calculate the torque on a superconducting sphere rotating in a uniform applied magnetic field. The London theory is combined with classical electrodynamics for a calculation of the direct effect of excess charge on a rotating superconducting sphere. Classical electrodynamics, with the assumption of a perfect Meissner effect, is used to calculate the torque on a superconducting sphere rotating in an arbitrary magnetic induction; this macroscopic approach yields results which are correct to first order. Using the same approach, the torque due to a current loop encircling the rotating sphere is calculated.

  19. Prediction of plantar shear stress distribution by artificial intelligence methods.

    PubMed

    Yavuz, Metin; Ocak, Hasan; Hetherington, Vincent J; Davis, Brian L

    2009-09-01

    Shear forces under the human foot are thought to be responsible for various foot pathologies such as diabetic plantar ulcers and athletic blisters. Frictional shear forces might also play a role in the metatarsalgia observed among hallux valgus (HaV) and rheumatoid arthritis (RA) patients. Due to the absence of commercial devices capable of measuring shear stress distribution, a number of linear models were developed. All of these have met with limited success. This study used nonlinear methods, specifically neural network and fuzzy logic schemes, to predict the distribution of plantar shear forces based on vertical loading parameters. In total, 73 subjects were recruited; 17 had diabetic neuropathy, 14 had HaV, 9 had RA, 11 had frequent foot blisters, and 22 were healthy. A feed-forward neural network (NN) and adaptive neurofuzzy inference system (NFIS) were built. These systems were then applied to a custom-built platform, which collected plantar pressure and shear stress data as subjects walked over the device. The inputs to both models were peak pressure, peak pressure-time integral, and time to peak pressure, and the output was peak resultant shear. Root-mean-square error (RMSE) values were calculated to test the models' accuracy. RMSE/actual shear ratio varied between 0.27 and 0.40 for NN predictions. Similarly, NFIS estimations resulted in a 0.28-0.37 ratio for local peak values in all subject groups. On the other hand, error percentages for global peak shear values were found to be in the range 11.4-44.1. These results indicate that there is no direct relationship between pressure and shear magnitudes. Future research should aim to decrease error levels by introducing shear stress dependent variables into the models.

  20. Re-evaluation of EMG-torque relation in chronic stroke using linear electrode array EMG recordings.

    PubMed

    Bhadane, Minal; Liu, Jie; Rymer, W Zev; Zhou, Ping; Li, Sheng

    2016-06-28

    The objective was to re-evaluate the controversial reports of EMG-torque relation between impaired and non-impaired sides using linear electrode array EMG recordings. Ten subjects with chronic stroke performed a series of submaximal isometric elbow flexion tasks. A 20-channel linear array was used to record surface EMG of the biceps brachii muscles from both impaired and non-impaired sides. M-wave recordings for bilateral biceps brachii muscles were also made. Distribution of the slope of the EMG-torque relations for the individual channels showed a quasi-symmetrical "M" shaped pattern. The lowest value corresponded to the innervation zone (IZ) location. The highest value from the slope curve for each side was selected for comparison to minimize the effect of electrode placement and IZ asymmetry. The slope was greater on the impaired side in 4 of 10 subjects. There were a weak correlation between slope ratio and strength ratio and a moderate to high correlation between slope ratio and M-wave ratio between two sides. These findings suggest that the EMG-torque relations are likely mediated and influenced by multiple factors. Our findings emphasize the importance of electrode placement and suggest the primary role of peripheral adaptive changes in the EMG-torque relations in chronic stroke.

  1. Chronic multifocal Mycobacterium fortuitum osteomyelitis following penetrating plantar trauma.

    PubMed

    Cruz, Andrea T; Antekeier, Shannon B

    2012-08-01

    We present the case of a 10-year-old girl with Mycobacterium fortuitum osteomyelitis following a plantar puncture wound with vegetative material. Nontuberculous mycobacterial (NTM) skin and soft tissue infections are well described in immunocompromised populations. However, NTM infection can also be seen in healthy hosts following direct inoculation. Magnetic resonance imaging examination demonstrated multifocal midfoot and metatarsal osteomyelitis. Surgical exploration revealed caseation necrosis and a chronic draining sinus tract. Combined surgical debridement and medical therapy resulted in clinical cure. A high index of suspicion and adequate collection and handling of surgical specimens facilitate the diagnosis and treatment of NTM skin and soft tissue infections.

  2. The deep band of the plantar aponeurosis of the human foot.

    PubMed

    Cralley, J C; Schuberth, J M; Fitch, K L

    1982-01-01

    The deep band of the plantar aponeurosis is a variable structure formed by fibers from both the medial and lateral portions of the plantar aponeurosis. This band courses directly to the plantar ligament of the fourth metatarsophalangeal joint. Proximally it is superficial. Distally it passes deep to the tendons of the flexor digitorum longus to attach at the metatarsophalangeal joint. The second plantar and third and fourth dorsal interosseous muscles as well as the transverse head of adductor hallucis have attachments to the deep aponeurotic band. This band becomes taut when the proximal phalanx of the fourth toe is extended. No recent references to this structure could be found. The function of the deep band of the plantar aponeurosis is unknown, although the anatomical arrangement may make it important in stabilizing the fourth ray of the foot during locomotion.

  3. Design and Test of a Soft Plantar Force Measurement System for Gait Detection

    PubMed Central

    Zhang, Xuefeng; Zhao, Yulong; Duan, Zhengyong; Liu, Yan

    2012-01-01

    This work describes a plantar force measurement system. The MEMS pressure sensor, as the key sensing element, is designed, fabricated and embedded into a flexible silicon oil-filled bladder made of silicon rubber to constitute a single sensing unit. A conditioning circuit is designed for signal processing and data acquisition. The characteristics of the plantar force sensing unit are investigated by both static and dynamic tests. A comparison of characteristics between the proposed plantar force sensing unit and a commercial flexible force sensor is presented. A practical experiment of plantar force measurement has been carried out to validate the system. The results demonstrate that the proposed measurement system has a potential for success in the application of plantar force measurement during normal gait. PMID:23208558

  4. Imaging of plantar fascia and Achilles injuries undertaken at the London 2012 Olympics.

    PubMed

    Elias, David A; Carne, Andrew; Bethapudi, Sarath; Engebretsen, Lars; Budgett, Richard; O'Connor, Philip

    2013-12-01

    Plantar fascia and distal Achilles injuries are common in elite athletes. Acute athletic injuries of the plantar fascia include acute plantar fasciopathy and partial or complete tears. Underlying most acute injuries is a background of underlying chronic plantar fasciopathy. Injuries may affect the central or less commonly lateral portions of the fascia and acute tears are generally proximal. Athletic Achilles injuries may occur at the mid tendon or the distal insertion, and there may be an underlying chronic tendinopathy. Acute or chronic paratendinopathy may occur as a separate entity or combined with Achilles injury. In this article, the spectrum of athletic injuries of the plantar fascia and Achilles is described, illustrated by imaging findings from the London 2012 Olympic games.

  5. Reconstruction of lateral forefoot using reversed medial plantar flap with free anterolateral thigh flap.

    PubMed

    Fujioka, Masaki; Hayashida, Kenji; Senju, Chikako

    2014-01-01

    Skin defects of the heel have frequently been reconstructed using the medial plantar flap; however, forefoot coverage has remained a challenge, because the alternatives for flap coverage have been very limited. We describe a case of malignant melanoma on the lateral forefoot that was radically removed and reconstructed successfully with a distally based medial plantar flap, together with a free anterolateral thigh flap. The advantages of this flap include that it does not reduce the vascular supply to the foot owing to reconstruction of the medial plantar vascular systems, reduces the risk of flap congestion, minimizes donor site morbidity, and enables the transport of structurally similar tissues to the plantar forefoot. We believe this technique is a reasonable reconstructive option for large lateral plantar forefoot defects.

  6. Maximum Velocities in Flexion and Extension Actions for Sport

    PubMed Central

    Jessop, David M.

    2016-01-01

    Abstract Speed of movement is fundamental to the outcome of many human actions. A variety of techniques can be implemented in order to maximise movement speed depending on the goal of the movement, constraints, and the time available. Knowing maximum movement velocities is therefore useful for developing movement strategies but also as input into muscle models. The aim of this study was to determine maximum flexion and extension velocities about the major joints in upper and lower limbs. Seven university to international level male competitors performed flexion/extension at each of the major joints in the upper and lower limbs under three conditions: isolated; isolated with a countermovement; involvement of proximal segments. 500 Hz planar high speed video was used to calculate velocities. The highest angular velocities in the upper and lower limb were 50.0 rad·s-1 and 28.4 rad·s-1, at the wrist and knee, respectively. As was true for most joints, these were achieved with the involvement of proximal segments, however, ANOVA analysis showed few significant differences (p<0.05) between conditions. Different segment masses, structures and locations produced differing results, in the upper and lower limbs, highlighting the requirement of segment specific strategies for maximal movements. PMID:28149339

  7. How Plantar Exteroceptive Efficiency Modulates Postural and Oculomotor Control: Inter-Individual Variability.

    PubMed

    Foisy, Arnaud; Kapoula, Zoï

    2016-01-01

    In a previous experiment, we showed that among young and healthy subjects, thin plantar inserts improve postural control and modify vergence amplitudes. In this experiment, however, significant inter-individual variability was observed. We hypothesize that its origin could be attributed to a different reliance upon feet cutaneous afferents. In order to test this hypothesis, we re-analyzed the data relative to 31 young (age 25.7 ± 3.8) and healthy subjects who participated in the first experiment after having classified them into two groups depending on their Plantar Quotient (PQ = Surface area of CoPfoam/Surface area of CoPfirm ground × 100). Foam decreases the information arising from the feet, normally resulting in a PQ > 100. Hence, the PQ provides information on the weight of plantar cutaneous afferents used in postural control. Twelve people were Plantar-Independent Subjects, as indicated by a PQ < 100. These individuals did not behave like the Normal Plantar Quotient Subjects: they were almost insensitive to the plantar stimulations in terms of postural control and totally insensitive in terms of oculomotor control. We conclude that the inter-individual variability observed in our first experiment is explained by the subjects' degree of plantar reliance. We propose that plantar independence is a dysfunctional situation revealing inefficiency in plantar cutaneous afferents. The latter could be due to a latent somatosensory dysfunction generating a noise which prevents the CNS from correctly processing and using feet somatosensory afferents both for balance and vergence control: Plantar Irritating Stimulus. Considering the non-noxious nature and prevalence of this phenomenon, these results can be of great interest to researchers and clinicians who attempt to trigger postural or oculomotor responses through mechanical stimulation of the foot sole.

  8. Increasing Elbow Torque Output of Stroke Patients by EMG-Controlled External Torque

    DTIC Science & Technology

    2007-11-02

    Abstract- A control algorithm for using homogenic EMG to control external assisting torque is developed for improving the elbow capability of...sacrificing performance. Keywords - Elbow , EMG, assisting torque, stroke I. INTRODUCTION Hemiparesis, which means partial loss of muscle strength...system to increase the total torque capability of the elbow for this class of patients. The system was controlled by surface EMG of biceps and

  9. Damping assembly for a torque converter clutch

    SciTech Connect

    Dull, D.C.

    1989-12-26

    This patent describes a turbine damped torque converter and clutch. It comprises: a pressure plate; a torque converter turbine; a torque converter impeller; means including a control chamber for the pressure plate means for controlling the apply and release of the clutch for engaging the clutch with the impeller; a torque converter output shaft; a planetary gear arrangement including an input gear drivingly connected with the pressure plate, a reaction gear drivingly connected with the turbine, an output member drivingly connected with the output shaft and pinion gear means meshing with the input gear and the reaction gear for drivingly interconnecting the turbine and the pressure plate at a drive ratio of the turbine to the pressure plate of less than 1:1; and one-way drive means disposed between the turbine and the output shaft for preventing the turbine from overrunning the output shaft.

  10. Torque equilibrium attitude control for Skylab reentry

    NASA Technical Reports Server (NTRS)

    Glaese, J. R.; Kennel, H. F.

    1979-01-01

    All the available torque equilibrium attitudes (most were useless from the standpoint of lack of electrical power) and the equilibrium seeking method are presented, as well as the actual successful application during the 3 weeks prior to Skylab reentry.

  11. Improved computed torque control for industrial robots

    NASA Technical Reports Server (NTRS)

    Uebel, Mark; Minis, Ioannis; Cleary, Kevin

    1992-01-01

    The authors examine the computed torque control problem for a robot arm with flexible, geared, joint drive systems which are typical in many industrial robots. The standard computed torque algorithm is not directly applicable to this class of manipulators due to the dynamics introduced by the joint drive systems. The proposed approach overcomes this problem by combining a novel computed torque algorithm with simple torque controllers at each joint of the robot. The control scheme is applied to a seven degree-of-freedom industrial manipulator, and the system performance in standard tasks is evaluated using both dynamic simulation and actual experiments. The results show that the proposed controller leads to improved tracking performance over a conventional PD (proportional plus derivative) controller.

  12. Fundamental limits of optical force and torque

    NASA Astrophysics Data System (ADS)

    Rahimzadegan, A.; Alaee, R.; Fernandez-Corbaton, I.; Rockstuhl, C.

    2017-01-01

    Optical force and torque provide unprecedented control on the spatial motion of small particles. A valid scientific question, that has many practical implications, concerns the existence of fundamental upper bounds for the achievable force and torque exerted by a plane wave illumination with a given intensity. Here, while studying isotropic particles, we show that different light-matter interaction channels contribute to the exerted force and torque, and analytically derive upper bounds for each of the contributions. Specific examples for particles that achieve those upper bounds are provided. We study how and to which extent different contributions can add up to result in the maximum optical force and torque. Our insights are important for applications ranging from molecular sorting, particle manipulation, and nanorobotics up to ambitious projects such as laser-propelled spaceships.

  13. Transmission of torque at the nanoscale

    NASA Astrophysics Data System (ADS)

    Williams, Ian; Oğuz, Erdal C.; Speck, Thomas; Bartlett, Paul; Löwen, Hartmut; Royall, C. Patrick

    2016-01-01

    In macroscopic mechanical devices, torque is transmitted through gearwheels and clutches. In the construction of devices at the nanoscale, torque and its transmission through soft materials will be a key component. However, this regime is dominated by thermal fluctuations leading to dissipation. Here we demonstrate the principle of torque transmission for a disc-like colloidal assembly exhibiting clutch-like behaviour, driven by 27 particles in optical traps. These are translated on a circular path to form a rotating boundary that transmits torque to additional particles confined to the interior. We investigate this transmission and find that it is determined by solid-like or fluid-like behaviour of the device and a stick-slip mechanism reminiscent of macroscopic gearwheels slipping. The transmission behaviour is predominantly governed by the rotation rate of the boundary and the density of the confined system. We determine the efficiency of our device and thus optimize conditions to maximize power output.

  14. Torque-mixing magnetic resonance spectroscopy.

    PubMed

    Losby, J E; Fani Sani, F; Grandmont, D T; Diao, Z; Belov, M; Burgess, J A J; Compton, S R; Hiebert, W K; Vick, D; Mohammad, K; Salimi, E; Bridges, G E; Thomson, D J; Freeman, M R

    2015-11-13

    A universal, torque-mixing method for magnetic resonance spectroscopy is presented. In analogy to resonance detection by magnetic induction, the transverse component of a precessing dipole moment can be measured in sensitive broadband spectroscopy, here using a resonant mechanical torque sensor. Unlike induction, the torque amplitude allows equilibrium magnetic properties to be monitored simultaneously with the spin dynamics. Comprehensive electron spin resonance spectra of a single-crystal, mesoscopic yttrium iron garnet disk at room temperature reveal assisted switching between magnetization states and mode-dependent spin resonance interactions with nanoscale surface imperfections. The rich detail allows analysis of even complex three-dimensional spin textures. The flexibility of microelectromechanical and optomechanical devices combined with broad generality and capabilities of torque-mixing magnetic resonance spectroscopy offers great opportunities for development of integrated devices.

  15. Torque-mixing Magnetic Resonance Spectroscopy

    NASA Astrophysics Data System (ADS)

    Losby, Joseph; Fani Sani, Fatemeh; Grandmont, Dylan; Diao, Zhu; Belov, Miro; Burgess, Jacob; Compton, Shawn; Hiebert, Wayne; Vick, Doug; Mohammad, Kaveh; Salimi, Elham; Bridges, Gregory; Thomson, Douglas; Freeman, Mark

    A universal, mechanical torque method for magnetic resonance spectroscopy is presented. In analogy to resonance detection by induction, a signal proportional to the transverse component of a precessing dipole moment can be measured as a pure mechanical torque in broadband, frequency-swept spectroscopy. Comprehensive electron spin resonance of a single-crystal, mesoscopic yttrium iron garnet disk at room temperature are presented to demonstrate the method. The rich detail allows analysis of even complex 3D spin textures.

  16. Mandibular lip bumper for molar torque control.

    PubMed

    Celentano, Giuseppe; Longobardi, Annalisa; Cannavale, Rosangela; Perillo, Letizia

    2011-01-01

    Treatment effects of lip bumpers alone include flaring of the mandibular incisors, distalization and uprighting of the mandibular first molars, and buccal expansion of the canines, premolars, and molar. Lip forces are transmitted through this appliance onto the molars. Moreover the lip bumper is able to derotate, expand or constrict, upright and reinforce the anchorage whereas torque control is lacking. Aim of this paper is the presentation of a new type of lip bumper that allows the molar torque control.

  17. Large amplitude oscillation of magnetization in spin-torque oscillator stabilized by field-like torque

    SciTech Connect

    Taniguchi, Tomohiro Kubota, Hitoshi; Imamura, Hiroshi; Tsunegi, Sumito

    2015-05-07

    Oscillation frequency of spin torque oscillator with a perpendicularly magnetized free layer and an in-plane magnetized pinned layer is theoretically investigated by taking into account the field-like torque. It is shown that the field-like torque plays an important role in finding the balance between the energy supplied by the spin torque and the dissipation due to the damping, which results in a steady precession. The validity of the developed theory is confirmed by performing numerical simulations based on the Landau-Lifshitz-Gilbert equation.

  18. 14 CFR 23.397 - Limit control forces and -torques.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Limit control forces and -torques. 23.397... Control Surface and System Loads § 23.397 Limit control forces and -torques. (a) In the control surface... limit pilot forces and torques are as follows: Control Maximum forces or torques for design...

  19. Torque and Learning and Behavior Problems in Children.

    ERIC Educational Resources Information Center

    Zendel, Ivan H.; Pihl, R. O.

    1980-01-01

    Findings indicate minimal differences, on diagnostic tests, between children who exhibited torque and those who did not. Torque is defined as the circling of any X in a clockwise direction. Torque is not associated with learning problems in school. Diagnostic utility of torque should be carefully considered. (Author)

  20. 14 CFR 23.397 - Limit control forces and -torques.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Limit control forces and -torques. 23.397... Control Surface and System Loads § 23.397 Limit control forces and -torques. (a) In the control surface... limit pilot forces and torques are as follows: Control Maximum forces or torques for design...

  1. 14 CFR 23.397 - Limit control forces and -torques.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Limit control forces and -torques. 23.397... Control Surface and System Loads § 23.397 Limit control forces and -torques. (a) In the control surface... limit pilot forces and torques are as follows: Control Maximum forces or torques for design...

  2. Fourth-order acoustic torque in intense sound fields

    NASA Technical Reports Server (NTRS)

    Wang, T. G.; Kanber, H.; Olli, E. E.

    1978-01-01

    The observation of a fourth-order acoustic torque in intense sound fields is reported. The torque was determined by measuring the acoustically induced angular deflection of a polished cylinder suspended by a torsion fiber. This torque was measured in a sound field of amplitude greater than that in which first-order acoustic torque has been observed.

  3. Laser-induced torques in metallic ferromagnets

    NASA Astrophysics Data System (ADS)

    Freimuth, Frank; Blügel, Stefan; Mokrousov, Yuriy

    2016-10-01

    We study laser-induced torques in bcc Fe, hcp Co, and L 10 FePt based on first-principles electronic structure calculations and the Keldysh nonequilibrium formalism. We find that the torques have two contributions, one from the inverse Faraday effect (IFE) and one from the optical spin-transfer torque (OSTT). Depending on the ferromagnet at hand and on the quasiparticle broadening the two contributions may be of similar magnitude, or one contribution may dominate over the other. Additionally, we determine the nonequilibrium spin polarization in order to investigate its relation to the torque. We find the torques and the perpendicular component of the nonequilibrium spin polarization to be odd in the helicity of the laser light, while the spin polarization that is induced parallel to the magnetization is helicity independent. The parallel component of the nonequilibrium spin polarization is orders of magnitude larger than the perpendicular component. In the case of hcp Co we find good agreement between the calculated laser-induced torque and a recent experiment.

  4. Knudsen torque on heated micro beams

    SciTech Connect

    Li, Qi; Liang, Tengfei; Ye, Wenjing

    2014-12-09

    Thermally induced mechanical loading has been shown to have significant effects on micro/nano objects immersed in a gas with a non-uniform temperature field. While the majority of existing studies and related applications focus on forces, we investigate the torque, and thus the rotational motion, produced by such a mechanism. Using the asymptotic analysis in the near continuum regime, the Knudsen torque acting on an asymmetrically located uniformly heated microbeam in a cold enclosure is investigated. The existence of a non-zero net torque is demonstrated. In addition, it has been found that by manipulating the system configuration, the rotational direction of the torque can be changed. Two types of rotational motion of the microbeam have been identified: the pendulum motion of a rectangular beam, and the unidirectional rotation of a cylindrical beam. A rotational frequency of 4 rpm can be achieved for the cylindrical beam with a diameter of 3μm at Kn = 0.005. Illustrated by the simulations using the direct simulation of Monte Carlo, the Knudsen torque can be much increased in the transition regime, demonstrating the potential of Knudsen torque serving as a rotation engine for micro/nano objects.

  5. Influence of obstructive sleep apnea syndrome in the fluctuation of the submaximal isometric torque of knee extensors in patients with early-grade osteoarthritis

    PubMed Central

    Silva, Andressa; Mello, Marco T.; Serrão, Paula R.; Luz, Roberta P.; Bittencourt, Lia R.; Mattiello, Stela M.

    2015-01-01

    OBJECTIVE: The aim of this study was to investigate whether obstructive sleep apnea (OSA) alters the fluctuation of submaximal isometric torque of the knee extensors in patients with early-grade osteoarthritis (OA). METHOD: The study included 60 male volunteers, aged 40 to 70 years, divided into four groups: Group 1 (G1) - Control (n=15): without OA and without OSA; Group 2 (G2) (n=15): with OA and without OSA; Group 3 (G3) (n=15): without OA and with OSA; and Group 4 (G4) (n=15) with OA and with OSA. Five patients underwent maximal isometric contractions of 10 seconds duration each, with the knee at 60° of flexion to determine peak torque at 60°. To evaluate the fluctuation of torque, 5 submaximal isometric contractions (50% of maximum peak torque) of 10 seconds each, which were calculated from the standard deviation of torque and coefficient of variation, were performed. RESULTS: Significant differences were observed between groups for maximum peak torque, while G4 showed a lower value compared with G1 (p=0.005). Additionally, for the average torque exerted, G4 showed a lower value compared to the G1 (p=0.036). However, no differences were found between the groups for the standard deviation (p=0.844) and the coefficient of variation (p=0.143). CONCLUSION: The authors concluded that OSA did not change the parameters of the fluctuation of isometric submaximal torque of knee extensors in patients with early-grade OA. PMID:26443974

  6. A reactive torque control law for gyroscopically controlled space vehicles

    NASA Technical Reports Server (NTRS)

    Farmer, J. E.

    1973-01-01

    A method of control is developed based on the reactive torques as seen by the individual CMG gimbals. The application of a torque to the gimbal of a CMG rotates the momentum vector and applies a torque to the spacecraft according to well-known laws. The response (rotation) of the vehicle produces a reverse or reaction torque opposing the torque producing the gimbal movement. The reactive torque and the pseudoinverse control schemes are contrasted in order to point out the simplicity of the first method. Simulation was performed only to the extent necessary to prove that reactive torque stabilization and control is feasible.

  7. Intraosseous lipoma of the calcaneus mimicking plantar fascitis.

    PubMed

    Karthik, K; Aarthi, S

    2011-06-01

    Benign lytic lesions of the calcaneus are rare and are usually asymptomatic. We report this case of a 55-year-old man with bilateral non-traumatic plantar heel pain, which was treated conservatively as plantar fasciitis. At three months follow-up, the patient had complete relief of symptoms in the left heel with partial relief of symptoms on the right side. However under the insistence of the patient an X-ray was taken, which revealed an expansile lytic lesion of the right calcaneus and a normal left heel. CT-scan revealed an expansile lytic lesion on the right calcaneus and an early lytic lesion in the left calcaneus. Following surgical intervention, the diagnosis was confirmed as intra-osseous lipoma and the patient was completely symptom free at two-year follow-up. Patients presenting with non-traumatic heel pain should be explained about the possible causes of heel pain, and should be offered X-ray at the first visit. In patients with X-ray showing unilateral lipoma of the calcaneus, CT scan should be offered to rule out involvement of the opposite side.

  8. Plantar pressures during level walking compared with other ambulatory activities.

    PubMed

    Lundeen, S; Lundquist, K; Cornwall, M W; McPoil, T G

    1994-06-01

    This study was designed to determine the magnitude of plantar pressures during level walking in comparison to other activities. These activities included climbing up stairs, going down stairs, a simple pivot while walking, and a crossover pivot while walking in normal individuals. Twelve volunteers, six men and six women, mean age 28 years, served as subjects. Data were collected on the dominant foot with an EMED-SF pressure sensor platform as each subject walked barefoot and did each of the five activities. Maximum plantar pressure (MPP) and pressure-time integral (PTI) was found in the metatarsal and heel regions. The results of repeated-measures analysis of variance tests showed that the five experimental conditions were statistically different for both MPP and PTI in the metatarsal and heel regions. Post hoc analysis indicated that MPP and PTI were decreased during the going down stairs condition in the heel and increased during the crossover pivot while walking and pivot while walking conditions for the metatarsal region.

  9. Plantar fasciitis/calcaneal spur among security forces personnel.

    PubMed

    Sadat-Ali, M

    1998-01-01

    A prospective single survey was conducted among Security Forces personnel at the Mobile Hospital, Ministry of Interior, Makkah Al-Mukarramah, Saudi Arabia. One hundred three patients presented to the orthopedic clinic with painful heel. A control group of patients from the other clinics without painful heel was also screened. The average age was 38.81 years and 38.1 years in the patient and the control group, respectively. The mean Quetelet index of body mass in the patient group was 30.36 kg/m2 and in the control group it was 26.71 kg/m2. There was a statistically significant difference of p < 0.05 between the two groups for Quetelet index of body mass. The right side was affected in 37 patients, the left side was involved in 45 patients, and 21 patients had pain bilaterally. Seventy-one patients had spur on the calcaneum. The prevalence of painful heel attributable to plantar fasciitis/calcaneum spur was 1.18%. This study suggests that obesity is a cause and initiator of heel pain and plantar fasciitis/calcaneal spur and that improper footwear aggravates the condition.

  10. Potentiation increases peak twitch torque by enhancing rates of torque development and relaxation.

    PubMed

    Froyd, Christian; Beltrami, Fernando Gabe; Jensen, Jørgen; Noakes, Timothy David

    2013-01-01

    The aim of this study was to measure the extent to which potentiation changes in response to an isometric maximal voluntary contraction. Eleven physically active subjects participated in two separate studies. Single stimulus of electrical stimulation of the femoral nerve was used to measure torque at rest in unpotentiated quadriceps muscles (study 1 and 2), and potentiated quadriceps muscles torque in a 10 min period after a 5 s isometric maximal voluntary contraction of the quadriceps muscles (study 1). Additionally, potentiated quadriceps muscles torque was measured every min after a further 10 maximal voluntary contractions repeated every min (study 2). Electrical stimulation repeated several times without previous maximal voluntary contraction showed similar peak twitch torque. Peak twitch torque 4 s after a 5 s maximal voluntary contraction increased by 45±13% (study 1) and by 56±10% (study 2), the rate of torque development by 53±13% and 82±29%, and the rate of relaxation by 50±17% and 59±22%, respectively, but potentiation was lost already two min after a 5 s maximal voluntary contraction. There was a tendency for peak twitch torque to increase for the first five repeated maximal voluntary contractions, suggesting increased potentiation with additional maximal voluntary contractions. Correlations for peak twitch torque vs the rate of torque development and for the rate of relaxation were r(2)= 0.94 and r(2)=0.97. The correlation between peak twitch torque, the rate of torque development and the rate of relaxation suggests that potentiation is due to instantaneous changes in skeletal muscle contractility and relaxation.

  11. Neck injury after repeated flexions due to parachuting.

    PubMed

    Mäkelä, J P; Hietaniemi, K

    1997-03-01

    A 37-yr-old, previously healthy officer developed a severe pain in the right shoulder and parethesia in the right I-III fingers during a high-altitude low-opening parachute jump. The pain started after a sudden neck flexion while he was checking the developing canopy, well before landing. Electroneuromyography revealed damage to the right C7 nerve root. Cervical radiography showed severe spondylosis and discus degeneration in the CV-VII region; magnetic resonance image demonstrated posterior disk protrusions in this area. Military aviators flying high-performance aircraft often have similar problems in the cervical spine; they have been attributed to effects of high + Gz forces in association with twisted head positions. Parachutists appear to face similar risks. Selection of the optimal head position during the parachute opening and use of light helmets should be emphasized.

  12. Combined flexion and extension cervical spine fractures with vascular injury.

    PubMed

    Lisanti, Christopher J; Hartness, Christopher

    2009-10-01

    We present a radiologic case report of a combined flexion and extension cervical spine fractures with associated vascular injury in a young patient who presented after a motorcycle crash with bilateral upper extremity paresthesias. CT and MRI examinations demonstrated an unstable anterior spondylolisthesis at C7/T1 with laminar/spinous process fracture of C7 and posterior longitudinal ligament avulsion requiring emergent surgery. Patient also had an extension teardrop fracture of C2 and focal right vertebral artery dissection. The case report reviews the classification of cervical spine injuries both by mechanism of injury and by stability/instability classification. Finally, we discuss the etiology and diagnosis of vascular injury including injury patterns that predispose to vascular trauma.

  13. Torque equilibrium attitudes for the Space Station

    NASA Technical Reports Server (NTRS)

    Thompson, Roger C.

    1993-01-01

    All spacecraft orbiting in a low earth orbit (LEO) experience external torques due to environmental effects. Examples of these torques include those induced by aerodynamic, gravity-gradient, and solar forces. It is the gravity-gradient and aerodynamic torques that produce the greatest disturbances to the attitude of a spacecraft in LEO, and large asymmetric spacecraft, such as the space station, are affected to a greater degree because the magnitude of the torques will, in general, be larger in proportion to the moments of inertia. If left unchecked, these torques would cause the attitude of the space station to oscillate in a complex manner and the resulting motion would destroy the micro-gravity environment as well as prohibit the orbiter from docking. The application of control torques will maintain the proper attitude, but the controllers have limited momentum capacity. When any controller reaches its limit, propellant must then be used while the device is reset to a zero or negatively-biased momentum state. Consequently, the rate at which momentum is accumulated is a significant factor in the amount of propellant used and the frequency of resupply necessary to operate the station. A torque profile in which the area curve for a positive torque is not equal to the area under the curve for a negative torque is 'biased,' and the consequent momentum build-up about that axis is defined as secular momentum because it continues to grow with time. Conversely, when the areas are equal, the momentum is cyclic and bounded. A Torque Equilibrium Attitude (TEA) is thus defined as an attitude at which the external torques 'balance' each other as much as possible, and which will result in lower momentum growth in the controllers. Ideally, the positive and negative external moments experienced by a spacecraft at the TEA would exactly cancel each other out and small cyclic control torques would be required only for precise attitude control. Over time, the only momentum build

  14. Torque equilibrium attitudes for the Space Station

    NASA Astrophysics Data System (ADS)

    Thompson, Roger C.

    1993-11-01

    All spacecraft orbiting in a low earth orbit (LEO) experience external torques due to environmental effects. Examples of these torques include those induced by aerodynamic, gravity-gradient, and solar forces. It is the gravity-gradient and aerodynamic torques that produce the greatest disturbances to the attitude of a spacecraft in LEO, and large asymmetric spacecraft, such as the space station, are affected to a greater degree because the magnitude of the torques will, in general, be larger in proportion to the moments of inertia. If left unchecked, these torques would cause the attitude of the space station to oscillate in a complex manner and the resulting motion would destroy the micro-gravity environment as well as prohibit the orbiter from docking. The application of control torques will maintain the proper attitude, but the controllers have limited momentum capacity. When any controller reaches its limit, propellant must then be used while the device is reset to a zero or negatively-biased momentum state. Consequently, the rate at which momentum is accumulated is a significant factor in the amount of propellant used and the frequency of resupply necessary to operate the station. A torque profile in which the area curve for a positive torque is not equal to the area under the curve for a negative torque is 'biased,' and the consequent momentum build-up about that axis is defined as secular momentum because it continues to grow with time. Conversely, when the areas are equal, the momentum is cyclic and bounded. A Torque Equilibrium Attitude (TEA) is thus defined as an attitude at which the external torques 'balance' each other as much as possible, and which will result in lower momentum growth in the controllers. Ideally, the positive and negative external moments experienced by a spacecraft at the TEA would exactly cancel each other out and small cyclic control torques would be required only for precise attitude control. Over time, the only momentum build

  15. The Arterial Folding Point During Flexion of the Hip Joint

    SciTech Connect

    Park, Sung Il; Won, Je Hwan Kim, Byung Moon; Kim, Jae Keun; Lee, Do Yun

    2005-04-15

    Purpose: Endovascular stents placed in periarticular vessels may be at a greater risk of neointimal hyperplasia and eventual occlusion than those placed in non-periarticular vessels. The purpose of this study was to investigate the location of maximal conformational change along the iliac and femoral artery, the folding point, during flexion of the hip joint and its location relative to the hip joint and the inguinal ligament. Methods: Seventy patients undergoing femoral artery catheterization were evaluated. The patients were 47 men and 23 women and ranged in age from 26 to 75 years (mean 54 years). The arteries (right:left = 34:36) were measured using a marked catheter for sizing vessels. Fluoroscopic images were obtained in anteroposterior and lateral projections in neutral position, and in the lateral projection in flexed position of the hip joint. The folding point was determined by comparing the lateral projection images in the neutral and flexed positions. The distance from the acetabular roof to the folding point and the distance from the inguinal ligament to the folding point was evaluated. Results: : The folding point was located 42.8 {+-} 28.6 mm cranial to the acetabular roof and 35.1 {+-} 30.1 mm cranial to the inguinal ligament. As the patient's age increased, the folding point was located more cranially (p < 0.001). Conclusions: The folding point during flexion of the hip joint was located 42.8 {+-} 28.6 mm cranial to the acetabular roof and 35.1 {+-} 30.1 mm cranial to the inguinal ligament. As the patient's age increased, the folding point was located more cranially. When a stent is inserted over this region, more attention may be needed during follow-up to monitor possible occlusion and stent failure.

  16. High-energy focussed extracorporeal shockwave therapy reduces pain in plantar fibromatosis (Ledderhose’s disease)

    PubMed Central

    2012-01-01

    Background Plantar fibromatosis is a benign disease creating nodules on the medial plantar side of affected patients. While surgical removal is regarded as the therapeutic mainstay, recurrence rates and impairment of daily activities remains substantial. High-energy focussed extracorporeal shockwave therapy has been suggested to be potentially effective in plantar fibromatosis in terms of pain reduction. Hypothesis High-energy focussed extracorporeal shockwave therapy reduces pain in plantar fibromatosis. Findings A total number of six patients (5 males, 58±4 years) were included with plantar fibromatosis (Ledderhose’s disease) associated with pain. Three patients were operated on previously, one had concomitant Dupuytren’s contracture. High-energy focussed ESWT was applied using a Storz Duolith SD1 (2000 impulses, 3 Hz, 1.24 mJ/mm2) in two sessions with 7 days between. Pain was 6±2 at baseline, 2±1 after 14 days and 1±1 after 3 months. Softening of the nodules was noted by all patients. No adverse effects were noted. Conclusions High-energy focussed extracorporeal shockwave energy reduces pain in painful plantar fibromatosis (Morbus Ledderhose). Further large-scale prospective trials are warranted to elucidate the value of high-energy focussed extracorporeal shockwave therapy (ESWT) in plantar fibromatosis in terms of recurrence and efficacy. PMID:23031080

  17. Achilles tendon and plantar fascia in recently diagnosed type II diabetes: role of body mass index.

    PubMed

    Abate, Michele; Schiavone, Cosima; Di Carlo, Luigi; Salini, Vincenzo

    2012-07-01

    Previous research has shown that plantar fascia and Achilles tendon thickness is increased in diabetes. The aims of present study were to assess whether tendon changes can occur in the early stages of the disease and to evaluate the extent of the influence of body mass index (BMI). The study population included 51 recent-onset type II diabetic subjects, who were free from diabetic complications, divided according to BMI into three groups (normal weight, overweight, and obese). Eighteen non-diabetic, normal-weight subjects served as controls. Plantar fascia and Achilles tendon thickness was measured by means of sonography. The groups were well balanced for age and sex. In all the diabetic subjects, plantar fascia and Achilles tendon thickness was increased compared to the controls (p < 0.001, p = 0.01, p = 0.003, respectively). A significant relationship was found between plantar fascia thickness and BMI values (r = 0.749, p < 0.0001), while the correlation between BMI and Achilles tendon was weaker (r = 0.399, p = 0.004). This study shows that plantar fascia and Achilles tendon thickness is increased in the early stages of type II diabetes and that BMI is related more to plantar fascia than Achilles tendon thickness. Further longitudinal studies are needed to evaluate whether these early changes can overload the metatarsal heads and increase the stress transmitted to plantar soft tissues, thus representing an additional risk factor for foot ulcer development.

  18. Plantar Fasciitis and the Windlass Mechanism: A Biomechanical Link to Clinical Practice

    PubMed Central

    Malone, Terry R.

    2004-01-01

    Objective: Plantar fasciitis is a prevalent problem, with limited consensus among clinicians regarding the most effective treatment. The purpose of this literature review is to provide a systematic approach to the treatment of plantar fasciitis based on the windlass mechanism model. Data Sources: We searched MEDLINE, SPORT Discus, and CINAHL from 1966 to 2003 using the key words plantar fasciitis, windlass mechanism, pronation, heel pain, and heel spur. Data Synthesis: We offer a biomechanical application for the evaluation and treatment of plantar fasciitis based on a review of the literature for the windlass mechanism model. This model provides a means for describing plantar fasciitis conditions such that clinicians can formulate a potential causal relationship between the conditions and their treatments. Conclusions/Recommendations: Clinicians' understanding of the biomechanical causes of plantar fasciitis should guide the decision-making process concerning the evaluation and treatment of heel pain. Use of this approach may improve clinical outcomes because intervention does not merely treat physical symptoms but actively addresses the influences that resulted in the condition. Principles from this approach might also provide a basis for future research investigating the efficacy of plantar fascia treatment. PMID:16558682

  19. Objective assessment of corticosteroid effect in plantar fasciitis: additional utility of ultrasound

    PubMed Central

    Moustafa, Asmaa Mahmoud Ali; Hassanein, Eshrak; Foti, Calogero

    2015-01-01

    Summary Background although plantar fascia thickening is well documented as a sonographic criterion for the diagnosis of plantar fasciitis (PF), however it was less evaluated as an objective measure of response to treatment. It is unknown to what extent if any different responses to different treatments are related to the ultrasound (US) morphology changes. We aimed to evaluate changes in US findings in correlation to pain reported. Methods this prospective observational trial included 21 plantar fasciitis patients (26 feet), resistant to conservative treatment for at least 2 months. Plantar fascia thickness and echogenicity were evaluated, compared to asymptomatic feet and correlated with visual analogue scale (VAS) and Heel Tenderness Index (HTI), before and after dexam-ethasone (DXM) iontophoresis in group I, and DXM injection in group II. Results increased thickness and reduced echogenicity were constant in symptomatic feet, with high statistical significant difference compared to asymptomatic side. Correlation between plantar fascia thickness with VAS and HTI before and after treatment showed statistically significant positive correlation (p<0.05). ROC curve test showed that reduction of plantar fascia thickness by US in response to DXM had 100% sensitivity, 65.2% specificity and 69% accuracy, with higher specificity and accuracy than VAS. Conclusion US changes showed concurrent validity correlated with self-reported clinical improvement. Accordingly, ultrasound can be considered an objective useful tool for monitoring response to corticosteroid in patients with plantar fasciitis. PMID:26958538

  20. Prolonged Intermittent Trunk Flexion Increases Trunk Muscles Reflex Gains and Trunk Stiffness.

    PubMed

    Voglar, Matej; Wamerdam, Jeffrey; Kingma, Idsart; Sarabon, Nejc; van Dieën, Jaap H

    2016-01-01

    The goal of the present study was to determine the effects of prolonged, intermittent flexion on trunk neuromuscular control. Furthermore, the potential beneficial effects of passive upper body support during flexion were investigated. Twenty one healthy young volunteers participated during two separate visits in which they performed 1 hour of intermittent 60 seconds flexion and 30 seconds rest cycles. Flexion was set at 80% lumbar flexion and was performed with or without upper body support. Before and after intermittent flexion exposure, lumbar range of motion was measured using inertial measurement units and trunk stability was assessed during perturbations applied in the forward direction with a force controlled actuator. Closed-loop system identification was used to determine the trunk translational admittance and reflexes as frequency response functions. The admittance describes the actuator displacement as a function of contact force and to assess reflexes muscle activation was related to actuator displacement. Trunk admittance gain decreased after unsupported flexion, while reflex gain and lumbar range of motion increased after both conditions. Significant interaction effects confirmed a larger increase in lumbar range of motion and reflex gains at most frequencies analysed following unsupported flexion in comparison to supported flexion, probably compensating for decreased passive tissue stiffness. In contrast with some previous studies we found that prolonged intermittent flexion decreased trunk admittance, which implies an increase of the lumped intrinsic and reflexive stiffness. This would compensate for decreased stiffness at the cost of an increase in cumulative low back load. Taking into account the differences between conditions it would be preferable to offer upper body support during activities that require prolonged trunk flexion.

  1. Prolonged Intermittent Trunk Flexion Increases Trunk Muscles Reflex Gains and Trunk Stiffness

    PubMed Central

    Wamerdam, Jeffrey; Kingma, Idsart; Sarabon, Nejc; van Dieën, Jaap H.

    2016-01-01

    The goal of the present study was to determine the effects of prolonged, intermittent flexion on trunk neuromuscular control. Furthermore, the potential beneficial effects of passive upper body support during flexion were investigated. Twenty one healthy young volunteers participated during two separate visits in which they performed 1 hour of intermittent 60 seconds flexion and 30 seconds rest cycles. Flexion was set at 80% lumbar flexion and was performed with or without upper body support. Before and after intermittent flexion exposure, lumbar range of motion was measured using inertial measurement units and trunk stability was assessed during perturbations applied in the forward direction with a force controlled actuator. Closed-loop system identification was used to determine the trunk translational admittance and reflexes as frequency response functions. The admittance describes the actuator displacement as a function of contact force and to assess reflexes muscle activation was related to actuator displacement. Trunk admittance gain decreased after unsupported flexion, while reflex gain and lumbar range of motion increased after both conditions. Significant interaction effects confirmed a larger increase in lumbar range of motion and reflex gains at most frequencies analysed following unsupported flexion in comparison to supported flexion, probably compensating for decreased passive tissue stiffness. In contrast with some previous studies we found that prolonged intermittent flexion decreased trunk admittance, which implies an increase of the lumped intrinsic and reflexive stiffness. This would compensate for decreased stiffness at the cost of an increase in cumulative low back load. Taking into account the differences between conditions it would be preferable to offer upper body support during activities that require prolonged trunk flexion. PMID:27768688

  2. Application of the restoring force method for identification of lumbar spine flexion-extension motion under flexion-extension moment.

    PubMed

    Borkowski, Sean L; Ebramzadeh, Edward; Sangiorgio, Sophia N; Masri, Sami F

    2014-04-01

    The restoring force method (RFM), a nonparametric identification technique established in applied mechanics, was used to maximize the information obtained from moment-rotation hysteresis curves under pure moment flexion-extension testing of human lumbar spines. Data from a previous study in which functional spine units were tested intact, following simulated disk injury, and following implantation with an interspinous process spacer device were used. The RFM was used to estimate a surface map to characterize the dependence of the flexion-extension rotation on applied moment and the resulting axial displacement. This described each spine response as a compact, reduced-order model of the complex underlying nonlinear biomechanical characteristics of the tested specimens. The RFM was applied to two datasets, and successfully estimated the flexion-extension rotation, with error ranging from 3 to 23%. First, one specimen, tested in the intact, injured, and implanted conditions, was analyzed to assess the differences between the three specimen conditions. Second, intact specimens (N = 12) were analyzed to determine the specimen variability under equivalent testing conditions. Due to the complexity and nonlinearity of the hysteretic responses, the mathematical fit of each surface was defined in terms of 16 coefficients, or a bicubic fit, to minimize the identified (estimated) surface fit error. The results of the first analysis indicated large differences in the coefficients for each of the three testing conditions. For example, the coefficient corresponding to the linear stiffness (a01) had varied magnitude among the three conditions. In the second analysis of the 12 intact specimens, there was a large variability in the 12 unique sets of coefficients. Four coefficients, including two interaction terms comprised of both axial displacement and moment, were different from zero (p < 0.05), and provided necessary quantitative information to describe the hysteresis in

  3. Ostectomy and Medial Plantar Artery Flap Reconstruction for Charcot Foot Ulceration Involving the Midfoot.

    PubMed

    Sato, Tomoya; Ichioka, Shigeru

    2016-01-01

    Charcot foot is a serious complication of diabetes, characterized by deformity and overlying ulceration. The condition most commonly affects the midfoot. However, little information is available on the use of a medial plantar artery flap to treat diabetic midfoot ulceration. The purpose of the present study was to evaluate the versatility of ostectomy and medial plantar flap reconstruction for midfoot plantar ulceration associated with rocker-bottom deformity secondary to Charcot foot. Four patients underwent ostectomy and medial plantar flap reconstruction. Before flap reconstruction, the devitalized soft tissues and bone were radically resected. After the infection had been controlled, the ulcerated portion was minimally excised, and the bony prominence underlying the ulcer was removed. A medial plantar artery flap was applied to the ulcer. The donor site was covered with a split-thickness skin graft or artificial dermis. In all patients, the ulcers healed and independent ambulation was achieved. However, 1 patient experienced ulcer recurrence, and subsequent infection necessitated a major amputation. Limb salvage is challenging in the setting of deformity and intractable plantar ulceration. The advantages of medial plantar artery flap reconstruction are that tissues with a rich blood supply are used to cover the exposed bone, and the flap can withstand the pressure and shear stress of the patient's body weight. However, a dominant artery in the foot is sacrificed. Therefore, the patency of the dorsalis pedis artery must be confirmed in every patient. The results of the present study have demonstrated that a medial plantar artery can be an effective alternative for diabetic patients with a plantar ulcer secondary to Charcot foot.

  4. A method to accurately estimate the muscular torques of human wearing exoskeletons by torque sensors.

    PubMed

    Hwang, Beomsoo; Jeon, Doyoung

    2015-04-09

    In exoskeletal robots, the quantification of the user's muscular effort is important to recognize the user's motion intentions and evaluate motor abilities. In this paper, we attempt to estimate users' muscular efforts accurately using joint torque sensor which contains the measurements of dynamic effect of human body such as the inertial, Coriolis, and gravitational torques as well as torque by active muscular effort. It is important to extract the dynamic effects of the user's limb accurately from the measured torque. The user's limb dynamics are formulated and a convenient method of identifying user-specific parameters is suggested for estimating the user's muscular torque in robotic exoskeletons. Experiments were carried out on a wheelchair-integrated lower limb exoskeleton, EXOwheel, which was equipped with torque sensors in the hip and knee joints. The proposed methods were evaluated by 10 healthy participants during body weight-supported gait training. The experimental results show that the torque sensors are to estimate the muscular torque accurately in cases of relaxed and activated muscle conditions.

  5. Propeller torque load and propeller shaft torque response correlation during ice-propeller interaction

    NASA Astrophysics Data System (ADS)

    Polić, Dražen; Ehlers, Sören; Æsøy, Vilmar

    2017-01-01

    Ships use propulsion machinery systems to create directional thrust. Sailing in ice-covered waters involves the breaking of ice pieces and their submergence as the ship hull advances. Sometimes, submerged ice pieces interact with the propeller and cause irregular fluctuations of the torque load. As a result, the propeller and engine dynamics become imbalanced, and energy propagates through the propulsion machinery system until equilibrium is reached. In such imbalanced situations, the measured propeller shaft torque response is not equal to the propeller torque. Therefore, in this work, the overall system response is simulated under the ice-related torque load using the Bond graph model. The energy difference between the propeller and propeller shaft is estimated and related to their corresponding mechanical energy. Additionally, the mechanical energy is distributed among modes. Based on the distribution, kinetic and potential energy are important for the correlation between propeller torque and propeller shaft response.

  6. Self-oscillation in spin torque oscillator stabilized by field-like torque

    SciTech Connect

    Taniguchi, Tomohiro; Tsunegi, Sumito; Kubota, Hitoshi; Imamura, Hiroshi

    2014-04-14

    The effect of the field-like torque on the self-oscillation of the magnetization in spin torque oscillator with a perpendicularly magnetized free layer was studied theoretically. A stable self-oscillation at zero field is excited for negative β while the magnetization dynamics stops for β = 0 or β > 0, where β is the ratio between the spin torque and the field-like torque. The reason why only the negative β induces the self-oscillation was explained from the view point of the energy balance between the spin torque and the damping. The oscillation power and frequency for various β were also studied by numerical simulation.

  7. Propeller torque load and propeller shaft torque response correlation during ice-propeller interaction

    NASA Astrophysics Data System (ADS)

    Polić, Dražen; Ehlers, Sören; Æsøy, Vilmar

    2017-03-01

    Ships use propulsion machinery systems to create directional thrust. Sailing in ice-covered waters involves the breaking of ice pieces and their submergence as the ship hull advances. Sometimes, submerged ice pieces interact with the propeller and cause irregular fluctuations of the torque load. As a result, the propeller and engine dynamics become imbalanced, and energy propagates through the propulsion machinery system until equilibrium is reached. In such imbalanced situations, the measured propeller shaft torque response is not equal to the propeller torque. Therefore, in this work, the overall system response is simulated under the ice-related torque load using the Bond graph model. The energy difference between the propeller and propeller shaft is estimated and related to their corresponding mechanical energy. Additionally, the mechanical energy is distributed among modes. Based on the distribution, kinetic and potential energy are important for the correlation between propeller torque and propeller shaft response.

  8. Torque shudder protection device and method

    DOEpatents

    King, Robert D.; De Doncker, Rik W. A. A.; Szczesny, Paul M.

    1997-01-01

    A torque shudder protection device for an induction machine includes a flux command generator for supplying a steady state flux command and a torque shudder detector for supplying a status including a negative status to indicate a lack of torque shudder and a positive status to indicate a presence of torque shudder. A flux adapter uses the steady state flux command and the status to supply a present flux command identical to the steady state flux command for a negative status and different from the steady state flux command for a positive status. A limiter can receive the present flux command, prevent the present flux command from exceeding a predetermined maximum flux command magnitude, and supply the present flux command to a field oriented controller. After determining a critical electrical excitation frequency at which a torque shudder occurs for the induction machine, a flux adjuster can monitor the electrical excitation frequency of the induction machine and adjust a flux command to prevent the monitored electrical excitation frequency from reaching the critical electrical excitation frequency.

  9. Torque shudder protection device and method

    DOEpatents

    King, R.D.; Doncker, R.W.A.A. De.; Szczesny, P.M.

    1997-03-11

    A torque shudder protection device for an induction machine includes a flux command generator for supplying a steady state flux command and a torque shudder detector for supplying a status including a negative status to indicate a lack of torque shudder and a positive status to indicate a presence of torque shudder. A flux adapter uses the steady state flux command and the status to supply a present flux command identical to the steady state flux command for a negative status and different from the steady state flux command for a positive status. A limiter can receive the present flux command, prevent the present flux command from exceeding a predetermined maximum flux command magnitude, and supply the present flux command to a field oriented controller. After determining a critical electrical excitation frequency at which a torque shudder occurs for the induction machine, a flux adjuster can monitor the electrical excitation frequency of the induction machine and adjust a flux command to prevent the monitored electrical excitation frequency from reaching the critical electrical excitation frequency. 5 figs.

  10. Feasibility study for convertible engine torque converter

    NASA Technical Reports Server (NTRS)

    1985-01-01

    The feasibility study has shown that a dump/fill type torque converter has excellent potential for the convertible fan/shaft engine. The torque converter space requirement permits internal housing within the normal flow path of a turbofan engine at acceptable engine weight. The unit permits operating the engine in the turboshaft mode by decoupling the fan. To convert to turbofan mode, the torque converter overdrive capability bring the fan speed up to the power turbine speed to permit engagement of a mechanical lockup device when the shaft speed are synchronized. The conversion to turbofan mode can be made without drop of power turbine speed in less than 10 sec. Total thrust delivered to the aircraft by the proprotor, fan, and engine during tansient can be controlled to prevent loss of air speed or altitude. Heat rejection to the oil is low, and additional oil cooling capacity is not required. The turbofan engine aerodynamic design is basically uncompromised by convertibility and allows proper fan design for quiet and efficient cruise operation. Although the results of the feasibility study are exceedingly encouraging, it must be noted that they are based on extrapolation of limited existing data on torque converters. A component test program with three trial torque converter designs and concurrent computer modeling for fluid flow, stress, and dynamics, updated with test results from each unit, is recommended.

  11. The Effects of Psoas Major and Lumbar Lordosis on Hip Flexion and Sprint Performance

    ERIC Educational Resources Information Center

    Copaver, Karine; Hertogh, Claude; Hue, Olivier

    2012-01-01

    In this study, we analyzed the correlations between hip flexion power, sprint performance, lumbar lordosis (LL) and the cross-sectional area (CSA) of the psoas muscle (PM). Ten young adults performed two sprint tests and isokinetic tests to determine hip flexion power. Magnetic resonance imaging was used to determine LL and PM CSA. There were…

  12. 49 CFR 572.165 - Upper and lower torso assemblies and torso flexion test procedure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 7 2014-10-01 2014-10-01 false Upper and lower torso assemblies and torso flexion...) ANTHROPOMORPHIC TEST DEVICES Hybrid III Six-Year-Old Weighted Child Test Dummy § 572.165 Upper and lower torso assemblies and torso flexion test procedure. (a) Upper/lower torso assembly. The test objective is...

  13. 49 CFR 572.165 - Upper and lower torso assemblies and torso flexion test procedure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 7 2013-10-01 2013-10-01 false Upper and lower torso assemblies and torso flexion...) ANTHROPOMORPHIC TEST DEVICES Hybrid III Six-Year-Old Weighted Child Test Dummy § 572.165 Upper and lower torso assemblies and torso flexion test procedure. (a) Upper/lower torso assembly. The test objective is...

  14. Interaction of viscoelastic tissue compliance with lumbar muscles during passive cyclic flexion-extension.

    PubMed

    Olson, Michael W; Li, Li; Solomonow, Moshe

    2009-02-01

    Human and animal models using electromyography (EMG) based methods have hypothesized that viscoelastic tissue properties becomes compromised by prolonged repetitive cyclic trunk flexion-extension which in turn influences muscular activation including the flexion-relaxation phenomenon. Empirical evidence to support this hypothesis, especially the development of viscoelastic tension-relaxation and its associated muscular response in passive cyclic activity in humans, is incomplete. The objective of this study was to examine the response of lumbar muscles to tension-relaxation development of the viscoelastic tissue during prolonged passive cyclic trunk flexion-extension. Activity of the lumbar muscles remained low and steady during the passive exercise session. Tension supplied by the posterior viscoelastic tissues decreased over time without corresponding changes in muscular activity. Active flexion, following the passive flexion session, elicited significant increase in paraspinal muscles EMG together with increase in the median frequency. It was concluded that reduction of tension in the lumbar viscoelastic tissues of humans occurs during cyclic flexion-extension and is compensated by increased activity of the musculature in order to maintain stability. It was also concluded that the ligamento-muscular reflex is inhibited during passive activities but becomes hyperactive following active cyclic flexion, indicating that moment requirements are the controlling variable. It is conceived that prolonged routine exposure to cyclic flexion minimizes the function of the viscoelastic tissues and places increasing demands on the neuromuscular system which over time may lead to a disorder and possible exposure to injury.

  15. Impact of the difference in the plantar flexor strength of the ankle joint in the affected side among hemiplegic patients on the plantar pressure and walking asymmetry.

    PubMed

    You, Young Youl; Chung, Sin Ho; Lee, Hyung Jin

    2016-11-01

    [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.

  16. Impact of the difference in the plantar flexor strength of the ankle joint in the affected side among hemiplegic patients on the plantar pressure and walking asymmetry

    PubMed Central

    You, Young Youl; Chung, Sin Ho; Lee, Hyung Jin

    2016-01-01

    [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

  17. Differences in impulse distribution in patients with plantar fasciitis.

    PubMed

    Bedi, H S; Love, B R

    1998-03-01

    The impulse distribution based upon vertical foot-floor reaction forces and time under the fore-, mid-, and hindfoot was determined using Tekscan's F-Scan system. This was compared in 40 barefoot patients with long-standing plantar fasciitis with an equal number of normal subjects. The patient group tended to load the hind- and midfoot to a lesser extent than the control group. Consequently, a greater proportionate load was borne by the forefoot. This result was highly significant for both the midfoot (P < 0.001) and forefoot (P = 0.002) comparisons. An objective biomechanical method such as this may be useful as a diagnostic aid, to identify individuals predisposed to this condition, and for evaluating the efficacy of various treatment modalities.

  18. Mycobacterial pseudotumor of the plantar fascia: how common is it?

    PubMed

    Sideras, Panagiotis A; Heiba, Sherif; Machac, Josef; Hechtman, Jaclyn; Vatti, Sridhar

    2013-01-01

    Mycobacterial spindle cell pseudotumor (MSCP) is an extremely rare complication of mycobacterial infections. It has been reported to occur in various sites such as skin, lymph nodes, bone marrow, lungs, and spleen. This tumor-like lesion can be confused clinically as well as radiographically with dermatofibroma, nodular fasciitis, xanthogranuloma, and Kaposi's sarcoma. While this lesion is rare and has been previously reported to occur only in superficial skin, we emphasize its consideration and inclusion in the differential diagnoses when a deep soft tissue mass is complicated by symptoms of deep tissue infection secondary to abscess formation in immunocompromised hosts. Here, we present the clinical and radiologic findings of a case of MSCP involving the deep plantar sheaths.

  19. Variable Torque Prescription: State of Art.

    PubMed Central

    Lacarbonara, Mariano; Accivile, Ettore; Abed, Maria R.; Dinoi, Maria Teresa; Monaco, Annalisa; Marzo, Giuseppe; Capogreco, Mario

    2015-01-01

    The variable prescription is widely described under the clinical aspect: the clinics is the result of the evolution of the state-of-the-art, aspect that is less considered in the daily literature. The state-of-the-art is the key to understand not only how we reach where we are but also to learn how to manage propely the torque, focusing on the technical and biomechanical purpos-es that led to the change of the torque values over time. The aim of this study is to update the clinicians on the aspects that affect the torque under the biomechanical sight, helping them to understand how to managing it, following the “timeline changes” in the different techniques so that the Variable Prescription Orthodontic (VPO) would be a suitable tool in every clinical case. PMID:25674173

  20. Thomas precession: Where is the torque

    SciTech Connect

    Muller, R.A. )

    1992-04-01

    Special relativity appears to violate the conservation of angular momentum {bold L} since it predicts that an accelerated gyroscope will precess, i.e., {bold L} will change in the absence of any applied torque. The paradox is resolved in a simple example by demonstrating that there is a torque present. The mass distribution in the gyroscope undergoes a relativistic distortion, and the center of mass is displaced away from the position of the accelerating force. The resulting torque {tau}={ital d}{bold L}/{ital dt}. The model also shows the physical origins of spin-orbit coupling and of the oscillating term.'' A related calculation shows why a moving magnetic dipole has an {ital electric} dipole moment.

  1. RFID Torque Sensing Tag System for Fasteners

    NASA Technical Reports Server (NTRS)

    Fink, Patrick W. (Inventor); Lin, Gregory Y. (Inventor); Ngo, Phong H. (Inventor); Kennedy, Timothy F. (Inventor)

    2016-01-01

    The present invention provides an RFID-based torque sensor that can be used to quickly monitor off the shelf fasteners including fasteners that are used in expensive satellites or other uses where fastener failure can be very costly. In one embodiment, an antenna, RFID ring and spring comprise a sensor tag that can be interrogated with an interrogation signal produced by an interrogator device. When sufficient torque is applied to the fastener, an RFID circuit is connected, and produces a radio frequency (RF) signal that can be read by the interrogator. In one embodiment, the RFID circuit does not transmit when the spring member is not compressed, thereby indicating insufficient tensioning of the fastener. The present invention offers the ability to remotely, quickly, and inexpensively verify that any number of fasteners are torqued properly upon initial installation. Where applicable, the present invention allows low cost monitoring over the life of the fastener.

  2. Torque for an Inertial Piezoelectric Rotary Motor

    PubMed Central

    Xing, Jichun

    2013-01-01

    For a novel inertial piezoelectric rotary motor, the equation of the strain energy in the piezoceramic bimorph and the equations of the strain energy and the kinetic energy in the rotor are given. Based on them, the dynamic equation of the motor is obtained. Using these equations, the inertial driving torque of the motor is investigated. The results show that the impulsive driving torque changes with changing peak voltage of the excitation signal, the piezoelectric stress constant, the thickness of the piezoceramic bimorph, and the rotor radius obviously. Tests about the motor torque are completed which verifies the theory analysis here in. The results can be used to design the operating performance of the motor. PMID:24470794

  3. AX-5 space suit bearing torque investigation

    NASA Technical Reports Server (NTRS)

    Loewenthal, Stuart; Vykukal, Vic; Mackendrick, Robert; Culbertson, Philip, Jr.

    1990-01-01

    The symptoms and eventual resolution of a torque increase problem occurring with ball bearings in the joints of the AX-5 space suit are described. Starting torques that rose 5 to 10 times initial levels were observed in crew evaluation tests of the suit in a zero-g water tank. This bearing problem was identified as a blocking torque anomaly, observed previously in oscillatory gimbal bearings. A large matrix of lubricants, ball separator designs and materials were evaluated. None of these combinations showed sufficient tolerance to lubricant washout when repeatedly cycled in water. The problem was resolved by retrofitting a pressure compensated, water exclusion seal to the outboard side of the bearing cavity. The symptoms and possible remedies to blocking are discussed.

  4. Effects of weight-bearing exercise on a mini-trampoline on foot mobility, plantar pressure and sensation of diabetic neuropathic feet; a preliminary study

    PubMed Central

    Kanchanasamut, Wararom; Pensri, Praneet

    2017-01-01

    ABSTRACT Objective: Foot and ankle exercise has been advocated as a preventative approach in reducing the risk of foot ulceration. However, knowledge about the appropriate types and intensity of exercise program for diabetic foot ulcer prevention is still limited. The current study aimed to examine the effects of an eight-week mini-trampoline exercise on improving foot mobility, plantar pressure and sensation of diabetic neuropathic feet. Methods: Twenty-one people with diabetic peripheral neuropathy who had impaired sensation perception were divided into two groups. The exercise group received a foot-care education program plus an eight-week home exercise program using the mini-trampoline (n = 11); whereas a control group received a foot-care education only (n = 10). Measurements were undertaken at the beginning, at the completion of the eight-week program and at a 20-week follow-up. Results: Both groups were similar prior to the study. Subjects in the exercise group significantly increased the range of the first metatarsophalangeal joint in flexion (left: p = 0.040, right: p = 0.012) and extension (left: p = 0.013) of both feet more than controlled subjects. There was a trend for peak plantar pressure at the medial forefoot to decrease in the exercise group (p = 0.016), but not in the control group. At week 20, the number of subjects in the exercise group who improved their vibration perception in their feet notably increased when compared to the control group (left: p = 0.043; right: p = 0.004). Conclusions: This is a preliminary study to document the improvements in foot mobility, plantar pressure and sensation following weight-bearing exercise on a flexible surface in people with diabetic neuropathic feet. Mini-trampoline exercise may be used as an adjunct to other interventions to reduce risk of foot ulceration. A larger sample size is needed to verify these findings. This trial is registered with COA No. 097.2/55. PMID:28326159

  5. Reduced elbow extension torque during vibrations.

    PubMed

    Friesenbichler, Bernd; Coza, Aurel; Nigg, Benno M

    2012-08-31

    Impact sports and vibration platforms trigger vibrations within soft tissues and the skeleton. Although the long-term effects of vibrations on the body have been studied extensively, the acute effects of vibrations are little understood. This study determined the influence of acute vibrations at different frequencies and elbow angles on maximal isometric elbow extension torque and muscle activity. Vibrations were generated by a pneumatic vibrator attached to the lever of a dynamometer, and were applied on the forearm of 15 healthy female subjects. The subjects were instructed to push maximally against the lever at three different elbow angles, while extension torque and muscle activity were quantified and compared between vibration and non-vibration (control) conditions. A change in vibration frequency had no significant effects on torque and muscle activity although vibrations in general decreased the maximal extension torque relative to the control by 1.8% (±5.7%, p>0.05), 7.4% (±7.9%, p<0.01), and 5.0% (±8.2%, p<0.01) at elbow angles of 60°, 90°, and 120°, respectively. Electromyographic activity increased significantly between ∼30% and 40% in both triceps and biceps with vibrations. It is speculated that a similar increase in muscle activity between agonist and antagonist, in combination with an unequal increase in muscle moment arms about the elbow joint, limit the maximal extension torque during exposure to vibrations. This study showed that maximal extension torque decreased during vibration exposure while muscle activity increased and suggests that vibrations may be counterproductive during activities requiring maximal strength but potentially beneficial for strength training.

  6. Atmospheric Gravitational Torque Variations Based on Various Gravity Fields

    NASA Technical Reports Server (NTRS)

    Sanchez, Braulio V.; Rowlands, David; Smith, David E. (Technical Monitor)

    2001-01-01

    Advancements in the study of the Earth's variable rate of rotation and the motion of its rotation axis have given impetus to the analysis of the torques between the atmosphere, oceans and solid Earth. The output from global general circulation models of the atmosphere (pressure, surface stress) is being used as input to the torque computations. Gravitational torque between the atmosphere, oceans and solid Earth is an important component of the torque budget. Computation of the gravitational torque involves the adoption of a gravitational model from a wide variety available. The purpose of this investigation is to ascertain to what extent this choice might influence the results of gravitational torque computations.

  7. Extraction of mechanical properties of foot plantar tissues using ultrasound indentation associated with genetic algorithm.

    PubMed

    Ling, Hang-Yin; Choi, Pong-Chi; Zheng, Yong-ping; Lau, Kin-Tak

    2007-08-01

    This paper demonstrates the use of ultrasound indentation technique for estimating the mechanical properties of foot plantar tissues in virtue of the reconstruction of the force response using genetic algorithm (GA) from an indentation test based on a quasi-linear viscoelastic (QLV) model. The indentation test on the plantar tissues covering the right first metatarsal head of a normal subject was carried out to verify the feasibility of the GA for the extraction of the tissue properties. The QLV properties of the plantar tissues were determined by the GA with a fixed Poisson's ratio. Such results were then compared with those obtained using a classical optimization method. Moreover, the GA was further employed to simultaneously determine the QLV properties as well as the Poisson's ratio of the plantar tissues. The correlations between the QLV properties and the Poisson's ratio are discussed.

  8. Benign dermoscopic parallel ridge pattern in plantar hyperpigmentation due to capecitabine

    PubMed Central

    Tognetti, Linda; Fimiani, Michele; Rubegni, Pietro

    2015-01-01

    We report the case of a 37-year-old woman (phototype II) who presented at our outpatient clinic with a two-month history of hyperpigmented plantar macules. Medical history revealed that the patient had taken capecitabine in the past three months as adjuvant chemotherapy for recurrent breast cancer. Dermoscopic examination of the plantar macules showed parallel ridge pattern with pigmentation in the furrows without obliteration of eccrine gland apertures. Besides in acral melanoma, parallel ridge pattern can also be observed in benign plantar lesions, such as congenital or acquired acral nevi, subcorneal hemorrhage, dye-related pigmentation and drug-induced hyperpigmentation, especially in patients with phototypes III–VI. The few reported cases of capecitabine-induced hyperpigmentation have been associated with hand and foot syndrome in patients with phototypes IV–V and palmar as well as plantar involvement. PMID:26114058

  9. Atypical presentation of plantar fasciitis secondary to soft-tissue mass infiltration.

    PubMed

    Ng, A; Beegle, T; Rockett, A K

    2001-02-01

    This article describes a patient with plantar fascial pain who presented to the office of one of the authors. Physical examination and the patient's description of the history of symptoms revealed classic signs and symptoms of plantar fasciitis. The patient was treated with numerous conservative modalities, including ultrasound, nonsteroidal anti-inflammatory medications, trigger-point injections, over-the-counter orthoses, and stretching exercises. When the pain was not relieved by these conservative measures, magnetic resonance imaging of the area was performed. Visualization of the insertional area of the plantar fascia revealed a mass inferior to, as well as infiltrated into, the plantar fascia. Surgical excision of the lesion resulted in complete elimination of the patient's pain.

  10. Autologous blood injection and botulinum toxin for resistant plantar fasciitis accompanied by spasticity.

    PubMed

    Logan, Lynne Romeiser; Klamar, Karl; Leon, Jerry; Fedoriw, Wladislaw

    2006-08-01

    An originally ambulatory 18-yr-old woman with spastic left hemiplegic cerebral palsy developed left plantar fasciitis with a gradual loss of function requiring use of a wheelchair. Her symptoms were resistant to physical therapy. Two hundred units of botulinum toxin A was diluted in 4 mL of saline and injected into the gastrocnemius. Three milliliters of autologous blood was injected into the plantar fascia. She reported decreased pain at 3 days postinjection. At 10 days, she had no pain on walking. Dorsiflexion increased and Ashworth and Tardieu improved. A stretching program was taught and a better-fitting night splint was obtained. At 21 days, she exhibited no pain and increased dorsiflexion. Autologous blood injection combined with botulinum toxin A may be an alternative treatment for resistant plantar fasciitis accompanied by spasticity. Our hypothesis is that chronic plantar fasciitis is a degenerative condition and thus is relieved when a mild inflammatory process is created that leads to healing.

  11. The relationship of pes planus and calcaneal spur to plantar heel pain.

    PubMed

    Prichasuk, S; Subhadrabandhu, T

    1994-09-01

    A prospective study of pes planus by using calcaneal pitch and calcaneal spur was carried out in 82 patients with plantar heel pain and in 400 normal subjects. The mean normal calcaneal pitch was 20.54 degrees. The mean calcaneal pitch in patients with plantar heel pain was 15.99 degrees, which was significantly lower than in normal subjects. The incidence of calcaneal spur in normal subjects and in patients with plantar heel pain was 15.5% percent (62 of 400) and 65.9% (54 of 82), respectively. Again, this was a highly significant difference. Excessive weight gain, aging, and gender may be important factors effecting the lowering of the pitch and the increasing of spur formation. These factors could lead to the development of plantar heel pain.

  12. Plantar fascia release and calcaneal spur excision for sub-calcaneal heel pain.

    PubMed

    Torudom, Yingyong

    2009-06-01

    Aim of this study was to evaluate the results of open plantar fascia release and calcaneal spur excision in patients with plantar fasciitis. The author studied retrospectively the results in 16 patients who had been treated with open plantar fascia release and calcaneal spur excision from 2002 to 2008. Two patients were men and fourteen were women. Their mean age was 43.3 years (39 to 52). Based on visual analog scale the results were pain free in 12 feet and some pain in four. There are two patients with superficial skin infection which can be manage with local wound care and oral antibiotic. We conclude that open plantar fascia release and calcaneal spur excision can relieve pain in patients who resist conservative treatment.

  13. Correction of Crossover Toe Deformity by Arthroscopically Assisted Plantar Plate Tenodesis.

    PubMed

    Lui, Tun Hing

    2016-12-01

    Plantar plate deficiency is the major pathology causing metatarsophalangeal joint instability. As the joint subluxates dorsally, the lumbrical is tethered at the medial side of the joint by the deep metatarsal ligament and becomes a deforming force for the development of crossover toe deformity. Plantar plate repair or reconstruction is a logical surgical treatment option. This can be performed through a dorsal or plantar approach. The purpose of this technical note is to report a minimally invasive technique of crossover toe deformity correction by suturing the plantar plate to the extensor tendon. It is indicated for symptomatic crossover toe deformity that is not responsive to nonsurgical treatment. It is contraindicated if the metatarsophalangeal joint is degenerated, destructed, or dislocated, or there is interdigital neuroma at the sides of the deformed toe, or the deformity is caused by bony deformities of the metatarsal head or the proximal phalanx.

  14. Torque limit of PM motors for field-weakening region operation

    SciTech Connect

    Royak, Semyon; Harbaugh, Mark M

    2012-02-14

    The invention includes a motor controller and technique for controlling a permanent magnet motor. In accordance with one aspect of the present technique, a permanent magnet motor is controlled by receiving a torque command, determining a physical torque limit based on a stator frequency, determining a theoretical torque limit based on a maximum available voltage and motor inductance ratio, and limiting the torque command to the smaller of the physical torque limit and the theoretical torque limit. Receiving the torque command may include normalizing the torque command to obtain a normalized torque command, determining the physical torque limit may include determining a normalized physical torque limit, determining a theoretical torque limit may include determining a normalized theoretical torque limit, and limiting the torque command may include limiting the normalized torque command to the smaller of the normalized physical torque limit and the normalized theoretical torque limit.

  15. Utilization of Physical Therapy Intervention Among Patients With Plantar Fasciitis in the United States.

    PubMed

    Fraser, John J; Glaviano, Neal R; Hertel, Jay

    2017-02-01

    Study Design Retrospective observational study. Background Plantar fasciitis is responsible for 1 million ambulatory patient care visits annually in the United States. Few studies have investigated practice patterns in the treatment of patients with plantar fasciitis. Objective To assess physical therapist utilization and employment of manual therapy and supervised rehabilitation in the treatment of patients with plantar fasciitis. Methods A retrospective review of the PearlDiver patient record database was used to evaluate physical therapist utilization and use of manual therapy and supervised rehabilitation in patients with plantar fasciitis between 2007 and 2011. An International Classification of Diseases code (728.71) was used to identify plantar fasciitis, and Current Procedural Terminology codes were used to identify evaluations (97001), manual therapy (97140), and rehabilitation services (97110, 97530, 97112). Results A total of 819 963 unique patients diagnosed with plantar fasciitis accounted for 5 739 737 visits from 2007 to 2011, comprising 2.7% of all patients in the database. Only 7.1% (95% confidence interval: 7.0%, 7.1%) of patients received a physical therapist evaluation. Of the 57 800 patients evaluated by a physical therapist (59.8% female), 50 382 (87.2% ± 0.4%) received manual therapy, with significant increases in utilization per annum. A large proportion (89.5% ± 0.4%) received rehabilitation following physical therapist evaluation. Conclusion Despite plantar fasciitis being a frequently occurring musculoskeletal condition, a small proportion of patients with plantar fasciitis were seen by physical therapists. Most patients who were evaluated by a physical therapist received manual therapy and a course of supervised rehabilitation as part of their plan of care. Level of Evidence Treatment, level 2a. J Orthop Sports Phys Ther 2017;47(2):49-55. doi:10.2519/jospt.2017.6999.

  16. [Calcaneus fractures as a complication of the percutaneous treatment of plantar fasciitis. Case report].

    PubMed

    Apóstol-González, S; Herrera, J; Herrera, I

    2014-01-01

    Plantar fasciitis, a self-limiting pathologic entity, is a common cause of heel pain in adult patients. Surgical treatment is indicated when the patient does not improve after receiving conservative treatment for 4-6 months with proper surveillance. The complications of percutaneous techniques include: infection, persistent pain, and neurologic injuries, among others. We report the case of a patient with calcaneus fracture following percutaneous plantar fasciotomy and resection of a calcaneal spur. We conducted a review and discussion of the literature.

  17. Flexion myelopathy of the thoracic spine. Case report.

    PubMed

    Fujibayashi, Shunsuke; Neo, Masashi; Nakamura, Takashi

    2007-01-01

    The authors report a rare case of surgically treated symptomatic thoracic kyphosis caused by dynamic compression in an elderly man. Myelopathy due to thoracic kyphosis has been reported in patients with congenital kyphosis, Scheuermann dorsal kyphosis, and Cushing disease, but to the authors' knowledge this is the first report of dynamic kyphosis in an elderly person. This otherwise healthy 84-year-old man presented with a 2-year history of progressive difficulty in walking and bilateral leg dysesthesia. Despite several cervical and lumbar surgeries, his symptoms gradually worsened. A radiological examination revealed severe thoracic kyphosis, with a lateral Cobb angle of 59 degrees from T-2 to T-12. On a dynamic computed tomography (CT) myelogram, severe thoracic spinal cord draping and stretching on flexion was demonstrated. On extension, however, imaging studies failed to show draping or stretching. Posterior corrective fusion was performed with instrumentation from T-2 to T-9. Postoperative CT myelography demonstrated no significant spinal cord compression with restoration of the cerebrospinal fluid space anterior to the spinal cord, and the successful correction of the kyphosis to 44 degrees. The patient's neurological sequelae gradually resolved throughout 6 months of follow up.

  18. Delensing gravitational wave standard sirens with shear and flexion maps

    NASA Astrophysics Data System (ADS)

    Shapiro, C.; Bacon, D. J.; Hendry, M.; Hoyle, B.

    2010-05-01

    Supermassive black hole binary (SMBHB) systems are standard sirens - the gravitational wave analogue of standard candles - and if discovered by gravitational wave detectors, they could be used as precise distance indicators. Unfortunately, gravitational lensing will randomly magnify SMBHB signals, seriously degrading any distance measurements. Using a weak lensing map of the SMBHB line of sight, we can estimate its magnification and thereby remove some uncertainty in its distance, a procedure we call `delensing'. We find that delensing is significantly improved when galaxy shears are combined with flexion measurements, which reduce small-scale noise in reconstructed magnification maps. Under a Gaussian approximation, we estimate that delensing with a 2D mosaic image from an Extremely Large Telescope could reduce distance errors by about 25-30 per cent for an SMBHB at z = 2. Including an additional wide shear map from a space survey telescope could reduce distance errors by nearly a factor of 2. Such improvement would make SMBHBs considerably more valuable as cosmological distance probes or as a fully independent check on existing probes.

  19. Wing Flexion and Aerodynamics Performance of Insect Free Flights

    NASA Astrophysics Data System (ADS)

    Dong, Haibo; Liang, Zongxian; Ren, Yan

    2010-11-01

    Wing flexion in flapping flight is a hallmark of insect flight. It is widely thought that wing flexibility and wing deformation would potentially provide new aerodynamic mechanisms of aerodynamic force productions over completely rigid wings. However, there are lack of literatures on studying fluid dynamics of freely flying insects due to the presence of complex shaped moving boundaries in the flow domain. In this work, a computational study of freely flying insects is being conducted. High resolution, high speed videos of freely flying dragonflies and damselflies is obtained and used as a basis for developing high fidelity geometrical models of the dragonfly body and wings. 3D surface reconstruction technologies are used to obtain wing topologies and kinematics. The wing motions are highly complex and a number of different strategies including singular vector decomposition of the wing kinematics are used to examine the various kinematical features and their impact on the wing performance. Simulations are carried out to examine the aerodynamic performance of all four wings and understand the wake structures of such wings.

  20. The effects of extracorporeal shock wave therapy on stroke patients with plantar fasciitis

    PubMed Central

    Kim, Tae Gon; Bae, Sea Hyun; Kim, Gye Yeop; Kim, Kyung Yoon

    2015-01-01

    [Purpose] The purpose of this research was to analyze the efficacy of extracorporeal shock wave therapy for the treatment of stroke patients with plantar fasciitis. [Subjects and Methods] This study included 10 stroke patients diagnosed with plantar fasciitis who were administered 3 sessions of extracorporeal shock wave therapy per week. After the last session, they performed stretching exercises for their Achilles tendon and plantar fascia for 30 min/day, 5 times a week for 6 months. The following parameters were measured and compared prior to therapy, 6 weeks after therapy, and 6 months after therapy: thickness of the plantar fascia, using an ultrasonic imaging system; degree of spasticity, using a muscle tension measuring instrument; degree of pain, using the visual analogue scale; and gait ability, using the Functional Gait Assessment. [Results] Decreased plantar fascia thickness, spasticity, and pain and increased gait ability were noted after therapy. These changes were significantly greater at 6 months after therapy than at 6 weeks after therapy. [Conclusion] These results indicated that extracorporeal shock wave therapy reduced tension in the plantar fascia, relieving pain and improving gait ability in stroke patients. PMID:25729207

  1. Plantar Pressures During Long Distance Running: An Investigation of 10 Marathon Runners

    PubMed Central

    Hohmann, Erik; Reaburn, Peter; Tetsworth, Kevin; Imhoff, Andreas

    2016-01-01

    The objective of this study was to record plantar pressures using an in-shoe measuring system before, during, and after a marathon run in ten experienced long-distance runners with a mean age of 37.7 ± 11.5 years. Peak and mean plantar pressures were recorded before, after, and every three km during a marathon race. There were no significant changes over time in peak and mean plantar pressures for either the dominant or non-dominant foot. There were significant between foot peak and mean plantar pressure differences for the total foot (p = 0.0001), forefoot (p = 0.0001), midfoot (p = 0.02 resp. p = 0.006), hindfoot (p = 0.0001), first ray (p = 0.01 resp. p = 0.0001) and MTP (p = 0.05 resp. p = 0.0001). Long-distance runners do not demonstrate significant changes in mean or peak plantar foot pressures over the distance of a marathon race. However, athletes consistently favoured their dominant extremity, applying significantly higher plantar pressures through their dominant foot over the entire marathon distance. Key points Fatigue does not increase foot pressures Every runner has a dominant foot where pressures are higher and that he/she favours Foot pressures do not increase over the distance of a marathon run PMID:27274662

  2. Integrated kinematics-kinetics-plantar pressure data analysis: a useful tool for characterizing diabetic foot biomechanics.

    PubMed

    Sawacha, Zimi; Guarneri, Gabriella; Cristoferi, Giuseppe; Guiotto, Annamaria; Avogaro, Angelo; Cobelli, Claudio

    2012-05-01

    The fundamental cause of lower-extremity complications in diabetes is chronic hyperglycemia leading to diabetic foot ulcer pathology. While the relationship between abnormal plantar pressure distribution and plantar ulcers has been widely investigated, little is known about the role of shear stress. Moreover, the mutual relationship among plantar pressure, shear stress, and abnormal kinematics in the etiology of diabetic foot has not been established. This lack of knowledge is determined by the lack of commercially available instruments which allow such a complex analysis. This study aims to develop a method for the simultaneous assessment of kinematics, kinetics, and plantar pressure on foot subareas of diabetic subjects by means of combining three commercial systems. Data were collected during gait on 24 patients (12 controls and 12 diabetic neuropathics) with a motion capture system synchronized with two force plates and two baropodometric systems. A four segment three-dimensional foot kinematics model was adopted for the subsegment angles estimation together with a three segment model for the plantar sub-area definition during gait. The neuropathic group exhibited significantly excessive plantar pressure, ground reaction forces on each direction, and a reduced loading surface on the midfoot subsegment (p<0.04). Furthermore the same subsegment displayed excessive dorsiflexion, external rotation, and eversion (p<0.05). Initial results showed that this methodology may enable a more appropriate characterization of patients at risk of foot ulcerations, and help planning prevention programs.

  3. How effective is acupuncture for reducing pain due to plantar fasciitis?

    PubMed Central

    Thiagarajah, Anandan Gerard

    2017-01-01

    INTRODUCTION Plantar fasciitis is a commonly seen outpatient condition that has numerous treatment modalities of varying degrees of efficacy. This systematic review aimed to determine the effectiveness of acupuncture in reducing pain caused by plantar fasciitis. METHODS Online literature searches were performed on the PubMed and Cochrane Library databases for studies on the use of acupuncture for pain caused by plantar fasciitis. Studies designed as randomised controlled trials and that compared acupuncture with standard treatments or had real versus sham acupuncture arms were selected. The Delphi list was used to assess the methodological quality of the studies retrieved. RESULTS Three studies that compared acupuncture with standard treatment and one study on real versus sham acupuncture were found. These showed that acupuncture significantly reduced pain levels in patients with plantar fasciitis, as measured on the visual analogue scale and the Plantar Fasciitis Pain/Disability Scale. These benefits were noted between four and eight weeks of treatment, with no further significant reduction in pain beyond this duration. Side effects were found to be minimal. CONCLUSION Although acupuncture may reduce plantar fasciitis pain in the short term, there is insufficient evidence for a definitive conclusion regarding its effectiveness in the longer term. Further research is required to strengthen the acceptance of acupuncture among healthcare providers. PMID:27526703

  4. Critical differences in lateral X-rays with and without a diagnosis of plantar fasciitis.

    PubMed

    Osborne, H R; Breidahl, W H; Allison, G T

    2006-06-01

    Plantar fasciitis is a clinical diagnosis and is often combined with some form of imaging to validate the diagnosis. The clinical utility of lateral X-rays lies in the fact that they are relatively inexpensive and may contribute to ruling out other osseous causes of pain. In this study 106 (27 plantar fasciitis (PF) and 79 controls) plain non-weight bearing lateral X-rays were examined by a blind examiner to document the key features of the lateral X-ray between images of individuals with and without plantar fasciitis. As expected calcaneal spurs were observed in both groups (85% PF and 46% controls). However, plantar fascia thickness and fat pad abnormalities resulted in the best group differentiation (p<0.0001) with sensitivity of 85% and specificity of 95% for plantar fasciitis. It was concluded that the key radiological features that differentiate the groups were not spurs but rather changes in the soft tissues. If it is deemed necessary to confirm the diagnosis of typical plantar fasciitis with imaging, a lateral non-weight bearing X-ray should be the first choice investigation especially if these key features are noted.

  5. Plantar Pressures During Long Distance Running: An Investigation of 10 Marathon Runners.

    PubMed

    Hohmann, Erik; Reaburn, Peter; Tetsworth, Kevin; Imhoff, Andreas

    2016-06-01

    The objective of this study was to record plantar pressures using an in-shoe measuring system before, during, and after a marathon run in ten experienced long-distance runners with a mean age of 37.7 ± 11.5 years. Peak and mean plantar pressures were recorded before, after, and every three km during a marathon race. There were no significant changes over time in peak and mean plantar pressures for either the dominant or non-dominant foot. There were significant between foot peak and mean plantar pressure differences for the total foot (p = 0.0001), forefoot (p = 0.0001), midfoot (p = 0.02 resp. p = 0.006), hindfoot (p = 0.0001), first ray (p = 0.01 resp. p = 0.0001) and MTP (p = 0.05 resp. p = 0.0001). Long-distance runners do not demonstrate significant changes in mean or peak plantar foot pressures over the distance of a marathon race. However, athletes consistently favoured their dominant extremity, applying significantly higher plantar pressures through their dominant foot over the entire marathon distance. Key pointsFatigue does not increase foot pressuresEvery runner has a dominant foot where pressures are higher and that he/she favoursFoot pressures do not increase over the distance of a marathon run.

  6. [The design of plantar pressure distribution monitoring system and preliminary clinical application].

    PubMed

    Zhu, Xianfeng; Zhao, Zilei; Xu, Donghao; Xu, Dongming

    2014-04-01

    Plantar pressure distribution can reflect the force of several key points on foot while standing and walking. A comprehensive understanding of the plantar pressure distribution makes great sense in the following aspects: the understanding of the normal foot biomechanics and function, clinical diagnosis, measurement of disease extent, postoperative efficacy evaluation, and rehabilitation research. A simple plantar pressure measurement device was designed in this study. This paper uses FlexiForce flexible sensor to pickup plantar pressure signal and USB A/D board to do data acquisition. The data are transferred into a laptop and processed by a VB-based software which can display, remember and replay the data. We chose patients with hallux valgus and normal people to measure the pressure distribution and make contrast analysis of plantar pressure with this device. It can be concluded that people with hallux valgus have higher pressure on the second metatarsophalangeal joint and the distribution move outward. The plantar pressure of patients postoperative could be greatly improved compared to the preoperative. The function of this device has been confirmed.

  7. Can subjective comfort be used as a measure of plantar pressure in football boots?

    PubMed

    Okholm Kryger, Katrine; Jarratt, Vicky; Mitchell, Séan; Forrester, Steph

    2017-05-01

    Comfort has been shown to be the most desired football boot feature by players. Previous studies have shown discomfort to be related to increased plantar pressures for running shoes which, in some foot regions, has been suggested to be a causative factor in overuse injuries. This study examined the correlation between subjective comfort data and objective plantar pressure for football boots during football-specific drills. Eight male university football players were tested. Plantar pressure data were collected during four football-specific movements for each of three different football boots. The global and local peak pressures based on a nine-sectioned foot map were compared to subjective comfort measures recorded using a visual analogue scale for global discomfort and a discomfort foot map for local discomfort. A weak (rs = -0.126) yet significant (P < 0.05) correlation was shown between the peak plantar pressure experienced and the visual analogue scale rated comfort. The model only significantly predicted (P > 0.001) the outcome for two (medial and lateral forefoot) of the nine foot regions. Subjective comfort data is therefore not a reliable measure of increased plantar pressures for any foot region. The use of plantar pressure measures is therefore needed to optimise injury prevention when designing studded footwear.

  8. MEASURING GRAVITATIONAL LENSING FLEXION IN A1689 USING AN ANALYTIC IMAGE MODEL

    SciTech Connect

    Cain, Benjamin

    2011-07-20

    Measuring dark matter substructure within galaxy cluster halos is a fundamental probe of the {Lambda}CDM model of structure formation. Gravitational lensing is a technique for measuring the total mass distribution which is independent of the nature of the gravitating matter, making it a vital tool for studying these dark-matter-dominated objects. We present a new method for measuring weak gravitational lensing flexion fields, the gradients of the lensing shear field, to measure mass distributions on small angular scales. While previously published methods for measuring flexion focus on measuring derived properties of the lensed images, such as shapelet coefficients or surface brightness moments, our method instead fits a mass-sheet transformation invariant Analytic Image Model (AIM) to each galaxy image. This simple parametric model traces the distortion of lensed image isophotes and constrains the flexion fields. We test the AIM method using simulated data images with realistic noise and a variety of unlensed image properties, and show that it successfully reproduces the input flexion fields. We also apply the AIM method for flexion measurement to Hubble Space Telescope observations of A1689 and detect mass structure in the cluster using flexion measured with this method. We also estimate the scatter in the measured flexion fields due to the unlensed shape of the background galaxies and find values consistent with previous estimates.

  9. A New Twist on Torque Labs

    ERIC Educational Resources Information Center

    Lane, W. Brian

    2014-01-01

    The traditional introductory-level meterstick-balancing lab assumes that students already know what torque is and that they readily identify it as a physical quantity of interest. We propose a modified version of this activity in which students qualitatively and quantitatively measure the amount of force required to keep the meterstick level. The…

  10. Torque Limits for Fasteners in Composites

    NASA Technical Reports Server (NTRS)

    Zhao, Yi

    2002-01-01

    The two major classes of laminate joints are bonded and bolted. Often the two classes are combined as bonded-bolted joints. Several characteristics of fiber reinforced composite materials render them more susceptible to joint problems than conventional metals. These characteristics include weakness in in-plane shear, transverse tension/compression, interlaminar shear, and bearing strength relative to the strength and stiffness in the fiber direction. Studies on bolted joints of composite materials have been focused on joining assembly subject to in-plane loads. Modes of failure under these loading conditions are net-tension failure, cleavage tension failure, shear-out failure, bearing failure, etc. Although the studies of torque load can be found in literature, they mainly discussed the effect of the torque load on in-plane strength. Existing methods for calculating torque limit for a mechanical fastener do not consider connecting members. The concern that a composite member could be crushed by a preload inspired the initiation of this study. The purpose is to develop a fundamental knowledge base on how to determine a torque limit when a composite member is taken into account. Two simplified analytical models were used: a stress failure analysis model based on maximum stress criterion, and a strain failure analysis model based on maximum strain criterion.

  11. Torque-balanced vibrationless rotary coupling

    DOEpatents

    Miller, Donald M.

    1980-01-01

    This disclosure describes a torque-balanced vibrationless rotary coupling for transmitting rotary motion without unwanted vibration into the spindle of a machine tool. A drive member drives a driven member using flexible connecting loops which are connected tangentially and at diametrically opposite connecting points through a free floating ring.

  12. Torque wrench allows readings from inaccessible locations

    NASA Technical Reports Server (NTRS)

    De Barnardo, M.

    1966-01-01

    Torque wrench with an adjustable drive shaft permits indicator to remain in view when used on sections of equipment with limited access. The shaft is capable of protruding from either side of the wrench head by means of spring loaded balls.

  13. Electric Field Driven Torque in ATP Synthase

    PubMed Central

    Miller, John H.; Rajapakshe, Kimal I.; Infante, Hans L.; Claycomb, James R.

    2013-01-01

    FO-ATP synthase (FO) is a rotary motor that converts potential energy from ions, usually protons, moving from high- to low-potential sides of a membrane into torque and rotary motion. Here we propose a mechanism whereby electric fields emanating from the proton entry and exit channels act on asymmetric charge distributions in the c-ring, due to protonated and deprotonated sites, and drive it to rotate. The model predicts a scaling between time-averaged torque and proton motive force, which can be hindered by mutations that adversely affect the channels. The torque created by the c-ring of FO drives the γ-subunit to rotate within the ATP-producing complex (F1) overcoming, with the aid of thermal fluctuations, an opposing torque that rises and falls with angular position. Using the analogy with thermal Brownian motion of a particle in a tilted washboard potential, we compute ATP production rates vs. proton motive force. The latter shows a minimum, needed to drive ATP production, which scales inversely with the number of proton binding sites on the c-ring. PMID:24040370

  14. Noncontact Measurements Of Torques In Shafts

    NASA Technical Reports Server (NTRS)

    Schwartzbart, Aaron

    1991-01-01

    Additional information extracted from eddy-current proximeter. Positioned over rotating shaft, measures both displacement of and torsion in shaft. Torque applied to shaft calculable from output of proximeter. Possible to extract torsion information from existing tape-recorded proximeter data.

  15. Anatomy of a bearing torque problem

    NASA Technical Reports Server (NTRS)

    Phinney, Damon D.

    1987-01-01

    In the early 1970s, an antenna despin drive was developed for MBB solar science satellite HELIOS. A problem with high bearing drag torque that was encountered on the two flight models of this drive, after successful tests were completed on twelve bearings, an engineering model, and the qualification unit is discussed.

  16. Torque-while-turnaround scan mirror assembly

    NASA Technical Reports Server (NTRS)

    Starkus, C. J.

    1977-01-01

    A scan mirror assembly which is part of a thematic mapper system is described with emphasis on mechanical aspects of the design. Features of the oscillating scan mirror mechanism include: a low level of structural vibration for the impact energies involved in mirror oscillation and return of energy lost during impact to the mirror by applying torque during the instant of impact.

  17. Planetary Torque in 3D Isentropic Disks

    NASA Astrophysics Data System (ADS)

    Fung, Jeffrey; Masset, Frédéric; Lega, Elena; Velasco, David

    2017-03-01

    Planetary migration is inherently a three-dimensional (3D) problem, because Earth-size planetary cores are deeply embedded in protoplanetary disks. Simulations of these 3D disks remain challenging due to the steep resolution requirements. Using two different hydrodynamics codes, FARGO3D and PEnGUIn, we simulate disk–planet interaction for a one to five Earth-mass planet embedded in an isentropic disk. We measure the torque on the planet and ensure that the measurements are converged both in resolution and between the two codes. We find that the torque is independent of the smoothing length of the planet’s potential (r s), and that it has a weak dependence on the adiabatic index of the gaseous disk (γ). The torque values correspond to an inward migration rate qualitatively similar to previous linear calculations. We perform additional simulations with explicit radiative transfer using FARGOCA, and again find agreement between 3D simulations and existing torque formulae. We also present the flow pattern around the planets that show active flow is present within the planet’s Hill sphere, and meridional vortices are shed downstream. The vertical flow speed near the planet is faster for a smaller r s or γ, up to supersonic speeds for the smallest r s and γ in our study.

  18. Air brake-dynamometer accurately measures torque

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Air brake-dynamometer assembly combines the principles of the air turbine and the air pump to apply braking torque. The assembly absorbs and measures power outputs of rotating machinery over a wide range of shaft speeds. It can also be used as an air turbine.

  19. 14 CFR 23.361 - Engine torque.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Structure Flight Loads § 23.361 Engine torque. (a) Each engine mount and its supporting structure must be designed for the effects of— (1... and supporting structure must be designed to withstand each of the following: (1) A limit...

  20. 14 CFR 23.361 - Engine torque.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Structure Flight Loads § 23.361 Engine torque. (a) Each engine mount and its supporting structure must be designed for the effects of— (1... and supporting structure must be designed to withstand each of the following: (1) A limit...

  1. 14 CFR 23.361 - Engine torque.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Structure Flight Loads § 23.361 Engine torque. (a) Each engine mount and its supporting structure must be designed for the effects of— (1... and supporting structure must be designed to withstand each of the following: (1) A limit...

  2. 14 CFR 23.361 - Engine torque.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Structure Flight Loads § 23.361 Engine torque. (a) Each engine mount and its supporting structure must be designed for the effects of— (1... and supporting structure must be designed to withstand each of the following: (1) A limit...

  3. 14 CFR 23.361 - Engine torque.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Structure Flight Loads § 23.361 Engine torque. (a) Each engine mount and its supporting structure must be designed for the effects of— (1... and supporting structure must be designed to withstand each of the following: (1) A limit...

  4. Clinical evaluation of 292 Genesis II posterior stabilized high-flexion total knee arthroplasty: range of motion and predictors.

    PubMed

    Fuchs, Mathijs C H W; Janssen, Rob P A

    2015-01-01

    The primary aim of the study was to evaluate the range of motion and complications after Genesis II total knee arthroplasty with high-flexion tibia insert (TKA-HF). Furthermore, difference in knee flexion between high flexion and standard inserts was compared. The hypothesis was that knee flexion is better after high-flexion TKA. A total of 292 TKA-HF were retrospectively reviewed. Mean follow-up was 24.3 months. The range of motion was compared between TKA-HF (high-flexion group) and a comparable cohort of 86 Genesis II TKA with a standard tibia insert (control group). Surgeries were performed by one experienced knee orthopedic surgeon. Knee flexion in the high-flexion group increased from 114.8° preoperatively to 118.0° postoperatively (P < 0.01). Knee extension in the high-flexion group increased from -4.5° preoperatively to -0.4° after surgery (P < 0.01). Mean knee flexion was 5.52° (± 1.46°) better in the high-flexion group compared with the control group (P < 0.01). Preoperative range of motion, body mass index, diabetes mellitus and patellofemoral pain significantly influenced range of motion. Few complications occurred after TKA-HF. The Genesis II TKA-HF showed good short-term results with limited complications. Knee flexion after Genesis II TKA-HF was better compared with a standard tibia insert.

  5. 40 CFR 1066.240 - Torque transducer verification and calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Torque transducer verification and...) AIR POLLUTION CONTROLS VEHICLE-TESTING PROCEDURES Dynamometer Specifications § 1066.240 Torque transducer verification and calibration. Calibrate torque-measurement systems as described in 40 CFR 1065.310....

  6. 40 CFR 1066.240 - Torque transducer verification.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Torque transducer verification. 1066... POLLUTION CONTROLS VEHICLE-TESTING PROCEDURES Dynamometer Specifications § 1066.240 Torque transducer verification. Verify torque-measurement systems by performing the verifications described in §§ 1066.270...

  7. 40 CFR 1066.240 - Torque transducer verification and calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 34 2013-07-01 2013-07-01 false Torque transducer verification and...) AIR POLLUTION CONTROLS VEHICLE-TESTING PROCEDURES Dynamometer Specifications § 1066.240 Torque transducer verification and calibration. Calibrate torque-measurement systems as described in 40 CFR 1065.310....

  8. 40 CFR 90.306 - Dynamometer torque cell calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Dynamometer torque cell calibration... Emission Test Equipment Provisions § 90.306 Dynamometer torque cell calibration. (a)(1) Any lever arm used...-cell or transfer standard may be used to verify the torque measurement system. (1) The master...

  9. 40 CFR 90.306 - Dynamometer torque cell calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Dynamometer torque cell calibration... Emission Test Equipment Provisions § 90.306 Dynamometer torque cell calibration. (a)(1) Any lever arm used...-cell or transfer standard may be used to verify the torque measurement system. (1) The master...

  10. 40 CFR 90.306 - Dynamometer torque cell calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Dynamometer torque cell calibration... Emission Test Equipment Provisions § 90.306 Dynamometer torque cell calibration. (a)(1) Any lever arm used...-cell or transfer standard may be used to verify the torque measurement system. (1) The master...

  11. 40 CFR 90.306 - Dynamometer torque cell calibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Dynamometer torque cell calibration... Emission Test Equipment Provisions § 90.306 Dynamometer torque cell calibration. (a)(1) Any lever arm used...-cell or transfer standard may be used to verify the torque measurement system. (1) The master...

  12. Performances improvements and torque ripple minimization for VSI fed induction machine with direct control torque.

    PubMed

    Abdelli, R; Rekioua, D; Rekioua, T

    2011-04-01

    This paper describes a torque ripple reduction technique with constant switching frequency for direct torque control (DTC) of an induction motor (IM). This method enables a minimum torque ripple control. In order to obtain a constant switching frequency and hence a torque ripple reduction, we propose a control technique for IM. It consists of controlling directly the electromagnetic torque by using a modulated hysteresis controller. The design methodology is based on space vector modulation (SVM) of electrical machines with digital vector control. MATLAB simulations supported with experimental study are used. The simulation and experimental results of this proposed algorithm show an adequate dynamic to IM; however, the research can be extended to include synchronous motors as well. The implementation of the proposed algorithm is described. It doesn't require any PI controller in the torque control loop. The hardware inverter is controlled digitally using a Texas Instruments TMS320F240 digital signal processor (DSP) with composed C codes for generating the required references. The results obtained from simulation and experiments confirmed the feasibility of the proposed strategy compared to the conventional one.

  13. Post-traumatic pseudoaneurysm of the medial plantar artery combined with tarsal tunnel syndrome: two case reports.

    PubMed

    Park, Sang-Eun; Kim, Ji-Chang; Ji, Jong-Hun; Kim, Young-Yul; Lee, Hwan-Hee; Jeong, Jae-Jung

    2013-03-01

    Pseudoaneurysms in the foot are more often reported in the lateral plantar artery than the medial plantar artery, most likely because of its more superficial location. There are no reports of pseudoaneurysm of the medial plantar artery after trauma. We present two cases of pseudoaneurysm of the medial plantar artery after blunt foot trauma and foot laceration. This pseudoaneurysm compressed a posterior tibial nerve, resulting in tarsal tunnel syndrome. The patients were treated successfully using transcatheter embolization without the need for surgical intervention. The tarsal tunnel syndrome also subsided. Here, the authors report these cases and provide a review of literature.

  14. EFFECT OF SECOND TOE-TO-HAND TRANSFER ON THE PLANTAR PRESSURE DISTRIBUTION OF THE DONOR FOOT

    PubMed Central

    Li, Bing; Chen, Da-wei; Yang, Yun-feng; Yu, Guang-rong

    2016-01-01

    ABSTRACT Objective: To investigate the effect of second toe-to-hand transfer on the plantar pressure distribution of the donor foot. Methods: Twelve normal fresh-frozen cadaveric foot specimens were subjected to an axial load of 600 N. An F-Scan plantar pressure analysis system was used to measure the forefoot plantar pressure. The testing was performed under the conditions of intact second toe, second toe removal with the second metatarsal head reserved, and second toe removal in combination with the distal one-third of the second metatarsal, respectively. Results: The peak pressure of the second metatarsal head was greater than other four forefoot plantar regions. There was no statistically significant change in the forefoot plantar pressure distribution after the second toe was removed (p > 0.05). When the second toe and the distal one-third of the second metatarsal were removed, the forefoot plantar pressure distribution changed significantly (p < 0.05). Conclusions: An intact second metatarsal is essential for the normal distribution of plantar pressure. Removal of the second toe with the second metatarsal head reserved had little influence on the plantar pressure distribution of the donor foot. Removal of the second toe and distal one-third of the second metatarsal resulted in abnormal plantar pressure distribution. Level of Evidence II, Experimental Study. PMID:26997913

  15. The Role of Arch Compression and Metatarsophalangeal Joint Dynamics in Modulating Plantar Fascia Strain in Running.

    PubMed

    McDonald, Kirsty A; Stearne, Sarah M; Alderson, Jacqueline A; North, Ian; Pires, Neville J; Rubenson, Jonas

    2016-01-01

    Elastic energy returned from passive-elastic structures of the lower limb is fundamental in lowering the mechanical demand on muscles during running. The purpose of this study was to investigate the two length-modulating mechanisms of the plantar fascia, namely medial longitudinal arch compression and metatarsophalangeal joint (MPJ) excursion, and to determine how these mechanisms modulate strain, and thus elastic energy storage/return of the plantar fascia during running. Eighteen runners (9 forefoot and 9 rearfoot strike) performed three treadmill running trials; unrestricted shod, shod with restricted arch compression (via an orthotic-style insert), and barefoot. Three-dimensional motion capture and ground reaction force data were used to calculate lower limb kinematics and kinetics including MPJ angles, moments, powers and work. Estimates of plantar fascia strain due to arch compression and MPJ excursion were derived using a geometric model of the arch and a subject-specific musculoskeletal model of the plantar fascia, respectively. The plantar fascia exhibited a typical elastic stretch-shortening cycle with the majority of strain generated via arch compression. This strategy was similar in fore- and rear-foot strike runners. Restricting arch compression, and hence the elastic-spring function of the arch, was not compensated for by an increase in MPJ-derived strain. In the second half of stance the plantar fascia was found to transfer energy between the MPJ (energy absorption) and the arch (energy production during recoil). This previously unreported energy transfer mechanism reduces the strain required by the plantar fascia in generating useful positive mechanical work at the arch during running.

  16. The Role of Arch Compression and Metatarsophalangeal Joint Dynamics in Modulating Plantar Fascia Strain in Running

    PubMed Central

    McDonald, Kirsty A.; Stearne, Sarah M.; Alderson, Jacqueline A.; North, Ian; Pires, Neville J.; Rubenson, Jonas

    2016-01-01

    Elastic energy returned from passive-elastic structures of the lower limb is fundamental in lowering the mechanical demand on muscles during running. The purpose of this study was to investigate the two length-modulating mechanisms of the plantar fascia, namely medial longitudinal arch compression and metatarsophalangeal joint (MPJ) excursion, and to determine how these mechanisms modulate strain, and thus elastic energy storage/return of the plantar fascia during running. Eighteen runners (9 forefoot and 9 rearfoot strike) performed three treadmill running trials; unrestricted shod, shod with restricted arch compression (via an orthotic-style insert), and barefoot. Three-dimensional motion capture and ground reaction force data were used to calculate lower limb kinematics and kinetics including MPJ angles, moments, powers and work. Estimates of plantar fascia strain due to arch compression and MPJ excursion were derived using a geometric model of the arch and a subject-specific musculoskeletal model of the plantar fascia, respectively. The plantar fascia exhibited a typical elastic stretch-shortening cycle with the majority of strain generated via arch compression. This strategy was similar in fore- and rear-foot strike runners. Restricting arch compression, and hence the elastic-spring function of the arch, was not compensated for by an increase in MPJ-derived strain. In the second half of stance the plantar fascia was found to transfer energy between the MPJ (energy absorption) and the arch (energy production during recoil). This previously unreported energy transfer mechanism reduces the strain required by the plantar fascia in generating useful positive mechanical work at the arch during running. PMID:27054319

  17. Saccadic Eye Movement Improves Plantar Sensation and Postural Balance in Elderly Women.

    PubMed

    Bae, Youngsook

    2016-01-01

    Vision, proprioception and plantar sensation contribute to the control of postural balance (PB). Reduced plantar sensation alters postural response and is at an increased risk of fall, and eye movements reduce the postural sway. Therefore, the aim of this study was to study the improvement of plantar sensation and PB after saccadic eye movement (SEM) and pursuit eye movement (PEM) in community-dwelling elderly women. Participants (104 females; 75.11 ± 6.25 years) were randomly allocated into the SEM group (n = 52) and PEM groups (n = 52). The SEM group performed eye fixation and SEM for 5 minutes, and the PEM group performed eye fixation and PEM for 5 minutes. The plantar sensation was measured according to the plantar surface area of the feet in contact with the floor surface before and after the intervention. Before and after SEM and PEM with the eyes open and closed, PB was measured as the area (mm(2)), length (cm), and velocity (cm/s) of the fluctuation of the center of pressure (COP). The plantar sensation of both feet improved in both groups (p < 0.01). Significant decreases in the area, length, and velocity of the COP were observed in the eye open and close in both groups (p < 0.01). The length and velocity of the COP significantly decreased in the SEM group compared to the PEM group (p < 0.05). In conclusion, SEM and PEM are effective interventions for improving plantar sensation and PB in elderly women, with greater PB improvement after SEM.

  18. 49 CFR 572.145 - Upper and lower torso assemblies and torso flexion test procedure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... lumbar spine and abdomen of a fully assembled dummy (drawing 210-0000) to flexion articulation between... in paragraph (c) of this section, the lumbar spine-abdomen assembly shall flex by an amount...

  19. 49 CFR 572.145 - Upper and lower torso assemblies and torso flexion test procedure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... lumbar spine and abdomen of a fully assembled dummy (drawing 210-0000) to flexion articulation between... in paragraph (c) of this section, the lumbar spine-abdomen assembly shall flex by an amount...

  20. 49 CFR 572.145 - Upper and lower torso assemblies and torso flexion test procedure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... lumbar spine and abdomen of a fully assembled dummy (drawing 210-0000) to flexion articulation between... in paragraph (c) of this section, the lumbar spine-abdomen assembly shall flex by an amount...

  1. 49 CFR 572.145 - Upper and lower torso assemblies and torso flexion test procedure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... lumbar spine and abdomen of a fully assembled dummy (drawing 210-0000) to flexion articulation between... in paragraph (c) of this section, the lumbar spine-abdomen assembly shall flex by an amount...

  2. Total Knee Arthroplasty for Severe Flexion Contracture in Rheumatoid Arthritis Knees

    PubMed Central

    Hwang, Youn Soo; Moon, Kyu Pill; Kim, Kyung Taek; Kim, Jin Wan; Park, Won Seok

    2016-01-01

    Flexion contracture deformities, as well as severe varus and valgus deformities of the knee joint, accompany osteoarthritis or rheumatoid arthritis (RA). In particular, severe flexion contracture deformity of the knee joint is often found in patients with RA, which renders them nonambulatory. This report describes a 26-year-old female patient diagnosed with RA 10 years ago. She had chronic joint pain, severe flexion contracture, valgus deformity in both knees, and limited range of motion in both knees and became nonambulatory. She underwent a total knee arthroplasty (TKA) and serial casting and physical therapy to restore stable joint movement and correct knee joint deformity. Her pain was successfully relieved, and she was able to walk after surgery. Here, we report the excellent results of TKA in this RA patient with severe flexion contracture of both knees. PMID:27894181

  3. HINGED CAST BRACE FOR PERSISTENT FLEXION CONTRACTURE FOLLOWING TOTAL KNEE REPLACEMENT

    PubMed Central

    Karam, Matthew D; Pugely, Andrew; Callaghan, John J; Shurr, Donald

    2011-01-01

    The reported incidence of persistent knee flexion contracture following total knee arthroplasty (TKA) has varied from 1-15 percent Various treatment modalities have been described in attempts to manage this often difficult problem. This paper describes a novel method of treatment by using a hinged cast brace (previously reported for treatment of femur fractures and knee contractures secondary to hemophilia and cerebral palsy) for use in patients with symptomatic knee flexion contractures. Application of this cast brace with frequent adjustment (every three to four days, initially) toward full extension can often improve knee extension, after physical therapy and other modalities such as extension-assist braces have failed. Care must be taken in the application and use of this device which utilizes frequent manipulations to reduce and maintain the knee flexion angle. We report two clinical cases in which this protocol was effectively used in decreasing symptomatic knee flexion contractures. PMID:22096423

  4. Development of a knee joint motion simulator to evaluate deep knee flexion of artificial knee joints.

    PubMed

    Takano, Y; Ueno, M; Kiguchi, K; Ito, J; Mawatari, M; Hotokebuchi, T

    2008-01-01

    A purpose of this study is to examine the effect that quadriceps femoris force gives to rotation angle and joint reaction force of total knee prosthesis during deep knee flexion such as a unique sitting style called 'seiza' in Japanese. For the evaluation, we developed the knee motion simulator which could bend to 180 degrees continually simulating the passive flexion performed by clinicians. A total knee prosthesis, which is a specially-devised posterior stabilized type and capable of flexion up to 180 degrees, was inserted into bone model. And this prosthesis pulled by three kinds of quadriceps femoris forces to perform parameter study. The results obtained in this study were showed the same tendency with those in the past cadaveric experiment. It is suggested that the rotation angle and joint reaction force of total knee prosthesis are affected by shape of prosthesis, a vector of quadriceps femoris force, and bony aliments during deep knee flexion.

  5. A model of flexion-extension movement in hip joint using polynomial interpolation

    NASA Astrophysics Data System (ADS)

    Toth-Taşcǎu, Mirela; Pater, Flavius; Stoia, Dan Ioan

    2013-10-01

    The study proposes a mathematical model of flexion-extension movement in hip joint based on Lagrange polynomial interpolation. In order to develop and validate the proposed model the angle of flexion-extension (F-E) in hip joint was analyzed. The two main reasons of this option rely on the importance of the hip joint in human locomotion and the fact that flexion-extension movement is developed in most of the human joints. The mathematical model of joint movement allows developing a more detailed kinematic analysis of the joint movements. The raw data representing the variation of the flexion-extension angle in hip joint was achieved by experimental kinematic analysis of a lot of ten young healthy subjects.

  6. Methods of torque ripple reduction for flux reversal motor

    NASA Astrophysics Data System (ADS)

    Vakil, Gaurang; Sheth, N. K.; Miller, David

    2009-04-01

    This paper presents two-dimensional finite element based results for various methods of torque ripple reduction in flux-reversal motors. The effects of variation in magnet and rotor pole heights, rotor pole skewing, and multiple teeth per rotor pole on the cogging torque, developed torque, torque ripple, and phase inductance and also an optimum value of the magnet and rotor pole heights, skew angle, and choice of teeth per rotor pole with the teeth depth resulting in torque ripple reduction are presented.

  7. Appropriateness of plantar pressure measurement devices: a comparative technical assessment.

    PubMed

    Giacomozzi, Claudia

    2010-05-01

    Accurate plantar pressure measurements are mandatory in both clinical and research contexts. Differences in accuracy, precision and reliability of the available devices have prevented so far the onset of standardization processes or the definition of reliable reference datasets. In order to comparatively assess the appropriateness of the most used pressure measurement devices (PMD) on-the-market, in 2006 the Institute the author is working for approved a two-year scientific project aimed to design, validate and implement dedicated testing methods for both in-factory and on-the field assessment. A first testing phase was also performed which finished in December 2008. Five commercial PMDs using different technologies-resistive, elastomer-based capacitive, air-based capacitive-were assessed and compared with respect to absolute pressure measurements, hysteresis, creep and COP estimation. The static and dynamic pressure tests showed very high accuracy of capacitive, elastomer-based technology (RMSE<0.5%), and quite a good performance of capacitive, air-based technology (RMSE<5%). High accuracy was also found for the resistive technology by TEKSCAN (RMSE<2.5%), even though a complex ad hoc calibration was necessary.

  8. [Characterization of chronic plantar ulcers in former leprosy patients].

    PubMed

    Grauwin, M Y; Gentile, B; Chevallard, A; Cartel, J L

    1994-01-01

    Between 1988 and 1992, 21 biopsies for pathological examination were taken from 20 Senegalese leprosy patients suffering from chronic plantar ulcers (CPU) suspected of malignant transformation. The diagnosis of squamous cell carcinoma was effectively made in 13 cases and that of pseudoepitheliomatous hyperplasia in the remaining 8 cases. The mean period of time between the onset of CPU and that of malignant transformation was 10 years (range: 1 to 15 years); the mean annual frequency of the malignant transformation was 2 per 1,000 CPU. In countries where pathological examination is not available, below knee amputation could be considered whenever main clinical signs of malignant transformation are present. In countries where pathological examination is available, the therapeutic decision may differ according to the diagnosis: below knee amputation supplemented with block dissection of inguinal lymph nodes whenever possible in cases of carcinoma; below knee amputation depending on the function status of the foot and on the volume of tumor in case of pseudo-epitheliomatous hyperplasia.

  9. [Tumoral proliferations in chronic plantar ulcers: how to treat?].

    PubMed

    Grauwin, M Y; Mane, I; Cartel, J L

    1996-01-01

    Between 1983 and 1994, 66 Senegalese leprosy patients were seen for cauliflower growths developed in chronic plantar ulcer (CPU), (2 patients had each 2 tumors). 68 biopsies for pathological examination were taken: the diagnosis of squamous cell carcinoma was effectively made in 39 cases (38 patients) and that of pseudo-epitheliomatous hyperplasia in the remaining 29 cases (28 patients). The mean annual frequency of cauliflower growths was 0.45 per 100 CPU. Among these tumors, the percentage of carcinoma was 57%. Of the 38 patients with a carcinoma, 5 refused amputation and all of them died. The 33 others were amputated and of these 8 died as a direct result of their carcinoma (24%). In the case of the 28 patients with hyperplasia, amputation was carried out on 18 patients and local excision on 10. In the months following the operation 8 recurrences were observed in 10 of the patients on whom excision had been carried out. These recurrences were treated by amputation. This gives a total of 93% of amputations in the cases of hyperplasia. These facts lead as to conclude that at least in countries where pathological examination is not available below knee amputation is the most reasonable action to take in the proliferative tumors developed on a CPU.

  10. Plantar soft tissue thickness during ground contact in walking

    NASA Technical Reports Server (NTRS)

    Cavanagh, P. R.

    1999-01-01

    A technique is introduced for the measurement of plantar soft tissue thickness during barefoot walking. Subjects stepped into an adjustable Plexiglas frame which ensured that the required bony landmarks were appropriately positioned relative to a linear ultrasound probe connected to a conventional 7.5 MHz ultrasound scanner. Clear images of the metatarsal condyles or other foot bones were obtained throughout ground contact. Subsequent analysis of the video taped images using a motion analysis system allowed the tissue displacement to be calculated as a function of time. The tissue underneath the second metatarsal head was shown to undergo an average maximum compression of 45.7% during the late stages of ground contact during first step gait in a group of five normal subjects with a mean unloaded tissue thickness of 15.2 mm. The technique has a number of applications, including use in the validation of deformation predicted by finite element models of the soft tissue of the foot, and the study of alterations in the cushioning properties of the heel by devices which constrain the displacement of the heel pad.

  11. Treatment of chronic plantar fasciopathy with extracorporeal shock waves (review)

    PubMed Central

    2013-01-01

    There is an increasing interest by doctors and patients in extracorporeal shock wave therapy (ESWT) for chronic plantar fasciopathy (PF), particularly in second generation radial extracorporeal shock wave therapy (RSWT). The present review aims at serving this interest by providing a comprehensive overview on physical and medical definitions of shock waves and a detailed assessment of the quality and significance of the randomized clinical trials published on ESWT and RSWT as it is used to treat chronic PF. Both ESWT and RSWT are safe, effective, and technically easy treatments for chronic PF. The main advantages of RSWT over ESWT are the lack of need for any anesthesia during the treatment and the demonstrated long-term treatment success (demonstrated at both 6 and 12 months after the first treatment using RSWT, compared to follow-up intervals of no more than 12 weeks after the first treatment using ESWT). In recent years, a greater understanding of the clinical outcomes in ESWT and RSWT for chronic PF has arisen in relationship not only in the design of studies, but also in procedure, energy level, and shock wave propagation. Either procedure should be considered for patients 18 years of age or older with chronic PF prior to surgical intervention. PMID:24004715

  12. Robot-Assisted Rehabilitation of Ankle Plantar Flexors Spasticity: A 3-Month Study with Proprioceptive Neuromuscular Facilitation.

    PubMed

    Zhou, Zhihao; Sun, Yao; Wang, Ninghua; Gao, Fan; Wei, Kunlin; Wang, Qining

    2016-01-01

    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

  13. Robot-Assisted Rehabilitation of Ankle Plantar Flexors Spasticity: A 3-Month Study with Proprioceptive Neuromuscular Facilitation

    PubMed Central

    Zhou, Zhihao; Sun, Yao; Wang, Ninghua; Gao, Fan; Wei, Kunlin; Wang, Qining

    2016-01-01

    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

  14. Femoral shortening in correction of congenital knee flexion deformity with popliteal webbing.

    PubMed

    Saleh, M; Gibson, M F; Sharrard, W J

    1989-01-01

    Severe knee flexion deformity with popliteal webbing or pterygium is considered to be uncorrectable. The soft tissues and, in particular, the main nerves and vessels are short relative to the bone. Femoral shortening was used in correction of such a deformity in a child with arthrogryposis. The operative procedure is described. Femoral shortening should be considered as an aid to correction of any severe knee flexion deformity.

  15. How does the neck flexion affect the cervical MRI features of Hirayama disease?

    PubMed

    Hou, Chao; Han, Hongbin; Yang, Xiaohong; Xu, Xiaojuan; Gao, Hui; Fan, Dongsheng; Fu, Yu; Sun, Yu; Liu, Bo

    2012-10-01

    Although flexion cervical MRI has been recommended for the diagnosis of Hirayama disease (HD), no study focused on the MR features at different neck flexion angles. Moreover, no uniform flexion angle has been confirmed in clinical practice. The purpose of this study is to quantitatively investigate the MRI typical signs of HD patients in different neck flexion degree and gives a suggestion to the MR scanning. Cervical MRI in neutral and different flexion positions (cervical flexion angle 20°, 25°, 30°, 35°, and 40°) were performed in 45 HD patients. Three MRI features including anterior shifting of the posterior wall of the cervical dural canal (ASD), widening of cervical epidural space, and epidural flow voids (EFV) at each flexed position were summarized. To evaluate ASD quantitatively, the widest cervical epidural space with the maximum sagittal diameters (d) and cervical canal sagittal diameter (D) at the same level were measured. The d/D values at different angles were calculated and compared. ASD was demonstrated in 34 out of 45 cases (75.6%) at 20° and in all cases (100%) at other 4 angles (χ (2) = 25.728, P < 0.05). Significant difference was demonstrated for the appearance rate of EFV (mean 72.8%) among different angles (χ (2) = 11.373, P = 0.021). The peak mean d/D value was found at 35°. Neck flexion angles have effects on ASD, widening of cervical epidural space and EFV. 25° is recommended as the least effective diagnostic flexion angle for MRI diagnosis of HD, and 35° may be the best one.

  16. In Vivo Kinematics of the Trapeziometacarpal Joint During Thumb Extension-flexion and Abduction-adduction

    PubMed Central

    Crisco, Joseph J.; Halilaj, Eni; Moore, Douglas C.; Patel, Tarpit; Weiss, Arnold-Peter C.; Ladd, Amy L.

    2014-01-01

    Purpose The primary aim of this study was to determine whether the in vivo kinematics of the trapeziometacarpal (TMC) joint differ as a function of age and sex during thumb extension-flexion and abduction-adduction motions. Methods The hands and wrists of 44 subjects (10 men and 11 women aged 18 to 35 years and 10 men and 13 women aged 40 to 75 years) with no symptoms or signs of TMC joint pathology were imaged with computed tomography (CT) during thumb extension, flexion, abduction, and adduction. The kinematics of the TMC joint were computed and compared across direction, age, and sex. Results We found no significant effects of age or sex, after normalizing for size, in any of the kinematic parameters. The extension-flexion and abduction-adduction rotation axes did not intersect, and both were oriented obliquely to the saddle-shaped anatomy of the TMC articulation. The extension-flexion axis was located in the trapezium and the abduction-adduction axis was located in the metacarpal. Metacarpal translation and internal rotation occurred primarily during extension-flexion. Discussion Our in vivo findings support previous cadaver and modeling studies that have concluded that the functional axes of the TMC joint are non-orthogonal and non-intersecting. However, in contrast to previous studies, we found extension-flexion and adduction-abduction to be coupled with internal-external rotation and translation. Specifically, internal rotation and ulnar translation were coupled with flexion, indicating a potential stabilizing screw-home mechanism. Clinical Relevance The treatment of TMC pathology and arthroplasty design require a detailed and accurate understanding of TMC function. This study confirms the complexity of TMC kinematics and describes metacarpal translation coupled with internal rotation during extension-flexion, which may explain some of the limitations of current treatment strategies and should help improve implant designs. PMID:25542440

  17. Influence of dorsiflexion shoes on neuromuscular fatigue of the plantar flexors after combined tapping-jumping exercises in volleyball players.

    PubMed

    Lapole, Thomas; Ahmaidi, Said; Gaillien, Benjamin; Leprêtre, Pierre-Marie

    2013-07-01

    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.

  18. Crouched gait in myelomeningocele: a comparison between the degree of knee flexion contracture in the clinical examination and during gait.

    PubMed

    Moen, Todd; Gryfakis, Nicholas; Dias, Luciano; Lemke, Laura

    2005-01-01

    The purpose of this study was to quantitatively evaluate, in patients with low lumbar and sacral level myelomeningocele who have knee flexion contractures, whether there are significant differences between the degree of knee flexion contracture measured clinically and the degree of actual knee flexion during gait, measured by computerized gait analysis. Patients were divided into two groups, those who walked with ankle-foot orthoses (AFOs) alone and those who walked with AFOs and crutches. In both groups, the patient's knee flexion contractures were measured clinically, and the degree of knee flexion was measured dynamically at two representative points in the gait cycle. In both groups and at both points of the gait cycle, the degree of knee flexion during gait was significantly greater than the degree of clinical knee flexion contracture. This should be taken into account when evaluating the crouch gait of children with myelomeningocele and planning the proper treatment.

  19. Torque generated by the flagellar motor of Escherichia coli.

    PubMed Central

    Berg, H C; Turner, L

    1993-01-01

    Cells of the bacterium Escherichia coli were tethered and spun in a high-frequency rotating electric field at a series of discrete field strengths. This was done first at low field strengths, then at field strengths generating speeds high enough to disrupt motor function, and finally at low field strengths. Comparison of the initial and final speed versus applied-torque plots yielded relative motor torque. For backward rotation, motor torque rose steeply at speeds close to zero, peaking, on average, at about 2.2 times the stall torque. For forward rotation, motor torque remained approximately constant up to speeds of about 60% of the zero-torque speed. Then the torque dropped linearly with speed, crossed zero, and reached a minimum, on average, at about -1.7 times the stall torque. The zero-torque speed increased with temperature (about 90 Hz at 11 degrees C, 140 Hz at 16 degrees C, and 290 Hz at 23 degrees C), while other parameters remained approximately constant. Sometimes the motor slipped at either extreme (delivered constant torque over a range of speeds), but eventually it broke. Similar results were obtained whether motors broke catastrophically (suddenly and completely) or progressively or were de-energized by brief treatment with an uncoupler. These results are consistent with a tightly coupled ratchet mechanism, provided that elastic deformation of force-generating elements is limited by a stop and that mechanical components yield at high applied torques. PMID:8298044

  20. Treatment of Chronic Plantar Heel Pain With Radiofrequency Neural Ablation of the First Branch of the Lateral Plantar Nerve and Medial Calcaneal Nerve Branches.

    PubMed

    Arslan, Aydın; Koca, Tuba Tulay; Utkan, Ali; Sevimli, Resit; Akel, İbrahim

    2016-01-01

    From March 2012 to February 2013, 37 patients experiencing plantar heel pain for ≥6 months despite treatment with physical therapy and other conservative treatment modalities were followed up. If neurogenic heel pain originating from the first branch of the lateral plantar nerve was present, with or without the medial calcaneal nerve, diagnostic nerve blocks to these nerves were performed for confirmation. If the pain was determined to be of neurogenic origin, radiofrequency neural ablation (RFNA) was applied to the corresponding sensory nerve endings. Pain was evaluated using the visual analog scale, and patients were followed for at least one year. A total of 41 feet from 37 patients (30 [81.1%] females, 7 [18.9%] males; mean age, 50.7 ± 1.6 years; mean body mass index, 30.6 ± 0.7 kg/m(2)) were included. The mean visual analog scale scores improved significantly from 1 to 6 to 12 months after the procedure relative to before the procedure, with 88% of all patients rating the treatment as either very successful or successful at 12 months postoperatively. RFNA applied to both the first branch of the lateral plantar nerve and the medial calcaneal nerve sensory branches (16 [39%] feet) and only the first branch of the lateral plantar nerve sensory branches (25 [61%] feet) showed similarly high levels of success. Of the 41 feet, 28 [68.3%] had received extracorporeal shockwave therapy, 35 [85.4%] had received steroid injections, and 22 [53.7%] had received both extracorporeal shockwave therapy and steroid injections before RFNA as an index procedure. All were unresponsive to these previous treatments. In contrast, almost all (88%) were treated successfully with RFNA. Despite a high incidence of neurologic variations, with a precise diagnosis and good application of the technique using the painful points, chronic plantar heel pain can be treated successfully with RFNA.