Lateral Head Of Gastrocnemius Muscle Research Articles

Caffeine Supplementation Improves Anaerobic Performance and Neuromuscular Efficiency and Fatigue in Olympic-Level Boxers.

Background: this study examined the effects of caffeine supplementation on anaerobic performance, neuromuscular efficiency and upper and lower extremities fatigue in Olympic-level boxers. Methods: Eight male athletes, members of the Spanish National Olympic Team, were enrolled in the study. In a randomized double-blind, placebo-controlled, counterbalanced, crossover design, the athletes completed 2 test sessions after the intake of caffeine (6 mg·kg−1) or placebo. Sessions involved initial measures of lactate, handgrip and countermovement jump (CMJ) performance, followed by a 30-seconds Wingate test, and then final measures of the previous variables. During the sessions, electromiography (EMG) data were recorded on the gluteus maximus, biceps femoris, vastus lateralis, gastrocnemius lateral head and tibialis anterior. Results: caffeine enhanced peak power (6.27%, p < 0.01; Effect Size (ES) = 1.26), mean power (5.21%; p < 0.01; ES = 1.29) and reduced the time needed to reach peak power (−9.91%, p < 0.01; ES = 0.58) in the Wingate test, improved jump height in the CMJ (+2.4 cm, p < 0.01), and improved neuromuscular efficiency at peak power in the vastus lateralis (ES = 1.01) and gluteus maximus (ES = 0.89), and mean power in the vastus lateralis (ES = 0.95) and tibialis anterior (ES = 0.83). Conclusions: in these Olympic-level boxers, caffeine supplementation improved anaerobic performance without affecting EMG activity and fatigue levels in the lower limbs. Further benefits observed were enhanced neuromuscular efficiency in some muscles and improved reaction speed.

The Ideal Location of the Lateral Hinge in Medial Closing Wedge Osteotomy of the Distal Femur: Analysis of Soft Tissue Coverage and Bone Density

Background: Although an appropriate hinge position to prevent unstable lateral hinge fractures is well established in medial opening wedge high tibial osteotomy, the position during medial closing wedge distal femoral osteotomy has not been elucidated. Purpose/Hypothesis: The purpose was to evaluate the ideal hinge position that would prevent an unstable lateral hinge fracture during biplanar medial closing wedge distal femoral osteotomy based on soft tissue coverage and bone density around the hinge area. The hypothesis was that the ideal hinge position could be clarified by analyzing soft tissue coverage and bone density around the lateral hinge area. Study Design: Controlled laboratory study. Methods: In 20 cadaveric knees (mean age, 70.3 ± 19.2 years), the femoral attachment of the gastrocnemius lateral head was quantitatively analyzed as a soft tissue stabilizer using digital photography and fluoroscopy. Then, medial closing wedge distal femoral osteotomy was performed, locating the lateral hinge either inside (group 1) or outside (group 2) the femoral attachment of the gastrocnemius lateral head, and the incidence of unstable lateral hinge fractures was compared between the 2 groups. Cortical bone density around the lateral hinge was measured using Hounsfield units on 30 computed tomography scans and reconstructed as a 3-dimensional mapping model. The transitional zone with low bone density was regarded as the safe hinge position with an increased capacity for bone deformation. Results: The upper and lower margins of the femoral attachment of the gastrocnemius lateral head were 9.1 ± 0.9 mm above and 8.0 ± 1.4 mm below the upper border of the lateral femoral condyle, respectively, and the femoral attachment of the gastrocnemius lateral head was widest in the anteroposterior dimension 0.4 ± 1.7 mm above the upper border of the lateral femoral condyle. The incidence of unstable lateral hinge fractures during osteotomy was significantly decreased in group 1 compared with group 2 (group 1: 0/10; group 2: 5/10; P = .01). An isolated transitional zone with low bone density was observed in all 30 knees and located 1.3 ± 0.8 mm above the upper border of the lateral femoral condyle. Bone density of the transitional zone with low bone density was significantly lower than surrounding femoral cortices (P < .001). Conclusion: Only the upper border of the lateral femoral condyle can be recommended as an ideal hinge position to prevent unstable lateral hinge fractures during biplanar medial closing wedge distal femoral osteotomy based on soft tissue coverage and bone density. Clinical Relevance: When the hinge is positioned at the upper border of the lateral femoral condyle during biplanar medial closing wedge distal femoral osteotomy, the risk of unstable hinge fractures can be minimized.

MRI presentation and pathogenesis of tennis legs

Objective To evaluate the imaging features of MRI of tennis legs and to explore the pathogenesis of tennis legs. Methods A retrospective analysis was made on the MRI images of 38 patients with tennis legs which met the criteria and were clinically diagnosed in our hospital from May 2014 to June 2018. All patients underwent non-enhanced MRI. Coronal T1WI、T2WI fast spin echo (TSE) and transverse proton density weighted imaging (PDWI) were performed. The signs of fluid collection between gastrocnemius muscle (GM) and soleus muscle (SM),muscle and tendon injuries, superficial vein dilatation of calf were observed and recorded. Results Coronal T1WI, T2WI TSE and transverse PDWI sequences showed 30 (75.0%) places fluid collection (hematoma or effusion) between medial head of the gastrocnemius muscle (MCM) and SM,11 (27.5%) places fluid collection (hematoma or effusion) between lateral head of gastrocnemius muscle (LGM) and SM,7 (17.5%) places fluid collection (hematoma or effusion) in MGM and 2 (5.0%) placesin SM. There were 17 (42.5%) places that hematoma or effusion spread around the fascia of the lower leg. The diameter and thickness of hematoma or effusion are about 1.7-22.3 cm and 0.2-3.5 cm,respectively. Rupture of the GM was seen in 37 (92.5%) places,including 37 places rupture of the MGM at the myotendinous junction, 15 places rupture of the LGM at the myotendinous junction, 24 places tendonrupture of MGM,3 places tendon rupture of MGM and LGM,and 2 places tendon rupture of LGM. The maximum diameter of tendon rupture was 1.2-27.0 mm. The muscle rupture of MGM was seen in one place,and muscle rupture of MGM and LGM was seen in one place at the same time. Rupture of the SM was seen in15 (37.5%) places,including 15 places rupture of the SM at the myotendinous junction, 2 places muscle rupture of SM, 6 places tendonrupture of SM. The maximum diameter of tendon rupture was 2.5-14.9 mm. Rupture of plantaris tendon (PT) was seen in 4 (10.0%) places. Superficial vein dilatation was seen in 3 (7.5%) places. Conclusion This study shows that the rupture of the MGM at the myotendinous junction and the tendon is the main responsibility of tennis leg. Key words: Tennis legs; Gastrocnemius muscle; Plantaris tendon; Soleus muscle

Force-Temporal Characteristics of EEG-EMG Coherence during Isometric Contraction of Lateral Head of Gastrocnemius Muscle.

Coherence between an electroencephalogram (EEG) and an electromyogram (EMG) of the soleus (SOL) muscle during an isometric contraction is observed in the beta-band (15 to 35 Hz) regardless of the contraction force. However, the dynamics on how a variation in coherence occurs over time in the head of the gastrocnemius (GLH) muscle, which is also known to have the same role as the soleus muscle, have yet to be considered. In this study, we focused on GLH and measured an EEG and EMG taken of the GLH muscle when executing an isometric contraction through the dorsiflexion of the right ankle joint for a 1-min period. Moreover, we investigated changes in the EEG-EMG coherence based on the contraction force and elapsed time. As a result, in most subjects, the peak coherence during a weak contraction force was continuously observed in the β-band, whereas the peak coherence during a strong contraction force was observed in the γ-band (35 to 60 Hz) for only the first 12 s. In addition, no significant coherence was observed. Therefore, it was suggested that muscle fatigue induced by a strong contraction force affects the peak coherence. Meanwhile, the inconsistencies observed between the properties of the peak coherence and SOL might be due to the differences in muscle composition.

Paralysis of the gastrocnemius medial head differentially affects gait patterns and muscle activity during level and stair ascent locomotion

BackgroundPrior studies have analyzed the activity of the gastrocnemius (GCM) medial and lateral heads as a single unit because it is technically challenging to separately analyze the function of each component in vivo. However, functional variation between the medial and lateral heads is expected due to their anatomical differences. Research questionWhat is the independent function of the medial GCM? How does paralysis of the GCM medial head affect gait kinematics?. MethodsTwelve healthy adults (two males and ten females; age: 28.2 [±7.72] years) that were scheduled to undergo neurolysis of the tibial nerve branch supplying the medial head of the GCM for aesthetic calf reduction participated in the study. Gait analysis was performed using a computerized opto-electric gait analysis system to measure kinematic data. Surface electromyography (EMG) was recorded simultaneously during the gait analysis. Surface electrodes were placed on seven muscles. Pre-procedure and 1-week and 3-month post-procedure data were compared using a linear mixed model. ResultsDuring level walking, decreased activity of the GCM medial head did not significantly change gait kinematics. However, a significant increase in GCM lateral head and hamstring activities occurred after a branch nerve block to the GCM medial head. During stair ascent, in contrast to level walking, changes in EMG activity only occurred in the GCM medial head, and post-procedure ankle dorsiflexion angles at the end of the terminal-stance phase significantly increased. Ankle plantarflexion angles during the push-off phase were also decreased when compared with pre-procedure values. SignificanceThe human body response to dysfunction of the GCM medial head depended on the type of locomotion.

Morphological variants of nerve to gastrocnemius muscle, an anatomical guide to perform surgical dissection

SUMMARY Background. The precise knowledge about distribution of nerves supplying the gastrocnemius muscle is clinically important. The present study aimed to observe the morphological variations in the nerve supply of gastrocnemius in a sample South Indian population. Methods. The study included 38 formalin fixed adult cadaveric lower limbs. Variation in the number and branching pattern of the nerve to gastrocnemius muscle was studied. An imaginary line connecting the medial and lateral epicondyles of the femur, was considered as the reference line to study the topographical origin of the nerves. Results. It was observed that tibial nerve was giving one, two or three branches to the medial head of gastrocnemius muscle in 47.4%, 44.7% and 7.9% cases, respectively. The lateral head of gastrocnemius was receiving single, double or triple branch from tibia nerve in 60.5%, 34.2% and 5% cases, respectively. The nerve that innervated lateral head of gastrocnemius was also supplying soleus in 81.6% cases. The nerve to medial head was found at a higher level than the nerve to lateral head in 27 (71.1%) cases, whereas in 11 (28.9%) cases both were originating at the same level. In 76.3% cases, the nerve to MG was originating above the reference line and in 23.7% cases, below it. The nerve to LG was diverged below the reference line in 84.2% cases, at the reference line in 7.9% cases and above it in 7.9% cases. Conclusion. We report variations in the number and topography of nerves supplying the gastrocnemius muscle, that are enlightening to the operating plastic surgeon during the procedures like triceps surae nerve block and calf reduction. This data can be used as an anatomical guide to perform the surgical dissection

A protocol to prospectively assess risk factors for medial tibial stress syndrome in distance runners

BackgroundMedial tibial stress syndrome (MTSS) is a lower leg injury with a reported incidence rate of up to 35% in active individuals. Although numerous prospective studies have tried to identify risk factors for developing MTSS, managing the syndrome remains difficult. One risk factor yet to be extensively explored in MTSS development is reduced lower leg girth. Further investigation of reduced lower leg girth is required due to the important role lower leg musculature plays in attenuating ground reaction forces during the gait cycle. Therefore, the primary aim of this study is to ascertain whether lower leg muscle morphology and function contribute to the development of MTSS. Our ultimate aim is to identify potential risk factors for MTSS that can be targeted in future studies to better manage the injury or, preferably, prevent individuals developing MTSS.MethodsThis study will be prospective in design and will recruit asymptomatic distance runners. All participants will be tested at base line and participants will have their training data longitudinally tracked over the following 12 months to assess any individuals who develop MTSS symptoms. At base line, outcome measures will include bilateral measures of lower limb anthropometry; cross sectional area (CSA) and thickness of the tibialis anterior, peroneals, flexor digitorum longus, flexor hallucis longus and thickness of soleus, medial and lateral head of gastrocnemius. Tibial bone speed of sound, ankle dorsiflexion range of motion, strength of the six previously described muscles, foot alignment and ankle plantar flexor endurance will also be assessed. Participants will also complete a treadmill running protocol where three-dimensional kinematics, plantar pressure distribution and electromyography data will be collected.DiscussionThis study will aim to identify characteristics of individuals who develop MTSS and, in turn, identify modifiable risk factors that can be targeted to prevent individuals developing this injury.

Assessment of Passive Stiffness of Medial and Lateral Heads of Gastrocnemius Muscle, Achilles Tendon, and Plantar Fascia at Different Ankle and Knee Positions Using the MyotonPRO.

BackgroundThe aim of this study was to assess the passive stiffness of the medial and lateral gastrocnemius (MG and LG), Achilles tendon (AT), and plantar fascia (PF) at different ankle and knee positions.Material/MethodsStiffness was assessed using a portable hand-held device (MyotonPRO). In 30 healthy participants (15 males, 15 females) with the knee fully extended or flexed 90°, stiffness of the MG, LG, AT, and PF was measured at 50° plantar flexion, 0° (neutral position), and 25° dorsiflexion (not for AT) of the ankle joint by passive joint rotation.ResultsWith the knee fully extended, passive dorsiflexion caused significant increase in muscle stiffness (P<0.001), whereas AT and PF stiffness increased with passive ankle dorsiflexion regardless of knee position (P<0.001). Increased stiffness was observed in MG compared to LG (P<0.001) and at the 3-cm site of AT compared to the 6-cm site (P<0.05). Stiffness was greater in LG compared to MG at −50° plantar flexion (P<0.001) and was greater in MG compared to LG at 25° dorsiflexion (P<0.05). Stiffness of AT increased in a distal-to-proximal pattern: 0 cm >3 cm >6 cm (P<0.001).ConclusionsStiffness assessed by use of the MyotonPRO was similar assessments using other techniques, suggesting that the MyotonPRO is capable of detecting the variations in stiffness of MG, LG, AT, and PF at different ankle and knee positions.

The effect of bone marrow mesenchymal stem cells on recovery of skeletal muscle after neurotization surgery in rat.

Objective(s):When the nerve is injured near its entrance to the muscle belly, we cannot perform conventional methods. One useful method in such a situation is neurotization surgery. In this study, Bone marrow mesenchymal stem cells (BMSCs) implanted into the paralyzed muscle after neurotization surgery. These cells can stimulate axon growth and motor endplate formation, also prevent muscle atrophy.Materials and Methods:Thirty-six adult male Sprague-Dawley rats were randomized into six groups: intact group, sham surgery group, control group, DMEM group, cell+DMEM group, denervated group. The motor nerve of the lateral head of gastrocnemius muscle was cut, and the proximal portion of the severed nerve was transplanted to the proximal third of the muscle paralysis. BMSCs with/or DMEM was injected into the site of injury. All animals were evaluated by withdrawal reflex latency (WRL), electromyography, muscle weight, histology and immunohistochemistry.Results:The WRL difference between the control and cell+DMEM groups at weeks 4 and 12 post-operation was statistically significant (P<0.05). The mean number of motor end plates in cell+DMEM group was more than control group (P<0.05). At 12 weeks post-operation, the difference of the mean nerve conduction velocity (NCV) between cell treated group and sham surgery groups were not statistically significant (P>0.05). In weeks 4 and 12 post-operation, the mean fiber diameters in cell+DMEM group were more than control group (P<0.05).Conclusion:The results of this study demonstrate that transplantation of BMSCs after neurotization surgery, prevent muscle atrophy and improve muscle function.

Experimental study on repairmen of high deep peroneal nerve injury by nerve transposition methods using different proximal tibialnerve muscular branches

Objective To study the effect of using different tibial nerve proximal muscle branchs to repair deep peroneal nerve injury in animal experiment, and to screen out the most optimal donor nerve branch. Methods From June, 2016 to August, 2016, 64 adult female SD rats were randomly divided into 4 groups, which were LHG (using lateral head of gastrocnemius to repair peroneal nerve) , MHG (using medial head of gastrocnemius to repair peroneal nerve) , SNB (using soleus nerve branch to repair peroneal nerve) , and blank. There were16 rats in each group. At 4 and 8 weeks after surgery, each group were tested on behavior, electrophysiology, muscle tension, muscle wet weight and histology, to evaluate function recovery of the muscles controlled by deep peroneal nerve in each group, and to compare recovery of the deep peroneal nerve repaired by different tibial nerve branches. Results Eight weeks after surgery, right foot of the rats in LHG, MHG and SNB group can be extended, toes can be completely opened. Rats in blank group showed limping gait, whose right foot can not be extended, right toe can not be opened, and muscle atrophied. At 4 and 8 weeks after the operation, the recovery rate of LHG, MHG, SNB group (at 4th weeks, 33.60 ±2.22) % , 33.07 ±2.38% and 35.91 ±2.02% ; at 8th weeks, 67.16 ±5.74) % , 66.56 ±3.18% and 73.17 ± 5.33%, respectively) was higher than blank group (7.71±1.05% and 7.84±0.78%, respectively) on CMAP amplitude, tibialis anterior muscle contractility, tibialis anterior muscle cell area, muscle cell area. SNB group was superior to the LHG group and LHG group. And the difference was statistically significant (P < 0.05) . Conclusion All the proxi- mal tibial nerve muscle branchs can be used to repair the deep peroneal nerve injury, and the soleus nerve branch is the preferred donor nerve. Key words: Nerver transposition; Common peroneal nerve injury; Tibial nerve; Lower extremity nerve function reconstruction; Rats

Arthroscopy-Assisted Fabella Excision: Surgical Technique

The fabella is an anatomic variant not seen in all individuals and can potentially be a source of chronic knee pain due to chondromalacia, osteoarthritis, fractures, or biomechanical pressure against the lateral femoral condyle. It is situated intra-articular, close to the lateral femoral condyle, the lateral gastrocnemius head tendon, and the fabellofibular ligament. Given its rarity, the diagnosis of a symptomatic fabella is often overlooked when evaluating patients with persistent posterolateral knee pain. However, this diagnosis should always be considered, especially in high-performance runners, bikers, and triathletes. Although nonoperative management can potentially resolve symptoms associated with this condition, fabella excision via arthroscopically assisted surgery is a reliable and safe alternative to treat patients who do not benefit from nonsurgical treatment. We present our technique detailing fabella excision for treatment of posterolateral knee pain, which includes an arthroscopic evaluation of the fabella to assess damage to the femoral condyle and minimize over-resection and potential damage to surrounding structures.

Anatomical aspects of the gastrocnemius muscles: A study in 47 fresh cadavers

This study offers objective dimensions of the gastrocnemius muscle and analyzes correlations between dimensional variables, with a view to providing guidance on the proportions of a healthy gastrocnemius muscle for both genders. This anatomical study was conducted at the Institute of Forensic Medicine Faculty of Medicine University of Belgrade, Serbia, from May until November 2014. We included 47 fresh cadavers (up to 12-h postmortem interval) both male and female. The inclusion criteria were absence of any trauma or degenerative findings in lower limbs, normally weighed, and age between 18 and 60 years. The exclusion criteria were significant difference in dimensions between legs and overweighed cadavers. After statistical analysis of gathered data, we were able to define the exact shape and average measures of the medial and lateral head of gastrocnemius muscle in male and female. Factors affecting muscle dimensions are also defined in this study. The method of dissection that we applied could be recommended for exploration of different anatomical structures of calf region. The reported dimensions and correlations are useful guide in planning cosmetic and reconstructive procedures with high accuracy.

The temporal relationship of thresholds between muscle activity and ventilation during bicycle ramp exercise in community dwelling elderly males.

[Purpose] To compare the appearance time of the ventilatory threshold point and the electromyographic threshold in the activity of the vastus lateralis, rectus femoris, biceps femoris long head and gastrocnemius lateral head muscles during ramp cycling exercise in elderly males. [Subjects and Methods] Eleven community dwelling elderly males participated in this study. Subjects performed exercise testing with an expiratory gas analyzer and surface electromyography to evaluate the tested muscle activities during ramp exercise. [Results] The electromyographic threshold for rectus femoris was not valid because the slope after electromyographic threshold was not significant as compared to that before electromyographic threshold. The slope of the regression line for vastus lateralis was significantly decreased after electromyographic threshold while biceps femoris and gastrocnemius were increased. The electromyographic threshold appearance times for vastus lateralis and gastrocnemius were significantly earlier than ventilatory threshold point. There were no difference in electromyographic threshold appearance times among three muscles. [Conclusion] These results suggest that the increase in the slope of the regression line after electromyographic threshold for vastus lateralis was decreased, possibly indicating to postpone muscular fatigue resulting from the activation of biceps femoris and gastrocnemius as biarticular antagonists. This recruitment pattern might be an elderly-specific strategy.

A novel mutation in DNAJB6, p.(Phe91Leu), in childhood-onset LGMD1D with a severe phenotype

To identify and characterize genetic mutation in a Korean family with limb-girdle muscular dystrophy 1 (LGMD1), we analyzed in the affected family members clinical features, DNAJB6 by Sanger sequencing, muscle structures by magnetic resonance imaging (MRI), and functional consequences of the identified mutation using a zebrafish model. The clinical phenotypes along with identification of a novel c.271T > C (p.(Phe91Leu)) mutation in DNAJB6 led to the diagnosis of LGMD1D in the affected family members. This mutation presents unique clinical and radiological features compared with other DNAJB6 mutants. All affected members examined showed reduced pulmonary function, and had nasal voice and dysphagia except the two members who were thirteen and twelve years of age at the time of examination. Muscle phenotypes developed between 8 and 11 years of age and were more severe as compared to previously reported LGMD1D patients with mutant DNAJB6. Patients' MRI scans exhibited early involvement of the lateral head of gastrocnemius, in contrast to its late involvement in reported LGMD1D cases. Functional study using zebrafish embryos demonstrated that p.Phe91Leu elicits more severe muscle defects than the reported p.Phe93Leu and p.Pro96Arg mutations. We conclude that a novel p.(Phe91Leu) mutation in DNAJB6 is associated with severe childhood-onset LGMD1D.

Pattern of Fascicular Involvement in Midportion Achilles Tendinopathy at Ultrasound

Background:The Achilles tendon is composed of fascicles from the soleus and gastrocnemius muscles, which are identifiable as discrete components at anatomical dissection.Hypothesis:The pattern of fascicular involvement in Achilles tendinopathy may be characterized at ultrasound, and this characterization is reliable between different observers.Study Design:Cross-sectional diagnostic study.Level of Evidence:Level 3.Methods:One hundred cases of Achilles tendinopathy were retrospectively evaluated by 2 blinded musculoskeletal radiologists. Using a short-axis anatomical map, each case was categorized as involving the fascicular territories of the medial head of gastrocnemius, lateral head of gastrocnemius, soleus, or combinations of these, or as indeterminate.Results:Both radiologists agreed on the fascicular involvement pattern in 93 of 100 cases; 20 involved only medial gastrocnemius territories, 8 lateral gastrocnemius, 15 soleus, 3 medial and lateral gastrocnemius, 21 medial gastrocnemius and soleus, 9 soleus and lateral gastrocnemius, and 16 the entire tendon, and 1 case was classified as indeterminate. In 7 cases, the interpretations were discordant. The kappa value was calculated as 0.92 (95% CI, 0.86-0.98) in keeping with a high level of interobserver agreement.Conclusion:As assessed at ultrasound, most cases of Achilles tendinopathy involve the medial head of gastrocnemius and/or soleus fascicles.Clinical Relevance:The provided observational data will increase understanding of patterns of Achilles tendinopathy.

Frequency analysis of electromyogram of the triceps surae muscle taken while the stroke patients walk

Background: Many groups have reported results of frequency analysis of electromyogram (EMG) while the muscle with spasticity contracts in stroke patients.However, very few reports on characteristics of the muscle with spasticity during exercise have been published, and the majority is static evaluation using Fast Fourier Transform (FFT). Purpose: We carried out and examined dynamic frequency characteristics of contraction characteristics of the triceps surae while the stroke patients walk using Wavelet Transform (WT) which analyzes temporal information and frequency information of conventional FFT at same time. Methods: Subject of the present study was nine healthy men (age 28.0± 2.83), healthy group (HG), and nine stroke patients (age 70.17± 9.38), stroke group (SG), who were in the recovery stage and the rehabilitation ward of our hospital. These patients have their hemiplegia after stroke, and can walk by themselves or while being supervised. We measured the dominant feet of the HG and the paralyzed legs of the SG. Surface EMGmonitored muscle activation while the subjects freely walked 10m on a walkway at the optimum speed. Also, a foot switch sensor was attached on the plantar part to identify a single walking cycle. EMGMaster (Ozawa Medical Instruments) was used for surface EMG to monitor medial and lateral heads of gastrocnemius muscle. The data after fourth steps from walking starts were analyzed. Integral EMG analysis and wavelet transform (12.5Hz to 200Hz) were carried out to any given data of three walking cycles. Calculated integrated values of both groups were normalized using the integrated values during a single walking cycle. Also, the frequency range was divided into two categories; a low-frequency band (LFB) of 45Hz and lower and highfrequency band of 75Hz and higher (HFB) to calculate the power density of HFB to LFB, H/L ratio, of each muscle. As a statistical analysis, the Wilcoxon signed-rank test was used to compare the integrated values and H/L ratio between the HG and SG. Results: Each evaluation item of the HG and SG was compared. The HG has a significantly high integrated value (p< 0.05), and the SG has significantly high H/L ratio (p< 0.05). Conclusion(s): Although muscle activity characteristics of the triceps surae of the stroke patients is low as an integrated value, the ratio of HFB is high as dynamic frequency characteristics. This indicates strong activity of fast fibers. By taking the facts of low integrated value and atrophy of the presence of fast-twitch fibers into account, synchronization defect in the motor units possibly caused a frequency rise. Implications: These findings are expected to help treatment to improve quality of muscle activity in rehabilitation for stroke patients to walk.

Activity of lower limb muscles during treadmill running at different velocities.

[Purpose] The present study aimed to determine changes in muscle activity while moving on a treadmill at various speeds. [Subjects] The activities of the left vastus lateralis, vastus medialis, hip adductors, lateral head of gastrocnemius, medial head gastrocnemius, soleus, and tibialis anterior of 10 healthy male university students were analyzed. [Methods] University students walked, jogged, and ran for 10 minutes each in random order, and then myogenic potentials were measured 10 minutes later for 30 seconds. The flexion angle of the lower limb upon initial contact, mid stance, and toe off were measured. [Results] The average walking, jogging, and running speeds were 3.6 ± 0.4, 6.7 ± 0.6, and 10.4 ± 1.3 km/h, respectively. The average electromyographic activities of the vastus medial, tibialis anterior, medial head of gastrocnemius, and lateral head of gastrocnemius significantly differed. All muscles were more active during jogging and running than walking. Only the soleus was more active during running than walking, and the activities of the hip adductors and vastus lateralis did not significantly differ. [Conclusion] Velocity is faster and the angles of the lower limbs and ground reaction force (GRF) are larger during running than walking. The vastus medialis and soleus worked more easily according to the angle of the knee joint, whereas the tibialis anterior worked more easily at faster velocities and the medial and lateral heads of the gastrocnemius worked more easily with an increased GRF.

Clinical outcome with Botulinum toxin-A in spastic cerebral palsy children with equinus gait

Objective: Analysis of spastic equinus gait, ankle movements, and spasticity change in Indian cerebral palsy (CP) children. Design: Prospective study with follow up at 2 weeks and 2 months after injection. Setting: Department of Physical Medicine and Rehabilitation, AIIMS, New Delhi between 2009 and 2011. Participants: 22 Spastic CP children (12 diplegic and 10 hemiplegic), 14 males and 8 females aged 2-8 years (mean 4.44 years) having gastrocnemius spasticity with equinus gait. Intervention: Botulinum Toxin-A marketed as Botox® (Allergan, Inc.) was administered in both the medial and lateral heads of gastrocnemius. Dosage: 4 Unit/kg/muscle, maximum of 50 U per injection site, 50 U/ml with 0.9% normal saline dilution. After injection, the children continued participating in routine rehab exercise therapy and provided ankle foot orthosis. Main Outcome Measure(s): Temporospatial parameter of gait (stride, step length, cadence, velocity, percentage contact of foot with ground), Spasticity as per modified Ashworth Scale, active and passive range of motion at ankle. Results: Significant improvement (n = 34, P 90% of children in terms of comfort, ease of care, and walking. The improvement lasted for 2 months. Conclusions: Botulinum Toxin-A injection is effective in treatment of equinus gait with easy OPD procedure and minimal side effects which are very tolerable.

A-34 装着型筋硬度計によるストレッチング時の筋粘弾性計測 : 腓腹筋内側頭・外側頭の筋粘弾性変化の類似性調査(筋特性の計測と動作への影響)

A-34 装着型筋硬度計によるストレッチング時の筋粘弾性計測 : 腓腹筋内側頭・外側頭の筋粘弾性変化の類似性調査(筋特性の計測と動作への影響)

MORPHOLOGICAL VARIATIONS OF MUSCLE PLANTARIS: ANATOMICAL AND CLINICAL INSIGHT

Address for Correspondence: Dr. Mohini M. Joshi, Associate Professor, Department of Anatomy, Rural Medical College, Pravra Institute of Medical Sciences Loni, Dist. Ahmadnagar Maharashtra, India. Mobile No: +919762601050. E-Mail: atharvamohini@gmail.com Access this Article online Quick Response code Web site: *1 Associate Professor, Department of Anatomy, Rural Medical College, Pravra Institute of Medical Sciences, Loni, Dist.Ahmadnagar Maharashtra, India. 2 Dean, Arbindo Institute of Medical Sciences, Indore, India. 3 Professor and Head, Department of Anatomy, Arbindo Institute of Medical Sciences, Indore, India. Background: Plantaris is the largest muscle in mammals other than primates. Plantaris muscle has been a subject of much confusion and Evolutionists have speculated on its phylogenetic significance, as a vestigial organ, while surgeons have removed it ‘useless vestige’ to employ its tendon as a spare part for the surgical repair. In humans it is reduced greatly in size, power, and function and may even be absent. Aim: With this background the aim of the present work is to study morphology, describe the observed variations of the Plantaris muscle, and to discuss the functional significance of Plantaris muscle. Methodology: For the present work 84 limbs available in the department of Anatomy were dissected. The posterior aspect of the knee was dissected using standard surgical equipment and dissection techniques. The Plantaris muscle was isolated and length of fleshy belly and tendon were measured. Any variations in origin, insertion and size were recorded. Result: Variation in insertion of the Plantaris has observed like insertion along medial margin of tendocalcaneus on to calcaneus, in front of tendocalcaneus on to calcaneus, fused to tendocalcaneus and insertion of the Plantaris on deep fascia of leg at the level of ankle. Other variations noted were two bellies of the Plantaris one from lateral supracondylar ridge and other from deep surface of Gastrocnemius, two heads of Plantaris: Both bellies were fused in the lower part producing bipennate arrangement, thin & thick belly of the Plantaris muscle. Variations also observed in relation to origin that the muscle is originating from deep surface of lateral head of Gastrocnemius & in other case origin from capsule. Bicipital Plantaris was seen where one head was originating from capsule of knee joint and other from lateral condyle. Conclusion: In order to avoid any inadvertent injury during surgical operations, variation of the Plantaris must be borne in mind. Awareness of the insertion pattern of the Plantaris tendon is also important for clinicians in the diagnosis of muscle tears and for surgeons performing reconstructive procedures. Considering the above facts, the existence and importance of the Plantaris muscle cannot be undermined.