Peroneus Research Articles

New surgical method for chronic rupture of the Achilles tendon

To improve the outcomes in patients with chronic ruptures of the Achilles tendon followed by advanced diastase and reduced function of the gastrocnemius muscle by using of new surgical method. The authors proposed a new method of Achilles tendon repair for diastase over 10 cm. It imposes transposition of the tendons of short fibular muscle and posterior tibial muscle. Schemes and stages of surgery are presented in figures. The authors described clinical example of patient with chronic rupture of the Achilles tendon, illustrations of surgical stages and the outcome. New surgical approach was applied in 16 patients. The control group consisted of 21 patients who underwent repair by Chernavsky, Krasnov. Clinical and biomechanical methods were used for evaluation. Functional myography and podography to assess the asymmetry of gait were performed. Our data confirmed the advantage of new approach.

IMPINGEMENT-SYNDROME OF PERONEUS BREVIS TENDON AFTER CALCANEAL FRACTURES (MORPHOLOGICAL ASPECTS)

Background. One of the main causes of pain in patients with consequences of calcaneal fractures is the lateral impingement syndrome. This term means lateral displacement of outer calcaneal wall at the moment of fracture, narrowing of anatomical space under the lateral malleolus and compression of soft tissues in this region, including tendons of short and long peroneal muscles. This leads to chronic traumatization of tendons, alteration of their normal tracking and development of tendinitis and tenosynovitis. At this moment there are no articles in foreign or Russian literature describing how prolonged traumatization influences the internal structure of the tendons. The purpose of this study was to evaluate the morphological changes in structure of peroneus brevis tendon after different duration of compression between outer wall of calcaneus and the tip of the lateral malleolus in patients with calcaneal malunion.Materials and methods. Fifteen patients with calcaneal malunion and lateral impingement syndrome were treated operatively between 2016 and 2017. To confirm the lateral impingement syndrome, the authors performed clinical examination and AP x-rays of ankle joint. Two peroneus brevis tendon specimens were obtained intraoperatively in each of 15 patients: one specimen from compressed and one from non-compressed area. Obtained specimens were histologically examined according to standard protocol.Results. Microscopically all specimens showed separation of collagen bundles with loose connective tissue degeneration, increase of vascularization and inflammation. The degree of these changes differed according to the compression duration. This allowed us to analyze the dynamics of these changes.Conclusion. The morphological changes in structure of peroneus brevis tendon during the compression between outer wall of calcaneus and the tip of the lateral malleolus correspond with dynamics of common pathologic reactions. Early stages showed signs of mechanical damage of bundles and inflammation. In prolonged impingement the intensity of inflammation decreases, but the connective tissue degeneration of the tendon continues with lipoid infiltration.

SPINAL AND PERIPHERAL DRY NEEDLING VERSUS PERIPHERAL DRY NEEDLING ALONE AMONG INDIVIDUALS WITH A HISTORY OF LATERAL ANKLE SPRAIN: A RANDOMIZED CONTROLLED TRIAL.

In addition to established interventions, dry needling may reduce impairments leading to greater functional abilities for individuals following ankle sprain. The purpose of this study was to compare effects of spinal and peripheral dry needling (DN) with peripheral DN alone on impairments and functional performance among individuals with a history of lateral ankle sprain. Randomized controlled trial. Twenty individuals with a history of lateral ankle sprain (18 bilateral, 2 unilateral) participated in this study (4 males, 16 females; mean age 28.9 + /- 9.2 years). During the first of two sessions, participants completed the Foot and Ankle Disability Index (FADI) and the Cumberland Ankle Instability Tool (CAIT) and their strength, unilateral balance, and unilateral hop test performance was assessed. Participants were randomly assigned to a spinal and peripheral DN group (SPDN), or a peripheral only DN group (PDN). Participants in the SPDN site group received DN to bilateral L5 multifidi and fibularis longus and brevis muscles on the involved lower extremity. Participants in the PDN group received DN to the fibularis muscles alone. Participants' strength, balance and hop test performance were reassessed immediately following the intervention, and at follow-up 6-7 days later, all outcome measures were reassessed. Three-way mixed model ANOVAs and Mann-Whitney U tests assessed between group differences for outcome variables with normal distributions and non-normal distributions, respectively. ANOVAs showed significant group by time interaction (p<0.05) for invertor strength, significant side by group and time by group interactions (p<0.05) for plantarflexor-evertor strength, no significant findings for dorsiflexor-invertor strength, significant side by time interaction (p<0.05) for unilateral balance, significant main effect of time (p<0.05) for triple hop for distance test, and significant main effect of side (p<0.05) for the CAIT. Mann-Whitney U tests showed no significance (p>0.05) for the side hop test or FADI. The results suggest that DN of the multifidi in addition to fibularis muscles does not result in improvements in strength, unilateral balance or unilateral hop test performance, compared to DN the fibularis muscles alone among individuals with a history of ankle sprain.

Revisiting the peroneal trochlea of the StW 352 calcaneus

&#x0D; &#x0D; &#x0D; StW 352, from Sterkfontein Member 4 (South Africa), is a partial calcaneus attributed to Australopithecus africanus and is dated to ~2.0–2.6 Ma. The unusual robusticity of the peroneal trochlea (PT) of StW 352 has been commented on by several authors. The size of hominin PTs has been hypothesised to be positively correlated with the degree of recruitment of peroneus longus during bipedal locomotion and/ or climbing. Given the potential functional relevance of an enlarged PT for reconstructing hominin activity patterns, we present the following previously unrecognised structural details of the reconstructed StW 352 that affect current interpretations of its functional morphology: (1) we estimate that the PT has been reattached to the body of the calcaneus ~5 mm dorso-distally from its original anatomical position; and (2) the presence of intrusive matrix has artificially misshaped the PT by expanding it laterally and proximodistally. Future studies of this specimen that apply geometric morphometrics, or other shape analysis tools, should compensate for these inaccuracies before undertaking comparisons between it and other calcanei. Additionally, given that the PT is likely smaller than previously reported for StW 352, caution should be exercised when using it to infer muscle function and extrapolate activity patterns of this individual, and thus by extension, within Australopithecus africanus in general. Lastly, these findings highlight the importance of not only the production of accurate reconstructions, but also the critical evaluation of the accuracy of existing reconstructions when working with damaged fossil material.&#x0D; &#x0D; &#x0D; &#x0D; &#x0D; Significance: &#x0D; &#x0D; &#x0D; &#x0D; This work epitomises the value of critically evaluating original fossil reconstructions, especially of postcranial elements.&#x0D; New technologies (e.g. microCT) offer non-destructive opportunities for evaluating/improving the accuracy of fossil reconstructions.&#x0D; Re-assessing StW 352 suggests peroneal muscles may have factored less prominently in A. africanus locomotion than previously thought.&#x0D; &#x0D; &#x0D; &#x0D;

The morphology of foot soft tissues is associated with running shoe type in healthy recreational runners

ObjectivesTo determine the differences in the morphology of foot soft tissues between runners using different types of running shoes. DesignCross-sectional study. MethodsThirty-eight recreational runners were divided into four groups based on running shoe type, namely, neutral shoes, motion control shoes, minimalistic shoes and neutral shoes with custom-made insoles. An arch height index and a relative arch deformation index were calculated for each participant. An ultrasound device was used to measure the cross-sectional area and/or the thickness of selected intrinsic foot muscles (abductor hallucis, flexor hallucis brevis and flexor digitorum brevis) and extrinsic foot muscles (flexor digitorum longus, tibialis anterior and the peroneus muscles), and the thickness of the plantar fascia, Achilles tendon and heel pad. ResultsRecreational runners using minimalistic shoes demonstrated stiffer foot arches than those using neutral shoes. Among the selected foot muscles, only abductor hallucis showed a significant morphological difference between shoe groups. Runners using minimalistic shoes had the thickest abductor hallucis. The minimalistic shoe runners also showed a thinner proximal plantar fascia and a thicker Achilles tendon than other runners. Insole runners had a thinner heel pad than neutral shoe runners. ConclusionsThis study suggests that the morphology of foot soft tissues is associated with running shoe type in recreational runners. A sudden change in running shoe type without adjusting training volume should be undertaken with caution, since it may take time for foot soft tissues to adapt to a new shoe condition.

Characteristics of muscle MRI of lower limbs in patients with GNE myopathy

Objective To summarize the characteristic of muscle MRI of lower limbs in patients with GNE myopathy and to explore the correlation between the fatty degenerative score of muscle MRI and clinical phenotype. Methods This was a prospective study. Seventeen patients with genetically confirmed GNE myopathy, having lower limb muscle MRI test and completed clinical and laboratory data.The degree of fatty degeneration in 18 muscles of lower limbs in each patient was grading. According to the GM-W score, these patients were divided into two groups. GM-W score ≤ 3 were divided into mild group (n=8) and GM-W score≥ 4 were divided into severe group(n=9). Kruskal-Wallis test was used to compare the fatty degenerative score in different muscles of the thigh and the calf level;Mann-Whitney U test was used to compare score of the same muscle between mild and severe group;Spearman rank correlation test was used to analysis the relationship between fatty degenerative score and the course of disease (year), GM-W score, creatinine kinase (IU/L), respectively. Results At the thigh level, the most severely involved muscle of GNE myopathy was semi-tendinosusand adductor, followed by semi-membranous, biceps femoris and gracilis. There was no statistically significant difference in the fatty degenerative score of the above-mentioned muscles (P=0.058). At the calf level, the most severely involved muscle was medial of soleus which score was 4.0(3.0, 4.0), followed by tibialis anterior,extensor digitorum longus and lateral of soleus. There was no significant difference of the above (P=0.259).The fatty degenerative score showed difference between the mild and severe group at sartorius and adductor (P<0.05).At the calf level, the fatty degenerative score in peroneus longus, medial of soleus, lateral of soleus, medial of gastrocnemius and lateral of gastrocnemius showed difference between groups(P<0.05).The total score of fatty degenerative of Lower limb muscles was positively correlated with GM-W score(r=0.730, P<0.05). There were positive correlations between the score of fatty degenerative of the sartorius, peroneal longus, lateral of soleus, medial of gastrocnemius, lateral of gastrocnemius and the GM-W scores(r=0.630, 0.845, 0.569, 0.591, 0.640, 0.659, P<0.05). The total score of fatty degenerative of Lower limb muscles was not correlated with the level of creatine kinase(P=0.582), course of disease(P=0.601) and age of onset(P=0.850). Conclusions GNE myopathy in the thigh level within the adductor muscle and posterior muscle involvement, calf level to the tibial anterior muscle early involvement. The total score of fatty degenerative of lower limb muscles is positively correlated with GM-W score, but not correlated with the level of creatine kinase, course of disease and age of onset. Key words: Magnetic resonance imaging; Comparative study; GNE myopathy

Posterior Malleolar Open Reduction and Internal Fixation Through a Posterolateral Approach for Trimalleolar Fractures.

The patient is prone for the operation. A longitudinal incision is made between the lateral border of the Achilles tendon and the posteromedial border of the fibula. The posterior aspect of the fibula is easily reached through the interval just lateral to the peroneal muscle. After debridement of the fracture, it can be reduced and is fixed with either (1) a buttress plate or (2) lag screw(s) with a neutralizing plate. The belly of the flexor hallucis longus is bluntly dissected off of the interosseous membrane and the lateral side of the tibia through the interval medial to the peroneal muscle. Retracting the muscle belly medially allows the posterior aspect of the tibia to be seen. The periosteum is incised to expose the posterior malleolar fracture. Loose fragments can be removed by levering the posterior fragment distally. Reduction is performed and is held temporarily by Kirschner wires. Fixation is undertaken using either lag screws or a slightly prebent 3-hole buttress plate. Placement of a lag screw through the most distal hole of the plate can help to close any possible gaps. Slight internal rotation of the lower leg allows the medial malleolus to be approached and fixed. Percutaneous anterior-to-posterior screw fixation is an alternative, but it frequently leads to a nonanatomical reduction of the fragment. This technique provides an adequate view of the fracture, an anatomical reduction in most cases, and sound fixation of the posterior malleolar fragment. Other advantages are that small fragments are easier to fix and small intra-articular fragments can be removed from the site of the fracture.

The Effect of Peroneal Muscle Strength on Functional Outcomes After the Modified Broström Procedure for Chronic Ankle Instability.

Although the peroneal muscles are known to be the major dynamic lateral stabilizers of the ankle, little information is available regarding the change in muscle strength and relation with the outcomes after lateral ligament repair surgery. The purpose of this study was to identify the effects of peroneal strength on the validated functional outcome measures after the modified Broström procedure (MBP) for chronic ankle instability. Forty-one patients (41 ankles) who underwent MBP using suture anchors were eligible and followed up to 2 years postoperatively. Functional evaluation consisted of the Foot and Ankle Outcome Score (FAOS), and Foot and Ankle Ability Measure (FAAM). The changes of peroneal strength were evaluated using an isokinetic dynamometer. Differences in the functional outcomes between the 3 groups divided according to the recovery rate of peroneal strength were analyzed. Peak torque and total work for eversion in 60 degrees/s angular velocity significantly improved from a mean 8.1 and 5.2 Nm preoperatively to 11.4 and 6.9 Nm at postoperative 2 years, respectively ( P < .001, P = .038). The deficit ratio of peak torque for eversion significantly improved from a mean 38.6% to 17.4%, and a significant side-to-side difference was found ( P = .011). There were no significant differences in FAOS, FAAM, and measurements of stress radiograph between the 3 groups. Although restoration of peroneal strength postoperatively was about 82.6% of the unaffected ankle, patient-reported function in daily and sport activities were satisfactorily improved. Postoperative isokinetic strength of the peroneals demonstrated no statistically significant effects on the functional outcomes after MBP. Level III, prospective comparative case series.

Lateral ankle pain and peroneal tendon subluxation in a patient with peroneal quartus muscle and superior peroneal retinaculum injury.

Lateral ankle pain and peroneal tendon subluxation in a patient with peroneal quartus muscle and superior peroneal retinaculum injury.

P.210 - Parasitic myositis due to Toxocara spp. infection

Infectious myositis is an uncommon muscle disease. It may be caused by viruses, bacteria, fungi or parasites. Parasitic myositis is usually related to geographic area, socioeconomic situation, cultural and dietary habits. The most common reported parasitic infections are trichinosis, cysticercosis and toxoplasmosis in infectious myositis. Herein we report a case with myositis due to Toxocara spp. infection. A 37 year old female patient presented with a 2 months history of pain on left thigh. The pain was localized at medial part of thigh and it was aggravated by pressure and movement. Non-steroidal anti-inflammatory drugs did not reduce pain. Pain affected her quality of life. Neurologic examination revealed mild weakness of hip adduction in the left lower extremity. She had pain and tenderness with palpation and movement. Skin rash was not observed. Deep tendon reflexes were preserved. Laboratory investigations showed marked eosinophilia (870/ µL). Serum creatinine kinase was normal (39 IU/L). Magnetic resonance imaging (MRI) showed scattered edema in the left adductor longus, vastus lateralis, biceps femoris, vastus medialis and bilateral peroneal muscles. Anti-Toxocara IgG (Western blot) was strongly positive. Clinical and radiologic findings were consistent with myositis and serologic test, eosinophilia supported the diagnosis of toxocariasis. Albendazole (400 mg twice daily for 3 weeks) and corticosteroid were given to patient. Patient's pain was disappeared at the first week of therapy. MRI was repeated after 6 months. It has been observed regression of edematous findings in the muscles. Parasitic infections should be also remembered in cases of myositis.

Conception and evaluation of a musculoskeletal finite element model of the foot

This work aims at developing a patient-specific Finite Element (FE) model of the foot in the context of predictive medicine. We propose here to include the realism of the anatomy by introducing all the detailed bony structures, ligaments and muscles segmented from the CT and MRI exams of the same patient. The model includes 30 bones modelled as articulated rigid-bodies connected with cables that simulate the 210 segmented ligaments in their actual positions and therefore define the articulations. The aponeurosis is modelled with fives parallel multipoint ligaments. A set of 15 extrinsic and intrinsic muscles based on linear axial muscle activation law is anatomically positioned in order to allow a natural movement of the foot. A FE mesh of the soft tissue was created by applying an automatic FE mesh generator to the surfaces resulting from MRI segmentation. The FE mesh has 95,883 elements and 56,806 nodes. Three soft tissue layers with Neo Hookean materials (Young moduli, Poisson Ratio) were created to represent a 1 mm skin layer (200, 0.485), the fat (30, 0.49) and muscle (60, 0.495) tissues. The foot model was evaluated by comparing its simulations with the pressure mat collected with the patient standing onto a Zebris FDM platform. For this, the patient weight was applied onto the foot model put in contact with a horizontal plate. The simulated pressures are close to the real ones (less than 2 N/cm 2 ) considering pressure measurement and subject weight uncertainties. Another evaluation of the model aimed at comparing the kinematics of the model resulting from simulated muscle activations with an actual 3D motion analysis of the patient foot coupled with an EMG monitoring of the tibialis posterior, tibialis anterior, soleus, medial gastrocnemius, lateral gastrocnemius and peroneus muscles. For an abduction/adduction 3D range of motion, the simulation is less than 4% different. Globally, this foot model provides realistic simulations in both static and dynamic frameworks. In addition to its use for predictive medicine, it could become relevant for the simulation of neuro-orthopedic surgical interventions, pressure ulcer prevention, orthotic devices analysis or educational purposes.

Effects of Peroneal Muscles Fatigue on Dynamic Stability Following Lateral Hop Landing: Time to Stabilization Versus Dynamic Postural Stability Index

Dynamic stability is a necessary requirement in many sports competitions. Muscle fatigue, which can impair stability, may be occurred in many sports competitions in which lateral movements and landing repeated frequently. To assess the effects of peroneal muscles fatigue on dynamic stability following lateral hop landing through measuring time to stabilization (TTS) and dynamic postural stability index (DPSI). Quasi-experimental. Laboratory study. A total of 20 recreationally active, healthy males with no lower-extremity injury during the previous 6 months participated in this study. Participants performed a lateral hop on a force plate before and immediately after a fatigue intervention using a Biodex dynamometer. For inducing fatigue, the participant made a prolonged eversion effort with 40% of the maximal voluntary contraction. Fatigue was met when the eversion torque declined by 50% of the initial value. TTS and DPSI were calculated using sequential averaging method and relevant formulas, respectively. Premeasures and postmeasures of TTS in the anteroposterior, mediolateral and vertical directions, resultant vector of TTS, stability indices in the anteroposterior, mediolateral and vertical directions, and DPSI. Means of the DPSI or its components did not change significantly due to fatigue (P > .05). Means of the TTS in the anteroposterior and mediolateral directions, and the mean of the resultant vector of the TTS increased significantly after fatigue (P < .05). The question that the dynamic stability is affected or not affected by fatigue depends on which of the TTS or DPSI is used for analysis. The TTS may be a sensitive measure to detect subtle changes in postural stability due to fatigue. But, the DPSI which may be changed after a more strenuous fatigue may be related to actual fatiguing situations.

Estimating the lower leg muscle activity from distal biosignals around the ankles.

Electromyogram signals (EMG) can be used not only to measure motions, but also to control devices such as exoskeleton robots. Sensor electrodes need to be placed on each muscle based on kinematics and anatomical characteristics. Wearable EMG measurement approach is also investigated in recent years. Electrodes are fixed to the clothes. In this paper, we propose a motion measurement method based on propagation characteristics of biopotential signal. An experiment with walking and plantar flexion motion as tasks. The results showed that the signals calculated from proposed method were comparable with that of conventional method. We confirmed that there were few individual differences for calculating the signals of tibialis anterior, gastrocnemius and peroneal muscles.

Análise eletromiográfica durante exercícios de propriocepção de tornozelo em apoio unipodal

Introduo: A propriocepo um componente do sistema somatossensorial que tem a capacidade de fornecer informaes aferentes ao Sistema Nervoso Central sobre a posio e o movimento dos segmentos de vrios receptores. Objetivo: Analisar a atividade eletromiogrfica dos msculos, tibial anterior e fibulares, importantes na estabilizao do tornozelo, dos msculos multfidos e transverso do abdmen, importantes na estabilizao da coluna lombar, durante exerccios de propriocepo. Mtodos: Os participantes responderam a um questionrio sobre os seus dados pessoais e antropomtricos e realizaram exerccios de propriocepo em apoio unipodal em diferentes aparelhos de propriocepo. Resultados: A prancha de equilbrio foi o equipamento em que apresentaram maiores valores de pico de contrao. Os msculos, tibial anterior, multfidos e os fibulares foram os que mais apresentaram diferenas significativas para os grupos masculino e feminino. Concluses: Dos msculos avaliados pela eletromiografia os que mais apresentaram diferenas significativas foram o tibial anterior, multfidos e os fibulares.

Evaluation of fibular muscles and prevalence of accessory fibular muscles on fetal cadavers.

The purpose of this study was to determine clinical importance and morphology of the fibularis longus, brevis, tertius muscles (presented as fibular muscles in this study), and prevalence of accessory fibular muscles (AFM) on fetal cadavers. In this study, 200 limbs from 100 embalmed fetuses (54 male and 46 female) were studied. Morphology of fibular muscles and the presence of AFM were observed through dissection on fetal legs bilaterally. The absence of fibularis tertius muscle (FT) and the presence of AFM were identified. Length and length of the tendon of AFM were measured. Insertion of AFM was also identified. Mean values and standard deviations of all parameters according to trimesters were calculated. All parameters were increased with age during the fetal period. We determined the absence of FT; no FT was observed in 40 legs of 200 extremities (20%). The AFM was present in 7 of 200 specimens (3.5%). AFM muscles were classified into two types according to their site of origin. The present study has revealed the morphology of the fibular muscles and prevalence of the presence of AFM on fetal cadavers. In addition, it has revealed the morphometric development and prevalence of the absence of FT in a large series, and their clinical importance was discussed.

Peroneal Sheath Volumes in Patients with Peroneal Tendon Injuries

Category: Sports Introduction/Purpose: Peroneal tendinopathy is a common condition of the ankle and may lead to substantial pain and disability. Low lying peroneus brevis (PB) muscle belly, accessory tendons and bony abnormalities have been implicated in peroneal tendon pathology. To date, studies have reported the presence of these variants or the distal extent of a muscle belly with the presumption that this reflects an increased intra-sheath volume. The goal of this study was to perform volumetric measurements of MR images of peroneal tendons in patients with peroneal pathology requiring surgical intervention and those without. Methods: Two fellowship trained musculoskeletal radiologists evaluated MR images of patients with and without peroneal tendon pathology. The volume of the peroneal tendon sheath and its contents were measured from the level of the tibial plafond down to the peroneal tubercle. The volumes were measured using the Vital Images 3D Vitoria program. The program allows calculation of volumes based on selected area outlines on each axial slice and then compiles each slice into a stacked volume. The presence of a peroneus quartus (PQ), synovitis and peroneal tendon tears were also recorded. Results: Fifty-one patients with peroneal pathology and 15 control patients were included. The mean distance of the PB muscle belly to the tip of the fibula was 5.55 ± 2.5 mm and 11.79 ± 4.07 mm for the groups with and without pathology, respectively (p=0.017). The mean total sheath volume was 7.06 ± 0.95 cc and 5.12 ± 0.53 cc (p=0.001), respectively. The mean PB and PQ combined volume was 1.31 ± 0.29 and 0.86 ± 0.24 cc (p=0.023), respectively. In isolation, the peroneal muscle volume was 0.87 ± 0.25 cc and 0.80 ± 0.25 cc (p=0.733), respectively. Conclusion: The volume of the peroneal tendon sheath and its contents are greater in the patients with peroneal tendinopathy that required surgery compared to controls. Despite the lower position of the muscle belly in the peroneal tendinopathy group, which is similar to previous studies, this was not reflected in increased volumetric measurements. However, when the PQ tendon was included this combined volume was significantly greater. Volumetric measurements are a more accurate way to assess the peroneal sheath in patients with peroneal pathology.

Anatomy of the long peroneal muscle of the leg.

The aim of the work was to perform a morphometric analysis of the long peroneal muscle (LPM) of the leg and explore the relationship between muscle belly and tendon. Ten lower limbs (8 right and 2 left) were fixed in formaldehyde and dissected using standard technique. The LPM was exposed from the proximal attachment to the top of a lateral malleolus. The tendon was subsequently freed and various measurements were taken. The tendon of the LPM enters deep into the muscle belly. Muscle fibres surround the tendon and descend as far down as 4 cm above the lateral malleolus. Muscle fibres insert mainly along posterior border of the tendon and on its medial surface, leaving lateral surface only partly covered. The LPM contains a long intramuscular segment of the tendon and area of the musculotendinous junction varies along the LPM. It makes the idea of uniform pennation pattern of the LPM unlikely.

Foot muscle morphology is related to center of pressure sway and control mechanisms during single-leg standing

Maintaining balance is vitally important in everyday life. Investigating the effects of individual foot muscle morphology on balance may provide insights into neuromuscular balance control mechanisms. This study aimed to examine the correlation between the morphology of foot muscles and balance performance during single-leg standing. Twenty-eight recreational runners were recruited in this study. An ultrasound device was used to measure the thickness and cross-sectional area of three intrinsic foot muscles (abductor hallucis, flexor digitorum brevis and quadratus plantae) and peroneus muscles. Participants were required to perform 30s of single-leg standing for three trials on a force plate, which was used to record the center of pressure (COP). The standard deviation of the amplitude and ellipse area of the COP were calculated. In addition, stabilogram diffusion analysis (SDA) was performed on COP data. Pearson correlation coefficients were computed to examine the correlation between foot muscle morphology and traditional COP parameters as well as with SDA parameters. Our results showed that larger abductor hallucis correlated to smaller COP sway, while larger peroneus muscles correlated to larger COP sway during single-leg standing. Larger abductor hallucis also benefited open-loop dynamic stability, as well as supported a more efficient transfer from open-loop to closed loop control mechanisms. These results suggest that the morphology of foot muscles plays an important role in balance performance, and that strengthening the intrinsic foot muscles may be an effective way to improve balance.

The Influence of Exercise Surface Inclination on Trunk and Lower Extremity Muscle Activity During Common Pilates Exercises

Pilates is a common series of exercises used for both clinical and general populations that incorporates a variety of body positions to vary exercise intensity. Several studies have examined muscle activity while performing Pilates exercise, however the effect of surface inclination on muscle activity is limited. PURPOSE: The purpose of this study is to compare muscle activity of the lower legs and trunk during common Pilates exercises performed at different angles of support. METHODS: Three male and eleven female college aged students (24.1±4.4yrs; 1.7±0.1m; 62.2±17.9kg) were recruited. All subjects performed 4 static (10 second hold) Pilates exercises (boat pose, bridge, plank, and single leg balance) during each of the three surface inclinations: 1) 17° incline, 2) floor, 3) 17° decline. The unilateral muscle activity of the external oblique (EO), rectus abdominus (RA), erector spinae (ES), gluteus medius (MED) and maximus (GM), tibialis anterior (TA), peroneals (PL), and the medial gastrocnemius (GAS) on the right side of the body were recorded using surface electrodes. The average root mean square of muscle activity over three trials was expressed as a percent of the individual muscles maximum voluntary contraction (MVIC) recorded at the beginning of the data collection. The %MVIC for each muscle group were compared using 1-way repeated measures ANOVAs for each pose during the three inclination conditions. RESULTS: During the boat pose, %MVIC for the RA was greater in the incline (46%) compared to the decline (19%, p = 0.002) and floor (28%, p = 0.027). During the decline plank, the %MVIC for the EO (43%) was greater in comparison to both the floor (35%, p=0.028) and the incline (29%, p = 0.005). The RA muscle activity also showed increased activity when on the decline (30%) in comparison to the incline (20%, p=0.036). The single leg balance pose showed greater activation of the TA muscle on the incline (27%) in comparison to the floor (19%, p=0.013). No differences were detected during the bridge pose. CONCLUSION: The results of this study suggest that trunk muscle activity can be altered by modifying the inclination angle. Such modifications may be useful in planning exercise progressions. Further investigation is required to examine the influence of surface inclination angle and long-term training benefits.

Lateral Leg Pain in an Avid Hiker After a Fall

HISTORY: A 62-year-old female with a history of hip OA and low back discomfort presents with left lateral leg pain that started after a fall onto her back 11 months ago. Pain is described as a constant throbbing in the left lateral calf, ankle, and dorsal foot. Pain worsens with ambulation and is relieved by rest. Noninvasive vascular studies ruled out claudication. Prior treatments included left L5 nerve root block, lumbar ESI, SI joint injection, chiropractic treatment, pain medications, and therapy with limited success. She presents to our sports medicine clinic for a diagnostic ultrasound of the left lateral leg region. PHYSICAL EXAMINATION: Guarded gait favoring weight bearing on right lower extremity. Mild tenderness over the proximal tibiofibular joint. No focal area of tenderness noted at lateral knee joint line or distal iliotibial band. Range of motion about the knee and ankle were both full without pain and strength was intact. Allodynia noted to light touch over left anterolateral leg, ankle, and dorsal foot. Straight leg raise and lumbar facet challenge were negative. Lumbar Spurling’s was positive on the left. DIFFERENTIAL DIAGNOSIS: 1. Superficial peroneal neuropathy 2. Common peroneal neuropathy 3. Lumbar radiculopathy TEST AND RESULTS: -MRI lumbar spine: Mild multilevel DJD without significant stenosis. -MRI left tibia-fibula: Subtle edema in the peroneal muscle area. Diffuse symmetric atrophy in both muscles. -EMG/NCV: Decreased amplitude in left superficial peroneal response (4 mV vs 12 mV on contralateral side) and mildly prolonged peak latency. No signs of lumbar radiculopathy. -Left lateral leg/knee ultrasound: Swollen superficial peroneal nerve at the site of penetration through peroneus longus muscular fascia (0.08 cm proximally and 0.22 cm distally). FINAL WORKING DIAGNOSIS: Left superficial peroneal neuropathy TREATMENT AND OUTCOMES: 1. Sonographically guided superficial peroneal nerve hydrodissection (HD) x 2 resulted in improvement in painless walking distance and decrease in pain scale by 50-60%. 2. Repeat elective EMG/NCV 2 months later demonstrated signs of re-innervation of the left superficial peroneal nerve evidenced by normalized and symmetric sensory response amplitude (8 mV) and peak latency measures with polyphasic motor unit potentials seen in the fibularis longus.