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We examined the effects of lower limb segmental muscle vibration (SMV) on intracortical and spinal excitability in 13 healthy participants (mean age: 34.9 ± 7.8 years, 12 males, 1 female). SMV at 30 Hz was applied to the hamstrings, gastrocnemius, and soleus muscles for 5 min. Paired-pulse transcranial magnetic stimulation protocols were used to investigate motor-evoked potential (MEP) amplitude, short-interval intracortical inhibition (SICI) and short-interval intracortical facilitation (SICF) from the abductor hallucis muscle (AbdH). These assessments were compared to the results of a control experiment (i.e., non-vibration) in the same participants. F-waves were evaluated from the AbdH on the right (vibration side) and left (non-vibration side) sides, and we calculated the ratio of the F-wave amplitude to the M-response amplitude (F/M ratio). These assessments were obtained before, immediately after, and 10, 20, and 30 min after SMV. For SICI, there was no change immediately after SMV, but there was a decrease over time (before vs. 30 min after, p = 0.021; immediately after vs. 30 min after, p = 0.015). There were no changes in test MEP amplitude, SICF, or the F/M ratio. SMV causes a gradual decrease in SICI over time perhaps owing to long-term potentiation. The present results may have implications for the treatment of spasticity.

Heel pad loss can cause serious problems in weight-bearing and locomotion. The medial plantar artery (MPA) flap is a suitable “like for like” replacement. Nineteen patients whose heels were reconstructed with MPA flap between July 2015 and February 2020 were studied. All patients were assessed based on flap survival, functionality, and patient satisfaction. Loss of heel pad was due to diabetic ulcer (11), trauma (6), tumor (1), and unstable scar (1). The largest flap measured 9 × 7 cm. Sixteen flaps were done as fasciocutaneous flaps and three in combination with abductor hallucis muscle (AbdH). All the flaps survived. The average functional scores at 6, 12, 18, and 24 months were 86.86, 89.62, 89.38 and 97.33 based on AOSAS-AH score. Average patients' satisfaction was 8.7/10. To conclude, the MPA system is a versatile vascular axis providing “like for like” tissue for heel pad reconstruction which is reliable and durable.

Background Dellon et al. have reported that chronic nerve compression of the tibial nerve inside the tarsal tunnel, caused by diabetes mellitus, can be relieved following open decompression surgery. However, the large skin incision resulting from Dellon's procedure may cause wound healing problems. The authors report the possibility of a minimally invasive full endoscopic procedure. Methods Operations were performed under local anesthesia without a pneumatic tourniquet. An anesthetic agent was applied at the proximal part of the flexor retinaculum of the foot, and a hypodermic needle was advanced into the tarsal tunnel. Tarsal tunnel pressure and blood circulation of the tibial nerve using indocyanine green assessment were measured preoperatively. One 1-cm portal skin incision was made at the anesthetized area and the Universal Subcutaneous Endoscope system was inserted into the tarsal tunnel. The flexor retinaculum, tibial nerve, blood vessels, and abductor hallucis muscle fascia were identified under endoscopic observation. After decompression of the tarsal tunnel, the authors measured tarsal tunnel pressure and blood circulation of the tibial nerve for analysis of the effectiveness of the endoscopic decompression during the procedure. Results Fourteen operations were compiled and analyzed. Postoperative clinical status was improved based on the preoperative modified Toronto Clinical Neuropathy Score. The mean tarsal tunnel pressure dropped to 4.5 mmHg during surgery from the initial preoperative 49.4 mmHg in resting position. Endoscopic indocyanine green assessment showed more than 30 percent improvement of the vascularity surrounding the tibial nerve. Conclusion The authors' minimally invasive full endoscopic procedure is a viable alternative approach for tarsal tunnel syndrome patients with diabetic foot neuropathy. Clinical question/level of evidence Therapeutic, IV.

Purpose: Previous research has indicated that the structure and function of abductor hallucis muscle (AbdH) would be adversely affected by hallux valgus (HV). However, the influence of long-distance running on AbdH in HV feet has not been explored. Therefore, this pilot study aimed to compare the imaging differences of AbdH between normal and HV feet after long-distance running. Methods: A total of 14 male adults were divided into two groups (Normal Foot Group (NFG), Hallux Valgus Group (HVG)) based on their foot morphology. A B-mode ultrasonic scanner was utilized for measuring AbdH thickness, cross-sectional area, and pennation angle before and after 5-km running test. Perceived soreness was monitored simultaneously using the visual analogue scale. Results: AbdH showed significantly differences between groups before and after the running test. Compared with NFG, HVG exhibited smaller value before the test while greater changes in all parameters although pennation angle failed to reach the significant level. Conclusions: These results further confirmed that HV could lead to the morphological alterations of AbdH. Also, AbdH of people with HV would endure more fatigue and soreness when performed the same long-distance running test with normal counterparts. Nevertheless, more studies are much needed for further verification.

BACKGROUND: Hallux valgus deformity of the big toe in adolescents accounts for 22%44% of all relevant cases. Despite a relatively large number of surgical treatment methods proposed to correct this deformity, treatment results are not always satisfactory. The problem of imbalance between the external traction of the abductor hallucis muscle and the contracted adductor muscle in hallux valgus remains controversial and is not covered in the literature. AIM: This study aimed to examine the results of hallux valgus deformity treatment, following the suggested combined technique. MATERIALS AND METHODS: Eight teenage patients (10 feet), aged 15 years on average, were assessed. Patients were undergoing treatment in the department of pediatric orthopedics of the Dana Hospital, Tel Aviv, within the period from 2015 to 2019. The average postoperative observation period was 30 months. This study suggested a new combined technique, including (1) modified oblique Chevron osteotomy with a V-shaped cut in the distal aspect of the first metatarsal with the dorsal wedge excision performed at the apex of its angulation, (2) valgus osteotomy of the medial cuneiform bone with the insertion of the V-shaped bone allograft, and (3) transfer of the dorsal portion of the pre-split tendon of abductor hallucis muscle to the base of the triangular medial capsular flap of the first metatarsophalangeal joint (MPJ). The tendon received optimal tension to restore the muscular balance. RESULTS: This surgical technique provided safe and stable correction of the hallux valgus deformity, restored muscular balance, avoided movement restriction of the first MPJ, and restored the function and strength of the abductor halluces muscle that prevented the recurrence of the deformity. The number of good and excellent results was much greater than those in published reports. CONCLUSIONS: Despite a relatively small group of patients, the suggested technique has shown improvements in hallux valgus deformity in adolescents.

Electrical stimulation is an established method that is used to improve muscle strength. The present study compared changes in the navicular drop test (NDT), muscle size, the five times sit to stand (5TSTS) test, the timed up and go (TUG) test, and the risk of falls in response to transcutaneous electrical nerve stimulation (TENS) plus short foot exercise (SFE) and SFE alone in 68 healthy elderly participants aged 65–75 years. Participants were randomly assigned to two groups: TENS plus SFE and SFE alone (with sham TENS). Measurements of NDT, muscle size, 5TSTS, TUG, and risk of falls were made before and after 4 weeks of training. The NDT was significantly improved by a median of 0.31 mm in the TENS plus SFE group and 0.64 mm in the SFE alone group (p < 0.001). Similarly, there was a significant improvement in Falls Efficacy Scale International (FES-I), 5TSTS, and TUG for both groups (p < 0.001). The abductor hallucis muscle size increased by 0.23 cm2 in the TENS plus SFE group and 0.26 cm2 in the SFE alone group (p < 0.001). There were no significant differences between the two groups for any variables (p > 0.05) except TUG, which showed a greater improvement in the TENS plus SFE group (p = 0.008). Our findings demonstrated that TENS plus SFE and SFE alone improved intrinsic foot muscle size. However, TENS plus SFE tended to improve NDT more than SFE alone, particularly in cases of severe muscle weakness. Thus, the combined use of TENS plus SFE could be recommended for muscle strengthening and balance programs for fall prevention in older adults.

Purpose Little is known about the reliability and value of intraoperative neurophysiological monitoring (IONM) in patients with Duchenne muscular dystrophy (DMD) undergoing scoliosis correction surgery. The aim of this study was to investigate the feasibility of IONM and the cortical excitability in these patients. Methods Fifteen patients with DMD and scoliosis and 15 patients with adolescent idiopathic scoliosis (AIS) underwent scoliosis correction surgery with the use of IONM. IONM consisted of transcranial electrical stimulation motor evoked potential (Tc-MEP) and somatosensory evoked potential (SSEP) monitoring. The highest Tc-MEP amplitudes were collected to test the feasibility. Preoperative compound muscle action potentials (CMAPs) and transcranial magnetic stimulation (TMS)-MEPs were recorded to test the cortical excitability. SSEPs were scored as elicitable or not elicitable. Results Tc-MEP amplitudes were significantly lower in the DMD group for both the gastrocnemius and tibialis anterior muscles. However, the abductor hallucis muscle had similar amplitudes in both the DMD as the AIS group. TMS/CMAP and Tc-MEP/CMAP ratios were similar in the DMD and AIS group (P = 0.126 and P = 0.792 respectively). Conclusions Tc-MEP and SSEP monitoring is feasible, particularly when Tc-MEPs are recorded from the abductor hallucis muscle in patients with DMD. Similar TMS/CMAP and Tc-MEP/CMAP ratios show that there were no differences observed in cortical excitability between the groups. IONM seems a feasible and valuable neurophysiological tool to signal possible surgically induced damage to the spinal cord during scoliosis correction surgery in patients with DMD.

Background: Tarsal tunnel syndrome (TTS) is an entrapment neuropathy in which the tibial nerve is compressed within the tarsal tunnel and causes sensory disturbance in the sole of the foot. In this manuscript, we summarized our early surgical cases of TTS. Materials and Methods: Six feet in five patients with TTS were treated surgically. The patients were aged 31–70 years (mean 53.1 years), and all of them complained of pain or dysesthesia of the sole of the foot sparing the heel. Magnetic resonance imaging (MRI) and nerve conduction test were performed preoperatively. In surgery, flexor retinaculum was dissected (tarsal tunnel opening [TTO]), the posterior tibial nerve was freed from the arteriovenous complex (neurovascular decompression [NVD]), and fascia of the abductor hallucis muscle was excised to decompress the medial and lateral plantar nerve (releasing fascial of abductor hallucis muscle [RFAH]). Results: Preoperative MRI confirmed that all seven cases were idiopathic TTS. Moreover, NCD demonstrated delayed sensory conduction velocity but not delayed distal motor latency. Surgical decompression was beneficial in 5 feet. The recurrence of symptoms was found in one case within 1 postoperative month. Conclusion: Surgical treatment for idiopathic TTS with TTO, NVD, and RFAH was generally good. However, symptoms recurred in one instance. Some methods to prevent adhesion and granulation in the reconstructed tarsal tunnel should be considered.

Highlights • Hemangioma is a rare slow growing benign soft tissue tumor of foot. • Its rarity could lead to delay in diagnosis and treatment for the patient. • Wide excision of the tumor is a valuable treatment option for this type of tumor., Introduction Haemangioma is a slow growing benign soft tissue tumor and its presentation in the foot is rare. Intramuscular haemangioma (IH) are usually found before 30 years of age, with gender predominance is still inconclusive. Presentation of case An 18-year-old woman came with pain and mass in the left foot for the past 3 years. Magnetic Resonance Imaging (MRI) of the left foot shown a heterogenous multilobulated mass, with previously thought originated from flexor digitorum brevis (FDB) muscle. Wide excision was performed and intraoperative findings showed that the mass actually originated from abductor hallucis muscle. Post-operative histopathological findings confirmed the diagnosis of cavernous-type of intramuscular haemangioma. Discussion The rare occurrence of intramuscular haemangioma of the foot can cause a delayed diagnosis and treatment to the patient. The differential diagnosis include lipoma, fibroma, enlargement of the lymph nodes, compartment syndrome, hematoma, hernia, and soft-tissue sarcoma. Anytime a soft tissue mass is identified in the skeletal muscle of a young adult, haemangioma should be considered. Conclusion Literature research identified very few cases of intramuscular haemangioma of the foot. Wide excision of the muscle is a feasible surgical treatment option.

Often times, conservative treatment is unsuccessful in long-term resolution of recalcitrant verrucae plantaris lesions. In addition to being aesthetically displeasing, severe cases that are left untreated can be debilitating, often leading to chronic pain, gait abnormalities, and further cutaneous spread. Inoculation through implantation of verrucae plantaris into a muscle was previously postulated to provoke an immune response against the human papilloma virus, resulting in auto-immunization. The purpose of this study was to determine the rate of recurrence following two methods of treatment: A) Surgical removal and subsequent implantation of verruca plantaris into the contralateral abductor hallucis muscle belly and B) Surgical excision of verrucae plantaris. A retrospective chart review of 43 consecutive patients was performed. Group A was comprised of 25 patients who underwent surgical removal of verrucae plantaris followed by implantation of a biopsied specimen into the contralateral abductor hallucis muscle belly. Group B was comprised of 18 patients who underwent only surgical removal of the verrucae. The presence or absence of verrucous lesions was recorded at a post-operative follow-up at an average of 27.5 months. Correlations between recurrence of disease and age, sex, and medical comorbidities were evaluated. Our results suggest that implantation of verruca plantaris into the abductor hallucis muscle belly yields no significant difference in clinical recurrence rates when compared to surgical removal.

Morphological changes of the abductor hallucis muscle (AbH) in flexible flatfoot (FF) individuals influence regulations of the medial longitudinal arch (MLA). Prolonged and repeated stretching of AbH in flexible flatfoot may cause changes in muscle reflex properties and further influence postural performance. However, AbH muscle reflex under different postural conditions have never been examined. The purpose of this study was to investigate differences in AbH H-reflex and postural performance between individuals with normal foot (NF) alignment and FF under prone, double-leg stance (DLS), and single-leg stance (SLS) conditions.Cross-sectional study.University laboratory.Individuals with FF (n = 12) and NF (n = 12).AbH H-reflex, AbH EMG and center of pressure (CoP) displacement.Under all postural conditions, AbH H-reflex was significantly lower in the FF group (P .05). Under the SLS condition, AbH EMG was significantly higher in the FF group (P .05), and CoP displacement for the medial-lateral and anterior-posterior directions were significantly higher in the FF group (P .05).With increased postural demand, FF individuals maintained their postural stability by recruiting greater AbH activities than through automatic stretch reflex, but FF individuals still showed inferior posture stability.

Lumbosacral spinal stenosis is a narrowing of the spinal canal, which compresses the nerves travelling through the lower back into the lower limbs. Symptomatic patients often have intermittent neurogenic claudication, and with diagnostic procedures at rest, it is difficult to evaluate it objectively Measurement of conduction in the cauda equine at rest and after walking may be a valuable tool in lumbosacral spinal stenosis work-up. The aim of our study was to compare results of magnetic in electrical stimulation, and the peripheral motor conduction time. Methods: M and F waves and compound muscle action potentials were recorded after L1 MS, S1 MS, and L1 ES. Results: The compound muscle action potential latency on L1 MS was 26.9 ± 2.6 milliseconds and on L1 ES was 25.6 ± 2.2 milliseconds, and the peripheral motor conduction time was 27.0 ± 2.5 milliseconds (analysis of variance P = 0.0008). The compound muscle action potential amplitude was 12 ± 11% of M-wave on L1 MS, 32 ± 18% on S1 MS, and 31 ± 17% on L1 ES. Conclusions: Dorsal MS reliably elicits responses in the abductor hallucis muscle. The latency of compound muscle action potentials on L1 MS is comparable to peripheral motor conduction time. A potential drawback of MS may be too weak stimulation at the proximal end of the cauda equina.

Title: The immediate effect of Russian electrical stimulation on m. abductor hallucis on postural stability in women with dysfunction of hallux valgus Objectives: The aim of this diploma theses is to investigate the immediate effect of Russian eletrical stimulation on m. abductor hallucis on postural stability in women with mild or moderate dysfunction of hallux valgus. Methods: This is an experimental pilot study in which 16 women aged 23-28 years participated. The entry criteria for participation in the research were: mild or moderate dysfunction of hallux valgus according to the Manchester scale, angle of hallux valgus ≥ 15ř at least on one lower limb. Probands could not participate in the research if: they completed a rehabilitation program to affect hallux valgus deformity, underwent surgery for hallux valgus deformity, suffered an injury of the lower limbs in the last six months before the start of the research or if they were pregnant. The examination of postural stability took place in the Kinesiology Laboratory of FTVS UK on the NeuroCom SMART EquiTest System posturograph. The following tests were selected: Sensory Organization Test, Motor Control Test, Weight Bearing Squat and Limits of Stability test. Russian stimulation was applied on the abductor hallucis muscle of both lower limbs...

The role of intrinsic muscles of the foot in the medial longitudinal arch mechanism was investigated in several recent studies. It is determined that the abductor hallucis muscle (AHM) has an important role in dynamic support of the arch. Objective of our preliminary study was to establish a relationship between the navicular drop index (NDI) and the AHM abduction force. A single group exploratory design was used. The participants were 127 athletes aged 8-16 years (m/f 74/53; 11.99 ± 2.11 years; 156.21 cm ± 15.51 cm; 47.61 kg ± 13.96 kg; 2-5 training h/week), examined at a regular sport medical checkup. Abductor hallucis force was measured by a digital Algometer FPX 25/220, which is a newly developed approach that should be properly assessed in further studies to establish standardization and qualification of the algometer for this specific use. Navicular drop test has been performed as originally developed by Brody. Data were analyzed using Student's t-test, Mann-Whitney U test, contingency coefficients and logistic regression. Average NDI was found to be significantly different comparing the group with positive abduction force and the group that cannot perform the active abduction. Logistic regression indicated that the variable representing impossible active abduction was significantly associated with NDI. Preliminary results showed that there was a strong relationship between the hallux active abduction force and NDI in young athletes: the higher abduction force correlates to lower NDI. To determine clinical relevance of our investigation, further study is planned in which hallux active abduction force and NDI would be compared and correlated pre- and postspecific strengthening program. © 2021 BMJ Publishing Group. All rights reserved.

OBJECTIVE: To examine the peripheral nervous system (PNS) in spinal cord injured (SCI) patients using two novel methods: (1) MScanFit MUNE; a motor unit number estimation method detecting motor unit loss and (2) muscle velocity recovery cycles (MVRCs) measuring muscle membrane properties which has previously shown depolarization of the muscle membrane in denervated muscles.METHODS: Thirty chronic SCI patients (lesion above Th10) and twenty-five gender -and age matched healthy controls (HC) were examined. MScanFit was recorded from peroneal nerve to anterior tibial muscle (TA) and tibial nerve to abductor hallucis muscle after excluding localized mononeuropathies. MVRCs were recorded from TA.RESULTS: Nerve conduction studies showed mononeuropathy in 8 patients (27%) (sciatic (2), -or peroneal nerve (6)). SCI patients had in average reduced motor unit number compared with HC and prolonged muscle refractory period and reduced supernormality.SIGNIFICANCE: A high prevalence of nerve lesion and a diffuse affection of the PNS following SCI are highly relevant findings that should be accounted for when planning neurorehabilitation for persons living with SCI.

Introduction Distal tarsal tunnel syndrome (DTTS) is characterised by compression of the tibial nerve as it passes underneath the abductor hallucis muscle belly. There is no current consensus on treatment for DTTS. This study was conducted to compare and evaluate the effect of ultrasound-guided botulinum toxin A (BTX-A) versus ultrasound-guided corticosteroid injection (CSI) for the treatment of DTTS. Methods This study was a single-centre, randomized, and double-blinded trial. The study protocol was submitted to the local ethics committee board and subsequently registered in a research registry. 88 patients with DTTS were randomly divided into 2 groups according to the treatment received. The patients were evaluated over 12 weeks. Evaluation was via the Foot Health Status Questionnaire (FHSQ). The primary outcome measures were pain and the secondary outcomes were function and the use of oral analgesics. All of the assessments were performed at baseline and at 3, 6, and 12 weeks after treatment. Results This is a randomized controlled trial evaluating the efficacy of BTX-A versus CSI in the treatment of DTTS. This study has limited inclusion and exclusion criteria and a well-controlled intervention. Conclusions The results of this trial will provide more evidence on which method can better treat DTTS. Trial registration We have registered this trial with the Australian New Zealand Clinical Trials Registry and the temporary trial number is 380,105.

Background The aim of this study was to provide a safe ultrasound-guided minimally invasive surgical approach for a distal tarsal tunnel release concerning nerve entrapments. Methods and results The study was carried out on ten fresh-frozen feet. All of them have been examined by high-resolution ultrasound at the distal tarsal tunnel. The surgical approach has been marked throughout the course of the medial intermuscular septum (MIS, the lateral fascia of the abductor hallucis muscle). After the previous steps, nerve decompression was carried out through a MIS release through a 2.5 mm (± 0.5 mm) surgical portal. As a result, an effective release of the MIS has been obtained in all fresh-frozen feet. Conclusion The results of our anatomic study indicate that this novel ultrasound-guided minimally invasive surgical approach for the release of the MIS might be an effective, safe and quick decompression technique treating selected patients with a distal tarsal tunnel syndrome.

BACKGROUND Intraoperative neuromonitoring using tc-MEPs satisfactorily detects motor tract integrity changes during spinal surgery. However, tc-MEP is affected by anesthesia and other factors, in which the stimulation threshold increases because the waveform amplitude decreases over time with the accumulation and boluses of anesthetics. METHODS We conducted a retrospective study of 139 patients. The average age was 30 years. Tc-MEPs were recorded bilaterally from the tibialis anterior muscle and the abductor hallucis muscle. Statistical tests were used to investigate the changes to evaluate anesthetic effects. RESULTS There were no significant differences in tc-MEP amplitude change (%) between the groups of propofol (13 %), remifentanil (22 %) and sufentanil (26 %, p < 0.01). Significant differences were found between the groups of propofol, remifentanil, and sufentanil (20 %) and bolus sufentanil (‒30 %), and bolus ketamine (730 %, p < 0.008). Major differences were observed between bolus sufentanil (‒30 %) and bolus ketamine (730 %, p < 0.001). When comparing tc-MEPs with no amplitude, no significant difference was found between the groups of propofol (26 %), remifentanil (24 %), and sufentanil (28 %, p < 0.007). Substantial difference was found between the groups of propofol, remifentanil, and sufentanil (mean 26 %) and the group where ketamine boluses were administered. We didn't observe any loss of amplitude (0 %, p < 0.0002). CONCLUSION IONM may be useless in patients where boluses of sufentanil are administered and also with Medical Research Council grades 3 and below. Consider applying IONM in patients with severe spinal deformity along with a higher age of over 50 and neurological deficit. Increasing stimulus intensity or facilitation techniques may be considered to improve the usefulness of tc-MEP. Our concept of findings supports the neurophysiological monitoring findings in other studies (Tab. 10, Ref. 45).

Despite the high availability of surface electromyography (sEMG), it is not widely used for testing the effectiveness of exercises that activate intrinsic muscles of foot in people with hallux valgus. The aim of this study was to assess the effect of the toe-spread-out (TSO) exercise on the outcomes of sEMG recorded from the abductor hallucis muscle (AbdH). An additional objective was the assessment of nerve conduction in electroneurography. The study involved 21 patients with a diagnosed hallux valgus (research group A) and 20 people without the deformation (research group B) who performed a TSO exercise and were examined twice: before and after therapy. The statistical analysis showed significant differences in the third, most important phase of TSO. After the exercises, the frequency of motor units recruitment increased in both groups. There were no significant differences in electroneurography outcomes between the two examinations in both research groups. The TSO exercise helps in the better activation of the AbdH muscle and contributes to the recruitment of a larger number of motor units of this muscle. The TSO exercises did not cause changes in nerve conduction. The sEMG and ENG are good methods for assessing this exercise but a comprehensive assessment should include other tests as well.

Objective: Despite suggestions that atrophied, or weak toe flexor muscles are associated with the formation of toe deformities, there has been little evidence to support this theory. This study aimed to determine whether the size of the toe flexor muscles differed in older people with and without toe deformities. \ud Methods: Forty-four older adults (>60 years) were recruited for the study. Each participant\ud had their feet assessed for the presence of hallux valgus or lesser toe deformities. Intrinsic and extrinsic toe flexor muscles were imaged with an ultrasound system using a standardised protocol. Assessor blinded muscle thickness and cross-sectional area was measured using Image J software. \ud Results: Participants with lesser toe deformities (n=20) were found to have significantly smaller quadratus plantae (p=0.003), flexor digitorum brevis (p=0.013), abductor halluces (p=0.004) and flexor halluces brevis (p=0.005) muscles than the participants without any toe deformities (n=19). Female participants with hallux valgus (n=10) were found to have significantly smaller abductor hallucis (p=0.048) and flexor halluces brevis (p=0.013) muscles than the female participants without any toe deformities (n=10; p\ud Conclusion: This is the first study to use ultrasound to investigate the size of the toe flexor muscles in older people with hallux valgus and lesser toe deformities compared to otherwise healthy older adults. The size of the abductor hallucis and flexor hallucis brevis muscles were decreased in participants with hallux valgus whereas the quadratus plantae, flexor digitorum brevis, abductor hallucis and flexor halluces brevis muscles were smaller in those participants with lesser toe deformities.

The medial and lateral plantar nerves are branched from the tibial nerve and move to the tip of the toes. A variation of medial plantar nerve was found on the left side of a 78-year-old Korean male cadaver. The tibial nerve was divided into the lateral and medial plantar nerves beneath the plantar flexor. The medial plantar nerve passed deep to plantar aponeurosis and superficial to the flexor digitorum brevis. It gave off a common plantar digital nerve and then divided into three proper plantar digital nerves near the metatarsal bases. In this article, we report a superficial course of the medial plantar nerve and describe its unique morphology and discuss the clinical significance of this variation.

Objective To identify the anatomical motor points of the abductor hallucis muscle in cadavers. Methods Motor nerve branches to the abductor hallucis muscles were examined in eight Korean cadaver feet. The motor point was defined as the site where the intramuscular nerve penetrates the muscle belly. The reference line connects the metatarsal base of the hallux (H) to the medial tubercle of the calcaneus (C). The x coordinate was the horizontal distance from the motor point to the point where the perpendicular line from the navicular tuberosity crossed the reference line. The y coordinate was the perpendicular distance from the motor point to the navicular tuberosity. Results Most of the medial plantar nerves to the abductor hallucis muscles divide into multiple branches before entering the muscles. One, two, and three motor branches were observed in 37.5%, 37.5%, and 25% of the feet, respectively. The ratios of the main motor point from the H with respect to the H-C line were: main motor point, 68.79%±5.69%; second motor point, 73.45%±3.25%. The mean x coordinate value from the main motor point was 0.65±0.49 cm. The mean value of the y coordinate was 1.43±0.35 cm. All of the motor points of the abductor hallucis were consistently found inferior and posterior to the navicular tuberosity. Conclusion This study identified accurate locations of anatomical motor points of the abductor hallucis muscle by means of cadaveric dissection, which can be helpful for electrophysiological studies in order to correctly diagnose the various neuropathies associated with tibial nerve components.

Myofascial pain syndrome is characterized by pain and a limited range of joint motion caused by muscle contracture related to motor-end-plate dysfunction and the presence of myofascial trigger points (MTrPs). It is the most frequent cause of musculoskeletal pain, with a worldwide prevalence varying between 13.7% and 47%. Of the patients with myofascial pain syndrome, approximately 17% have pain in the medial hindfoot area. The abductor hallucis muscle is located in the medial, posterior region of the foot and is related to painful plantar syndromes. The objective of this study was to describe the distribution of the medial plantar nerve and their anatomical relationship with MTrPs found in the literature. Thirty abductor hallucis muscles were dissected from 15 human cadavers (8 males and 7 females). The muscles were measured, and the distribution data of the medial plantar nerve branches in each quadrant were recorded. For statistical analysis, we used generalized estimation equations with a Poisson distribution and a log logarithm function followed by Bonferroni multiple comparisons of the means. The data are expressed as the mean ± standard deviation. The level of significance was adjusted to 5% (p<0.05). A high concentration of nerve branches was observed in the first quadrant (Q1) of the abductor hallucis muscle, which is the same area in which the MTrPs are described. The topography of the entry points of the branches of the medial plantar nerve to the abductor hallucis muscle correlates with the topography of the muscular trigger points. The anatomical structure of the MTrPs may be useful for a better understanding of the pathophysiology of myofascial disorders and provide a basis for surgical and clinical treatments.

Introduction In this study we collected reference values for the across-tarsal-tunnel conduction of the motor tibial nerve (mTN). Methods The mTN compound muscle action potentials (CMAPs) from the abductor hallucis muscle were obtained by stimulating below/above the malleolus and the popliteal fossa. The effect of weight, height, body mass index (BMI), foot and leg length, sex, and age were evaluated using univariate and multivariate correlation analyses, and predictive equations for each mTN conduction parameter were developed. Results On the basis of data from 185 subjects, there were differences between women and men in all anthropometric parameters and for some nerve conduction values. Through multivariate analysis, age, but not sex, was found to have a significant impact. Height affected both distal and proximal conduction velocity. BMI affected CMAP amplitude. Discussion mTN conduction is influenced by various demographic and anthropometric factors. For all intrinsic factors, height demonstrated the greatest effect on mTN conduction across the tarsal tunnel.

Low-dose droperidol has been widely used as an antiemetic during and after surgery. Although high-dose droperidol affects motor-evoked potential, the effects of low-dose droperidol on motor-evoked potential amplitude are unclear. The aim of this study was to investigate whether low-dose droperidol affects motor-evoked potential amplitude. We retrospectively reviewed the data of patients who underwent spine surgery under general anesthesia with motor-evoked potential monitoring from February 2016 to 2017. The outcome was the motor-evoked potential amplitude of the bilateral abductor pollicis brevis muscle, tibialis anterior muscle, and abductor hallucis muscle within 1 and 1-2 h after droperidol administration, compared with the baseline motor-evoked potential value. Thirty-four patients were analyzed. The median dose of droperidol was 21 µg/kg. The motor-evoked potential amplitudes of all muscles were significantly reduced after droperidol administration and recovered to baseline values within 2 h. The reduction of all motor-evoked potential amplitudes after droperidol administration was 37-45% of baseline values. There were no significant differences in other drugs administered. There were no serious adverse effects of droperidol administration. Motor-evoked potential amplitude was suppressed by low-dose droperidol. During intraoperative motor-evoked potential monitoring in spine surgery, anesthesiologists should pay careful attention to the timing of administration of droperidol, even at low doses. Based on the results of this study, we are conducting a randomized controlled trial.

Background This study aims to analyse the clinical results of ultrasound-guided surgery for the decompression of the tibial nerve, including its distal medial and lateral branches, to treat tarsal tunnel syndrome. These structures are the complete flexor retinaculum and the deep fascia of the abductor hallucis muscle, including individualised release of the medial and lateral plantar nerve tunnels. Method This is a retrospective review of 81 patients (36 men and 45 women) with an average age of 41 years old (32–62) and an average clinical course of 31 months (8–96) compatible with idiopathic tarsal tunnel syndrome, who underwent ultrasound-guided decompression of the proximal and distal tarsal tunnel between February 2015 and November 2017 (both months included), with a minimum follow-up of 18 months. Results Based on the Takakura et al. scale for the 81 patients, 76.54% obtained excellent results, 13.58% good results, and 9.87% poor results. The patients with the longest course of symptoms displayed the worst results. Conclusion Although 9% of patients did not improve, ultrasound-guided tarsal tunnel release might be a viable alternative to conventional open approaches.

BACKGROUND: Lateralising calcaneal osteotomy for pes cavus is generally regarded to be harder to shift than a medialising calcaneal osteotomy for pes planus. The aim of our study was to determine the structures which restrain a lateral shift. METHODS: Lateralising calcaneal osteotomy was performed on four soft-embalmed cadavers via a standard lateral approach and the lateral calcaneal shift was measured before and after the release of flexor retinaculum. Further exploratory dissection around the osteotomy site revealed the abductor hallucis muscle to be the main restraint to the lateral shift of the calcaneus. Subsequently, lateralising calcaneal osteotomy was performed on another four cadavers and the abductor hallucis muscle fascia as well as the plantar fascia was released. The lateral shift was measured before and after the fascia release, and compared with the results achieved following the flexor retinaculum release in the first four cadavers. RESULTS: Lateralising calcaneal osteotomy alone resulted in an average of 4.5-mm lateral shift in the first four cadaveric specimens. Releasing the flexor retinaculum led to a further 3-mm increase of lateral shift on average. In the next four cadaveric specimens, lateralising calcaneal osteotomy alone resulted in an average of 5.5-mm lateral shift. Release of abductor hallucis muscle fascia and the plantar fascia in these four specimens increased the lateral shift by an additional 7 mm on average. Hence, release of abductor hallucis muscle fascia resulted in an extra 4-mm shift on average compared with what is achieved with flexor retinaculum release. CONCLUSIONS: Abductor hallucis muscle fascia was discovered to be one of the main structures limiting the lateral shift in lateralising calcaneal osteotomy. Release of fascia over this muscle as well as the plantar fascia should help in improving lateral shift. Further experimental and clinical research is necessary to confirm the findings of this pilot study.

Introduction This study investigated whether the prolongation of the cauda equina conduction time (CECT) was related to the type of neurogenic intermittent claudication due to lumbar spinal stenosis. Methods In total, 149 patients who underwent surgery due to lumbar spinal stenosis with neurogenic intermittent claudication were classified into three groups as follows: cauda equina-type(n = 67), radicular-type(n = 29), and mixed-type(n = 53). Cauda equina conduction time was measured by placing disc electrodes on the abductor hallucis muscle, electrically stimulating the tibial nerve of the ankle and recording the compound muscle action potentials and F-waves. Motor evoked potentials from the abductor hallucis muscle were measured after magnetically stimulating the lumbosacral spine. Cauda equina conduction time was calculated from the latencies of compound muscle action potentials, F-waves, and motor evoked potentials. The measurement of the dural sac cross-sectional area were assessed using computed tomography myelography or MRI. Results The values of CECT were as follows: cauda equina-type, 5.6 ± 1.1 ms; mixed-type, 5.1 ± 0.9 ms; and radicular-type, 4.0 ± 0.9 ms. The values of dural sac cross-sectional area were as follows: cauda equina-type, 42.8 ± 18.7 mm; mixed-type, 49.6 ± 20.9 mm; and radicular-type, 75.3 ± 19.1 mm. In the cauda equina-type and mixed-type patients, CECT was significantly prolonged and there were negative correlations between CECT and dural sac cross-sectional area. Conclusions Cauda equina conduction time differed according to the type of lumbar spinal stenosis. The prolongation of CECT may be caused by the demyelination of the CE. Cauda equina conduction time may be a useful measure for evaluating the dysfunction of the CE rather than radiculopathy for patients with lumbar spinal stenosis.