{"title":"Flexor hallucis longus and tibialis anterior: A synergistic relationship.","authors":"Jacob Fanous, Charles L Rice","doi":"10.1016/j.jelekin.2024.102966","DOIUrl":null,"url":null,"abstract":"<p><p>Flexor hallucis longus (FHL) is an important muscle of the foot and ankle during locomotion, contributing to hallux and plantar flexion. For optimal hallux flexion the ankle needs to be stabilized against plantar flexion which may require action of the dorsiflexors. Due to the deep location of the FHL contractile drive assessed by electromyography (EMG) has not been explored systematically. Thus, the purpose was to test the relationship between the FHL and tibialis anterior (TA), the main dorsiflexor. Using indwelling EMG during isometric maximal voluntary contractions (MVC) of hallux and ankle joint actions, 10 participants (3-females, 7-males) aged 23 ± 1.4 years were tested in custom hallux-flexion and ankle dynamometers, with bipolar wire electrodes recording from the FHL, soleus and TA muscles. During MVC, forces were 169.2 ± 28.5 N, 285.5 ± 65.4 N, and 712.3 ± 313.8 N for hallux flexion, dorsiflexion, and plantar flexion, respectively. During maximal hallux flexion, TA EMG was 53 % (±26.5) of its maximum with negligible soleus activity, 4.7 % (±3.1). No significant correlations were found between TA activity and strength, foot characteristics, sex, height, weight, or soleus activity. This higher level of relative EMG recorded from the TA during maximal hallux flexion has not been observed in prior studies during walking and indicates that the relationship between the FHL and TA is task dependent, thus highlighting the important synergistic role of the TA in allowing optimal toe flexion.</p>","PeriodicalId":56123,"journal":{"name":"Journal of Electromyography and Kinesiology","volume":"80 ","pages":"102966"},"PeriodicalIF":2.0000,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Electromyography and Kinesiology","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1016/j.jelekin.2024.102966","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"NEUROSCIENCES","Score":null,"Total":0}
Flexor hallucis longus and tibialis anterior: A synergistic relationship.
Flexor hallucis longus (FHL) is an important muscle of the foot and ankle during locomotion, contributing to hallux and plantar flexion. For optimal hallux flexion the ankle needs to be stabilized against plantar flexion which may require action of the dorsiflexors. Due to the deep location of the FHL contractile drive assessed by electromyography (EMG) has not been explored systematically. Thus, the purpose was to test the relationship between the FHL and tibialis anterior (TA), the main dorsiflexor. Using indwelling EMG during isometric maximal voluntary contractions (MVC) of hallux and ankle joint actions, 10 participants (3-females, 7-males) aged 23 ± 1.4 years were tested in custom hallux-flexion and ankle dynamometers, with bipolar wire electrodes recording from the FHL, soleus and TA muscles. During MVC, forces were 169.2 ± 28.5 N, 285.5 ± 65.4 N, and 712.3 ± 313.8 N for hallux flexion, dorsiflexion, and plantar flexion, respectively. During maximal hallux flexion, TA EMG was 53 % (±26.5) of its maximum with negligible soleus activity, 4.7 % (±3.1). No significant correlations were found between TA activity and strength, foot characteristics, sex, height, weight, or soleus activity. This higher level of relative EMG recorded from the TA during maximal hallux flexion has not been observed in prior studies during walking and indicates that the relationship between the FHL and TA is task dependent, thus highlighting the important synergistic role of the TA in allowing optimal toe flexion.
期刊介绍:
Journal of Electromyography & Kinesiology is the primary source for outstanding original articles on the study of human movement from muscle contraction via its motor units and sensory system to integrated motion through mechanical and electrical detection techniques.
As the official publication of the International Society of Electrophysiology and Kinesiology, the journal is dedicated to publishing the best work in all areas of electromyography and kinesiology, including: control of movement, muscle fatigue, muscle and nerve properties, joint biomechanics and electrical stimulation. Applications in rehabilitation, sports & exercise, motion analysis, ergonomics, alternative & complimentary medicine, measures of human performance and technical articles on electromyographic signal processing are welcome.