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Medial gastrocnemius and soleus muscle‐tendon unit, fascicle, and tendon interaction during walking in children with cerebral palsy
Author(s) -
Barber Lee,
Carty Chris,
Modenese Luca,
Walsh John,
Boyd Roslyn,
Lichtwark Glen
Publication year - 2017
Publication title -
developmental medicine and child neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.658
H-Index - 143
eISSN - 1469-8749
pISSN - 0012-1622
DOI - 10.1111/dmcn.13427
Subject(s) - fascicle , cerebral palsy , ankle , gait , gastrocnemius muscle , soleus muscle , anatomy , tendon , gait analysis , statistical parametric mapping , plantar flexion , medicine , physical medicine and rehabilitation , skeletal muscle , magnetic resonance imaging , radiology
Aim This study investigates the in vivo function of the medial gastrocnemius and soleus muscle‐tendon units ( MTU ), fascicles, and tendons during walking in children with cerebral palsy ( CP ) and an equinus gait pattern. Method Fourteen children with CP (9 males, 5 females; mean age 10y 6mo, standard deviation [ SD ] 2y 11mo; GMFCS level I=8, II =6), and 10 typically developing (6 males, 4 females; mean age 10y, SD 2y 1mo) undertook full body 3D gait analysis and simultaneous B‐mode ultrasound images of the medial gastrocnemius and soleus fascicles during level walking. Fascicle lengths were analysed using a semi‐automated tracking algorithm and MTU s using OpenSim. Statistical parametric mapping (two‐sample t ‐test) was used to compare differences between groups ( p <0.05). Results In the CP group medial gastrocnemius fascicles lengthened during mid‐stance gait and remained longer into late‐stance compared to the typically developing group ( p <0.001). CP medial gastrocnemius fascicles shortened less during stance (1.16mm [ SD 1.47mm]) compared to the typically developing group (4.48mm [ SD 1.94mm], p <0.001). In the CP group the medial gastrocnemius and soleus MTU and tendon were longer during early‐ and mid‐stance ( p <0.001). Ankle power during push‐off ( p =0.015) and positive work ( p <0.002) and net work ( p <0.001) were significantly lower in the CP group. Interpretation Eccentric action of the CP medial gastrocnemius muscle fascicles during mid‐stance walking is consistent with reduced volume and neuromuscular control of impaired muscle. Reduced ankle push‐off power and positive work in the children with CP may be attributed to reduced active medial gastrocnemius fascicle shortening. These findings suggest a reliance on passive force generation for forward propulsion during equinus gait.