Medial gastrocnemius and soleus muscle‐tendon unit, fascicle, and tendon interaction during walking in children with cerebral palsy

Abstract

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 10 y 6 mo, standard deviation [SD] 2 y 11 mo; GMFCS level I = 8, II = 6), and 10 typically developing (6 males, 4 females; mean age 10 y, SD 2 y 1 mo) undertook full body 3 D 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 MTUs 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 (1.16 mm [SD 1.47 mm]) compared to the typically developing group (4.48 mm [SD 1.94 mm], 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. (PsycINFO Database Record (c) 2017 APA, all rights reserved)Queensland Cerebral Palsy and Rehabilitation Research Centre, Faculty of Medicine, University of Queensland, Brisbane, QLD, Australia. Other Publishers: Mac Keith Press. Release Date: 20170406. Correction Date: 20170724. Publication Type: Journal (0100), Peer Reviewed Journal (0110). Format Covered: Electronic. Document Type: Journal Article. Language: EnglishGrant Information: Barber, Lee. Major Descriptor: Cerebral Palsy; Muscles; Walking. Classification: Neurological Disorders & Brain Damage (3297). Population: Human (10); Male (30); Female (40). Location: Australia. Age Group: Childhood (birth-12 yrs) (100); School Age (6-12 yrs) (180). Methodology: Empirical Study; Quantitative Study. References Available: Y. Page Count: 9. Issue Publication Date: Aug, 2017. Publication History: First Posted Date: Apr 1, 2017; Accepted Date: Feb 7, 2017. Copyright Statement: Mac Keith Press. 2017.Sponsor: Department of Health, Health Service and Clinical Innovation Division, Preventive Health Unit, Australia. Other Details: Health and Medical Research Physiotherapy Research Fellowship. Recipients: No recipient indicated <br />Sponsor: University of Queensland, Australia. Other Details: Early Career Researcher Grant. Recipients: No recipient indicated <br />Sponsor: National Health and Medical Research Council. Other Details: Early Career Fellowship, Career Development Fellowship. Recipients: Barber, Lee; Boyd, Roslyn <br />Sponsor: Merchant Charitable Foundation. Recipients: No recipient indicated <br />Sponsor: Children’s Hospital Foundation. Grant: 10415. Recipients: No recipient indicated <br />