Academic Seminars

Quadriceps Strength Asymmetry in Transtibial Amputees
August 19, 2019

Doctoral Candidate Amy Sibley to present her thesis
Friday, August 23, 2019
3 PM – 4 PM

IREB 270

Ms. Sibley holds an MSc in Biomedical Engineering and is completing her PhD at the University of Roehampton under the supervision of Drs Neale Tillin and Siobhán Strike. She will be defending her thesis in October 2019. She currently lectures in Sport Rehabilitation at London South Bank University.

Analyses of inter-limb asymmetries compare the performance of one limb in respect to another. Strength asymmetries are typically measured by quantifying the inter-limb difference in maximum strength (the maximum force a muscle can produce). In individuals with unilateral trans-tibial amputations (characterised by the loss of the ankle joint and the surrounding musculature on one limb) there are decreases in quadriceps maximal strength on the amputated, and to a lesser extent, the intact limb, when compared to a non-injured population. This results in substantial inter-limb maximum strength asymmetries of ~42%. However, little is known about the extent of asymmetry in explosive strength (the muscle’s capacity to rapidly exert force), which may arguably be more functionally relevant to human movement. As transtibial amputees are increasingly encouraged to exercise for health and quality of life, understanding how strength asymmetries result in altered movement patterns is vital to inform healthy movement prescription. Additionally, the effects of long-term disuse on musculature are unknown. By investigating the neuromuscular characteristics of transtibial amputees, who have shown asymmetrical knee extensor loading during gait, we can determine the magnitude of strength loss, and start to unpack the determinants underpinning these changes.

This presentation will discuss strength asymmetries at the quadriceps in transtibial amputees and their influence on functional gait capacity. Furthermore, the results of a novel study that has manipulated asymmetry to investigate the neuromuscular mechanisms underpinning long-term disuse will be presented.