TITLE:
A non-Invasive Assessment of Ground Reaction Forces in the Human Leg in Response to Walking, Jogging, Running and Jumping
AUTHORS:
Jessica Pingel, Adrian Harrison
KEYWORDS:
Muscle, Activity, Acoustic Myography
JOURNAL NAME:
Open Journal of Orthopedics,
Vol.10 No.7,
July
29,
2020
ABSTRACT: Running is one of the most popular forms of exercise. Even though regular exercise is beneficial to human health, running is also often associated with an increased risk of injury. Lack of shock absorption in running shoes has often been stated as one of the main reasons for why running-related injuries have been on the increase. The aim of the present study was to assess the degree to which ground reaction forces (GRF) can be dissipated in the human leg in a barefoot subject, in connection with diverse physical activities. Acoustic myography (AMG), a non-invasive technique that records pressure waves from contracting muscles as well as the harmonic damping of ligaments, was applied to four anatomical sites on the subject’s leg, during barefoot walking, jogging, running and jumping. The data for walking on a hard surface show much lower ESTiTM parameters than those for the soft surface, and these lower values are observed mainly for sites 1 (toes; 65%) and 2 (ankle; 53%), respectively. AMG parameters for jogging reveal this gait to have very low ESTiTM parameters for site 1 and site 2 (ESTi 2 - 3), yet similar for both surfaces. The data for running on a hard and soft surface revealed much lower ESTiTM parameters (38%) than those for sites 3 (knee) and 4 (hip). The data from the big jump, reveal that on a hard surface, the lowest ESTiTM parameters were for sites 1 (toes; 46%) and 2 (ankle; 27%), compared to values on a soft surface. The speed with which GRFs were transmitted up the leg varied from site to site and also with the type of activity, ranging from undetectable to approx. 60 m/sec. The present study reveals that the ankle joint is exposed to the greatest forces during jumping and running. In addition, this study has confirmed that exercising on a hard surface does indeed increase the stress forces on the toes and ankles. It is interesting to note that the data reveal that toes and ankles absorb most of the GRF during running, while the knee and hip joint remain unaffected, although a more detailed study involving a larger number of subjects and shoe types is now needed.