What a productive study session with my friend and colleague Dave Freiday, RTSm, MATcs. We took it upon ourselves to try and digest the gait cycle. Yikes! For those have spent time working on this, you will know it is a bit a daunting task. The foot is comprised of 28 bones, 55 separate articulations and thousands of tactile sensory endings. We chose to study 4 of the more predominate axis that are considered during gait. We recognize that ever single joint and bone is vital for us to understand but these four joints will give some direction to what is happening at the other joints. The joints are the talo-crural, sub-talar, mid tarsal oblique joint and mid tarsal longitudinal axis.
Our goal was to determine what actions are occurring at these four joints and get a during the 5 different steps of gait, heel strike, full foot loading, mid stance, heel lift and toe off. The foot acts a mobile adaptor, a shock absorber and a rigid lever to push off of. Ideal function of the foot during gait requires pronation and supination at each joint and a transfer between each joint. Pronation seems to be associated with shock absorption and supination with propulsion.
Dave and I started to recognize some themes associated with the joint motions as gait occurs. The last bit of our study session was us with a model foot talking through each component of the gait cycle and becoming comfortable with the different language used. The language used with the foot is hard to articulate. “Pronation” for example sometime is called valgus, eversion, abduction and dorsi-flexion. Although all of these are not entirely accurate while describe the joint motion, we felt it was important to become comfortable with them all. We recognized if we found the point that was touching the ground that we could determine what the other joints were doing. Near the end of our session, it was time to flex our chops. We each took a few moments and walked the other through the 5 processes of gait and what motions were happening at each axis. Our mechanical though processes helped us digest and regurgitate the information easier than we thought. Thank you RTS! Its was one of more challenging study sessions we have done.
I am lucky to have such great friends and colleagues to study with.
Brandon Green- RTSm, MATcs, MAT Jumpstart
Strata Biomechanics Blog 