Running Mechanics, Part II
By Lauren Evans
Note: This is the second in a series of articles addressing proper form and running mechanics.
Proper running mechanics are vital to improving speed while simultaneously reducing effort. An efficient runner can cover the same amount of distance at the same speed as a less efficient runner with extra energy to spare. The good news here is that running economy is the most trainable part of running if you take to it quickly. Contrarily, other aspects such as VO2 Max and lactate threshold will take a considerable amount of training and time. The entire body should be considered when addressing running mechanics, including the head and shoulders, arms and hands, back and core, hips, legs and foot strike. By improving running mechanics, a runner can lower heart rate, reduce perceived effort, and of utmost importance to most runners--run faster!
The first step in addressing running mechanics is to be evaluated by a knowledgeable professional coach. A coach can evaluate running mechanics by observing you run and through video stride analysis. There are several individuals that offer the full deal of video-taping, gait analysis, and coaching to improve running economy. Once you have identified what needs to be improved, be sure to focus on one correction at a time to reduce confusion. Once one is corrected, move on to the next improvement in efficiency.
Lever Action & Shortening of the Joints
The lever action begins as the leg swings forward from follow through to initiate foot-strike. As the distance of the lever increases, a force must be greater to produce an equal velocity to that of a shorter lever. This principle is conserved in running as the runner move his leg forward quicker as the leg contracts and shortens. The limbs are shortened as we lift our knee, snap our ankle towards our buttocks, and swing our leg forward. All is driven by the rapid contraction of the hamstring. Think ‘rapid fire’ of the hamstring. As the ankle lifts vertically (not backwards), the support shifts to the opposite leg which is simultaneously falling. Try to relax the opposing hamstring.
The muscles remain relaxed as long as they can when the leg swings forward, then down and backward toward foot strike.
Foot-Strike
For every action, there is an equal and opposite reaction. Thus, the landing surface pushes back with a force equal to that of the foot-strike. The runner is pushed forward and upward, in the opposite direction of impact. (Think of having a mildly ‘S’-shaped body position.) To maximize forward movement, the foot must strike underneath the body to minimize breaking forces. Upward movement can be minimized while forward movement should be maximized. You’re not competing to be the best at bounding!
At foot-strike, several actions occur. By striking on the mid-foot and by minimizing heel-strike, you are creating a significant spring with the Achilles tendon. The knee flexes, the shin rotates inward, the ankle flexes, and the foot naturally pronates. All of this movement helps absorb the shock of the force that is 3-4 times your body weight. As the foot and leg change into a strong lever capable of sustaining this force, the body is preparing to thrust downward and backwards as the hip, knee, ankle, foot, and then big toe extend.
Follow-Through
Follow-through is initiated with the ‘air-time’ before the forward swing of the leg occurs as the hip flexor snaps the leg up and the pelvis rotates forward. In comes the thigh, which is assisted by flexion of the knee. The shortening of the lever allows for a quicker forward movement. Before the foot begins to descend towards the place of impact, more ‘air time’ occurs when the foot and leg align themselves again for foot strike. If the foot is moving backwards at a force equal to the forward movement of the trunk, efficiency will be maximized.
Several keys can help you improve the efficiency of the lever action, foot strike and follow-through. First, focus on rapid fire of your hamstring as you lift to commence the lever action. Then, think quick relaxation of the leg until it descends to impact. Finally, by improving the range of motion in your hips, knees, and ankles through stretching and strengthening exercises, you will improve your running efficiency.
See you on the roads!
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References
Cavanagh, P., & Kram, R. (1990). Stride Length in Distance Running: Velocity, body dimensions, and added mass effects. In P.R. Cavanagh (Ed.), Biomechanics of Distance Running (pp. 35-63). Champaign, IL: Human Kinetics.
Dallam, G., & Romanov, N. (2001) Developing Improved Running Mechanics. In USA Triathlon Newsletter (US) Pose Tech Corp (2008) www.posetech.com.
Edington, C., Frederick, E.C., & Cavanagh, P. (1990). Rearfoot Motion in Distance Running. In P.R. Cavanagh (Ed.), Biomechanics of Distance Running (135-161). Champaign, IL: Human Kinetics.
Hughes, D. (2008). The Art of Running: A Biomechanical Look at Efficiency. In texastrack.com. Murray, P. (2008).
Slocum, D.B., & James, S.L. (1968). Biomechanics of running. Journal of the American Medical Association, 205, 721-728.
Williams, K. (1990). Relationships Between Distance Running Biomechanics and Running Economy. In P.R. Cavanagh (Ed.). Biomechanics of Distance Running (271-299). Champaign, IL: Human Kinetics.