Source of Power: Rotation [3] – Coupling

The entire point of rotation is to couple distinct body parts into a single movement translating energy from one plane to another plane.


1. Swimming Freestyle and Backstroke – thSuper_cavitating propellore rotation involved in performing these strokes occurs along the longitudinal axis, the counter rotation of the hips against the pull of the arms turns the torso into a propellor blade resulting in forward propulsion. The legs are used to provide propulsion as well, and they rotate from the hips resulting in their surface areas (i.e. thighs and shins) equally acting as propellors providing propulsion. This coupling of legs to hips, and hips to torso to arms results in the longest possible lever allowing an Olympic level swimmer to generate maximum power.  It is this coupling what most (if not all) age group and masters swimmers and triathletes are missing from their technique.

A model for arm-leg and opposite hip movement which athletes and coaches may want to emulate for 25_P_51XR_Mustang_N6WJ_Precious_Metal_Reno_Air_Race_2014_photo_D_Ramey_Loganthe long axis strokes is that of the contra-rotating propellor.  This design eliminates yawing (left or right) caused by the rotation of the primary propellor, by adding a second propellor which rotates in the opposite direction.  In swimming, the opposite hip to the pull and kick may function similar to the opposing propellor by offseting the assymetry created by pulling on one side at a time, single sided breathing, differences in pull strength (left vs right),  as well as variations in kick size and depth, and strength imbalances between the athlete’s two legs, and in their core. Contra-rotating_propellers The coordination of coupling, breathing, body position and synchronicity of all these movements becomes more recognizable by replacing the image of a swimmers pull, with the unilateral stroke of a canoe paddler.  Both athletes seek to maximize propulsion by minimizing side vectors, and driving all power into the vector pointing directly forward, but both apply the force offset from the center line requiring counterbalancing actions.  How the athlete coordinates their movements to balance propulsion and drag and offset vectors is critical to directing all effort forward and not losing it in sideways movement.



2. Swimming Breaststroke and Butterfly – the rotation involved occurs across the short axis of the body (transverse plane) as the stroke is designed to either worm the body forward (fly), or coil and explode (breaststroke). Coupling of the upper and lower bodies is perhaps even more important than that in the long axis strokes because the frontal drag created during short axis rotation may be significantly greater than during long axis rotation.  In fact, the image of the supercavitating propellor above, with its angled blades Sine_and_Cosine_svgresembles in many ways the angle of the swimmers torso during the breathing phase of both short axis strokes.  The bubbles created by the propellor traces a sine/cosine wave which again resembles the path which the swimmer takes through the water.  The propellor may be again a useful concept for athletes to apply when swimming.  The symmetry between the athlete and the propellor reveals that coupling is a 3-dimensional process, and the skills developed in the long axis strokes should be transferable and beneficial to the short axis competitor (and vice versa).

mphelps load fly stroke

SwimSwam Article: Why Coupling Motions Boost Distance per Stroke (DPS)


3. Running – the lumbar spine / pelvis junction is similar to the universal joint of a mechanics wrench (see image below).  Average runners either rotate along the short axis (i.e. lumbar flexion/extension) resulting in a gazelle stride, or they rotate longitudinally (i.e. hip and spine rotation on a fixed pelvis) resulting in a gliders stride.  Elite runners do both: they rotate across both axes simultaneously universal wrenchallowing them the power of the gazelle stride toe-off and resulting stride length; however, instead of lopping along they translate the vertical energy of the gazelle stride into a glider stride rotating horizontally during the flight phase of running lengthening their stride even more, while minimizing vertical travel.


4. Cycling – the same concepts of rotation apply to cycling.  Average cyclists rotate through the hips using a stabilized upper body against which to power through their stroke with legs acting as pistons.  Elite cyclists do not stabilize anywhere, they have relaxed grips, they have relaxed shoulders, yet they rotate through every spinal joint and through their lumbar spine/pelvic junction.  Their flexibility allows for the long axis rotation to be translated to short axis rotation and power resulting in the ability to generate massive watts for hours, where an average cyclists may only sustain a similar power output for minutes.


Elite athletes, consistent peak performers are not superhuman beings which can muster a level of energy or suffer pain beyond ‘average’ humans.  Instead, elite athletes simply have greater flexibility throughout body and mind allowing them to generate power across wider range of muscles, across a wider range of motion, and translate that power efficiently into propulsion.


Athletes who only train hard are not only wasting their time, but are risking physical injury, mental burn-out and emotional max-out believing that if they can only figure out how to push harder, or push longer then they will rise to a new level.  Worse, coaches who train age group athletes with this mentality are themselves responsible for the drop out rate, burn out and injuries suffered by both age group and masters athletes.

There is an alternative way to train…  train smart, train with the long term in mind, with health, with enjoyment, fun, and technique as the primary goals.  Let the outcomes, the results, and the podium take care of themselves (they will when an athlete is coached and trained properly).