In a previous blog on maximizing functional outcomes after total hip replacement, the important difference between joint motion and the joint position was described. Appreciating the difference with regard to implant safety and creating dynamic muscular stability was detailed with respect to using joint motion to turn on the hip muscles. The Applied Functional Science® principle of “Load To Explode” (LTE) serves as the basis of these training strategies. This blog will discuss how to tweak both beginning position and the range of motion to optimize the client’s “Load To Explode” abilities.
There are 3 phases of LTE that movement specialists should focus on. When the motion of the hip joint is assessed during the global analysis movements of 3DMAPS, there are 3 functional movements questions to be answered. Let’s use the left Opposite Side Lateral Chain to assess right hip adduction. The distance of the left foot lunge and arm reach would be modified for safety in the beginning. The first functional questions are: Does the right hip go through the motion of adduction? Next, if the motion is occurring: Can the client decelerate this motion? Finally, if the motion is decelerated: Can the client transform the deceleration of adduction into an acceleration of abduction?
BEGINNING POSITION
When the client demonstrates this success, then the tweaks of beginning position and range of motion shift from a safety emphasis to a functional emphasis. Beginning position refers to where in the available range of full hip motion does the loading movement begin. By tweaking the beginning position with the Safety Syntax of Applied Functional Science in the frontal plane, the challenge to the body can be very gradually increased. Very simply in this example, after starting with a wide base of support, the beginning distance between the feet is reduced. The result of this is that when the hip adduction motion occurs (as part of the global movement), the joint moves closer to an adducted position.
RANGE OF MOTION
The change of the beginning position goes hand-in-hand with tweaking the range of motion. The range of motion (ROM) of LTE is the amount (degrees) of joint motion that occurs before the Load is transformed into the Explode. In the early stage of recovery from a hip replacement, a relatively large amount of joint adduction motion may be required to have the proprioceptors create the desired muscle response from the hip abductors. From a functional standpoint, the quicker this response occurs, the more functional the client becomes. In walking the hip abductor muscles must decelerate this motion in less than 0.3 seconds. Therefore our training programs must progress towards authenticity by having strategies to decrease this LTE muscle response time.
One way (but not the only way) to combine these strategies is to take the successful LTE, keep the beginning position the same and start to reduce the ROM allowed. When the movement can be decelerated using less motion, then the speed of the movement can be increased. With success at LTE in a smaller ROM at a faster speed, the next step would be to change the beginning position so the motion being used moves towards an adducted position. With the new beginning position, the ROM and speed might revert back so that success is “guaranteed.” Then the ROM is reduced and the speed is increased again as long as the client demonstrates success. This process is then repeated until the motion of LTE is smaller (more functional) and the eventual joint position is adducted (once unsafe, but now authentic to function).
This example of tweaking beginning position and range of motion is a Principled Strategy. The Strategies emanate from the Principles or truths of human movement. Therefore it can be used for other hip motions, but also more globally for any joint motion that is part of a functional movement.