Accommodating power 16 dating 23
Free weights do have a shortcoming when it comes to performance enhancement for athletes.‘One is limited in the amount of weight they can lift by the weakest point of the range of movement (3).” After working through the “sticking point” (weakest point), as the joint angle nears end range of motion, the muscles have greater leverage to perform the movement.Each mechanism has its benefits and negative aspects. Weight Stack or Leverage Machines isolate/recruit prime movers while the athlete follows the restricted range of motion designed into the machine.Typically force is generated in only one plane of motion, with minimal recruitment in other planes.The major hip extensors are the gluteus maximus, adductor magnus, and hamstring musculature (biceps femoris, semimemranosis, semitendinosis).In 2002 Caterisano et al conducted a study on thigh muscle contribution during the partial, parallel, and full squat.With this in mind, the 315lbs may not be enough to overload the working muscles at the end range of motion, creating less transfer of training to on field results.Another issue lies in the fact that, when training for power, the athlete will accelerate with load great velocity.
Those being free weights, selectorized or plate loaded machines, and band (elastic tension) training.
As the athlete nears the end range of motion, the muscle tension will be minimal in that momentum has taken over for the last 10-20 degrees of extension, creating a deactivation like symptom in the musculature, when the greatest muscle activation is necessary.
So why not perform quarter squat as they follow the specificity guidelines with regard to lower extremity joint angles?
The body has no input on stabilizing the spine, pelvis, or knees during movement as the seated/prone position against a stable platform does this for you, thus “there is a decrease in neural activation of the stabilizer musculature.
(1)” In other words, the body does not need to maximally recruit any stabilizer muscles of the working limb because no control of the weight is necessary in that the welded lever arm only has one set range of motion.