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LEARNING OBJECTIVES
Upon completion of this chapter the student should be able to demonstrate the following competencies and proficiencies concerning plyometrics:
Have a basic understanding of neurophysiological principles related to plyometric exercise
Describe and understand the stretch-shortening cycle and how it relates to plyometric exercise
Understand when it is appropriate to initiate plyometrics into a rehabilitation program
Have an understanding of proper technique for upper body and lower body plyometric exercises
Be able to know the proper progression of plyometric exercise
Describe and implement upper-body and lower-body plyometric exercises
Be able to design a basic plyometric exercise program from rehabilitation to return to play
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As the athlete gets closer to returning to his or her desired sport, the clinician must be certain that the injured athlete has enough range of motion (ROM), endurance, proprioception, strength, and power to perform at preinjury levels. A way to increase balance, neuromuscular control, muscular strength, and power is through the incorporation of plyometric exercise into the rehabilitation program. During the stages of a rehabilitation program the athlete is performing exercises to increase range of motion, muscular endurance, proprioception, neuromuscular control, muscular strength (e.g., free weights, machine weights, isokinetic training), and muscular power to prepare the muscles for the stress of training, practice, and competition. These muscles also have to be able to produce explosive power. Incorporating plyometric training into a rehabilitation program is a way in which the clinician can increase explosive strength (power) in their patient.
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Plyometric training can be defined as the use of a countermovement (quick stretch) to produce a strong powerful concentric action through the use of the elastic properties of the tendons and muscles.1 Russian scientists developed plyometric exercise as a method for training speed strength (power).2 Plyometric training became synonymous with exercises aimed at combining strength with speed of movement to enhance muscular power.3–8 The body's proprioceptive awareness, neuromuscular function, functional patterns, and heightening of reflexes can be obtained by incorporating plyometric exercises into a patient's rehabilitation and training.9
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PLYOMETRIC FUNDAMENTALS
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The neurophysiological model and mechanical model are two proposed models that explain how plyometrics can increase the muscle's ability to generate explosive power.8 The neurophysiological model involves the use of kinetic (stored) energy the muscles produce when placed on a quick stretch. This quick stretch that the muscle undergoes is called the stretch reflex. The stretch reflex (Fig. 9-1) occurs by the stimulation of the muscle spindles that are located in parallel with the muscle fibers. Muscle spindles are mechanoreceptors that are stimulated when a muscle undergoes a quick stretch (rate and duration). During exercise when a muscle undergoes a quick stretch, the muscle spindles are activated, sending a reflexive message to the spinal cord via 1a fibers, which synapse with the alpha motor neuron, causing increased tension in the ...