title: Intensity rankings of plyometric exercises using joint power absorption.
abstract: BACKGROUND
  Athletic trainers and physical therapists often progress patients through rehabilitation by selecting plyometric exercises of increasing intensity in preparation for return to sport. The purpose of this study was to quantify the intensity of seven plyometric movements commonly used in lower-extremity rehabilitation by joint-specific peak power absorption and the sum of the peak power.
  
  
  METHODS
  Ten collegiate athletes performed submaximal plyometric exercises in a single test session: vertical jump, forward jump, backward jump, box drop, box jump up, tuck jump, and depth jump. Three-dimensional kinematics and force platform data were collected to generate joint kinetics. Peak power absorption normalized to body mass was calculated at the ankle, knee, and hip, and averaged across repetitions. Joint peak power data were pooled across athletes and summed to obtain the sum of peak power. Movements were ranked from 1 (low) to 7 (high) based on the sum of peak power and joint peak power (ankle, knee, hip).
  
  
  RESULTS
  The sum of peak power did not correspond with standard low, medium, and high subjective intensity ratings or joint peak power in all joints. Mixed model analyses revealed significant variance between the sum of peak power and joint peak power ranks in the forward jump, backward jump, box drop, and depth jump (P<0.05), but not in the vertical jump, box jump up, and tuck jump.
  
  
  CONCLUSIONS
  Results provide intensity rankings that can be used directly by athletic trainers and physical therapists in developing protocols for rehabilitation specific to the injured joint.
authors.affiliation: Department of Mechanical Engineering, University of Denver, Denver, CO, USA.
authors.forename: Kathryn G
authors.initials: KG
authors.lastname: Van Lieshout
authors.affiliation: Sports Physical Therapy, University of Colorado Hospital, Denver, CO, USA.
authors.forename: Joy G
authors.initials: JG
authors.lastname: Anderson
authors.affiliation: Department of Mechanical Engineering, University of Denver, Denver, CO, USA.
authors.forename: Kevin B
authors.initials: KB
authors.lastname: Shelburne
authors.affiliation: Department of Mechanical Engineering, University of Denver, Denver, CO, USA. Electronic address: bradley.davidson@du.edu.
authors.forename: Bradley S
authors.initials: BS
authors.lastname: Davidson
mesh_terms: D000328:Adult; D000465:Algorithms; D000843:Ankle Joint / Q000502:physiology*; D056352:Athletes; D001696:Biomechanical Phenomena; D015331:Cohort Studies; D015444:Exercise; D005260:Female; D006801:Humans; D007596:Joints / Q000502:physiology*; D007719:Knee Joint / Q000502:physiology*; D035002:Lower Extremity; D008297:Male; D009068:Movement / Q000502:physiology*; D059385:Plyometric Exercise; D012046:Rehabilitation / Q000379:methods*; D013177:Sports; D055815:Young Adult
keywords: Jumping; Knee; Landing; Physical therapy; Rehabilitation