The effectiveness of low volume versus high volume upper extremity plyometric exercises on the kinematics and kinetics of the shoulder
Authors: Arnsdorff, Kimberly1; Anderson, Sonya1; Burton, Kristin1; Voight, Daniel1; Riemann, Bryan2, Davies, George1,
Institutions (All): 1. Physical Therapy, Armstrong Atlantic State University, Savannah, GA, United States. 2. Health Sciences, Biodynamics and Human Performance Center, Armstrong Atlantic State University, Savannah, GA, United States.
Arnsdorff, K, Anderson, S, Burton, K, Voight, D, Riemann, BL, Davies, GJ. The effectiveness of low volume versus high volume upper extremity plyometric exercises on the kinematics and kinetics of the shoulder. (Completed-September,2012) (Research poster accepted, APTA-CSM, San Diego, CA., 2013) (Nominated for one of the top Orthopaedic Section poster abstracts; Nominated for Grand Prize for best research poster). JOSPT. 43(1):A88 (Abst.-OPO2220), 2013
Purpose/Hypothesis: Many studies have demonstrated lower extremity (LE) plyometric (PLYO) exercises to be an effective means of increasing power. PLYO exercise provides both the intensity and specificity of training an athlete often requires to minimize risk of injury when returning the athlete to their sport. In turn, physical therapists are now beginning to implement upper extremity (UE) PLYO into the terminal stages of rehabilitation. However, discrepancies exist between studies concerning the optimal volume of training parameters for UE PLYO exercises. Hence, the purpose of this study was to determine the effects of a high volume versus a low volume UE PLYO training program for the following outcomes: isokinetic strength, power, and throwing velocity. We hypothesized the high volume PLYO training group would exhibit significant improvements in isokinetic strength, power, and throwing velocity in comparison to the low volume PLYO training group.
Number of Subjects: 54
Materials/Methods: Healthy, physically active participants were randomly assigned to either the high volume (n=27) or low volume (n=27) PLYO training groups. Isokinetic peak torque, time to peak torque, single arm seated shot put throw, the Closed Kinetic Chain Upper Extremity Stability Test (CKCUEST), and throwing velocity were assessed pre- and post-training. Training consisted of 6 UE PLYO exercises which were performed 2x/week for 8 weeks. The numbers of repetitions chosen to administer to both training groups were based on previous studies, in which discrepancies existed concerning optimal training parameters. The number of repetitions was increased in a periodized fashion over the 8 week training program. The high volume group consistently performed 50% more repetitions per exercise session compared to the low volume group, throughout the training progression.
Results: There were no significant differences between the groups for any of the outcome measures. Significant improvements between the pre and post tests were revealed for the seated shot put throw (p < 0.001, 95% CIdiff:18.7—36.4cm), CKCUEST (p < 0.001, 95% CIdiff:3.7—5.0 touches), isokinetic internal rotation (IR) peak torque at 300°/s (p = .039, 95% CIdiff:.1—2.7Nm/kg), isokinetic IR time to peak torque at 300°/s (p = .024, 95% CIdiff:.003—.04s), and maximum throwing velocity (p = .002, 95% CIdiff:.67—2.6mph).
Conclusions : Similar gains in power, torque production, and throwing velocity were achieved between the high and low volume UE PLYO training protocols used. Therefore, peak performance and sport-specific rehabilitation of the UE can be achieved by stressing the implicated soft tissues with less volume and less time.
Clinical Relevance: Within the limitations of this study and the specific parameters used in the training, there were no differences in the low versus high volume training. Therefore, for clinical efficacy and to minimize stress during the training, a low volume PLYO program can be used to create a training effect.
KEYWORDS: ballistic, dynamic strength, velocity.
International Meeting Presentation:
Davies, GJ, Arnsdorff, K, Anderson, S, Burton, K, Voight, D, Riemann, B. Comparison of medium volume versus high volume upper extremity plyometric exercises on shoulder performance. Research Platform Presentation. 4th International Congress of Shoulder and Elbow Therapists. Nogoya, Japan, April 11-13, 2013