Jason Nelson

Document Type

Thesis - University Access Only

Award Date


Degree Name

Master of Science (MS)

Department / School

Health, Physical Education, and Recreation


There were two purposes of this research study. The first purpose of this study was to determine the strength difference between an isokinetic pretest and post-test, after six weeks, for the internal and external rotators of the dominant throwing arm. The second purpose was to determine which form of training was more beneficial, Theraband exercise bands (medium and heavy resistance) or free weights (5 and 8 lbs). The subjects (n = 21) involved were from regional National Association of Intercollegiate Athletics (NAIA) and National Collegiate Athletic Association, Division II (NCAA II) baseball programs. The NAIA subjects ranged in age from 19 to 23 years; there were 2 seniors, 5 juniors, 2 sophomores, and 2 freshmen. Their mean weight was 89.45 kg, and their mean height was 185.93 cm. The NCAA II subjects ranged in age from 18 to 22 year; there were 3 seniors, 1 junior, 1 sophomore, and 5 freshmen. Their mean weight was 80.49 kg, and their mean height was 1"84.6 cm. The players went through an isokinetic pretest for the internal and external rotators at speeds of 180 deg•sec·1 and 300 deg•sec·1. Both Cybex and Biodex dynamometers were used. After a six-week strength training program of the internal and external rotators, which was incorporated into their off-season workouts, the players were post-tested to compare the results. Data received from the isokinetic dynamometer was recorded in preparation for entry into Statistical Package for the Social Sciences or SPSS. Data were analyzed with a General Linear Model of a Repeated Measures Analysis of Variance (RMANOV A) design with time (pre vs. post) and treatment (Thera-bands vs. weights) as factors. Variables measured include peak torque, total work, and average power. When a significant F-ratio was obtained from the treatment (Thera-bands vs. weights), a Student -Newman - Keuhls test was used to locate significant differences. Data are reported as mean± SD. Six-week of strength training resulted in a significant difference between peak torque, average power, and total work at both 180 deg•sec·1 and 300 deg•sec·1 for both internal and external rotation. However, there was no significant difference between Thera-band exercise bands and free weights. The findings indicated that both forms of strength training are beneficial to the internal and external rotators of the dominant throwing arm. The decision on what type of strength training to use will be left up to the coaches, clinicians, and players. Overall, the building and rebuilding of the internal and external rotator muscles is necessary to maintain stamina, strength, and injury prevention throughout a season of baseball.

Library of Congress Subject Headings

Baseball -- Training Weight training -- Physiological aspects Pitching (Baseball) -- Physiological aspects Shoulder joint -- Rotator cuff



Number of Pages



South Dakota State University