Influence of a warm-up protocol involving the kinetic chain in overhead athletes' range of motion and isometric strength
Courtney E Weber
Overhead throwing activities require full range of motion (ROM) at the hips and shoulders to generate optimal rotation and force for the overhead movement. The generation of this force takes place in a proximal to distal sequence in the human body. The lumbo-pelvic hip complex (LPHC) initiates the generation of force for the arm and allows for full range of motion at the torso. Previous research has found baseball players to be at risk for a decrease in hip ROM following a full season of play. Engaging in a full body warm up could allow for an increased ROM and isometric strength of the joints typically associated with the mechanics of throwing. Purpose: To investigate the effects of a full body warm-up on shoulder and hip range of motion and isokinetic strength of an overhead athlete. Providing more information on how to improve the isokinetic strength and range of motion for athletes will assist the sports medicine world in preventing injuries and help keep athletes healthy and able to compete at a competitive level. Methods: To assess shoulder rotational range of motion, participants will be placed in the supine position with their shoulder and elbow at a 90-degree angle. A rolled towel will be used to support the arm at the elbow. The test administrator will actively watch the participant to ensure full range of motion is being tested. The digital inclinometer will be placed on the back and front side of the forearm in line with the ulnar bone to measure the mobility of the shoulder. The dynamometer will be placed close to the palm and back side of the wrist to measure the strength of the shoulder joint. To assess rotational range of motion and isokinetic strength of the hips, the participant will be asked to sit up straight with their feet hanging off the side of the table with their knees flexed to 90 degrees for measurements and a towel will be placed under the knee for comfort. To measure hip mobility the digital inclinometer will be placed along the fibula. The dynamometer will be placed close to the inside and outside ankle to measure the strength of the hip joint. To obtain the isokinetic strength of the athlete’s musculature the test administrator will ask the participant to push against the resistance of the dynamometer for three seconds. This will be repeated for two trials in the pre warmup measurement and the post warmup measurements. The participants will be randomly assigned to three different groups. Participants in the control group will remain seated for ten minutes between measurements. The participants engaging in the kinetic chain warmup will be given exercises that engage the musculature of the LPHC to complete in the 10-minute time frame between measurements. The participants engaging in the upper extremity warmup will be given static stretching exercises that engage the musculature of the upper body to complete in the 10-minute time frame between measurements. Both trials will be averaged from each protocol and then used to compare the data between the pre-warmup and post-warmup measurements. Expected Results and Conclusion: The participants will be randomly assigned to three groups. The control protocol will have no significant difference between the pre-warmup and post-warmup ROM and isokinetic strength. The upper extremity warmup protocol will only experience an increase in the isokinetic strength and ROM at the shoulder joint. Finally, the kinetic chain warmup protocol will result in an increase in the ROM and isokinetic strength at the hip and shoulder joints.
Courtney Weber is a junior exercise science major who plans to be a Physician’s Assistant. She is a member of the Lander University Honors College and the women’s soccer team. She is currently working on a research project with Dr. Barfield in the PEES department. Her interests include playing ultimate frisbee and travelling.