Document Type



CrossFit is a fitness routine that utilizes the American kettlebell swing in their workouts. The Russian swing has been the traditional swing movement performed with the kettlebell swung to chest height, but with the American swing the kettlebell is propelled to an overhead position, which may increase the risk for a lumbar spine injury. However, research has yet to evaluate the American kettlebell swing mechanics and its influence on spinal injuries. Therefore, the purpose of this study was to examine the kinematics of the lumbar spine from maximum hip extension to the overhead position of the American kettlebell swing with two different loads (16kg and 24kg), five subjects and three focus positions the hike, Russian height and overhead. Fourteen 3D joint reflective markers were placed on the right side of the body. A two-dimensional kinematic analysis of the lumbar spine, shoulder and elbow were conducted with DartFish Pro Suite v 6.0 on repetitions 2-4 with the results compared to a literature review of safe lumbar spine positions. Results determined lumbar extension and shoulder angles were highest during the OH position. Lumbar angles were fairly consistent between weights with the greatest mean amount of hyperextension approximately 25° past neutral. Shoulder angles were higher in all positions with the 16kg kettlebell in comparison to the 24kg kettlebell. Elbow angles were highest during the H position. Velocities ranged from approximately 550 deg/sec to -550 deg/sec with most results between 150 deg/sec to -150 deg/sec. Further research is needed to determine the lumbar spine injury risk.


Athletic Training

Thesis Comittee

Pamela J. Russell (Thesis Director)

Robert Haslam

Robert Colandreo

Copyright and Permissions

Original document was submitted as an Honors Program requirement. Copyright is held by the author.