Estimating Lumbar Spinal Loads During a Golf Swing Using an EMG -Assisted Optimization Model Approach

The purpose of this study was to estimate the lumbar spinal loads at L4--L5 level during a golf swing using musculoskeletal modeling techniques. This study also examined the activation patterns of individual lower trunk muscles during a golf swing using surface electromyographic (EMG) techniques. Data were collected from five college golfers (average handicap = 0.8, SD = 1.1). Four S-VHS camcorders and two force plates were used to obtain the 3-D kinetics and kinematics of the lower trunk. The EMG-assisted and EMG-assisted optimization models were used to estimate lower trunk muscle forces. The major findings of this study were that (a) the compressive load increased steadily after the end of backswing (EB) and reached its maximum of 605% body weight during the acceleration phase, and the mean peak compressive load of 4,300 N was recorded near the instant of the ball/driver impact; (b) the mean antero-posterior (A/P) shear load increased gradually after EB and reached its peak (882 N) at around the middle of follow-through (MF); (c) the mean medio-lateral (M/L) shear load was mostly acting toward the right during the take away phase and the direction was reversed sometime during the early downswing and reached its peak (-252 N) around MF; and (d) the timing and pattern of the lumbar spinal forces obtained in this study are very different from the corresponding forces reported in the literature. The results demonstrate that the L4--L5 motion segment is subjected to considerable compressive, A/P shear, and M/L shear loads during a golf swing. The repetitive changing direction of the shear load during a golf swing may cause the fatigue fracture of pars interarticularis. The results also suggest that a golf swing with reduced backswing and follow-through may alleviate the risk of back injury. This alternative swing pattern limits the range of motion of the trunk and, consequently, reduces passive tensions of the lower trunk muscles and lumbar spinal loads.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Kinesiology and Community Health

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Lim, Young-Tae

Contributors dc:contributor

• John W. Chow

• Applied Mechanics

Language dc:language

eng

Identifier

(MiAaPQ)AAI9955642

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/86424