ESTIMATING LUMBAR SPINAL LOADS DURING A GOLF SWING USING AN EMG-ASSISTED OPTIMIZATION MODEL APPROACH

Abstract

This study estimated the lumbar spinal loads at L4-L5 level during a golf swing using musculoskeletal modeling techniques. Data were collected from five college golfers. Four S-VHS camcorders and two force plates were used to obtain 3-D kinetics and kinematics of the golfer’s motion and 10 surface electrodes were used to record the activity of selected lower trunk muscles. The EMG-assisted optimization model was used to estimate lower trunk muscle forces. The results demonstrate that the L4-L5 motion segment is subjected to considerable compressive (4,300 N), antero-posterior (A/P) shear (882 N), and medio-lateral (M/L) shear loads (-252 N) during a golf swing. The repetitive changing direction of the shear load during a golf swing may increase the chance of fatigue fracture of pars interarticularis. The results also suggest that a golf swing with shortened backswing and follow-through may reduce the risk of back injury.