The effect of load on biomechanics of the back and upper limb in a bench to shoulder lift during the WorkHab Functional Capacity Evaluation.

BACKGROUND

Limited literature exists investigating biomechanical changes during a Functional Capacity Evaluation (FCE).

OBJECTIVE

To determine change in joint angle measurement between minimum load to safe maximum load in the bench to shoulder lift of the WorkHab FCE.

METHODS

Dartfish ProSuite was used to analyse bench to shoulder lift video from 28 subjects. Measurements of joint angle at lumbar spine, thoracic spine, elbow and shoulder at four points in the ascending and descending lift phases (0/3, 1/3, 2/3, 3/3) in the minimum load and safe maximum lift were collected. Paired t-tests were used to analyse differences in joint angles between lifts.

RESULTS

Significant differences in joint angles were identified in the thoracic spine, elbow and shoulder at maximal weight. Increased extension occurred: Thoracic spine at 3/3 ascending [2.922, 95% CI 0.8, 3.8, p = 0.004]. Increased flexion occurred: elbow ascending [1/3:6.405, 95% CI -11.8, 1.8, p = 0.008],[3/3:15.575, 95% CI 4.2, 27.0, p = 0.009]; elbow descending [0/3:18.446, 95% CI 9.5, 27.4, p = 0.000]; shoulder ascending [3/3:16.785, 95% CI 11.8, 21.8, p < 0.001]; shoulder descending [0/3:16.647, 95% CI 10.6, 22.7, p < 0.001].

CONCLUSIONS

This study provides insight into the biomechanical changes during a bench to shoulder lift and support observations and clinical reasoning used in determining the safe maximal lift.