Electromyographic Profile of the Shoulder During Stability Exercises With Kettlebells

CONTEXT: Shoulder rehabilitation can be a difficult task due to the dynamic nature of the joint complex. Various weight training implements, including kettlebells (KB), have been utilized for therapeutic exercise in the rehabilitation setting to improve shoulder girdle strength and motor control. The KBs are unique in that they provide an unstable load and have been purported to promote greater muscle activation versus standard dumbbells. Recent literature has examined the efficacy of KB exercises for global strengthening and aerobic capacity; however, electromyographic data for shoulder-specific activities are lacking.

OBJECTIVE: To examine muscle activation patterns about the rotator cuff and scapular musculature during 5 commonly-utilized KB exercises.

DESIGN: Cross-sectional analysis of a single group.

SETTING: Clinical biomechanics laboratory.

PARTICIPANTS: Ten participants performed all exercises in a randomized order.

MAIN OUTCOME MEASURES: Mean electromyographic values for each subject were compared between exercises for each target muscle.

RESULTS: Significant differences (P < .05) between exercises were observed for all target muscles except for the infraspinatus.

CONCLUSIONS: The data in this study indicates that certain KB exercises may elicit activation of the shoulder girdle at different capacities. Physical therapy practitioners, athletic trainers, and other clinical professionals who intend to optimize localized strengthening responses may elect to prescribe certain exercises over others due to the inherent difference in muscular utilization. Ultimately, this data may serve to guide or prioritize exercise selection to achieve higher levels of efficacy for shoulder strength and stability gains.