The influence of ‘American’ and ‘Russian’ kettlebell swings on glenohumeral positioning

Abstract

BACKGROUND: Shoulders are one of the most common sites for pain and/or dysfunction among athletes especially with overhead exercise. With increasing interest in bootcamp and CrossFit® style exercise has come an increase in the numbers of people participating in this style of exercise. One popular exercise is the kettlebell swing. The kettlebell swing can be done either overhead also called the American swing or to shoulder height called the Russian swing. To date, no research has been undertaken on the change in the positioning of the humeral head on the glenoid fossa when comparing overhead to shoulder height kettlebell swings.

AIM: To explore the relationship between overhead (American) and shoulder height (Russian) kettlebell swings and changes in humeral head positioning.

METHODS: Two separate studies were undertaken. Firstly, a group study of 8 participants and, secondly three case studies were undertaken. In both studies, participants had both shoulders scanned using ultrasound imaging both before and after a fatiguing exercise protocol. Measures taken by ultrasound were; subacromial distance, coracoacromial ligament length, coracohumeral distance and coracoacromial ligament to humeral head distance.

The exercise protocol consisted of 3 sets of 20 Russian kettlebell swings or 3 sets of 15 American kettlebell swings. Participants were assigned a kettlebell weight based on the finding of a mid-thigh pull assessment of full body strength. Participants then returned after one week to be crossed over into the other swing style group. In the case studies the sets of swings were increased from 3 to 5 to increase the level of fatigue.

RESULTS: One participant in the group study became injured between the data collection sessions, unrelated to the study, and was unable to complete the fatiguing exercise protocol. Both the data from the group study and the case studies showed no change pre- to postexercise, in any of the ultrasound measures; subacromial distance, coracoacromial ligament length, coracohumeral distance and coracoacromial ligament to humeral head distance.

CONCLUSION: Neither study showed changes in glenohumeral positioning (in the measured dimensions) between pre and post-exercise. Measurement of the coracoacromial ligament to the humeral head may be a useful measure of glenohumeral positioning, due to its clarity and ease of measurement using ultrasound and it is recommended that further investigation into this measure be undertaken. The mid-thigh pull was a useful tool in measuring full body strength and may be useful in prescribing kettlebell weights in future studies.