Shoulder injuries are common not only in the sporting arena but in the health and fitness environment as well. Recent research by Kolber et al (2013) found a significant association between doing exercise in the ‘high-5’ position and anterior shoulder instability leading to a range of common shoulder injuries. The high-5 position (or ‘at risk position’ as it is otherwise known) is when there is 90° or more of shoulder abduction and 90° or more of shoulder external rotation as depicted in figure 1.
Fig 1. The High-5 position
The shoulder joint is a ball and socket synovial joint where the head of the humerus (ball) meets the glenoid fossa (socket). This creates a mobile joint that can be stabilised by way of ligament and muscular tension. The joint is surrounded by tissue known as the joint capsule which can also contribute to its stability. As a result of the balance between mobility and stability, the shoulder joint is often susceptible to a range of injuries especially when the humeral head is placed in certain positions. Stability is increased if the head of the humerus is compressed into the glenoid fossa thereby reducing the potential for excessive translation (movement of the humerus away from the fossa). Strengthening the rotator cuff and other scapular musculature (trapezius, rhomboids etc) can help provide the compressive force required to stabilise this particular joint.
Exercises performed in the high-5 position have been shown to increase the risk of humeral translation and thereby the risk of injuries such as joint capsule and ligament damage (Tzannes 2002). In the health and fitness industry, exercises that are often responsible for this include behind-the-neck pull downs, behind-the-neck shoulder press, bench press (to chest) and dips. Performing these exercises with good technique however, can reduce humeral translation and in turn reduce the risk of associated injury.
Lat pull down
These should be performed to the front of the chest instead of behind the neck (Kolber et al 2013) to avoid shoulder instability. The bar should be pulled down to chin level only to avoid excessive strain on rotator cuff muscles (going below chin level would require a degree of internal rotation of the humerus).
The starting point should be with the upper arm roughly parallel to the floor and the hands about 20 degrees angle forward (colado et al 2009). Perform the exercise in a standing position to activate core musculature (Harman 1994) and bend the knees slightly to reduce pressure on the intervertebral discs (Wilke et al 2001).
The bar or dumbbells should be lowered until the upper arm is roughly parallel to the floor. This would mean that when performing a bench press with a bar, the bar should stop about 3-4cms above the chest (Colado, et al 2009).
It is impossible to keep the shoulder joint in a stable position when performing dips using a bench or chair. It is possible however to perform dips using a specific dip machine but care must be taken not to lean too far forward and place the shoulder in an unstable position.
When the above exercises (and others) are performed with the hands in peripheral vision (i.e. the hands can be seen at all times without having to move the head) then it is likely that the shoulder joint is in a stable position and humeral translation is kept to a minimum. This in turn would reduce the risk of shoulder injury and also help strengthen the shoulder joint for those undergoing shoulder rehabilitation. Gym users across the country are often overloaded with instructions on technique therefore in order to minimise the amount of instruction that is needed a simple cue for clients of ‘keep hands in peripheral vision’ for all exercises could be used. Using a simple cue such as this could help to improve technique and ultimately reduce the number of injuries that are becoming more common in the health and fitness industry.
Colado, J.C., & Garcia-Masso, X. (2009) Technique and safety aspects of resistance exercises: a systematic review of the literature. The Physician and Sports Medicine. 2(37): 104-111
Harman, E. (1994) Weight training safety – a biomechanical perspective. Strength and Conditioning Journal. 16(5): 55-60
Kolber, M.J., Corrao, M., & Hanney, W.J. (2013) Characteristics of anterior shoulder instability and hyperlaxity in the weight-training population. Journal of Strength and Conditioning Research. 27(5):1333–9
Tzannes, A.(2002) Clinical examinations of the unstable shoulder. Sports Medicine. 32: 447-7
Wilke, H., Neef, P., Hinz, B., Seidel, H., & Claes, L. (2001) Clinical Biomechanics. Intradiscal pressure together with anthropometric data--a data set for the validation of models. 16(Suppl 1):S111-26
About the Author
Morc Coulson is a senior lecturer in Health-Related Exercise in the Department of Sport & Exercise Sciences at the University of Sunderland. He has published many books in the area of Health & Fitness which have become key texts for many institutions and training providers around the UK and overseas. The Fitness Instructors Handbook and The Complete Guide to Personal Training are among his titles.