Is thoracic spine posture important for shoulder pain?

Shoulder pain has long been regarded as a postural problem, which develops as a result of improper positioning of the spine, shoulder blades, head and shoulder joint. Early anecdotal evidence speculated that a ‘slouched’ posture of the thoracic spine (known as increased thoracic kyphosis) causes the shoulder blades to downwardly rotate. This was believed to reduce the space in the shoulder joint and cause ‘impingement’ of the soft tissues within the joint. In physiotherapy practice today, advice to maintain an upright spinal posture and exercises to encourage greater thoracic extension during shoulder movement are common components of shoulder pain treatment. However, the existence of an ideal postural alignment is not grounded in concrete evidence.

This systematic review included ten studies which examined if thoracic kyphosis was associated with shoulder pain, function or range of motion. The review found a moderate level of evidence of no association between increased thoracic kyphosis and shoulder pain. This conclusion was based on six studies which reported very similar degrees of thoracic kyphosis in groups of people with and without shoulder pain. The review also found strong evidence that greater shoulder range of motion is achieved in an extended thoracic posture compared to a maximum flexed thoracic spine. However, these latter studies used the extremes of sitting postures and restricted the thoracic spine from moving, which does not reflect how the shoulder girdle naturally operates.

The finding that thoracic kyphosis does not differ significantly between groups with and without shoulder pain goes hand in hand with other recent systematic reviews, which have demonstrated that shoulder blade position and muscle EMG activity do not follow a predictable pattern in people with and without shoulder pain. The current review provides some evidence that thoracic kyphosis may not be an important factor in shoulder pain. This challenges the rationale behind physiotherapists providing advice on thoracic spine posture to patients with shoulder pain. It also encourages future research and clinical practice to examine the role of other factors, both physical and non-physical, in the development of shoulder pain.