This very recent study has demonstrated that some people with frozen shoulder actually have significantly more movement when under a general anaesthetic than when awake. This has challenged the conventional belief that stiffness in frozen shoulder is due to capsular tightness/contracture. This raises the question, could muscle guarding and spasm be the cause of stiffness in some with frozen shoulder?
This finding has implications for management of frozen shoulder. If there is indeed an active (muscle) restriction to movement in frozen shoulder, does this mean physiotherapy intervention should be more active based? I.e. trying to reduce muscle tightness and guarding by loading, stretching and targeted education?
Further research is warranted, but nonetheless, this could be an important first step in unraveling the complexities of frozen shoulder.