In the young and healthy shoulder, cranially directed forces during abduction are counteracted by co-contraction of the rotator cuff muscles. In this way, it is prevented that the humerus moves... Show moreIn the young and healthy shoulder, cranially directed forces during abduction are counteracted by co-contraction of the rotator cuff muscles. In this way, it is prevented that the humerus moves cranially towards the acromion, thus entrapping subacromial tissues. During ageing however, shoulder tissues are subject to marked degeneration, which particularly concerns the rotator cuff muscles. This may have two consequences. First, due to reduced contribution of the upper parts of the rotator cuff to the abduction movement, the deltoid has to compensate, which results in a more cranially, instead of mediocranially directed force. Second, reduced stabilising force by the rotator cuff may jeopardise counteraction of cranial deltoid forces. These changes could lead to cranialisation of the humerus with painful compression of subacromial tissues, as observed in patients with Subacromial Pain Syndrome (SAPS). Previous studies have shown that by co-contraction of arm adductors, humeral-head depression may be accomplished, for the purpose of unloading subacromial tissues. In this thesis, we investigated the role of adductor co-contraction in the ageing asymptomatic population and in patients with SAPS. This has resulted in eight scientific publications with which the fundaments for evidence-based therapy in SAPS have been built, with as cornerstone training of adductor co-contraction. Show less
Background:Physical exercises targeting proprioception are part of conservative therapy for Subacromial Pain Syndrome (SAPS). However, the effect of such exercises on proprioception itself has not... Show moreBackground:Physical exercises targeting proprioception are part of conservative therapy for Subacromial Pain Syndrome (SAPS). However, the effect of such exercises on proprioception itself has not been orderly established, hampering the advancement of treatment protocols and implementation. We summarised the evidence for a loss of proprioception in SAPS and defined the type of interventions that target and improve proprioception in SAPS. Methods:Two reviewers independently analysed 12/761 articles that evaluated joint position, kinaesthetic or force sense in patients with SAPS. Results:Patients with SAPS had reduced joint position sense during abduction. There was no evidence for a loss of kinaesthetic sense or force sense. Stretching, strengthening and stabilisation exercises improved joint position and kinaesthetic sense in SAPS. Microcurrent electrical stimulation and kinesiotaping did not improve proprioception in SAPS. Conclusions:The lack of evidence on proprioception in SAPS is striking. We found limited evidence for a loss of joint position sense in the higher ranges of abduction in SAPS. Active training programmes including strengthening and stabilisation exercises showed superiority in terms of enhancing proprioception relative to passive methods like kinesiotaping. The results of this narrative synthesis should be used as a base for providing value-based and data-driven treatment solutions to SAPS. Show less
Henseler, J.F.; Witte, P.B. de; Groot, J.H. de; Zwet, E.W. van; Nelissen, R.G.H.H.; Nagels, J. 2014
