Dry Needling and Functional Improvement

Dry Needling (DN) is a skilled intervention that uses acupuncture filiform needles that are inserted into myofascial trigger points or other tissues underneath the skin. It is used to treat myofascial or neuromusculoskeletal pain and to improve movement impairments. Although more and more physical therapists add this treatment tool to their skill box, there is uncertainty about its working mechanism and its efficacy. The latter is partially due to the challenging task of finding and using a true control or sham treatment. The investigators will use blunted needles, which will not perforate the skin, as sham treatment. This study will assess if DN of a trigger point in the gluteal muscles increases pain pressure threshold in that muscle, in another muscle innervated by the same segment (L4/5) and in an area not supplied by the same segment (i.e. the ipsilateral posterior shoulder). In addition, this study will assess if functionality, as measured by the Oswestry Disability Index (ODI) and 15-point Global Rating of Change Scale (GRoC) questionnaires, improves after 2-3 treatments (1 week) of DN.