Pilot Study On Effect Of Ipsilateral Long Kinetic Chains On Shoulder Elevation Strength

Abstract

There is growing evidence to suggest that kinetic chains extend far beyond the core muscles, following myofascial meridians that interestingly appear to overlap with classically-known acupuncture channels. Strengthening programs during the rehabilitation of musculoskeletal injuries utilize kinetic chain exercises; however, how lower extremity strength potentially directly affects upper extremity strength has not been quantified. PURPOSE: To examine quantitatively the effect on shoulder elevation strength (SES) in the sagittal plane on ipsilateral lower extremity tibialis anterior muscle activation. METHODS: Twenty young healthy adult volunteers (half women, half men), ages 20-60 years, having no shoulder pain were recruited. Participants had baseline SES evaluated with a hand-held dynamometer applied just proximal to the radial styloid with the arm held in 90-degree elevation in the sagittal plane. The participants underwent the following interventions: SES and ipsilateral anterior tibialis muscle activation (IATMA) while standing, SES and IATMA while seated with legs dangling, and SES with ipsilateral gastrocnemius activation while seated with legs dangling. RESULTS: In females, IATMA, in standing and seated position, reduced SES by a mean percentage of 12.57 and 14.88, respectively, from baseline. SES with gastrocsoleus activation (reciprocal relaxation of anterior tibialis) reduced SES by a mean percentage of 3.93 from baseline. In males, IATMA, in standing and seated position, reduced SES by a mean percentage of 5.58 and 10.84, respectively, from baseline. SES with gastrocsoleus activation (reciprocal relaxation of anterior tibialis) reduced SES by a mean percentage of 3.3 from baseline. CONCLUSIONS: IATMA directly reduces SES; it also produces a greater decrement in SES compared to ipsilateral gastrocsoleus activation. This kinetic chain effect appears coincident with known myofascial meridians.