Increased shoulder muscle stretch reflex elicitability in supine subject posture

Lars Niklas Heinke*, Axel Knicker, Kirsten Albracht

*Korrespondierende*r Autor*in für diese Arbeit

Publikation: Beitrag in FachzeitschriftZeitschriftenaufsätzeForschungBegutachtung


BACKGROUND: Muscle stretch reflexes are widely used to examine neural muscle function. The knowledge of reflex response in muscles crossing the shoulder is limited.
OBJECTIVE: To quantify reflex modulation according to various subject postures and different procedures of muscle pre-activation steering.
METHODS: Thirteen healthy male participants performed two sets of external shoulder rotation stretches in various positions and with different procedures of muscle
pre-activation steering on an isokinetic dynamometer over a range of two different pre-activation levels. All stretches were applied with a dynamometer acceleration of 104°/s² and a velocity of 150°/s. Electromyographical response was measured via sEMG. RESULTS: Consistent reflexive response was observed in all tested muscles in all experimental conditions. The reflex elicitation rate revealed a significant muscle main effect (F (5,288) = 2.358, ρ = .040; η² = .039; ƒ = .637) and a significant test condition main effect (F (1,288) = 5.884, ρ = .016; η² = .020; ƒ = .143). Reflex latency revealed a significant muscle pre-activation level main effect (F (1,274) = 5.008, ρ = .026; η² = .018; ƒ = .469). CONCLUSION: Muscular reflexive response was more consistent in the primary internal rotators of the shoulder. Supine posture in combination with visual feedback of muscle pre-activation level enhanced the reflex elicitation rate.
ZeitschriftIsokinetics and Exercise Science
Seiten (von - bis)1-8
PublikationsstatusVeröffentlicht - 17.12.2019