CONCENTRIC AND ISOMETRIC ACTIONS IN PROPRIOCEPTIVE NEUROMUSCULAR FACILITATION STRETCHING TECHNIQUES

Abstract

931 The purpose was to compare proprioceptive neuromuscular facilitation (PNF) stretching techniques to improve range of motion (ROM) in hip flexion and shoulder internal rotation. PNF techniques included an isometric action of the target muscle group (hip extensors or shoulder external rotators) using 0%, 50%, or 100% of maximal voluntary isometric force (MVIF) measured using a Biodex® dynamometer, and either did or did not include a concentric action of the muscles opposing the target muscles. Twelve students of mean (± SD) age 21 ± 3 yr volunteered. ROM was the largest joint angle attained with assistance from the investigator (i.e., “passive” ROM). Stretching was performed on five separate days. The mean of the five baseline ROM measures served as the value for “no concentric, 0% MVIF”. Mean values (in degrees): TableTableResults of two-way repeated measures ANOVAs revealed significantly greater ROM (p < 0.001) at both the hip and shoulder after PNF techniques that included both a concentric action and a high percentage of MVIF. The two components of PNF techniques appear to contribute independently to the improved ROM, and the effect of the isometric action is dose-dependent.