Steven Pheasant and Richard Haydt
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Background: Previous studies have shown that the Slumped-Forward Head posture is associated with decreased glenohumeral external rotator strength, while an erect posture has been associated with positive changes in strength. Clinically, it has been observed that similar changes in hip abductor strength occur in response to various sitting postures.
Purpose: The purpose of this study is two-fold, first to determine the impact sitting posture has on lower extremity hip abductor strength, and second, determine if those who demonstrate a ≥10% strength decline from “erect-sitting” to “slumped-siting” also demonstrate a decline in functional hip strength as measured by the Y-balance test. Given the unforeseen events of the Covid-19 pandemic, the second phase of this research is now a proposal study, a form in which it should be completed in the future.
Methods: Fifty subjects ages 18-26 participated in this study. Each subject was placed in four postures for five minutes. Said postures were prone, erect-sitting, prone, and slumped-sitting, after which dominant leg hip abductor strength was measured with the subject in side-lying and their dominant leg up, with their non-dominant leg maintained at thirty degrees of hip and knee flexion. Measurements were recorded utilizing the Micro-FET3 Hand Held Muscle Testing Dynamometer (HHMTD). Subjects who demonstrated a ≥10 decline in strength from erect-sitting to slumped-sitting posture were assessed again for part two of the study at a later date. Part two of the study required subject's to assume the same postures listed above for five minutes, yet after each posture assumed, the subjects functional dominant leg hip abductor strength was measured utilizing the Y-balance test.
Results: For 28 subjects of phase one of study: 25% of the population demonstrated greater than 10% decline in hip abductor strength following five minutes in the slumped-sitting posture, who would have completed phase two data collection, which has been illustrated as a protocol.
Conclusions: The Slumped Forward Head posture has shown a negative effect on hip abductor strength.
sitting posture, hip abduction strength
Medicine and Health Sciences
Cassaro, Joseph III; Struble, Gerald; George, Trevor; and Wozniak, Robert, "Does Sitting Posture Prior to Testing Single Leg Dynamic Balance Influence Performance?" (2020). Student Research Poster Presentations 2020. 59.