ABSTRACT
Clinicians frequently incorporate unstable sitting devices into training plans for improving proximal postural muscle control; however, the effect of unstable sitting conditions on postural adjustments during dynamic activities has not been fully explored. The aim of this study was to characterize early postural adjustments (EPAs) and anticipatory postural adjustments (APAs) under stable and unstable sitting conditions. Using a cross-sectional laboratory study design, 13 healthy college student volunteers used their dominant hand to reach forward and push a target under stable and unstable sitting conditions; subjects sat on an air-filled rubber cushion for the unstable condition. EPAs and APAs were quantified by recording muscle activation of the trunk and lower extremity muscles using electromyography (EMG). The center of pressure (COP) was measured using a force plate. The resulting EMG integral of the ipsilateral gastrocnemius muscle was larger during the EPA phase and smaller during the APA phase under unstable conditions (pâ¯=â¯0.014 and pâ¯=â¯0.041, respectively). COP amplitude in the anterior-posterior direction, path length, and velocity, was larger during the APA phase (pâ¯=â¯0.035, pâ¯=â¯0.023, and 0.023, respectively). This suggests greater distal muscle activation during EPAs in unstable sitting conditions, specifically in the ipsilateral gastrocnemius muscle. In addition, APAs adjusted by reducing the activity of the ipsilateral gastrocnemius muscle and increasing the anterior-posterior shift in the COP to compensate for the expected additional perturbation due to an unstable surface.
Subject(s)
Adaptation, Physiological/physiology , Anticipation, Psychological/physiology , Postural Balance/physiology , Psychomotor Performance/physiology , Sitting Position , Adolescent , Adult , Cross-Sectional Studies , Electromyography/methods , Female , Healthy Volunteers , Humans , Male , Muscle, Skeletal/physiology , Posture/physiology , Pressure , Torso/physiology , Young AdultABSTRACT
BACKGROUND: Advanced treatment of oral cancer increases survival rates; however, it also increases the risk of developing shoulder dysfunction, dysphagia, oral dysfunction, donor site morbidity and psychological issues. This single-arm preliminary pilot study aims to explore the effects of a six-month early intervention program following reconstructive surgery in oral cancer survivors. METHODS: A total of 65 participants were analyzed following reconstructive surgery. Outcome measurements were taken during the first visit, and at one, three and six months after reconstructive surgery. RESULTS: Scapular muscle strength and shoulder range of motion progressively improved during the 6-month follow-up. The mean Disability of the Arms, Shoulder and Hand (DASH) score showed significant improvement at 1 month (p < .001). Health related QoL showed significant differences between baseline and 6-months post-surgery scores on global health and on most of the function and symptom scales. The predicted return-to-work rate was 80% at one year after the operation. Return-to-work rate differs in different vocational types, with a higher rate of return in the skilled or semi-skilled (87.5%) and self-employed (86.7%). CONCLUSIONS: We suggest that early integrated intervention program with a follow-up of at least six months following reconstructive surgery may help develop and identify intervention guidelines and goals in the initial six months of treatment following neck dissection in oral cancer survivors.