1.
Effects of Short-Term Unilateral Strength Training on Measures of Postural Control When Wearing "Operationally Relevant" Backpack Loads.
Krajewski, KT, Bansbach, HM, McLean, L, McKenzie, C, Rawcliffe, A, Graham, SM, Flanagan, SD, Pourmoghaddam, A, Dettmer, M, Connaboy, C
Journal of strength and conditioning research. 2020;(10):2743-2750
Abstract
Krajewski, KT, Bansbach, HM, McLean, L, McKenzie, C, Rawcliffe, A, Graham, SM, Flanagan, SD, Pourmoghaddam, A, Dettmer, M, and Connaboy, C. Effects of short-term unilateral strength training on measures of postural control when wearing "operationally relevant" backpack loads. J Strength Cond Res 34(10): 2743-2750, 2020-To examine the effects of "operationally relevant" loads on postural stability and to determine the effects of unilateral and bilateral strength training programs on postural stability in healthy, recruit-aged men. Fifteen subjects were randomly assigned to either a unilateral (UL; n = 7) or bilateral (BL; n = 8) strength training group, which performed strength training 3 times a week for 4 weeks. Subjects completed the following pretest and post-test assessments: 1 repetition maximum in bilateral (1RM-BL) and unilateral (1RM-UL) stance positions and bilateral and unilateral balance tasks with eyes open and eyes closed. Balance tasks were performed over 3 loading conditions: body mass (BM), 50% BM, and 70% BM. Sample entropy (SE) and root mean square (RMS) were calculated from the center of pressures collected during each balance assessment. The UL strength training group showed significant improvement after training in both 1RM-UL (p < 0.01) and 1RM-BL (p < 0.01). The BL strength training group only showed significant improvement in 1RM-BL (p = 0.01). There was a significant main effect of load on RMS (p < 0.05) across all balance tasks with RMS increasing with increasing load. Sample entropy was found to decrease with increasing load in the unilateral eyes open and bilateral stance tasks. Significant increases in strength (∼10 to -29%) were observed; however, increased strength alone is not enough to mitigate the effects of load carriage on the postural control, even when training is performed in stance positions that are posturally challenging. Therefore, "operationally relevant" loads negatively impact postural stability in novice load carriers when assessing nonlinear measures.
2.
Dalfampridine to Improve Balance in Multiple Sclerosis: Substudy from a Randomized Placebo-Controlled Trial.
Prosperini, L, Castelli, L, De Giglio, L, Bonanno, V, Gasperini, C, Pozzilli, C
Neurotherapeutics : the journal of the American Society for Experimental NeuroTherapeutics. 2020;(2):704-709
-
-
Free full text
-
Abstract
This was a substudy of a randomized, double-blind, placebo-controlled trial originally designed to explore the effect of dalfampridine on information processing speed (2013-002558-64 EU Clinical Trials Register) in patients with multiple sclerosis (MS). A total of 120 patients were originally randomized in a 2:1 ratio to receive dalfampridine 10 mg or placebo twice daily for 12 weeks. Here, we sought to explore the effect of dalfampridine on static balance in single-task and dual-task conditions in a subgroup of 41 patients. They underwent static posturography in quiet standing (single-task) and while performing the Stroop test (dual-task) at randomization (baseline), after 12 weeks and after a 4-week wash-out period. Baseline characteristics of active group (n = 27) did not differ from those of placebo group (n = 14). Dalfampridine treatment was associated with better balance control than placebo in both single-task (F = 4.80, p = 0.034) and dual-task (F = 6.42, p = 0.015) conditions, with small-to-moderate effect sizes (Cohen's f2 = 0.122-0.162). The beneficial effect of dalfampridine was not retained 4 weeks after its discontinuation. The rate of accidental falls per month did not differ between the two groups (p = 0.12). Our preliminary findings suggest that dalfampridine can be considered a potential option to treat balance impairment due to MS. Larger sample sizes are needed to verify if the beneficial effect of dalfampridine on balance can be translated into a reduced risk of accidental falls.
3.
Vitamin D Supplementation Improves the Effects of the Rehabilitation Program on Balance and Pressure Distribution in Patients after Anterior Cervical Interbody Fusion-Randomized Control Trial.
Skrobot, W, Perzanowska, E, Krasowska, K, Flis, DJ, Dzik, KP, Kloc, W, Kaczor, JJ, Antosiewicz, J
Nutrients. 2020;(12)
Abstract
STUDY DESIGN A double-blinded, randomized controlled trial. BACKGROUND Surgery is effective in reducing pain intensity in patients with cervical disc disease. However, functional measurements demonstrated that the results have been not satisfactory enough. Thus, rehabilitation programs combined with the supplementation of vitamin D could play an essential role. METHODS The study recruited 30 patients, aged 20 to 70 years, selected for anterior cervical interbody fusion (ACIF). The patients were randomly divided into the placebo (Pl) and vitamin D (3200 IU D3/day) supplemented groups. The functional tests limits of stability (LOS), risk of falls (RFT), postural stability (PST), Romberg test, and foot pressure distribution were performed before supplementation (BS-week 0), five weeks after supplementation (AS-week 5), four weeks after surgery (BSVR-week 9), and 10 weeks after supervising rehabilitation (ASVR-week 19). RESULTS The concentration of 25(OH)D3 in the serum, after five weeks of supplementation, was significantly increased, while the Pl group maintained the same. The RFT was significantly reduced after five weeks of vitamin D supplementation. Moreover, a further significant decrease was observed following rehabilitation. In the Pl group, no changes in the RFT were observed. The overall postural stability index (OSI), LOS, and the outcomes of the Romberg test significantly improved in both groups; however, the effects on the OSI were more pronounced in the D3 group at the end of the rehabilitation program. CONCLUSIONS Our data suggest that vitamin D supplementation positively affected the rehabilitation program in patients implemented four weeks after ACIF by reducing the risk of falls and improving postural stability.
4.
Postural Balance Effects Associated with 400, 4000 or 10,000 IU Vitamin D3 Daily for Three Years: A Secondary Analysis of a Randomized Clinical Trial.
Burt, LA, Gabel, L, Billington, EO, Hanley, DA, Boyd, SK
Nutrients. 2020;(2)
Abstract
Vitamin D supplementation is proposed as a fall prevention strategy, as it may improve neuromuscular function. We examined whether three years of vitamin D supplementation (400, 4000 or 10,000 IU daily) affects postural sway in older adults. Three hundred and seventy-three non-osteoporotic, vitamin D-sufficient, community-dwelling healthy adults, aged 55-70 years, were randomized to 400 (n = 124), 4000 (n = 125) or 10,000 (n = 124) IU daily vitamin D3 for three years. Sway index was assessed at baseline, 12-, 24- and 36-months using the Biosway machine. We tested participants under four conditions: eyes open or eyes closed with firm (EOFI, ECFI) or foam (EOFO, ECFO) surfaces. Secondary assessments examined sway in the anterior-posterior (AP) and medio-lateral (ML) directions. Linear mixed effects models compared sway between supplementation groups across time. Postural sway under EOFO and ECFO conditions significantly improved in all supplementation groups over time. Postural sway did not differ between supplementation groups at any time under any testing conditions in normal, AP or ML directions (p > 0.05 for all). Our findings suggest that high dose (4000 or 10,000 IU) vitamin D supplementation neither benefit nor impair balance compared with 400 IU daily in non-osteoporotic, vitamin D-sufficient, healthy older adults.