Effects of Whole Body Vibration Training in Pre-Frail and Frail Skilled Nursing Home Residents

BACKGROUND: Frailty syndrome is a geriatric medical condition characterized by diminished muscular strength and endurance, weight loss, and weakened physiologic function. Frailty syndrome tends to manifest itself amongst morbidities and, consequently, individual health complications are regularly targeted by clinicians with the physical state of frailty often left untreated. A majority of nursing home residents are believed to suffer from frailty syndrome; therefore, this group of older adults deserves our attention. Unloaded whole body vibration training (WBVT) has been shown to improve strength and functional performance in higher functioning older adults without frailty syndrome. PURPOSE: To determine and compare the effects of 12 weeks of WBVT to standard care alone (CON) on body composition, strength, functional performance, and inflammation in 20 (16 female) pre-frail and frail skilled nursing home residents (82 ± 5 years). METHODS: This was a non-randomized controlled trial. Participants were recruited from three skilled nursing facilities in Tallahassee, FL. Participants (WBVT: n=14; CON: n=11) were screened for frailty syndrome using the FRAIL scale. Handgrip (HG) and isometric knee extension strength (KE) were measured using a hand and mechanical push-pull dynamometer. Bioelectrical impedance was used to determine lean mass (LM), fat mass (FM), skeletal muscle index (SMI), and phase angle (PA; a measure of tissue health). Inflammation was assessed using an enzyme-linked immunosorbent assay to measure resting serum concentrations of C-reactive protein (CRP). The short physical performance battery (SPPB) and timed up-and-go (TUG) were used to assess functionality. Participants were assigned to either 12 weeks of WBVT (2x/wk) or CON. WBVT consisted of 3x10 of 4 lower body exercises with 50 seconds of vertical vibration (25-40 Hz) per set. CON continued with day-to-day activities and followed doctor’s orders. One-way analysis of variance (ANOVA) was used to analyze baseline data between the WBVT and CON groups. Dependent variables were analyzed using a 2 x 2 (group x time) factorial ANOVA with repeated measures on the last factor. When a significant group-by-time interaction and/or time effect was identified, between-groups and within-group comparisons were performed using independent and paired t-tests. Significance was set at p≤0.05. RESULTS: Twenty participants completed the intervention (WBVT: n=10; CON: n=10). The FRAIL Scale identified 5 participants as pre-frail (WBVT: n=4) and 15 as frail (CON: n=9). Sarcopenia (low SMI and HG or SPPB) was identified in 9 participants (WBVT: n=6), of which 4 were obese (WBVT: n=3). BMI classification ranged from underweight to stage-3 obesity (15.3-38.2 kg/m2). Hypertension (85%), depression (75%), Alzheimer’s or dementia (50%), and diabetes mellitus (55%) were the most frequent medical conditions reported. Nineteen participants were treated with polypharmacy (>5 drugs) and all required assistive devices for ambulation. All WBVT participants completed the 24 exercise sessions. There were no differences between groups in baseline measures of body composition, strength, functional performance, and inflammation. There was no significant change in LM, FM, PA, or CRP in either group. There were significant time effects on body mass (F1,18=8.869, p=0.008, η2=0.330) and BMI (F1,18, p=0.014, η2=0.293). The standard care group increased their body mass (p=0.022) and BMI (p=0.028), but neither body mass nor BMI were different between groups post-intervention (p>0.05). There was a significant group-by-time interaction (F1,18=5.434, p=0.032, η2=0.232) for KE. WBVT significantly improved KE (p=0.003), but KE was not different between groups post-intervention (p>0.05). There was a significant group-by-time interaction for SPPB performance (F1,18=4.84, p=0.041, η2 = 0.212). Total SPPB score improved by 15.6% following WBVT (p=0.089) with a magnitude of change in the WBVT (∆ SPPB=+0.7 units) that was greater (p=0.041) than CON (∆ SPPB=-0.4 units). CONCLUSION: WBVT in pre-frail and frail skilled nursing home residents was well tolerated and occurred without adverse health complications. WBVT can be used in skilled nursing facilities to counteract losses in leg strength and some measures of physical function. WBVT interventions of longer frequency and duration could demonstrate to be useful for greater improvements in strength and functional performance.