Comparison of Lower Extremity Muscles During Balance in Adults 30-70 Years

Research Objectives: To investigate the muscle use of bilateral (B) gluteus medius (GM), gluteus maximus (Gmax), anterior tibialis (AntTib), and gastrocnemius (Gastroc) in subjects 30-69 years during single leg stance (SLS).

Design: Descriptive study as subjects were stratified by age & exercise with sEMG while subjects performed SLS.

Setting: General community testing

Participants: Volunteer sample. Exclusions of orthopedic or neurological issues that interfered with balance. Screening using the Mini Mental & the Global Physical Activity Questionnaire. 30-39 years N = 26, 40-49 years N =25, 50-59 years N = 30, 60-69 years N = 31, total N = 112.

Interventions: sEMG during SLS as the subjects were scored on the Community Balance Measure Scale (CBMS).

Main Outcome Measures: sEMG mean activation of B GM, GMAX, AntTib, Gastroc, CBMS, & exercise frequency. Statistical analysis with p<.05.

Results: No correlation of GM, Gmax, or Gastroc with CBMS. Weak correlation of AntTib right(R) with CBMS score (.008). Significant difference in muscle activation by decade for GM R (.009), AntTib left (L) (.004), Gastroc R (.023) & L (.012), & approaching significant difference for AntTib R(.073). B GM, Gmax, Gastroc, & AntTib R activation no significant difference with exercise 3x/wk while AntTib L activation significantly increased (.040). Exercise at 5x/wk did not change activation of B GM, GMax, and AntTib L. Exercise at 5x/wk significantly changed AntTib R (.049), & approached a change for B Gastroc (.056). Exercise appeared to positively impact muscle activation the most in the 60s.

Conclusions: SLS is part of the CBMS. Changes were noted as subjects aged 30-69 years. Exercise at 3x/wk only affected activation of AntTib L. Exercise at 5x week positively affected more muscles over various age groups. Subjects in 60s displayed the most notable changes possibly leading to improved balance. Individuals use ankle strategies less in their 60s, any activities that increase use of ankle musculature could lead to improved balance.

Author(s) Disclosures: There are no conflicts of interest for any of the authors of this research.