Effect of a Corrective Exercise Program on the Frequency Spectrum of Ground Reaction Force during Drop-Landing in Older Adults with Genu Valgum

Objectives :

The aim of this study was to evaluate the effects of a corrective exercise protocol on the frequency spectrum of Ground Reaction Force (GRF) in older adults with genu valgum during double-leg drop-landing task.

Methods & Materials:

 The is a quasi-experimental study (a registered clinical trial with code: IRCT2016110230657N1). Participants were 26 elderly men with genu valgum (13 in intervention group and 13 in control group). The GRF data were measured by two force plates (Kistler Group, Winterthur, Switzerland). The corrective exercise was performed for 16 weeks, 3 sessions per week. All participants signed a written consent form and the study design was approved by the ethics committee. Those subjects with a history of injury were excluded from the study. The two-way repeated measures ANOVA was used for statistical analysis.

Results :

The mean age of participants in the intervention and control groups were 63.92±2.21 and 64.01±2.62 years, respectively. Based on the ANOVA results, the effect of time factor on the frequency with a power of 99.5% in vertical GRF (P=0.003) and the number of essential harmonics in anterior-posterior direction (P=0.006) was significant in the left leg. The effect of group factor on the 99.5% frequency power (P=0.006) and the number of essential harmonics of vertical GRF (P=0.047) in the left leg was also significant. Furthermore, the interaction effect of group and time on the 99.5% frequency power (P<0.001) and the number of essential harmonics of vertical GRF (P=0.001) in the left leg was significant. The results of paired t-test showed that the number of essential harmonics in vertical GFR in the left leg during drop-landing task in the intervention group was significantly greater in the post-test phase than in the pre-test phase (P=0.018).

Conclusion:

 Corrective exercise program improved GRF frequency during drop landing in older adults with genu valgum.