Altered muscle synergy patterns in individuals with medial gonarthrosis also present in unaffected side

Abstract-Text (inkl. Referenzen und Bildunterschriften)

INTRODUCTION Individuals with knee osteoarthrosis (KOA) often exhibit diminished locomotor capabilities and changes in muscle activity. The analysis of muscle synergies allows for insight into the neuromuscular organization of cyclic tasks like locomotion [1]. Plasticity of these synergies has been observed in patients with KOA and post-TKA [1,2]. Whether this plasticity is limited to the affected side remains unclear, but can be relevant for early intervention and the identification of compensatory mechanisms. METHODS 18 participants (KOA group: 7 with stage 3-4 KOA, 64.8±9.1 yrs; 170.5±9.7 cm; 75.8±12.1 kg; CTRL group: 11 healthy age-matched, 63.6±7.7 yrs; 170.5±9.6 cm; 72.2±11.5 kg) performed 10 trials of overground level walking at self-selected speed. 14-Channel sEMG was used to record 7 muscles per leg (Fig. 1). EMG signals were decomposed using non-negative matrix factorization, synergies were classified through k-means clustering [1]. Analysis was employed using SPM for activation patterns, and 1-way ANOVA for muscle weights. Post-hoc comparisons were conducted through pairwise t-tests with Benjamini-Hochberg adjusted p-values, Cohen's d was applied for effect sizes (ES). RESULTS In intragroup comparison, SPM revealed similar activation patterns in contralateral legs, no significant differences were observed in the respective muscle weights. In intergroup analysis, the KOA group's synergy 1 revealed increased ST and BF weights (ST: ES = .09, p < .01; BF: ES = 1.55, p < .01). DISCUSSION & CONCLUSION The two synergies of knee extensors (Fig. 1, syn 1) and -flexors (Fig. 1, syn 2) in CTRL merged into a single synergy in the KOA group in both limbs (Fig. 2, syn 1). This leads to the conclusion, the plasticity of neuromuscular organization associated with KOA might be more ingrained and not limited to the symptomatic side. REFERENCES [1] Santuz, A. et al. Int. J. Neur. Syst, no 05, 2017: 1750007 [2] Ardestani, M. et al. J Electromyogr Kinesiol, 37 2017: 90-100