Relationship between muscle activity characteristics and physical therapy parameters during posterior gait assistance with knee-ankle-foot orthosis in severe acute stroke hemiplegic patients.

[Purpose] This study aimed to verify muscle activity patterns during posterior gait assistance with a knee-ankle-foot orthosis (KAFO) in patients with severe acute stroke hemiplegia and clarify its relationships with physical therapy parameters. [Participants and Methods] We measured activity in the rectus femoris, biceps femoris, tibialis anterior, and gastrocnemius muscles in 30 patients with acute stroke during KAFO posterior gait assistance and examined their muscle activity patterns using the Japan Coma Scale (JCS), Brunnstrom Recovery Stage (BRS), Berg Balance Scale (BBS), Functional Movement Screen (FMS), and Functional Independence Measure (FIM). We divided lower extremity muscle activity into first and second half of the stance phase, compared muscle activity during the first half of the stance phase and the second half of the stance phase. In addition, the relationship between muscle activity during gaiting and each parameter was analyzed. [Results] All four muscles showed significantly higher values in the first half of the stance phase than in the second half of the stance phase. Rectus femoris first half of the stance phase muscle activity showed a moderate correlation with the BRS, BBS, and FMS scores. [Conclusion] The amount of gastrocnemius muscle activity when KAFO assists walking from behind increases in the latter half of stance in healthy individuals. However, in patients with stroke, the activity was lower and deviated from the gastrocnemius muscle activity during walking in healthy individuals.