Physical Therapy Korea
pISSN 1225-8962 eISSN 2287-982X

Mean ± standard deviation muscle activity and muscle activity ratio during concentric, isometric, and eccentric contraction, with and without biofeedback

Variable Muscle contraction Without biofeedback With biofeedback Mean difference (95% CI) p-value
Infraspinatus (%MVIC) Concentric 20.39 ± 5.65 28.86 ± 4.46 3.04 (0.45–5.63) 0.025
Isometric 28.15 ± 10.76 36.94 ± 11.86 1.71 (0.44–3.86) 0.001
Eccentric 15.87 ± 4.51 18.20 ± 4.89 3.13 (0.74–5.51) 0.014
Posterior deltoid (%MVIC) Concentric 11.29 ± 6.60 7.97 ± 4.81 3.31 (1.41–5.21) 0.002
Isometric 8.24 ± 3.42 6.01 ± 2.26 2.23 (0.93–3.53) 0.002
Eccentric 10.19 ± 4.19 9.10 ± 3.57 1.08 (0.05–2.11) 0.040
Activity ratio Concentric 2.38 ± 1.30 4.68 ± 2.47 –2.30 (–3.51 to –1.09) 0.002
Isometric 3.81 ± 1.72 6.50 ± 2.02 –2.69 (–4.03 to –1.33) 0.002
Eccentric 1.83 ± 1.11 2.23 ± 1.00 –0.39 (–0.85 to 0.06) 0.080

Values are presented as mean ± standard deviation. %MVIC, percentage of maximal voluntary isometric contraction; CI, confidence interval.

Phys. Ther. Korea 2023;30:237~244 https://doi.org/10.12674/ptk.2023.30.3.237
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