Muscle activation patterns during forward stepping after total knee arthroplasty

Total knee arthroplasty (TKA) patients commonly experience neuromuscular adaptations that may affect stair climbing competence. This study identified multimuscle pattern (MMP) changes in postoperative female TKA patients during stair climbing with a support vector machine (SVM). It was hypothesized that TKA patients adopt temporal and spectral muscle activation characteristics indicative of muscle atrophy and cocontraction strategies. Nineteen female subjects [10 unilateral sex-specific TKAs, 62.2 ± 8.6 yr, body mass index (BMI) 28.2 ± 5.4 kg/m2; 9 healthy control subjects, 61.4 ± 7.4 yr, BMI 25.6 ± 2.4 kg/m2] were recruited. Surface electromyograms (EMGs) were obtained for seven lower limb muscles of the affected limb of TKA subjects and a randomly assigned limb for control subjects during stair climbing. Stance phase (±30%) EMG data were wavelet transformed and normalized to total power. Data across all muscles were combined to form MMPs and analyzed with a SVM. Statistical analysis was performed with binomial tests, independent group t-tests, or independent group Mann-Whitney U-tests in SPSS ( P < 0.05). SVM results indicated significantly altered muscle activation patterns in the TKA group for biceps femoris (recognition rate 84.2%), semitendinosus (recognition rate 73.7%), gastrocnemius (recognition rate 68.4%), and tibialis anterior (recognition rate 68.4%). Further analysis identified no significant differences in spectral activation characteristics between groups. Temporal adaptations, indicative of cocontraction strategies, were, however, evident in TKA MMPs. This approach may provide a valuable tool for clinical neuromuscular function assessment and rehabilitation monitoring.

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Differences in Baseline Joint Moments and Muscle Activation Patterns Associated With Knee Osteoarthritis Progression When Defined Using a Clinical Versus a Structural Outcome

Journal of Applied Biomechanics ◽

10.1123/jab.2019-0127 ◽

2020 ◽

Vol 36 (1) ◽

pp. 39-51 ◽

Cited By ~ 1

Author(s):

Kerry E. Costello ◽

Janie L. Astephen Wilson ◽

William D. Stanish ◽

Nathan Urquhart ◽

Cheryl L. Hubley-Kozey

Keyword(s):

Total Knee Arthroplasty ◽

Knee Osteoarthritis ◽

Knee Arthroplasty ◽

Muscle Activation ◽

Radiographic Progression ◽

Principal Component ◽

Rectus Femoris ◽

Muscle Activation Patterns ◽

Osteoarthritis Progression ◽

Total Knee

Both structural and clinical changes can signify knee osteoarthritis progression; however, these changes are not always concurrent. A better understanding of mechanical factors associated with progression and whether they differ for structural versus clinical outcomes could lead to improved conservative management. This study examined baseline gait differences between progression and no progression groups defined at an average of 7-year follow-up using 2 different outcomes indicative of knee osteoarthritis progression: radiographic medial joint space narrowing and total knee arthroplasty. Of 49 individuals with knee osteoarthritis who underwent baseline gait analysis, 32 progressed and 17 did not progress using the radiographic outcome, while 13 progressed and 36 did not progress using the arthroplasty outcome. Key knee moment and electromyography waveform features were extracted using principal component analysis, and confidence intervals were used to examine between-group differences in these metrics. Those who progressed using the arthroplasty outcome had prolonged rectus femoris and lateral hamstrings muscle activation compared with the no arthroplasty group. Those with radiographic progression had greater mid-stance internal knee rotation moments compared with the no radiographic progression group. These results provide preliminary evidence for the role of prolonged muscle activation in total knee arthroplasty, while radiographic changes may be related to loading magnitude.

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