Muscle Activation in Knee Osteoarthritis
Condition: Knee Osteoarthritis
MeSH terms: Osteoarthritis; Osteoarthritis, Knee
Study type: Observational

Summary: 
      Muscle activity, as a possible fundamental cause of functional limitation, has been
      extensively investigated in knee osteoarthritis (KOA). Many trials investigated muscle
      activity during dynamic movements and functional tasks in KOA. In addition, gender-related
      differences has been also investigated during functional movements in KOA. However, no trial
      investigated gender-related differences in muscle activation during static movement in KOA.
    

Detailed description: 
      Muscle activity, as a possible fundamental cause of functional limitation, has been
      extensively investigated in knee osteoarthritis (KOA). Interestingly, studies concentrated
      mainly on investigation of muscle activity during dynamic movements and different functional
      tests. Moznuzzaman et al displayed greater muscle activation during sitting to standing test
      (STS) and standing to sitting test in KOA patients compared to healthy participants.
      Interestingly, some studies investigated muscle activation standing up from a knee-height
      seat during STS and illustrated a greater muscle activation amongst KOA patients compared to
      healthy controls. Moreover, Amer et al found greater muscle activation while performing STS
      from a lower height seat compared to a knee-height seat amongst women and men patients with
      uni/bilateral KOA. These findings might be of interest due to compensatory mechanisms
      observed by female patients during STS transition increases loading on the joint surfaces and
      consequently leading to progression of KOA. Furthermore, different studies also presented
      gender-differences of muscle activation during different weight-bearing tasks (gait, STS,
      stair ascend/descend, and squat) amongst patients with KOA and healthy control.
      Interestingly, both studies showed women with KOA representing higher muscle activation
      compared to men. Therefore, an analytical comparative study might be useful for
      identification of gender-differences in muscle activation amongst patients with KOA.

      Investigation of static muscle activity during functional movements is very rare in KOA.
      Zhang et al investigated muscle activation after single whole body vibration trial in
      standing position at 0°, 30° and 60° static knee flexion angles amongst women with KOA.
      Authors found that muscle activation in 60° was greater compared to 30°, and it was also
      greater in 30° compared to 0°. Based on our literature search, no further study examined
      muscle activity in static knee flexion in KOA. However, investigating static knee flexion
      might be useful as it could be related to different knee moments in KOA.
    

Intervention name(s): Electromyography (EMG) measurement
Intervention type(s): Device
Intervention description(s): Electromyography (EMG) measurement of m. quadriceps femoris and semitendinosus muscle during static functional tasks
Observational model: Cohort
Time perspective: Cross-Sectional
Sampling method: Non-Probability Sample
Study population: 
        Patients with radiologically diagnosed KOA