KNEE JOINT EFFUSION AND CRYOTHERAPY ALTER LOWER CHAIN KINETICS AND MUSCLE ACTIVITY

Background: Following a joint effusion, muscle inhibition takes place. It has been shown that cryotherapy can disinhibit the quadriceps muscle after a joint effusion by a resting measure (Hoffmann reflex) of motor recruitment.

Research question/s: Does cryotherapy, when applied after a joint effusion, alter quadriceps muscle recruitment and restore muscle function?

Methodology:Subjects: 45 healthy subjects (26 male, 19 female, 21 ± 2 yrs).

Experimental procedure: Subjects were randomly assigned to one of three groups: control (CON, no ice and no effusion), effusion (EFF, 55 ml effusion in the knee joint and sham ice bag) or effusion/cryotherapy (EFFICE, effusion and ice pack). Measures of muscle function and electromyographic (EMG) activity during knee extension were taken pre-injection, post-injection, and 30 and 60 minutes post-injection.

Measures of outcome: Muscle function (knee, hip and ankle peak joint torque, peak and average power) and EMG activity (average and peak vastus medialis, vastus lateralis, medial hamstrings and gastrocnemius muscle normalised EMG activity).

Main finding/s:

Muscle function: There were significant decreases in knee peak torque (30 min) and peak power (30 and 60 min) in the EFF group, but not in the CON or EFFICE groups after the injection.

Conclusion/s: Following an experimentally induced knee joint effusion, …