Effects of Leg-Press Training With Moderate Vibration on Muscle Strength, Pain, and Function After Total Knee Arthroplasty: A Randomized Controlled Trial.

OBJECTIVES: To examine the effects of a time-saving leg-press training program with moderate vibration on strength parameters, pain, and functional outcomes of patients after total knee arthroplasty (TKA) in comparison with functional physiotherapy.

DESIGN: Randomized controlled trial.

SETTING: Outpatient rehabilitation department at a university teaching hospital.

PARTICIPANTS: Patients (N=55) with TKA were randomly allocated into 2 rehabilitation groups.

INTERVENTIONS: Six weeks after TKA, participants either underwent isokinetic leg-press training combined with moderate vibration (n=26) of 15 minutes per session or functional physiotherapy (n=29) of 30 minutes per session. Both groups received therapy twice a week for a period of 6 weeks. Participants were evaluated at baseline (6wk after TKA) and after the 6-week rehabilitation program.

MAIN OUTCOME MEASURES: The main outcome measure was maximal voluntary contraction (MVC) of the involved leg. Secondary outcome measures were pain assessed with a visual analog scale (VAS), range of motion, stair test, timed Up and Go test, and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC).

RESULTS: Both groups showed statistically significant improvements in MVC of knee extensors measured on the knee dynamometer (leg-press group: from 0.8±.06 to 1±.09Nm/kg body weight [BW], physiotherapy group: from 0.7±.06 to 0.9±.06Nm/kg BW; P<.05) and in closed kinetic chain on the leg press (leg-press group: from 8.9±.77 to 10.3±1.06N/kg BW, physiotherapy group: from 6.7±.54 to 9.1±.70N/kg BW; P<.05) and in pain at rest (leg-press group: from 2±.36 to 1.3±.36 on the VAS, physiotherapy group: from 1.2±.28 to 1.1±.31; P<.05), WOMAC scores, and functional measurements after 6 weeks of training. There was no significant difference between the 2 groups concerning strength, pain, and functional outcomes after training (P>.05).

CONCLUSIONS: Isokinetic leg-press training with moderate vibration and functional physiotherapy are both effective in regaining muscle strength and function after TKA; however, isokinetic leg-press training is considerably less time consuming.