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

• Muscle weakness and functional impairments often persist for years after total knee arthroplasty.
• Untrained women, older people with knee osteoarthritis, and patients after total knee arthroplasty achieve improvements of knee muscle strength through whole-body vibration training and progressive resistance training.
• Both functional physiotherapy and leg-press training with moderate vibrations are effective in improving strength and function in patients after total knee arthroplasty.
• Leg-press training involving moderate vibration is a safe, effective, and time-saving procedure in restoring muscle strength and functional capacity shortly after total knee arthroplasty.

ObjectivesTo 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.DesignRandomized controlled trial.SettingOutpatient rehabilitation department at a university teaching hospital.ParticipantsPatients (N=55) with TKA were randomly allocated into 2 rehabilitation groups.InterventionsSix 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 MeasuresThe 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).ResultsBoth 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).ConclusionsIsokinetic 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.