Abstract
BACKGROUND:
Although exercise is recommended for knee osteoarthritis, to the best of our knowledge there have been no studies comparing isometric and isokinetic exercise in relation to the degree of osteoarthritis.
OBJECTIVE:
To compare the effectiveness of isokinetic and isometric exercise programs in terms of pain, physical function and muscle strength in relation to the severity of knee osteoarthritis.
METHOD:
A total of 73 females, aged 50-65 years with bilateral Grade II(n= 36) and Grade III (n= 37) knee osteoarthritis were randomly assigned to an isokinetic [Grade II (n= 19), Grade III (n= 18)], or isometric exercise group [Grade II (n= 17), Grade III (n= 19)]. The isokinetic groups underwent a concentric strengthening program at 90°/s and 120°/s once per day, and the isometric groups underwent an isometric strengthening program at 3 times per day for 15 days. Transcutaneous electrical nerve stimulation, ultrasound and hot packs were applied for all groups. The primary outcome measure was pain evaluated by visual analogue scale and secondary outcome measures of Western Ontario {&} McMaster Universities Osteoarthritis Index, sit-stand, standing-up from a chair and 15-m walking, ascend/descend stairs, and concentric flexor and extensor peak torque at 90, 120, 180 and 300°/s were measured in all patients before and after 15 days of treatment.
RESULTS:
A significant difference was determined between the isokinetic grade III group and the isometric grade III group adjusted to baseline values at 15 days post-treatment in respect of flexion peak torque value at 120°/s.The change in the peak torque value in the isokinetic grade III group was greater than that of the the isometric grade III group (108%, 59%, respectively). No statistically significant differences were found between the groups in the other outcome measures and isokinetic peak torque values at different velocities.
CONCLUSION:
The concentric flexion torque at 120°/s improved more in the isokinetic grade III group than in the isometric grade III group.