Abstract: Peak Torque(PT),Total Work(TW),Average Power(AP),Torque Acceleration Energy(TAE),Set Total Work(STW),Endurance Ratio (ER)and DOrsal/plantar ratio of ankle dorsal and plantarflexion were tested in 101 patients with lumbar disc protrusion using a Cybex一6000 isokinetic muscle test-ing instrument.The results showed the most tested of the affected side was signficantly lower than that onthe opposite side. The PT,TW and STW of the affected side was lower 70一80%than that on the oppo-site side. The rest was lower 20一30%than another side. No significant difference of endurance ratios be-tween the affected and unaffected sides was noted.

Key words: isokinetic muscle testing instrument, lumbar disc protrusion, muscle strength testing