Effectiveness of Voluntary Isometric Exercises and Electrical Stimulation in Strengthening of Quadriceps Femoris after Removal of Knee Immobilization in Middle Aged and Old Patients; A Comparative Study

Electrical stimulation has been used for many years in rehabilitation medicine to prevent atrophy or to increase muscle strength, but the use of electrical stimulation for muscle strengthening in research and clinical practice has become increasingly popular in recent years. The quadriceps femoris is the thigh muscle group that suffers the greatest amount of atrophy. This study aimed to compare the effects of electrical stimulation and voluntary isometric contraction for increasing the quadriceps strength and the girth of thigh in middle aged and old patients after removal of cast immobilization. 87 patients whose knees were immobilized following lower extremity fracture were randomly allocated into two groups: the electrical stimulation and voluntary isometric exercise group. The patients trained for 20 minutes, 3 days a week over a period of 6 weeks. The subject's thigh circumference and muscle power were evaluated before and after treatment. The increase in quadriceps strength of the electrical stimulation group (28%) was significantly less than that of voluntary isometric exercise group (40%). However, there was no significant difference between the two treatment modalities in increasing circumference of thigh (1.42 ± 0.27 & 1.41 ±0.36, P=0.96). This study showed that although electrical stimulations is an alternative and potentially effective means to increase the strength of quadriceps following knee immobilization in middle-aged and old patients, it is not more effective than voluntary isometric exercise.