Citations
Objective: The purpose of this study was to examine the strength of the knee and pulmonary function comparing collegians and hockey players in college.
Method: KINㆍCOM isokinetic dynamometer and medigraph were used to evaluate strength of the right lower extremity and pulmonary function to 30 male students comprising 15 hockey players and 15 collegians with no significant difference in age, weight, and height between the two groups. All subjects used their right lower limb as dominant limb.
Results: 1) The significant differences between collegians and hockey players were found in the peak torque at 60o/sec,
180o/sec. 2) The siginficant differences between collegians and hockey players were found in forced vital capacity, forced expiratory volume in one second and expiratory reserve volume on the pulmonary function. 3) The significant correlation between isokinetic strength and pulmonary function were found in peak torque.
Conclusion: It is turned out that hockey players in college have much better isokinetic strength and pulmonary function than collegians, so it is suggested this result have to be considered in selecting hockey players and exercise prescription. (J Korean Acad Rehab Med 2002; 26: 228-232)
Objective: To evaluate the standards of handicapped driver's ability test in Korea and available driving aids in cervical cord injured persons.
Method: Forty-two cervical cord injured persons (C5∼C8) were evaluated with BTE (Baltimore Therapeutic Equipment) work simulator. The isotonic turning torque was measured during clockwise and counter-clockwise turning. And isometric turning torque was measured at 12 directions.
Results: By the isotonic measurement, the turning torque increased in the lower level of injury. In the C6 tetraplegics, the counter-clockwise turning torque was significantly higher than clockwise. Among 25 persons with C5 or C6 tetraplegia, only 2 with C6 tetraplegia could operate the power steering with the lowest wheel turning torque (3.0 Nm). Only three persons (1 person with C7 tetraplegia, 2 persons with C8 tetraplegia) could pass the handicapped driver's ability test of Korea (9.4 Nm). By the isometric measurement, turning torque was lowest at left upper quadrant (10 to 12 o'clock direction) in clockwise rotation.
Conclusion: Among the 42 cervical cord injured persons, only 3 persons with C7 and C8 tetraplegia could pass the handicapped driver's ability test of Korea. And among 25 C5 and C6 tetraplegia, only 2 persons with C6 tetraplegia could operate the power steering. It seems to be essential to modify the standards of handicapped drivers ability test and to evolve the driving aids for the C5 and C6 tetraplegics in Korea.
Objective: To analyze the patterns of isokinetic knee torque curves in normal population and determine the characteristics of those curves.
Method: Two hundred and eightly-six normal subjects were included. The isokinetic knee torque curves were divided into three parts; to the angle of peak torque generation, to the point 10∼20 degrees prior to end of joint motion, and to the end of joint motion. Each part was classified as convex(1), flat(2) and concave(3) type according to the shape. The curves were named such as 1-2-2 in order. Types of the curves, peak torque, angle of knee at peak torque, total acceleration energy, age, and sex of the subjects were compared.
Results: For knee extensors, frequencies of the curve types were 1-2-2(A), 1-2-1(B), 1-3-1(C), and 1-3-2(D). Mean ages of type A and B curves were slightly higher than types of C and D. Mean peak torque was greatest in type D. For knee flexors, the frequencies were 1-2-2(A), 1-2-1(B), and 1-1-2(C). Female predominance were found in type B while type C was found mostly in male. Mean peak torque was greatest in type C.
Conclusion: The most common torque curve type was 1-2-2 for knee extensors and flexors. Torque curve types of knee extensors showed differences in age and torque curve types of knee flexors showed differences in sexual distribution.
Objective: Inappropriate neural control of the quadriceps femoris muscle group has been implicated in patellofemoral pain syndrome (PFPS) and the methods of biomechanical assessment of PFPS has been developed recently. The aims of the present investigation were to evaluate the effects of therapeutic exercise in the alleviation of PFPS and to develope objective clinical test for PFPS.
Method: We investigated the onset time of the isometric contraction of vastus medialis oblique muscle (VMO) and the vastus lateralis muscle (VL) under four different conditions: knee flexion and extension in weight bearing (standing) and non-weight bearing (sitting on chair) situations. For each condition, onset times of EMG activities and onset times for VMO and VL were determined from five trials of isometric contraction. In addition, we compared knee flexor and extensor torques in control group and subjects with PFPS. To evaluate the effects of the exercise we compared the onset time difference (onset time of VL-onset time of VM) and quadriceps muscle torque at pre- and post- exercise in PFPS groups.
Results: In PFPS group, onset time of VMO during knee extension was significantly longer than the onset time of VL and the knee extensor torque was considerably weaker in comparison with normal group. Although onset time difference was not changed after exercise program, there were significant increase in knee extensor torque in subjects with PFPS.
Conclusion: The role of exercise in the rehabilitation of quadriceps functions is to reduce the pain, to strengthen the knee extensor, and further accurate diagnostic tools and methods for the result of therapeutic exercise in PFPS are needed.
Objective: This study was designed to evaluate the relation of leg length discrepancy on ankle muscle strength.
Method: Twenty four adult women were tested (12 leg length equality and 12 leg length discrepancy). Leg length was measured by tape ruler from anterior superior iliac spine to medial malleolus, three times by three different trained examiners. The muscle strength (bilateral ankle dorsiflexors and plantarflexors) was measured by using Cybex 340 dynamometer at 30 degree/sec and 120 degree/sec.
Results: The mean value of leg length discrepancy was 0.89⁑0.24 cm. In leg length discrepancy group, the peak torque of ankle plantarflexor were 44.50⁑20.94 Nm in long leg and 51.83⁑12.75 Nm in short leg at 30 degree/sec angular velocity (p＜0.05).
Conclusion: We concluded that there were significant increase in plantar flexor peak torques of short leg than those of long legs at 30 degree/sec (P＜0.05). Perhaps the difference of the muscle strength might be due to compensatory mechanism of short leg in propulsion during gait.
Objective: The purpose of this investigation was to document the isokinetic performance deficiencies of the invertor and evertor muscles of chronically sprained ankles.
Method: Eversion/Inversion testing was performed by a Cybex 6000 isokinetic dynamometer at the speeds of 60o/sec and 120o/sec on 17 subjects who had unilateral chronic ankle sprain. Values were compared between the involved and uninvolved sides.
Results: The inversion peak torque deficits between the involved and uninvolved extremities were significantly greater than eversion deficits at 60o/sec and 120o/sec. Evertor/Invertor peak torque ratios of involved sides at 60o/sec were significantly greater than uninvolved sides.
Conclusion: We conclude that chronic ankle sprains associate an ankle invertor weakness rather than an evertor weakness. Ankle invertor weakness might be resulted from a disuse atrophy and painful ankle inversion. Further prospective study is needed to determine the relationship between the invertor weakness and the chronic ankle sprain.
Objective: To investigate the torque curves and heart rate responses to isometric, eccentric and concentric isokinetic exercises with a maximal voluntary contraction of the right knee and elbow joints in 30 healthy men(26.6⁑2.2 years).
Method: Subjected performed the eccentric and concentric isokinetic exercises with 10 repetitions at 60o/sec, while performing the isometric exercises at a joint angle of 60 degrees for the same period of time with Cybex 6000. Peak torque, angle of peak torque, and total work were measured and the flexor-to-extensor ratios of peak torque were calculated.
Heart rates were recorded simultaneously at rest and immediately after the exercise, and the time required to return to the resting heart rate level was also recorded for each exercise session.
Results: Peak torque and total work for the eccentric exercise were significantly higher than those for the concentric exercise(p＜0.01) of the knee and elbow joints. Eccentric peak torques for flexors and extensors of the knee joint occurred at a significantly longer muscle length than the concentric peak torques(p＜0.01).
Flexor-to-extensor ratios of a peak torque of the knee joint between the eccentric and concentric isokinetic exercises did not show a significant difference.
Torques at a joint angle of 60 degrees were highest in the eccentric isokinetic exercise, followed in the order by isometric, and then concentric isokinetic exercises of the knee joint(p＜0.01), and concentric torque at a joint angle of 60 degrees was significantly lower than those of the eccentric and isometric exercises of the elbow joint.
The increase in heart rate and the time of returning to the resting heart rate level were independent of the size of the contracting muscle mass and the types of exercise. The increment ratio for the heart rate was 70.4⁑23.6%.
Conclusion: In conclusion, the response of heart rate to the exercise is not influenced by the contracting muscle mass or the types of exercise in a short duration of maximal voluntary contraction, implying that special precautionary measures are not required for the isometric, eccentric and concentric isokinetic exercises.
Isometric contractions of muscles in upper extremities occur frequently during ordinary daily activities. The isometric handgrip exercise can be one of the best methods for the evaluation and treatment of patients with disability of upper extremity. However these isometric contractions can impose sudden and significant high stresses to the cardiovascular system.
The purpose of this study was to document the torque patterns and cardiovascular responses of subjects by the isometric handgrip exercises and hopefully to provide a guidance for the safe evaluations and prescriptions of isometric exercises.
Eighty healthy male subjects from 21 to 60 years of age performed isometric handgrip exercises using a Baltimore therapeutic equipment work simulator. The peak torque, time to peak torque, and torque at each second were measured by a six-second isometric strength trial program. The blood pressure and heart rate were measured simultaneously at rest and at each minute during isometric exercises at 30%, 50%, and 70% of the peak torque.
There were no differences in the peak torque, time to peak torque, and torque at each second between age groups(p＞0.05). After the onset of peak torque, the torque gradually decreased and recorded 72.8% of the peak torque at 6 seconds.
The mean arterial pressure and heart rate increased significantly during exercise(p＜0.001), but returned to the resting state immediately when the exercise stopped. The mean arterial pressures were significantly different when the duration of exercise prolonged at 50% and 70% of the peak torque(p＜0.05). And also the mean arterial pressures increased significantly when the strength of exercise increased as well(p＜0.001).
We have concluded that attentions should be given to patient's cardiovascular state, and duration and strengh of exercise when the isometric handgrip exercises are prescribed for the evaluation and treatment of patients.
The understandings of the characteristics of eccentric exercise are very important because all sports and daily activities under the gravity force should be well coupled between concentric contraction and eccentric contraction as accelerator and decelerator respectively. We tested 40 knee flexors and extensors of 20 normal young persons at different anglular velocities of 60o/sec and 120o/sec using Cybex 6000(A division of Lumax, New York) isokinetic dynamometer in order to know the characteristics of eccentric isokinetic contraction parameters by comparing with concentric isokinetic parameters.
Compared to the concentric isokinetic contraction, eccentric isokinetic the peak torque and average power values of knee extensor and flexor muscles showed negative values which means that eccentric contractions were coupled with concentric contractions as decelerator and energy absorptioner. The peak torque values of eccentric contraction were 38∼61%, 44∼79% higher in flexor and extensor, respectively than those of concentric contraction and not so decreased as the peak torque of concentric contraction decreased in high angular velocity. The average power values of knee flexor and extensor muscles were definitely low in eccentric contracton than those of concentric contraction but were increased simultaneously with high angular velocity contraction. Further studies about the velocity dependency, muscle soreness, methodology to measure real eccentric activities and other parameters of eccentric contraction are needed imminently.
First
Prev
