Isokinetics and Exercise Science - Volume 1, issue 1

Authors: Davies, George J. | Malone, Terry R. | Timm, Kent E.

Article Type: Editorial

DOI: 10.3233/IES-1991-1101

Citation: Isokinetics and Exercise Science, vol. 1, no. 1, pp. 6-6, 1991

Article Type: Editorial

DOI: 10.3233/IES-1991-1102

Citation: Isokinetics and Exercise Science, vol. 1, no. 1, pp. 7-8, 1991

Authors: Ellenbecker, Todd S.

Article Type: Research Article

Abstract: The purpose of this study was to determine whether significant strength differences exist between the dominant and nondominant arms of highly skilled tennis players. The relationship of this strength to the speed of a maximal effort tennis serve was also studied. Isokinetic testing of 22 highly skilled male tennis players was done using a Cybex II dynamometer and a Discipline RTD computerized data reduction system. Tests were conducted bilaterally for shoulder internal/external rotation, flexion/extension, forearm pronation/supination, and wrist flexion/extension. Speeds of 90, 210, and 300 deg/sec were used. Initial postimpact ball velocity of 15 maximal tennis serves was measured …by a CMI radar gun and RCA video camera. Significantly greater (p < .005) isokinetic strength was found in the dominant arm for shoulder internal rotation and flexion, as well as wrist flexion and forearm pronation. Shoulder extension and wrist extension were also stronger (p < .001) on the dominant arm. No differences were found between extremities for shoulder external rotation and forearm supination. Mean postimpact ball velocity measured by a radar gun was 107.8 ± 6.3 miles per hour and did not significantly correlate with any pattern of isokinetically measured strength. Postimpact ball velocity measured by video digitizing was 117.3 ± 10.4 miles per hour. Results from this investigation show greater dominant arm isokinetic muscular strength, as well as specific ratios of muscle strength surrounding joints of the upper extremity. These strength data did not correlate with the speed of a maximal effort tennis serve. These data are important for design of muscle conditioning and rehabilitation programs for athletes in unilaterally dominant upper extremity sports. Show more

Keywords: Tennis, isokinetics, muscle strength, upper extremity, arm, dominance

DOI: 10.3233/IES-1991-1103

Citation: Isokinetics and Exercise Science, vol. 1, no. 1, pp. 9-21, 1991

Authors: Tis, Laurie L. | Perrin, David H. | Snead, David B. | Weltman, Arthur

Article Type: Research Article

Abstract: A plethora of research has examined bilateral and reciprocal concentric strength relationships of the thigh musculature in a variety of athletic populations. However, little research has reported strength values of the trunk and hip musculature. Thus, the purpose of this investigation was to examine concentric and eccentric strength of the trunk and hip flexor and extensor muscle groups in female runners. Twenty-one habitual female runners were assessed for trunk and hip strength via isokinetic dynamometry (KinCom, Chattecx Corp.). Strength was reported in newtons (N) and calculated as the average force over the range of motion in which the joint was …tested. Eccentric strength at the trunk was greater than concentric strength. Similar results were found at the hip. Reciprocal muscle group ratios revealed that concentric trunk flexion was 52% of extension. Eccentric trunk flexion was 39% of extension. Concentric hip flexion was 98% of extension. Eccentric hip flexion was 103% of extension. The ratios were not significantly different. These findings establish previously unreported isokinetic strength values for the trunk and hip in female runners. Show more

Keywords: Isokinetics, trunk, hip, female runners

DOI: 10.3233/IES-1991-1104

Citation: Isokinetics and Exercise Science, vol. 1, no. 1, pp. 22-25, 1991

Authors: Dvir, Zeevi | Halperin, Nahum | Shklar, Arie | Robinson, Dror

Article Type: Research Article

Abstract: This study examines the relationship between force moments generated by the quadriceps femoris muscle group during concentric and eccentric isokinetic activity and the level of patellofemoral pain experienced in patellofemoral pain syndrome (PFPS) patients. The experimental population consisted of 55 patients with active PFPS (21 females, 34 males; mean age 21.1 yr; age range 19–42 yr) who were tested both concentrically and eccentrically on a Kin/Com isokinetic dynamometer system through a 0–90 deg flexion arc of knee motion. Testing consisted of four maximal efforts of concentric quadriceps femoris activity followed by eccentric activity, separated by a 10-s pause, across the …speeds of 30, 60, and 120 deg/sec. The subject's patellar pain level was assessed throughout the testing process using the Borg Category Ratio Scale. Analysis of variance with repeated measures determined that pain perception did not vary between female and male subjects, even though male quadriceps output was significantly greater than that of females, and that eccentric activity produced significantly greater pain than concentric activity. It was concluded that an inverse relationship exists between PFPS pain and isokinetic velocity and that a close association exists between level of pain and magnitude of joint load. Show more

Keywords: Quadriceps, patellofemoral pain, concentric activity, eccentric activity, isokinetic activity

DOI: 10.3233/IES-1991-1105

Citation: Isokinetics and Exercise Science, vol. 1, no. 1, pp. 26-30, 1991

Authors: Dvir, Zeevi | Halperin, Nahum | Shklar, Arie | Robinson, Dror

Article Type: Research Article

Abstract: The isokinetic moment-angular position curves of the quadriceps femoris were studied in a group of 21 women and 34 men presenting with patellofemoral pain syndrome (PFPS). The study focused on a specific irregularity of the torque curve, namely a sudden “break” in the monotonicity of the curve. Breaks appeared in 47% and 44% of the female and male groups, respectively, and during eccentric activity, exclusively, predominantly at the velocity of 30 deg/sec. The break occurred close to the location of the peak torque moment, at an average angle of 45 deg flexion, and lasted for about 10 deg in the …total arc of motion. The extent of load reduction due to the break effect was 25%-30% of subject body weight. A close association between the pain provoked during isokinetic loading and the break phenomenon was indicated in all subjects. The results suggest the applicability of incorporating analysis of the break phenomenon in the evaluation of patients with active PFPS. Show more

Keywords: Quadriceps, patellofemoral pain, break phenomenon, eccentric activity

DOI: 10.3233/IES-1991-1106

Citation: Isokinetics and Exercise Science, vol. 1, no. 1, pp. 31-35, 1991

Authors: Wilk, Kevin E. | Keirns, Michael A. | Andrews, James R. | Clancy, William G. | Arrigo, Christopher A. | Erber, Donna J.

Article Type: Research Article

Abstract: Rehabilitation following anterior cruciate ligament reconstruction surgery has changed significantly in the past 5 yr. Today, rehabilitation protocols emphasize immediate motion, immediate weight bearing, and early strengthening exercises. An aggressive rehabilitation program based on the healing rate, biomechanics of the knee joint, and principles of muscle physiology is imperative for successful rehabilitation. This study reports the isokinetic muscular performance data of 100 male recreational athletes collected 6 months postsurgery. The results demonstrated statistically significant differences (p < 0.001) for all knee extension parameters, including peak torque to body weight, total work to body weight, and average power to body …weight ratios at 180 deg/sec and 300 deg/sec. In contrast, knee flexion testing exhibited no significant differences in any of the above parameters. The results indicate that 6 months following anterior cruciate ligament-patellar tendon graft (ACL-PTG) reconstruction utilizing an aggressive rehabilitation program, hamstring muscular strength is equal bilaterally. However, the quadriceps continues to exhibit a 20%-25% deficit in recreational athletes. Show more

Keywords: Anterior cruciate ligament (ACL), aggressive rehabilitation, isokinetic parameters, criterion-based protocol

DOI: 10.3233/IES-1991-1107

Citation: Isokinetics and Exercise Science, vol. 1, no. 1, pp. 36-43, 1991

Authors: Timm, Kent E.

Article Type: Research Article

Abstract: The purpose of this clinical investigation was to examine the effects of several different treatment approaches, one of which included isokinetic exercise, on the relative success of chronic low-back pain rehabilitation over 5 yr. Under a descriptive paradigm, 100 subjects (31 females, 69 males; mean age 42 yr; age range 22–67 yr) underwent an 8-wk period of management in one of four different treatment groups: Modality, Back School, Clinical Exercise, Integrated. Initial findings revealed pain relief results of 32% (Modality) to 88% (integrated) and return to work results of 55% (Modality) to 100% (Integrated). Findings at 5 yr revealed continued …work results of 8% (Modality) to 82% (Integrated) and further treatment results of 6% (integrated) to 95% (Modality). Only the Integrated group (.91) demonstrated a significant correlation (p = .01) to rehabilitation success. It was concluded that an integrated program which includes isokinetic exercise was the most effective means of those evaluated for the successful 5-yr management of chronic low-back pain patients. Show more

Keywords: Isokinetics, spinal rehabilitation, low-back pain, industrial, functional restoration

DOI: 10.3233/IES-1991-1108

Citation: Isokinetics and Exercise Science, vol. 1, no. 1, pp. 44-48, 1991

Authors: Engle, Robert P.

Article Type: Research Article

Abstract: Acromioclavicular (AC) joint injury is a common problem encountered in contemporary sports medicine. Treatment approaches vary widely and often include a period of postinjury rehabilitation. In this paper, the course of postoperative AC joint reconstruction rehabilitation in a single professional athlete is analyzed. Isokinetic data, a frequently used indicator of patient progress, are presented and discussed as they pertain to this patient.

Keywords: Acromioclavicular joint injury, isokinetics

DOI: 10.3233/IES-1991-1109

Citation: Isokinetics and Exercise Science, vol. 1, no. 1, pp. 49-55, 1991