Effect Of Isokinetic Strength Training Research Articles

Neuromuscular and functional responses to concentric and eccentric strength training in older adults

The type of muscle action is important when designing exercise interventions for older individuals and may result in different effects. In this study we performed a systematic review of controlled trials comparing the effects of concentric and eccentric resistance training, performed on isokinetic dynamometers, on lower extremity muscular and functional performance in older adults (CDR42017075316). Six databases (Pubmed, CINAHL, SPORTDiscus, PEDro, Cochrane Central and Embase) were searched. Outcomes of interest concerned neuromuscular and functional performance. Trials should consider 65 years or older individuals participating in concentric and/or eccentric training on isokinetic dynamometers, at least twice a week, during at least four weeks. Results should be compared to a control group or between different contraction types. A qualitative analysis of data was done. Quality assessment considered the Cochrane Risk of Bias Tool. The initial search returned 10376 studies and four trials were considered for inclusion. Three trials compared the effects of concentric training with the ones of control groups, and one compared the effects of concentric with the ones of eccentric training. All trials focused on knee extensor and flexor muscles, and one also focused on ankle dorsiflexors and plantarflexors. Training programs included three sessions/week lasting 8-12 weeks. Concentric training improved strength, power, and muscle antagonist coactivation compared to the control. Concentric and eccentric training improved knee isometric, concentric and eccentric strength and self-paced step test, with no effect on gait speed. They did not consider muscle structural parameters. The findings of beneficial effects of isokinetic concentric and eccentric resistance training on muscle strength and power in older adults were consistent. However, there is a lack of trials addressing the effects of isokinetic strength training on muscle structure and functionality.

The role of isokinetic muscle strength training in rehabilitation after rotator cuff repair

Objective To explore the effect of isokinetic strength training on post-operative rehabilitation of rotator cuff injury after arthroscopy. Methods Forty patients who had received arthroscopic repair of a rotator cuff tear no less than 3 months previously and who had normal joint movement were selected and randomly divided into a routine training group (the control group) and an isokinetic strength training group (the experimental group), each of 20. Both groups did internal and external rotation strength training with Thera-Band elastic bands, 10-20 times/session, 3 sessions/day. The experimental group additionally underwent isokinetic strength training of the shoulder for 15-20 minutes twice a week. Isokinetic strength tests were performed after 3 and 6 months at test speeds of 60°/s and 180°/s. The evaluation indexes included the internal and external rotation peak torque, peak TQ/BW, the deficit of the affected shoulder joint, the peak torque difference and peak TQ/BW difference before and after training. Results Both groups had improved significantly after the treatment, but the improvement in the experimental group was significantly greater than in the control group, on average. Conclusion Isokinetic muscle strength training is helpful to recover strength after arthroscopic repair of a rotator cuff injury, especially the rapid external rotation muscle strength. It is worthy of clinical application. Key words: Rotator cuff injury; Isokinetic training; Rehabilitation

English

Introduction: A 29-year old male athlete (body mass: 64 kg; height: 172 cm)sustained complete ACL rupture of the right knee. He was a martial-arts player and the injurywas repetitive, overuse in nature due to cyclic unilateral loading and unloading of the rightknee during training sessions. Rupture was diagnosed through detailed patient history, clinicalphysical examination and was confirmed through magnetic resonance imaging (MRI) of theright knee. Surgical reconstruction of the ACL was planned and a patellar tendon graft wasused. His baseline isokinetic data was recorded 4 months after the surgery. Objective: Thiscase study describes the effects of isokinetic strength training on knee biomechanics andphysical function of an ACL-reconstructed martial-arts athlete. Setting: Pakistan Sports BoardIslamabad. Study period: 40 days. Materials and Methods: Biodex System 3 Pro was used totrain the athlete for 15 sessions on alternate day basis. Average peak torque, average power,total work and peak torque to body weight ratio were recorded for hamstring and quadricepsbefore and after isokinetic rehabilitation. The athlete was positioned in the dynamometer withupright back while hip and knee were flexed to 90 degrees. Unilateral isokinetic contractionswere performed according to a premeditated exercise protocol. Both hamstring and quadricepswere tested isokinetically at five different movement speeds (30deg/sec, 90deg/sec, 150deg/sec, 210deg/sec, and 270deg/sec). Five contractions were performed at each speed duringboth knee flexion and extension. At baseline, average peak torque was higher at lower speedsfor both hamstring and quadriceps. Results: As a result of rehabilitation, average peak torquefor hamstring and quadriceps significantly improved at speeds of 150deg/sec and 90deg/secrespectively. Average power, peak torque to body weight ratio, total work was also improved forboth hamstring and quadriceps. Two physical performance tests - agility run test and verticaljump test - were used to assess the effects of training and both performance tests improved 51%and 100% respectively. Conclusion: Isokinetic training improved the strength of quadricepsand hamstring after ACL reconstruction. Hamstring muscle demonstrated greater traininginducedincrements in torque production compared to quadriceps at all contraction velocities.

KNEE BIOMECHANICS AND PHYSICAL PERFORMANCE;

Introduction: A 29-year old male athlete (body mass: 64 kg; height: 172 cm)sustained complete ACL rupture of the right knee. He was a martial-arts player and the injurywas repetitive, overuse in nature due to cyclic unilateral loading and unloading of the rightknee during training sessions. Rupture was diagnosed through detailed patient history, clinicalphysical examination and was confirmed through magnetic resonance imaging (MRI) of theright knee. Surgical reconstruction of the ACL was planned and a patellar tendon graft wasused. His baseline isokinetic data was recorded 4 months after the surgery. Objective: Thiscase study describes the effects of isokinetic strength training on knee biomechanics andphysical function of an ACL-reconstructed martial-arts athlete. Setting: Pakistan Sports BoardIslamabad. Study period: 40 days. Materials and Methods: Biodex System 3 Pro was used totrain the athlete for 15 sessions on alternate day basis. Average peak torque, average power,total work and peak torque to body weight ratio were recorded for hamstring and quadricepsbefore and after isokinetic rehabilitation. The athlete was positioned in the dynamometer withupright back while hip and knee were flexed to 90 degrees. Unilateral isokinetic contractionswere performed according to a premeditated exercise protocol. Both hamstring and quadricepswere tested isokinetically at five different movement speeds (30deg/sec, 90deg/sec, 150deg/sec, 210deg/sec, and 270deg/sec). Five contractions were performed at each speed duringboth knee flexion and extension. At baseline, average peak torque was higher at lower speedsfor both hamstring and quadriceps. Results: As a result of rehabilitation, average peak torquefor hamstring and quadriceps significantly improved at speeds of 150deg/sec and 90deg/secrespectively. Average power, peak torque to body weight ratio, total work was also improved forboth hamstring and quadriceps. Two physical performance tests - agility run test and verticaljump test - were used to assess the effects of training and both performance tests improved 51%and 100% respectively. Conclusion: Isokinetic training improved the strength of quadricepsand hamstring after ACL reconstruction. Hamstring muscle demonstrated greater traininginducedincrements in torque production compared to quadriceps at all contraction velocities.

The Effects of Isokinetic Strength Training on Strength at Different Angular Velocities: a Pilot Study

The Effects of Isokinetic Strength Training on Strength at Different Angular Velocities: a Pilot Study

The therapeutic effects of isokinetic strength training combined with intra-articular injection of hyaluronate and joint mobilization for patients with knee osteoarthritis

Objective To observe any effects of using isokinetic strengthening exercises combined with intra-articular injection of sodium hyaluronate and joint mobilization in treating patients with knee osteoarthritis (KOA).Methods Eighty-one KOA patients were divided into a combined treatment group,a conventional treatment group and a control group.The combined treatment group received isokinetic strengthening training,intra-articular injections of sodium hyaluronate and joint mobilization therapy; the conventional treatment group received the injections and mobilization only; the control group was instructed to do ankle pumps at home on their own.Before the start of treatment and after 4 weeks,knee pain was self-assessed [using a visual analogue scale (VAS) for pain] along with knee range of motion (ROM),quality of life (using the WOMAC condensed health survey rating scale) and indexes of isokinetic strength [including the knee flexors,extensor peak torque (PT),and the flexion and extension angles corresponding peak torque (AOPT)] in both groups.Results After 4 weeks of treatment,statistically significant improvements compared to the baseline values were observed in both groups.The combined treatment group,however,improved to a significantly greater extent than the conventional treatment group in terms of all of the measures.Conclusion Isokinetic strength training combined with intra-articular injections of sodium hyaluronate and joint mobilization has a synergistic effect in enhancing knee stability and improving the performance in activities of daily life of KOA patients. Key words: Knee osteoarthritis; Isokinetic strength training; WOMAC index

Isokinetic training increases ulnar bending stiffness and bone mineral in young women

Numerous studies have investigated the effects of physical activity on bone health; however, little is known about the effects of isokinetic strength training on bone. While bone mineral density (BMD) is widely used to assess bone health and fracture risk, there are several limitations of this measure that warrant new technology development to measure bone strength. The mechanical response tissue analyzer (MRTA) assesses bone strength by measuring maximal bending stiffness ( EI). We hypothesized that isokinetic strength training of the elbow flexors and extensors would increase ulnar EI, BMD, and bone mineral content (BMC) in young women. Fifty-four women trained the nondominant arm 3 times per week for 20 weeks; 32 trained concentrically (CON) and 22 trained eccentrically (ECC). Subjects were assessed for the following variables pre- and post-training: CON and ECC peak torque of the elbow flexors and extensors with isokinetic dynamometry, ulnar mineral content and density using dual-energy X-ray absorptiometry, and ulnar EI using MRTA. Isokinetic training increased CON (17%) and ECC (17%) peak torque, even when controlling for changes in the untrained arm. Eccentric training increased CON and ECC peak torque while CON training improved CON peak torque only. Isokinetic training increased ulnar EI 28%, which was statistically greater than the untrained arm. Ulnar EI increased 25% with CON training and 32% with ECC training. Both training modes resulted in greater EI gains compared to the untrained limb. Isokinetic training increased ulnar BMC (2.7%) and BMD (2.3%), even when controlling for untrained ulna changes. Both training modalities resulted in BMC and BMD increases; however, only CON training yielded gains when controlling for changes in the untrained limb. In conclusion, isokinetic strength training increases ulnar EI, BMC, and BMD in young women; no statistical differences were noted between CON and ECC training modes.

Effects of isokinetic strength training on walking in persons with stroke: A double-blind controlled pilot study

Objectives: The goal most often stated by persons with stroke is improved walking function. The purpose of this study was to determine the effects of isokinetic strength training on walking performance, muscle strength, and health-related quality of life in survivors of chronic stroke. Methods: Twenty participants (age, 61.2 ± 8.4 years) with chronic stroke were randomized into 2 groups. The experimental group undertook maximal concentric isokinetic strength training, whereas the control group received passive range of motion of the paretic lower extremity 3 times a week for 6 weeks. The Kin-Com Isokinetic Dynamometer (Chattanooga Group Inc., TN) was used for both the strengthening and passive range of motion exercises. The Mann-Whitney U test was used to compare the changes in scores (postintervention minus baseline) between the control and experimental groups for a composite lower extremity strength score, walking speed (level-walking and stair-walking) and health-related quality of life measure (36-Item Short Form Health Survey [SF-36]). Results: Both the experimental and control groups increased their strength and walking speed postintervention; however, there were no differences in the changes in walking speed between the groups. There was a trend (P =.06) toward greater strength improvement in the experimental group compared with the control group. No changes in SF-36 scores were found in either group. Conclusions: Intervention aimed at increasing strength did not result in improvements in walking. The results of this study stress the importance of controlled clinical trials in determining the effect of specific treatment approaches. Strength training in conjunction with other task-related training may be indicated. Copyright © 2001 by National Stroke Association

Effects of isokinetic strength training on concentric and eccentric torque development in the ankle dorsiflexors of older adults.

This study quantifies concentric and eccentric dorsiflexor muscle torque at various movement velocities and determines the neuromuscular effects from short-term practice of repeated maximal voluntary contractions using an isokinetic resisted exercise program in older adults. Twenty-eight subjects (76.3+/-4.6 years) trained concentric and eccentric dorsiflexion 3 days per week for 2 weeks at 30 degrees, 90 degrees, and 180 degrees/s through 40 degrees of dorsiflexion range of motion. Peak torque, rate of torque development, surface electromyography, and strength curves at each velocity were compared before and after training. Increases were found for concentric (27%) and eccentric (20%) dorsiflexor peak torque and concentric rate of torque production (20%-53%) across all movement velocities (p < .01). Training also significantly increased dorsiflexor concentric (64%) and eccentric (55%) surface electromyography; taken together, this is evidence of apparent adaptation of neural factors in older adults with short-term training. These findings support that eccentric and concentric strength training enhances the control and production of ankle muscle dorsiflexor torque in older adults, with implications for improving functional mobility of the ankle joint.

Effect of isokinetic strength training on functional ability and walking efficiency in in adolescents with cerebral palsy

Effect of isokinetic strength training on functional ability and walking efficiency in in adolescents with cerebral palsy