Isokinetic Peak Torque Of Quadriceps Research Articles

Which Tests Predict 6-Month Isokinetic Quadriceps Strength After ACL Reconstruction? An Examination of Isometric Quadriceps Strength and Functional Tests at 3 Months.

Restoration of quadriceps strength after anterior ligament reconstruction (ACLR) is a persistent challenge for patients and clinicians. Inadequate recovery of quadriceps strength has been linked to increase risk of re-injury. Developing methods of early identification of strength deficits is essential to allow clinicians to provide more individualized interventions early in the rehabilitation process. To determine whether 3-month isometric quadriceps strength, the Y-Balance Test (YBT), and the anterior step-down test are predictive of isokinetic quadriceps strength at six months in adolescents after ACLR. Retrospective cohort. Thirty-six adolescent patients with primary ACLR (58% female, 36% with concomitant meniscal repair, age: 15.7 ± 1.6 years). At three months post-operative, isometric quadriceps strength via isokinetic dynamometer, YBT-Lower Quarter, and anterior step-down tests were completed. At six months post-operative, an isokinetic knee strength assessment was completed. Regression analysis was used to evaluate the predictive relationship between 3-month isometric tests and 6-month isokinetic knee extension tests. Three-month post operative isometric quadriceps peak torque predicted isokinetic quadriceps peak torque at 6 months, F(1,34) = 19.61, p <0.001. Three-month isometric quadriceps peak torque accounted for 36.6% of the variance in normalized isokinetic quadriceps peak torque at 6 months with adjusted R2 = 34.7%. Including YBT anterior reach (β = 0.157, p = 0.318) in regression added 1.9% of variance when predicting 6-month isokinetic quadriceps peak torque, F (2,33) = 10.32, p <0.001, R2 = 0.385, ΔR2 = 0.019. At three months post-ACLR, isometric strength testing appears more optimal than other functional tests in predicting isokinetic quadriceps peak torque in later stages of rehabilitation for adolescents. Clinicians should use tests at three months that measure quadriceps strength if aiming to predict isokinetic quadriceps peak torque at six months post-ACLR, rather than using functional tests such as the YBT-LQ or anterior step-down. Level 3.

A comparison between hypertonic dextrose prolotherapy and conventional physiotherapy in patients with knee osteoarthritis.

The aim of the present study was to compare the efficacy of hypertonic dextrose prolotherapy (HDP) with conventional physiotherapy (CPT) in improving symptoms in females with knee osteoarthritis (OA). The present study included 60 patients with a diagnosis of knee OA. The patients were randomly assigned to the HDP (n=30) and CPT (n=30) groups. The patients in the HDP group were treated with a dextrose injection into the knee joint (25% dextrose) and around the knee (15% dextrose) in two sessions for 1 month, while those in the CPT group received a hot pack, transcutaneous electrical nerve stimulation and therapeutic ultrasound in five sessions a week for 4 weeks. Prior to commencing the treatment, and at 1 and 3 months post-treatment, all the patients were evaluated using the visual analog scale (VAS), Western Ontario and McMaster Osteoarthritis Index (WOMAC), the goniometric measurement of active knee range of motion (ROM), a 50-m walking test and isokinetic knee muscle strength measurements. There were no statistically significant differences between the two groups as regards the demographic characteristics at pre-treatment (P>0.05). However, at 1 and 3 months post-treatment, the scores of all the outcome parameters were significantly improved in the HDP group compared with the CPT group (P<0.05 for all). In both groups, a significant improvement was observed in the VAS scores, WOMAC total values and ROM following the treatments, with the greatest improvement observed in the HDP group (P<0.001). The isokinetic quadriceps peak torque measurements were increased in both groups following treatment. All the scores exhibited a statistically significant improvement in the HDP group at both 1 and 3 months post-treatment. On the whole, the results of the present study demonstrate that both HDP and CPT are effective treatment modalities to relieve pain, and increase functionality and strength in patients with knee OA. However, greater improvements in pain and functionality can be achieved with prolotherapy.

Feasibility And Responsiveness Of Isokinetic Quadriceps Function In Patients With Chronic Obstructive Pulmonary Disease

Peripheral muscle dysfunction has been associated with impaired health status and increased mortality in patients with chronic obstructive pulmonary disease (COPD). This highlights the importance of assessing and targeting peripheral muscle strength and endurance during pulmonary rehabilitation (PR). However, information regarding the feasibility and responsiveness of isokinetic quadriceps function following PR is limited. PURPOSE: To evaluate whether and to what extent the isokinetic evaluation of quadriceps muscle function meets the pre-defined test criteria in COPD patients; to determine the response to PR of isokinetic quadriceps muscle function. METHODS: A retrospective analysis of 2033 COPD patients (age: 65 ± 9 years, 52% male, forced expiratory volume in 1st second: 49 ± 22% predicted) following PR was performed. Individualized exercise training consisted of endurance, interval and strength straining and/or neuromuscular electrical stimulation. Isokinetic quadriceps function assessment consisted of 30 maximal extension-flexion contractions with a full range of motion at a fixed angular speed of 90°/s (computerized dynamometer). Criteria for a correct test performance were: completion of all 30 repetitions, peak torque reached within first five repetitions, and presence of work fatigue. Differences between pre and post PR were tested using paired t-tests. RESULTS: Pre PR, 27% of the patients did not fulfil one or more of the predefined test-criteria. In patients with a correct pre and post PR isokinetic test (n = 989), isokinetic quadriceps peak torque (∆ = 8 ± 12 Nm) and total work (∆ = 229 ± 234 J) were responsive to PR (both p-values<0.001). There was no change in work fatigue index following PR. CONCLUSION: Based on the current test criteria, three in four patients with COPD performed the isokinetic quadriceps test correctly during a baseline PR assessment. PR has a beneficial effect on isokinetic quadriceps peak torque and total work, but not work fatigue index, in patients with COPD. Supported by Lung Foundation grant (#5.1.18.232).

Short-term isokinetic and isometric strength outcomes after anterior cruciate ligament reconstruction in adolescents

ObjectivesTo examine differences in knee strength outcomes after ACL reconstruction according to quadriceps tendon (QT) or hamstring tendon (HT) autograft in adolescents. DesignRetrospective cohort. MethodsSurgical and clinical outcome data were collected. Analyses were conducted separately for female and male cohorts and grouped by graft type (HT or QT). A Mann-Whitney U test of independent samples was used to examine group differences according to graft type. Results107 females (age = 15.6 ± 1.5 years) and 94 males (age = 15.7 ± 1.5 years) were included. Mean time since surgery ranged from 7.2 to 7.9 months. Those with a QT autograft had decreased normalized isokinetic quadriceps peak torque on the involved limb compared to the HT group (p < 0.01, ES = 0.71–0.89). Normalized isometric hamstring peak torque was decreased for those with HT autograft in the female cohort (p = 0.02, ES = 0.57). ConclusionNormalized isokinetic quadriceps peak torque was reduced by 18–20% on the involved limb in those with a QT autograft. Normalized isometric hamstring peak torque was decreased by 13% for those with HT autograft in the female cohort. Method of strength testing may be an important consideration to fully appreciate strength deficits after ACL reconstruction according to graft type.

Eccentric versus conventional cycle training to improve muscle strength in advanced COPD: A randomized clinical trial

ObjectivesTo compare eccentric (ECC) and conventional concentric (CON) cycle training on quadriceps muscle strength in advanced COPD. Secondary objective was to assess functional capacity. MethodsA parallel-group, assessor-blind, randomized trial was conducted. Severe COPD patients were randomized to either an ECC (n = 13) or CON (n = 11) cycling program for 30-min, 3 times/week for 10 weeks. ECC group trained at ∼4-fold higher power than the CON group at similar relative heart rate intensity. ResultsIsometric and isokinetic quadriceps peak torque improved after ECC but not CON; between group difference was significant for isometric peak muscle force (p < 0.05). Peak cycling power and endurance time increased in both groups (p < 0.05). Dyspnea at peak cycling power improved only after ECC training (p < 0.05). Sensory intensity ratings of dyspnea and leg fatigue were significantly lower (p < 0.05) during ECC compared with CON at equivalent relative heart rate intensities. ConclusionsECC could be an effective alternative and/or adjunct modality to pulmonary rehabilitation in severely ventilatory limited COPD patients.

Does Kinesiology Taping Improve Muscle Strength and Function in Knee Osteoarthritis? A Single-Blind, Randomized and Controlled Study.

This study aims to evaluate the efficacy of kinesiology taping (KT) on pain, movement restriction, walking speed, daily living activities, and isokinetic muscle performance in female patients with knee osteoarthritis. The study included 61 female patients (mean age 53.5±3.5 years; range 50 to 60 years) who were admitted to Physical Medicine and Rehabilitation Outpatient Clinic with complaints of mechanical knee pain. Knee osteoarthritis was diagnosed according to the clinical/ radiological criteria of the American College of Rheumatology and patients with Kellgren-Lawrence grade 2 and 3 were included. Patients were randomly divided into two groups. Both groups received transcutaneous electrical nerve stimulation for 30 minutes, hot pack for 30 minutes, and therapeutic ultrasound for 10 minutes in a day for three weeks (five days in a week). Also, one group was treated with KT (KT group, n=31) while the other group was treated with sham-KT (sham-KT group, n=30) one time a week for three weeks. A home program of around the knee strengthening exercises was recommended for all patients. All patients were evaluated with visual analog scale, Western Ontario and McMaster Osteoarthritis Index (WOMAC) values, goniometric measurement of active knee range of motion, 50-meter walking distance, and isokinetic knee extensor muscle peak torque measurements before treatment, at the end of treatment, and at one month and three months after treatment. There was a significant improvement in after treatment and first month visual analog scale values in the KT group compared to the sham-KT group (p<0.05). In the KT group, the WOMAC pain and WOMAC total scores decreased significantly after treatment compared to the sham-KT group (p<0.05). Visual analog scale values were significantly decreased after treatment in both groups (p<0.05). In both groups; WOMAC pain, stiffness, physical function, and total values decreased significantly after treatment (p<0.05). In both groups, isokinetic quadriceps peak torque measurements were increased after treatment (p<0.05). The application of KT to females with knee osteoarthritis appears to be a method that may be effective on pain and functional capacity.

EVALUATION OF THE RELATIONSHIP BETWEEN ISOKINETIC STRENGTH AND FIELD PERFORMANCE IN PROFESSIONAL MALE VOLLEYBALL PLAYERS

The purpose of this study was to investigate the relationship between the isokinetic quadriceps and hamstring strength and, sprinting ability, agility and vertical jump performance in male volleyball players. Twenty professional male volleyball players (average age 24.5±1.1 years; mean body height 186.5±5.02 cm; mean body mass 75.34±8.39 kg) participated in this study voluntarily. For each player, isokinetic concentric muscle strength tests were performed at 60°/s and 300°/s, jump performance was evaluated by countermovement jump (CMJ) and squat jump (SJ) tests, sprint ability was determined by single sprint performance (10-30 m), and agility performance was measured using the T drill agility test. There were statistically significant correlation between peak torque of extensor and flexor muscles strength at 60°/s, 300°/s contraction velocities and squat jump, countermovement jump (p 0.05). Moreover, statistically significant relations were found between the performances of athletes in different field tests (p<0.05). This study has shown that isokinetic peak torque of quadriceps and hamstring are significant predictor for field based anaerobic tests, SJ and CMJ, that are similar to the actions made in the game for volleyball players. Article visualizations:

Knee Objective Stability and Isokinetic Thigh Muscle Strength after Anterior Cruciate Ligament Reconstruction: A Randomized Six-Month Follow-Up Study

Purpose: The most frequently used grafts for intra-articular anterior cruciate ligament (ACL) reconstruction are the autologous patellar tendon (PT) or doubled semitendinosus and gracilis tendons (STG) autografts. There are still controversies about graft selection for primary ACL reconstruction. Methods: A prospective, randomized study was conducted on 57 patients who underwent arthroscopically assisted ACL reconstruction between January 2010 and February 2011. In 29 patients ACL reconstruction was performed with hamstring tendon autograft (STG group), and in 28 patients the ACL reconstruction was performed with patellar tendon autograft (PT group). At 6 months follow-up, all patients have performed the isokinetic extensor and flexor muscles strength and KT-1000 measurements. Results: At 6 months after surgery, we found significantly lower average isokinetic quadriceps peak torque in the PT group compared to the STG group at angular velocity of 60°/s. However, at the same time we did not find significant difference in flexor muscle power comparing both groups. The manual maximum KT-1000 arthrometer side-to-side difference was 1.7 ± 1.7 mm for the PT group and 1.9 ± 1.6 mm for the STG group (P=0.398). No significant correlation was found between the knee objective stability (KT-1000 measurements) and the isokinetic thigh muscle strength (extensors, Spearman’s rho=0.057, P=0.671; flexors, Spearman’s rho=0.094, P=0.489). Conclusions: Both hamstring and patellar tendon autografts provided good objective stability at 6 months after surgery In addition, regardless of which graft was used, a considerable percentage of patients continue to have strength deficits. In our opinion, the ACL-reconstructed leg should have 85% or greater return to the strength of the normal leg as one criterion before release to full sports activities. We were particularly intrigued to find only half of the competitive athletes achieved this goal at 6 months after surgery.

Knee muscle strength at varying angular velocities and associations with gross motor function in ambulatory children with cerebral palsy

The aim of this study was to evaluate the relationships of muscle strength at different angular velocities and gross motor functions in ambulatory children with cerebral palsy (CP). This study included 33 ambulatory children with spastic CP aged 6-15 years and 15 children with normal development. Children with CP were categorized into level I (n=17) or level II (n=16) according to Gross Motor Function Classification System (GMFCS) levels. All children underwent curl-up test and isokinetic tests of the knee extensor and flexor muscle. Children with CP underwent the gross motor function assessments, including the Gross Motor Function Measure (GMFM-66) and the gross motor subtests of Bruininks-Oseretsky Test of Motor Proficiency (BOTMP). The hamstring-quadriceps ratio (HQ ratio) was calculated as 100%×(isokinetic peak torque of hamstring (knee flexor)/isokinetic peak torque of quadriceps (knee extensor)). Children with GMFCS level II had lower BOTMP and GMFM-66 scores, curl-up scores, HQ ratio, and knee muscle strength, especially knee flexor, compared to those with GMFCS level I. The regression analysis showed that knee flexor torques at 60 and 90°/s are mainly related to balance (r(2)=0.167, p=0.011) and strength (r(2)=0.243, p=0.002) while knee flexor torques at 120°/s mainly contribute to running speed and agility (r(2)=0.372, p<0.001). These findings suggest that children with CP had knee strength deficits, especially knee flexor. Postural muscle (knee flexor) strength dominated gross motor function than antigravity muscle strength (knee extensor). The knee flexor strength at different angular velocities was associated with various gross motor tasks. The HQ ratio may be used as a potential biomarker to probe the therapeutic effectiveness for muscle strengthening in these children. These data may allow clinician for formulating effective muscle strengthening strategies for these children.

Isokinetic quadriceps and hamstring muscle strength and knee function 5 years after anterior cruciate ligament reconstruction: comparison between bone-patellar tendon-bone and hamstring tendon autografts

Existing clinical studies have not proven which graft is to be preferred in anterior cruciate ligament (ACL) reconstruction. In recent years, bone-patellar tendon-bone and hamstring tendons have been the most frequently used graft types. Muscle strength deficit is one of the consequences after ACL reconstruction. The aim of this study was to evaluate possible differences in hamstring and quadriceps muscle strength and knee function 5 years after ACL reconstruction between the BPTB and the STG groups. The study group consisted of 288 patients (132 women, 156 men) with a unilateral ACL rupture who had received a BPTB (175 patients) or STG (113 patients) ACL reconstruction. Lower extremity concentric isokinetic peak extension and flexion torques were assessed at the angular velocities of 60 degrees /s and 180 degrees /s. The International Knee Documentation Committee (IKDC), the Tegner activity level, the Lysholm knee and the Kujala patellofemoral scores were also collected. Isokinetic quadriceps peak torque (percentage of the contralateral side) was 3.9% higher in the STG group than in the BPTB group at the velocity of 60 degrees /s and 3.2% higher at the velocity of 180 degrees /s and the isokinetic hamstring peak torque 2% higher in the BPTB group than in the STG group at the velocity of 60 degrees /s and 2.5% higher at the velocity of 180 degrees /s. In both groups the subjects had weaker quadriceps and hamstring muscle strength in the injured extremity compared with the uninjured one. In the single-leg hop test (according to the IKDC recommendations) there was a statistically significant difference (P = 0.040) between the groups. In the STG group, 68% of the patients had the single-leg hop ratio (injured vs. uninjured extremity) > or =90%, 31% of the patients 75-89% and 1% of the patients <75%, while in the BPTB group the corresponding percentages were 72, 21 and 7%. However, no statistically significant differences in clinical outcome were found between the groups as determined by the IKDC, Tegner activity level, Lysholm knee and Kujala patellofemoral scores.

Effect of a lateral step-up exercise protocol on quadriceps and lower extremity performance.

Closed kinetic chain exercises have been promoted as more functional and more appropriate than open kinetic chain exercises. Limited research exists demonstrating the effect of closed kinetic chain exercise on quadriceps and lower extremity performance. The purpose of this study was to determine the effect of a lateral step-up exercise protocol on isokinetic quadriceps peak torque and the following lower extremity activities: 1) leg press, 2) maximal step-up repetitions with body weight plus 25%, 3) hop for distance, and 4) 6-m timed hop. Twenty subjects participated in a 4-week training period, and 18 subjects served as controls. For the experimental group, a repeated measure ANOVA comparing pretest and posttest values revealed significant improvements in the leg press (p < or = .05), step-ups (p < or = .05), hop for distance (p < or = .05), and hop for time (p < or = .05) and no significant increase in isokinetic quadriceps peak torque (p > or = .05). Over the course of the training period, weight used for the step-up exercise increased (p < or = .05), repetitions decreased (p < or = .05), and step-up work did not change (p > or = .05). For the control group, no significant change (p > or = .05) occurred in any variable. The inability of the isokinetic dynamometer to detect increases in quadriceps performance is important because the isokinetic values are frequently used as criteria for return to functional activities. We conclude that closed kinetic chain testing and exercise provide additional means to assess and rehabilitate the lower extremity.

Effect of a Lateral Step-up Exercise Protocol on Quadriceps Isokinetic Peak Torque Values and Thigh Girth

Knee injury rehabilitation often includes the step-up exercise. However, the authors have been unable to locate documentation of the effect of the step-up exercise on lower extremity strength indices. The purpose of this study was to determine the effect of a six-week lateral step-up exercise protocol on quadriceps muscle group strength. Twenty female nonathletes (age = 20 +/- 1.5 yrs, ht = 162.6 +/- 4.9 cm, wt = 64.1 +/- 0.5 kg) were randomly assigned to a control or experimental group. Pretest concentric and eccentric strength measures were obtained at 60 degrees /sec on a Kin-Com isokinetic dynamometer. Thigh girth measurements were obtained 10 and 20 cm superior to the knee joint line. An independent t-test of the difference between pre and post isokinetic strength and girth measurements between the control and experimental groups revealed no significant difference (p > .05). In addition, no significant difference was found for the exercised and nonexercised extremity for the experimental group (p > .05). These findings suggest that this lateral step-up protocol did not provide sufficient overload to increase isokinetic strength of the quadriceps muscle group or increase thigh girth in healthy subjects. In addition, open chain assessment of muscle strength may not adequately assess strength changes incurred via closed chain exercise. Clinicians should use caution in assuming that step-up exercises provide sufficient overload to increase thigh girth or isokinetic quadriceps peak torque values. J Orthop Sports Phys Ther 1992;15(3):151-155.