Peak Torque Ratio Research Articles

Isokinetic strength training program for muscular imbalances in professional soccer players

The aim of the study was to investigate the effect of a muscular training program on soccer players’ performance of which initially appeared imbalances or deficits. The study was conducte on 68 professional soccer players (age, 24.1±5.7 years; weight, 76.8±5.7 kg; height, 1.82±7 cm) participating in the championship of the first Greek national division over 2 years. During the preparation period, all the players performed an isokinetic test of knee flexors and extensors (60° s−1 and 180° s−1). These initial measurements detected muscular imbalances or deficits in 27 players (40%). The 27 players followed a specific isokinetic training program for 2 months, 3 times per week. After completion of the isokinetic training program, the 68 players repeated the isokinetic test. The analysis revealed significant differences between the pre-and post-training measures at both angular velocities in peak torque values, in differences from one limb to the other, and in peak torque ratios for flexors and extensors. Consequently, the application of this specific isokinetic training program can restore imbalances in knee muscle strength efficiently.

Assessment of agonist–antagonist shoulder torque ratios in individuals with paraplegia: a new interpretative approach

Cross-sectional study. To evaluate isokinetic shoulder flexor-extensor (F/E) and abductor-adductor (Ab/Ad) torque ratios in individuals with paraplegia using a new interpretative approach. We proposed to study torque ratios according to joint angle sections (15 degrees angle subgroups) over a selected range of motion. Pathokinesiology Laboratory, Montreal, Canada. Sixteen individuals with complete motor paraplegia, without shoulder pain or impairment, were included in this study. After a preloading period of 1 s, maximum isokinetic concentric contractions of all muscle groups were completed at 30, 60 and 120 degrees s(-1) over the entire tested ranges of motion (70 to -35 degrees for the flexion-extension and 15 to 60 degrees for the abduction-adduction). After the continuous torque curves were rebuilt, the mean F/E and Ab/Ad torque ratios were calculated and analyzed every 15 degrees. A significant modification of the F/E (F=66.3; P<0.001) and Ab/Ad (F=100.6; P<0.001) torque ratios was observed according to the 15 degrees angle subgroup evaluated. More precisely, a progressive decline of both the F/E and Ab/Ad ratios was noted as the shoulder flexion or abduction progressed. Angular velocity did not have any influence on torque ratio values. Angle subgroup torque ratio analysis leads to a better estimation of the balance between the agonist and antagonist muscle groups than does traditional peak torque ratio analysis. In individuals with paraplegia, this precise estimation of torque ratios may lead to the development of specific shoulder strengthening programs to prevent muscle imbalance and its consequences.

Abnormal isokinetic time-to-peak torque of the medial rotators of the shoulder in subjects with impingement syndrome

The time-to-peak torque (TPT) and the peak torque ratio of the lateral to medial rotators (LR/MR) during isokinetic lateral and medial rotation of the shoulder were evaluated in patients with shoulder impingement and in healthy subjects. Fifteen patients with shoulder impingement on the dominant side and 9 healthy subjects were evaluated. TPT and LR/MR were measured bilaterally during isokinetic concentric lateral and medial rotation at 60 degrees/s and 180 degrees/s. The impingement group showed a bilateral decrease in the TPT during medial rotation for both 60 degrees/s and 180 degrees/s. No differences were found in the LR/MR between the groups. It is proposed that decreased (TPT) of the medial rotators can be used as a tool for early detection of shoulder impingement. Notably, the decreased time-to-peak torque of the medial rotators may occur before the alteration in the peak torque ratio.

Contributory factors to the results of gravity-assisted pivot-shift test for anterior cruciate ligament injury: the significance of muscle torque around the knee

Gravity-assisted pivot-shift (GAPS) test is a newly advocated test for anterior cruciate ligament (ACL) injury. It induces anterolateral rotatory instability with valgus stress to the knee applied by gravitational force during patient's active knee motion. We investigated prospectively the relationships between the results of the GAPS test and the possible contributory factors and sought to clarify the determinant factors of the GAPS test. A total of 54 knee joints of 54 patients with unilateral ACL injury (29 males, 25 females, average 23.4 +/- 9.0 years old) were enrolled in this study and were divided into two groups, i.e., positive GAPS test group and negative GAPS test group. Muscle torque around the knee joints measured before surgery, configuration of the femoral condyle and tibial posterior slope angle measured on lateral radiograph, and other clinical factors were compared between the two groups using Mann-Whitney U test or chi-square test. According to the results of these analyses, factors having a statistically significant difference were additionally evaluated using multiple logistic regression analysis to reveal items with strong relevance to a positive GAPS test. The results of the multiple logistic regression analysis showed that the flexor/extensor peak torque ratio of contralateral uninjured knees and sex had a significant correlation with the results of the GAPS test. The relatively less flexor muscle torque compared with extensor muscle torque, and being a female patient were considered to be the determinant factors of a positive GAPS test.

Reliability of isokinetic strength imbalance ratios measured using the Cybex NORM dynamometer

The main aim of this study was to examine the absolute and relative reliability of some commonly used strength imbalance indices such as concentric hamstring-to-concentric quadriceps ratio, eccentric hamstring-to-concentric quadriceps ratio and bilateral concentric and eccentric strength ratios. An additional aim was to examine the reliability of the peak torque and work of the knee extensor and flexor muscles measured using the Cybex NORM dynamometer. Eighteen physically active healthy subjects (mean +/- standard deviation, age 23 +/- 3 years, height 176 +/- 5 cm, body mass 74 +/- 8 kg) were tested three times with 96 h between sessions. Peak torque, average work, unilateral and bilateral ratios were determined at 60, 120, 180 and -60 degrees s(-1). Low (0.34) to moderate (0.87) relative reliability (intraclass correlation coefficient, ICC) was found for strength imbalance ratios with eccentric hamstring-to-concentric quadriceps ratio showing the greater ICC (>0.80). High ICC values (0.90-0.98) were found for peak torque and average work. Absolute reliability (standard error of measurement) ranged from 3.2% to 8.7% for strength imbalance ratios and from 4.3% to 7.7% for peak torque and average work measurements. This study established the reliability of the most common strength imbalance ratios and of absolute isokinetic muscle strength assessed using the Cybex NORM.

Hamstrings to quadriceps peak torque ratios diverge between sexes with increasing isokinetic angular velocity

Our purpose was to determine if females demonstrate decreased hamstrings to quadriceps peak torque (H/Q) ratios compared to males and if H/Q ratios increase with increased isokinetic velocity in both sexes. Maturation disproportionately increases hamstrings peak torque at high velocity in males, but not females. Therefore, we hypothesised that mature females would demonstrate decreased H/Q ratios compared to males and the difference in H/Q ratio between sexes would increase as isokinetic velocity increased. Studies that analysed the H/Q ratio with gravity corrected isokinetic strength testing reported between 1967 and 2004 were included in our review and analysis. Keywords were hamstrings/quadriceps, isokinetics, peak torque and gravity corrected. Medline and Smart databases were searched combined with cross-checked bibliographic reference lists of the publications to determine studies to be included. Twenty-two studies were included with a total of 1568 subjects (1145 male, 423 female). Males demonstrated a significant correlation between H/Q ratio and isokinetic velocity (R=0.634, p<0.0001), and a significant difference in the isokinetic H/Q ratio at the lowest angular velocity (47.8+/-2.2% at 30 degrees /s) compared to the highest velocity (81.4+/-1.1% at 360 degrees /s, p<0.001). In contrast, females did not demonstrate a significant relationship between H/Q ratio and isokinetic velocity (R=0.065, p=0.77) or a change in relative hamstrings strength as the speed increased (49.5+/-8.8% at 30 degrees /s; 51.0+/-5.7% at 360 degrees /s, p=0.84). Gender differences in isokinetic H/Q ratios were not observed at slower angular velocities. However, at high knee flexion/extension angular velocities, approaching those that occur during sports activities, significant gender differences were observed in the H/Q ratio. Females, unlike males, do not increase hamstrings to quadriceps torque ratios at velocities that approach those of functional activities.

Test-Retest Reliability of Isokinetic Knee Extension and Flexion

Sole G, Hamrén J, Milosavljevic S, Nicholson H, Sullivan SJ. Test-retest reliability of isokinetic knee extension and flexion. Objective To assess reliability of isokinetic peak torque and work for knee flexion and extension. Design Single-group test-retest. Setting University laboratory. Participants Eleven men and 7 women (mean age, 21y). Interventions Not applicable. Main Outcome Measure Peak torque and work for concentric and eccentric knee extension and flexion were recorded at 60°/s for 3 trials on 2 occasions. Intraclass correlation coefficient model 3,1 (ICC 3,1), standard error (SE) of measurements, and smallest real differences were calculated for the maximum and for the mean peak torque and work of the 3 repetitions. Results Relative reliability was “very high” for peak torque and work (ICC range, >.90). The SE measurements ranged between 5% and 10% of the initial values for both peak torque and work. The smallest change that indicates a real improvement for a single subject (smallest real differences) ranged from 12% to 25% for peak torque and work variables and from 25% to 30% for the peak torque ratios. Conclusions Isokinetic concentric and eccentric knee extensor and flexor strength variables are reliable when measured by the same examiner in asymptomatic subjects.

Identification of feigned maximal shoulder external rotation effort

Objective: To examine the efficiency of the difference between the isokinetic eccentric to concentric strength ratios at high and low velocities (DEC) for identifying feigned maximal shoulder external rotation effort. Background: Previous studies have indicated that the DEC is a powerful identifier of feigned maximal effort. However comparison of maximal versus feigned maximal shoulder external rotation effort has not been undertaken. Due to the high prevalence of rotational shoulder disorders and their chronic ramifications in terms of occupational disability such a study is of specific interest. Design: Maximal and feigned maximal shoulder external rotation isokinetic efforts were compared. Setting: Functional evaluation unit at an occupational rehabilitation centre. Subjects: Seventeen healthy male volunteers aged between 20 and 40 years old. Main measure: Concentric and eccentric isokinetic tests at 30°/s and 120°/s in maximal and feigned maximal experimental conditions. DEC was calculated by subtracting the 30°/s eccentric/concentric peak torque ratios from the 120°/s ones for both experimental conditions. Results: A case-by-case analysis revealed that the DEC scores derived from the feigned effort were significantly greater than their maximal counterparts in all cases, leading to a cut-off value (0.81) which could distinguish between maximal and feigned performances. Conclusions: The findings indicate that the DEC is highly effective in identifying feigned shoulder external rotation effort in normal subjects.

Entire Flexor Carpi Radialis Tendon Harvest for Thumb Carpometacarpal Arthroplasty Alters Wrist Kinetics

To investigate the clinical outcome of thumb carpometacarpal arthroplasty with entire-thickness flexor carpi radialis (FCR) ligament reconstruction and tendon interposition and to investigate the isokinetic wrist flexion/extension torque and flexion fatigue strength of the surgically treated wrist compared with the nonsurgically treated wrist. Thirty-nine patients with osteoarthritis who had unilateral thumb carpometacarpal arthroplasty with the entire FCR tendon were studied prospectively with a minimum follow-up period of 24 months. Preoperative Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire score, grip, pinch, and postoperative DASH score, grip, pinch, and Biodex (Shirley, NY) isokinetic wrist flexion/extension torques were recorded. The nonsurgically treated extremity served as the control for each patient with unilateral ligament reconstruction and tendon interposition. Peak torque ratios and fatigue were measured for the control and surgically treated extremities with the Biodex. Postoperative DASH scores were 12 +/- 4 and were improved significantly from preoperative scores of 43 +/- 4. The surgically treated extremity showed a significantly lower wrist flexion-to-extension peak torque ratio than the control extremity. The control extremity had 2.5 times greater wrist flexion fatigue resistance than the surgically treated side. After surgery the surgically treated extremity had significantly improved grip strength and thumb-index tip pinch compared with the preoperative status. Our data show conclusively that wrist flexion extension torque ratio decreases and wrist flexion fatigue resistance decreases when the entire FCR tendon is harvested even though the final outcome is favorable and uniformly based on traditional DASH, grip, and pinch scores.

Soccer Players' Muscular Imbalances: Restoration with an Isokinetic Strength Training Program

The aim of the study was to investigate the effect of a muscular training program on soccer players' performance which initially appeared imbalanced or bilaterally asymmetrical. During the preparation period, 35 soccer players performed an isokinetic measurement of knee flexors and extensors (60 degrees(-1) and 180 degrees sec.(-1)). 15 of these had muscular imbalances or deficits and followed a specific isokinetic training program for 2 mo., 3 times per week. After the completion of the isokinetic training program, the 35 players underwent the same isokinetic test. Significant differences were noted between the pre- and posttraining measures at both angular velocities in peak torque values, in differences from one limb to the other, and in peak torque ratios for flexors and extensors. Consequently, the application of this specific isokinetic training program can restore imbalances in knee muscle strength efficiently.

Influence of Professional Dance Training on Peak Torque and Proprioception at the Ankle

To investigate the influence of professional dance training on the peak torque ratio of plantar flexion to dorsiflexion (PF/DF), angle replication ability, and balance in comparison to age-matched and gender-matched controls. The effects of injuries sustained before and during the study time period were also assessed. Prospective age-matched and gender-matched nonrandomized intervention study. Premises of the Orthopedic University Hospital, Heidelberg, where measuring apparatus belonging to the hospital was used for the tests. One group of 42 dancers (31 female, 11 male) in professional training (State Academy) and 40 age-matched and gender-matched controls with no prior dance or specific sport training. Isokinetic tests for peak torque at 30 degrees /s and 120 degrees /s, a passive angle-replication test (Biodex system 3), and a test of 1-legged standing were each carried out on 2 measurement dates (M1, M2): at the beginning of a season of professional dance training (M1) and after 5 months of such training (M2). Symptoms and/or injuries sustained during this period were ascertained continuously by means of questionnaires and interviews. A significant increase in peak torque in PF was observed in both dancer groups and male controls between M1 and M2. A significant increase in PF/DF peak torque ratio at 30 degrees /s was observed in both male groups between M1 and M2. At M2, no significant differences in PF/DF peak torque ratio could be found between male dancers and controls, but at 30 degrees /s between the female groups. However, in both female groups, the PF/DF ratio was not found to increase significantly between M1 and M2. In the angle-replication and 1-legged standing test, no consistent improvement was observed between M1 and M2 in either dancers or controls. In the angle-replication test, there were no significant differences between dancers and controls at M2. In the 1-legged standing test, the dancers did significantly better than controls. A total of 7 ankle injuries were recorded, but no difference was found between injured and uninjured subjects in the proprioceptive tests either at M1, as the predicator, or at M2 as the residual. Dance training did not increase the peak torque ratio of PF/DF within 5 months, but a group difference was found between the women groups. Ballet training alone without concurrent additional coordinative training does not lead to improvements in ankle joint position sense or improved measures of balance within this period of observation.

INTRINSIC CONSTRAINT OF UNLINKED TOTAL ELBOW REPLACEMENTS—THE ULNOTROCHLEAR JOINT

Background: Many unlinked total elbow replacement designs with radically differing articular geometries exist, suggesting that there is no consensus regarding an optimal design. A feature inherent to the articular design is the intrinsic constraint afforded to the joint by the implant. Our aim was to compare the intrinsic constraints of unlinked implants with that of the normal ulnotrochlear joint. Methods: We tested twelve cadaveric ulnotrochlear joints with a custom-made multiple-axis materials testing machine. With compressive loads ranging from 10 to 100 N, the joints were moved in either valgus or varus directions at 90° of flexion. The ulnotrochlear components from a single example of five medium-sized unlinked elbow replacements (Ewald, Kudo, Pritchard ERS, Sorbie-Questor, and Souter-Strathclyde) were also tested. The recorded measurements included the torques and forces, angular displacement, and axial displacement of the humerus relative to the ulna. Results: In general, the peak torque and the constraint ratio significantly increased with increasing compressive load for the implants as well as for the normal elbow. In valgus displacement, the Souter-Strathclyde implant had the highest and the Sorbie-Questor had the smallest peak torque and the Souter-Strathclyde had the highest and the Ewald had the smallest constraint ratio. In varus displacement, the Kudo had the highest and the Ewald had the smallest peak torque and constraint ratio. Conclusions: The constraint ratio is a characteristic that is useful for describing elbow joint behavior and for comparing the behavior of implants with that of the human elbow. Of the unlinked implants tested, the Souter-Strathclyde and Kudo prostheses most closely approximated the behavior of the human elbow joint. Implants that resemble the human elbow in appearance do not replicate normal behavior consistently, whereas other implants that do not resemble the human elbow closely do not deviate markedly from human behavior. Thus, much basic information about elbow form and function is needed to improve the performance of total elbow prostheses.

New Isokinetic Parameters For The Outcome Assessment Of Accelerated Rehabilitation After Anterior Cruciate Ligament Reconstruction

Strengthening of muscle power and restoration of dynamic performance have been emphasized in accelerated rehabilitation after anterior cruciate ligament reconstruction (ACLR). It is necessary to find proper ways to assess the outcome of rehabilitation process, especially in the early stage for better monitoring and adjustment of the rehabilitation process. However, the evaluation of rehabilitation outcome has been confined to the simple increase of isokinetic muscle torque after surgery. PURPOSE To investigate the changes of isokinetic torque curves during the controlled ambulatory phase in patients who received rehabilitation program after ACLR with the effort of finding useful isokinetic parameters on the outcome of accelerated rehabilitation. METHODS Twenty patients with ACL reconstruction (mean age 33 years (23–47), 16 males, 4 females) were randomly divided into two training groups. One (n = 10) was accelerated training (AT) group composed of open and closed kinetic chain(CKC) exercises and the other (n = 10) was conventional training (CT) group consisting of mainly CKC and conditioning exercises. Both groups underwent each assigned exercise program during controlled ambulatory phase from 6 to 12 weeks after surgery in our facility. Various isokinetic parameters at the angular velocity of 180°/sec (peak torque, time to peak torque, angle of peak torque, average power and work fatigue ratio) were obtained at 6 and 12 weeks after surgery. As new parameters to evaluate the dynamic performance of the knee muscles, the ratio of peak torque to time to peak torque (PTR) and the ratios of peak torque to angle from starting to peak torque (PAR) were calculated to determine the changes of torque curves. RESULTS After 6 weeks of training programs, two training groups showed significantly increases of peak torque, total work and average power of knee extensor(p = 0.007 in AT vs 0.009 in CT). However, only AT group showed a significant decrease in time to peak torque (202 ± 69 → 156 ± 37msec, p = 0.024) of knee extensor during this period. PTR (0.303 ± 0.267→0.550 ± 0.327(AT), 0.256 ± 0.148→0.367 ± 0.124(CT)) and PAR (2.17 ± 1.67→3.80 ± 1.91(AT), 1.94 ± 1.00→2.54 ± 0.70(CT)) significantly increased in both training groups. So, the isokinetic time-torque curve and angle-torque curve of the knee extensor shifted to the left and upward side after training. These ratios of AT groups were significantly higher than those of CT group(p = 0.010(PTR), p = 0.005(PAR)). CONCLUSIONS AT group showed more prominent increases of PTR and PAR than CT group. We suggest the PTR and PAR as new parameters to assess the outcome of accelerated rehabilitation after ACLR in the controlled ambulatory phase.

New Isokinetic Parameters For The Outcome Assessment Of Accelerated Rehabilitation After Anterior Cruciate Ligament Reconstruction

Strengthening of muscle power and restoration of dynamic performance have been emphasized in accelerated rehabilitation after anterior cruciate ligament reconstruction (ACLR). It is necessary to find proper ways to assess the outcome of rehabilitation process, especially in the early stage for better monitoring and adjustment of the rehabilitation process. However, the evaluation of rehabilitation outcome has been confined to the simple increase of isokinetic muscle torque after surgery. PURPOSE To investigate the changes of isokinetic torque curves during the controlled ambulatory phase in patients who received rehabilitation program after ACLR with the effort of finding useful isokinetic parameters on the outcome of accelerated rehabilitation. METHODS Twenty patients with ACL reconstruction (mean age 33 years (23–47), 16 males, 4 females) were randomly divided into two training groups. One (n = 10) was accelerated training (AT) group composed of open and closed kinetic chain(CKC) exercises and the other (n = 10) was conventional training (CT) group consisting of mainly CKC and conditioning exercises. Both groups underwent each assigned exercise program during controlled ambulatory phase from 6 to 12 weeks after surgery in our facility. Various isokinetic parameters at the angular velocity of 180°/sec (peak torque, time to peak torque, angle of peak torque, average power and work fatigue ratio) were obtained at 6 and 12 weeks after surgery. As new parameters to evaluate the dynamic performance of the knee muscles, the ratio of peak torque to time to peak torque (PTR) and the ratios of peak torque to angle from starting to peak torque (PAR) were calculated to determine the changes of torque curves. RESULTS After 6 weeks of training programs, two training groups showed significantly increases of peak torque, total work and average power of knee extensor(p = 0.007 in AT vs 0.009 in CT). However, only AT group showed a significant decrease in time to peak torque (202 ± 69 → 156 ± 37msec, p = 0.024) of knee extensor during this period. PTR (0.303 ± 0.267→0.550 ± 0.327(AT), 0.256 ± 0.148→0.367 ± 0.124(CT)) and PAR (2.17 ± 1.67→3.80 ± 1.91(AT), 1.94 ± 1.00→2.54 ± 0.70(CT)) significantly increased in both training groups. So, the isokinetic time-torque curve and angle-torque curve of the knee extensor shifted to the left and upward side after training. These ratios of AT groups were significantly higher than those of CT group(p = 0.010(PTR), p = 0.005(PAR)). CONCLUSIONS AT group showed more prominent increases of PTR and PAR than CT group. We suggest the PTR and PAR as new parameters to assess the outcome of accelerated rehabilitation after ACLR in the controlled ambulatory phase.

Three-Dimensional Computed Tomography Imaging Evidence of Regeneration of the Semitendinosus Tendon Harvested for Anterior Cruciate Ligament Reconstruction

The purpose of this study was to evaluate the regeneration of semitendinosus tendons harvested for anterior cruciate ligament (ACL) reconstruction using 3-dimensional (3D) computed tomography (CT) imaging and to compare the degree of regeneration with hamstring strength. Twenty-nine patients who underwent ACL reconstruction using ipsilateral autogenous semitendinosus tendons were examined before surgery and 6 and 12 months after surgery by 3D CT imaging. The types of regenerated tendons and the proximal shift of the muscle-tendon junction were evaluated. The types of regenerated semitendinosus tendons varied from case to case. There was a positive correlation between the peak torque ratio of the hamstring muscle strength and the proximal shift of the muscle-tendon junction 6 months after surgery. The proximal shift did not affect the peak torque ratio 12 months after surgery, however. A proximal shift of the muscle-tendon junction may help to explain the individual differences in early postoperative hamstring muscle strength recovery.

Concentric isokinetic dynamometry of the shoulder: Which parameters discriminate between healthy subjects and patients with shoulder disorders?

There is no consensus on the optimal isokinetic dynamometry parameters to clinically assess shoulder disorders. Therefore, this study aimed to establish which parameters are best able to discriminate between shoulder patients and healthy subjects, focusing on peak torques and peak torque ratios. Isokinetic dynamometric measurements of both shoulders were made in 20 healthy subjects and these data were compared with baseline measurements in 9 patients with shoulder disorders. The different outcome measures were compared by testing for significant group differences between patients and healthy subjects and by scoring how the patient data compared to the normal range of values found in healthy subjects. Significant differences between patients and healthy subjects were found for the peak torques, but not for the agonist-antagonist peak torque ratios. In addition, there were significant differences for the dominant/non dominant ratios of the peak torques but not for the dominant/non dominant ratios of the peak torque ratios. The percentage of patients with a standard deviation score outside the 90% normal distribution of healthy subjects was largest (>78%) for the involved/uninvolved (I/U) ratio of the peak torques. It was concluded that bilateral comparison of peak torques is the most appropriate outcome parameter to distinguish patients from healthy subjects.

Knee angle does not affect ankle eversion to inversion peak torque ratios derived from an isokinetic dynamometer

The purpose of this study was to examine varying degrees of knee flexion on isokinetic eversion (E) to inversion (I) strength ratios. Twenty healthy subjects volunteered for this study. Concentric (CON) peak torque (PT) of both ankles (dominant, non-dominant) at three different angles of knee flexion (15°, 30°, 45°) and two different velocities (30°/s, 120°/s) was assessed with ankle plantar flexion maintained at 10°. The E CON :I CON ratios at 30°/s ranged from 0.87 to 1.04 across all three angles, while those at 120°/s ranged from 0.86 to 1.00 indicating no differences in ratios between knee-flexion angles or ankles. However, there was a trend in lower ratios evident in the dominant compared to non-dominant ankles. These results suggest that subjects may be positioned with knee flexion angles ranging from 15° to 45° without influencing the outcome of the ankle eversion and inversion strength measurements.

Groin injuries in professional rugby league players: a prospective study

Altogether, 100 uninjured professional rugby league players were evaluated over a 2-year period. Their height, body mass, sum of skinfolds, girths and bone diameters were recorded. A Cybex 340 isokinetic dynamometer was used to determine peak torque, work, power, endurance ratios and peak torque ratios of the hip abductors and adductors (5 repetitions at 0.52 and 2.08 rad · s− 1; 20 repetitions at 3.66 rad · s− 1) and knee flexors and extensors (4 repetitions at 1.04 and 3.14 rad · s− 1; 30 repetitions at 5.22 rad · s− 1). Hip abduction and adduction were also assessed with the hip in external rotation. Discriminant function analysis was conducted on all predictor variables to develop a multivariate predictive model capable of classifying players with a high degree of accuracy into groups with and without a groin injury. The model consisted of eight variables and correctly classified 91.7% of the non-injured players and 90.5% of the injured players. The correct classification for the model as a whole was 91.4%. The aetiological factors identified as being related to injury of the groin musculotendinous unit included abduction and adduction-with-rotation peak torque, angle of adduction and abduction-with-rotation peak torque, strength ratio of hip muscle groups, bilateral difference in extension peak torque, femur diameter and body mass.

Knee Flexor: Extensor Isokinetic Ratios in Young Male Gymnasts and Swimmers

The purpose of the study was to determine young male gymnasts’ and swimmers’ knee flexor:extensor (F:E) ratios during isokinetic testing at different velocities. Nine gymnasts (10.3 ± 0.5 years) and 14 swimmers (10.5 ± 0.5 years) participated. Concentric isokinetic peak torque was measured by a Cybex® Norm dynamometer at different angular velocities (60,120, and 180°/s) during unilateral knee extensions and flexions after gravity correction. Significant differences were found only in gymnasts’ knee F:E peak-torque ratios between the angular velocities of 60 and 120°/s (p &lt; 0.01), as well as 60–180°/s (p &lt; .01), whereas swimmers’ ratios were unchanged. Gymnasts presented significantly higher F:E ratios than swimmers did at the angular velocities of 120°/s (p &lt; .01) and 180°/s (p &lt; .001). The reciprocal ratios provided some indication that the training context of young athletes can influence the balance between agonistic and antagonistic activity of the lower limbs’ major muscle groups.

Relation between isokinetic muscle strength and functional capacity in recreational athletes with chondromalacia patellae

Objectives: To investigate the effects of isokinetic exercise on pain and functional test scores of recreational athletes with chondromalacia patellae (CMP) and to examine the correlation between isokinetic parameters and...