Quadriceps Peak Torque Research Articles

Blood Flow Restriction Training Applied With High-Intensity Exercise Does Not Improve Quadriceps Muscle Function After Anterior Cruciate Ligament Reconstruction: A Randomized Controlled Trial

Background: A major goal of rehabilitation after anterior cruciate ligament reconstruction (ACLR) is restoring quadriceps muscle strength. Unfortunately, current rehabilitation paradigms fall short of this goal, such that substantial quadriceps muscle strength deficits can limit return to play and increase the risk of recurrent injuries. Blood flow restriction training (BFRT) involves the obstruction of venous return to working muscles during exercise and may lead to better recovery of quadriceps muscle strength after ACLR. Purpose: To examine the efficacy of BFRT with high-intensity exercise on the recovery of quadriceps muscle function in patients undergoing ACLR. Study Design: Randomized controlled trial; Level of evidence, 2. Methods: A total of 34 patients (19 female, 15 male; mean age, 16.5 ± 2.7 years; mean height, 169.0 ± 19.7 cm; mean weight, 73.2 ± 17.7 kg) scheduled to undergo ACLR were randomly assigned to 1 of 4 groups: concentric (n = 8), eccentric (n = 8), concentric with BFRT (n = 9), and eccentric with BFRT (n = 9). The exercise component of the intervention consisted of patients performing a single-leg isokinetic leg press, at an intensity of 70% of the patients’ 1-repetition maximum during either the concentric or eccentric action, for 4 sets of 10 repetitions 2 times per week for 8 weeks beginning at 10 weeks postoperatively. Patients randomized to the BFRT groups performed the leg-press exercise with a cuff applied to the thigh, set to a limb occlusion pressure of 80%. Isometric and isokinetic (60 deg/s) quadriceps peak torque, quadriceps muscle activation, and rectus femoris muscle volume were assessed before ACLR, after BFRT, and at the time that patients returned to activity and were converted to the change in values from baseline for analysis. Also, 1-way analyses of covariance were used to compare the change in values for each dependent variable between groups after BFRT and at return to activity (P ≤ .05). Results: No significant differences were found between groups for any outcome measures at either time point (P > .05). Conclusion: An 8-week BFRT plus high-intensity exercise intervention did not significantly improve quadriceps muscle strength, activation, or volume. On the basis of our findings, the use of BFRT in conjunction with high-intensity resistance exercise in patients undergoing ACLR to improve quadriceps muscle function may not be warranted. Registration: NCT03141801 (ClinicalTrials.gov identifier)

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.

Quadriceps Muscle Size, Quality, and Strength and Self-Reported Function in Individuals With Anterior Cruciate Ligament Reconstruction.

Ultrasound imaging provides a cost-effective method of measuring quadriceps morphology, which may be related to self-reported function after anterior cruciate ligament reconstruction (ACLR). To compare quadriceps morphology and strength between limbs in individuals with ACLR and matched control limbs and determine their associations with self-reported function. Cross-sectional study. Research laboratory. Forty-two individuals with ACLR (females = 66%; age = 21.8 ± 2.6 years; time since ACLR = 50.5 ± 29.4 months) and 37 controls (females = 73%; age = 21.7 ± 1.2 years). Quadriceps peak torque (PT) and rate of torque development were assessed bilaterally. Ultrasonography was used to measure the cross-sectional area (CSA) and echo intensity (EI) of the rectus femoris, vastus lateralis (VL), and vastus medialis. Self-reported function was assessed via the International Knee Documentation Committee (IKDC) score and Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales. Paired-samples t tests were calculated to compare involved and uninvolved limbs. Independent t tests were conducted to compare groups (α = .05). Linear regression was performed to analyze associations between quadriceps function and self-reported function after accounting for time since ACLR, activity level, and sex, and models for EI added subcutaneous fat as a covariate. Isometric PT did not differ between limbs or groups. Involved limbs had a lower rate of torque development compared with the control (P = .01) but not the uninvolved limbs (P = .08). Vastus lateralis CSA was smaller in the involved than in the uninvolved (P < .01) but not the control limbs (P = .10). Larger VL CSA (ΔR2 = 0.103) and lower VL EI (ΔR2 = 0.076) were associated with a higher IKDC score (P < .05). Larger VL CSA was associated with greater KOOS Symptoms (ΔR2 = 0.09, P = .043) and Sport and Recreation (ΔR2 = 0.125, P = .014) scores. Lower VL EI was associated with higher KOOS Symptoms (ΔR2 = 0.104, P = .03) and Quality of Life (ΔR2 = 0.113, P = .01) scores. Quadriceps PT and rate of torque development were not associated with IKDC or KOOS subscale scores. Quadriceps morphology was associated with self-reported function in individuals with ACLR and may provide unique assessments of quadriceps function.

Comparing Changes in Knee Muscle Strength after Reconstruction of the Anterior and Posterior Cruciate Ligaments

Purpose: The purpose of this study was to identify changes in knee muscle strength after reconstruction of the anterior cruciate liga ment (ACL) and the posterior cruciate liga­ment (PCL). Methods: Thirteen subjects (males) with anterior ligament injury and ten subjects (males) with posterior ligament injury voluntarily par­ ticipated in this study. Both groups were evaluated at the pre-and post-reconstruction stages using an isokinetic dynamometer. Peak torque, total work, and the hamstrings to quadriceps (H/Q) peak torque ratio were calculated at angular velocities of 60°/sec and 180°/sec. Statistical analysis was conducted on SPSS 18.0 for Windows using t-tests to compare mean differences. Results: At an angular velocity of 60°/sec, both the ACL and PCL groups showed a significant increase in muscle strength in the flexors and extensors. Muscle strength in the extensors was significantly increased in the PCL group compared to the ACL group. At an angular velocity of 180°/sec, the ACL group showed a significant increase in muscle endurance in the flexors and extensors, and the PCL group showed a significant increase in muscle endurance in the flexors. At angular velocities of 60°/sec and 180°/sec, the H/Q peak torque ra­ tio increased in the ACL group but decreased in the PCL group. Consequently, the H/Q peak torque ratio was significantly different for the two groups. Conclusion: The results suggest that the patients with ACL injury should focus on strengthening the knee extensors and that the pa­ tients with PCL injury need to strengthen the knee flexors.

Decreased quadriceps force steadiness following anterior cruciate ligament reconstruction is associated with altered running kinematics

BackgroundAnterior cruciate ligament reconstruction is associated with quadriceps dysfunction and altered knee mechanics, but the relationship between these outcomes is not clear. Inclusion of metrics such as the stability of torque output could provide additional insights into the relationship between quadriceps dysfunction and knee mechanics. The purposes of this study were to: (1) measure the difference in quadriceps force steadiness between anterior cruciate ligament reconstructed and contralateral limbs; and (2) assess the relationship of quadriceps force steadiness and peak torque with knee flexion excursion during running. MethodsTwenty-eight participants (14 female, age 20 (5) years) underwent quadriceps strength testing and gait analysis. Force steadiness was measured with the standard deviation and coefficient of variation of the participants' detrended torque. Knee flexion excursion was calculated during the stance phase of running trials. Differences between limbs for force steadiness and peak torque were assessed with paired sample t-tests, and a Pearson's product-moment correlation coefficient determined the relationship between pairs of variables. FindingsAnterior cruciate ligament reconstructed limbs presented with a significant deficit in relative force steadiness compared to the contralateral limb (4.03 (1.04) % and 3.58 (1.41) % (P < .05), respectively). In addition, the relationship of quadriceps strength and force steadiness with knee flexion excursion was altered in anterior cruciate ligament reconstructed limbs due to the inability of the quadriceps to sustain a controlled force output. InterpretationThese results suggest that considering both the magnitude and quality of force production can provide important insight into comprehensive quadriceps function.

Immediate effect of maximal treadmill walking on muscle fatigue and postural stability in children with cerebral palsy

AimPostural instability and muscle fatigue are from elementary causes of deteriorations in children with cerebral palsy (CP). The aim of this study was to investigate the immediate effect of maximal treadmill walking on muscle fatigue and postural stability in children with hemiplegic CP.Patients and methodsThirty (17 boys and 13 girls) children with hemiplegic CP of both sexes, aged from 5 to 11years, participatedin this study. Muscle fatigue and postural stability were assessed for every child by using isokinetic dynamometer and pediatric reaching test, respectively, before and after maximal treadmill walking at two separated sessions.ResultsThe results showed that there were no significant differences in fatigue index (P=0.33 and 0.1), peak torque of quadriceps and hamstring muscles (P=0.52 and 0.14), and anterior and lateral reaching tests of postural stability (P=0.46 and 0.63) before and after maximal treadmill walking.ConclusionMaximal treadmill walking does not cause muscle fatigue or postural instability in children with hemiplegic CP.

The Importance of Functional Hamstring/Quadriceps Ratios in Knee Osteoarthritis

Osteoarthritis (OA) is the most common chronic joint condition. Muscle dysfunction plays a critical role in the pathogenesis of knee OA. It has been suggested that the agonist-antagonist strength relationship for the knee may be better described by a functional hamstring/quadriceps (H/Q) ratio (Hconcentric/Qeccentric: the representative of knee flexion and Qeccentric/Hconcentric: the representative of knee extension). Therefore, in this study, the authors aimed to investigate this ratio and its importance for knee OA. Cross-sectional study. Research clinic. Patients or Other Participant(s): Twenty healthy women and 20 women with grade 2 or grade 3 primer knee OA between the age of 50 and 80 years were included in this study. Concentric and eccentric peak torque of quadriceps and hamstring muscles were evaluated for all individuals in patient and control groups with a Cybex isokinetic device. Functional H/Q ratio is calculated manually. Functional H/Q torque ratios were analyzed between the patients with OA and healthy individuals by using the isokinetic system. The values of peak torque of hamstring concentric and eccentric and quadriceps concentric for the patient group were significantly lower than the control group (P < .05). No statistically important difference was found for quadriceps eccentric peak torque between 2 groups (P > .05). H/Q ratio for extension in the patient group was significantly higher than the control group (P < .05), whereas the H/Q ratio for flexion in the patient group was significantly lower than the control group (P < .05). This study showed the weakness of both quadriceps and hamstring muscles in patients with knee OA. The combination of functional H/Q ratio with hamstring and quadriceps muscles concentric and eccentric strength values can help to analyze the knee functions and develop preventive-therapeutic approaches for knee OA.

Periodized versus Non-periodized Stretch Training on Gymnasts Flexibility and Performance.

Static stretching (SS) can increase joint range of motion (ROM), due to neural, morphological, and physio-psychological factors. Periodized training programs (PD) (e. g., strength, power) are adopted to induce greater adaptations while avoiding overtraining. However, the effectiveness of periodized stretch training adaptations are unknown. Therefore, the objective of this study was to compare the effects of periodized and non-periodized (NP) stretching programs on flexibility, hamstrings stiffness and muscle performance. Sixteen gymnasts were allocated to either periodized or non-periodized SS training and tested pre- and post-8 weeks for countermovement jump height, hip flexors, hip extensors and dorsiflexors ROM, hamstrings stiffness and hamstrings and quadriceps peak torque. Both stretch training groups significantly and similarly increased hip extensor (33.2%), hip flexor (25.2%), and dorsiflexor (23.8%) ROM, hamstrings peak torque (7.9%) and jump height (8.1%) from pre - to post- training. Both groups decreased hamstrings stiffness across the last ten angles (32.1%). PD elicited consistently large magnitude flexibility effect size changes compared to small and moderate magnitude changes for the non-periodized. Therefore, 8-week PD and NP SS programs can decrease young gymnasts' muscle-tendon stiffness and increase muscle performance. However, effect sizes indicate that PD stretch training was more advantageous to increasing flexibility and improving performance.

Optimizing Between-Session Reliability for Quadriceps Peak Torque and Rate of Torque Development Measures.

Grindstaff, TL, Palimenio, MR, Franco, M, Anderson, D, Bagwell, JJ, and Katsavelis, D. Optimizing between-session reliability for quadriceps peak torque and rate of torque development measures. J Strength Cond Res 33(7): 1840-1847, 2019-Quadriceps peak torque and rate of torque development (RTD) have relevance for athletic performance and recovery after knee injury. The number of repetitions performed to determine RTD varies between studies, and the associated measurement error has not been established. The purpose of this study was to determine the number of repetitions necessary to optimize the between-session reliability for isometric quadriceps peak torque and RTD measures and to quantify estimates of measurement error. Twenty participants (age = 21.7 ± 1.7 years, height = 172.5 ± 16.0 cm, body mass = 76.0 ± 15.5 kg, and Tegner = 7.1 ± 1.2) volunteered for this study. Quadriceps isometric peak torque and RTD (50, 100, 150, 200, and 250 ms, and maximum torque) were obtained during 2 testing sessions. Between-session reliability was determined using intraclass correlation coefficients (ICC2,k), using the minimal detectable change (MDC) and coefficient of variation (CoV) to quantify measurement error. Between-session reliability was best maximized by using the average of the 3 repetitions with the highest peak torque. Reliability was good for quadriceps peak torque (ICC2,3 = 0.98; MDC = 51.1 N·m; CoV = 38.0%) and ranged from moderate to good for quadriceps RTD measures (ICC2,3 = 0.61 to 0.91; MDC = 264.8 to 738.3 N·m·s; CoV = 38.1-57.9%). Measures of late RTD were less variable and more reliable than early RTD and average RTD measures. These results provide confidence when measuring between-session changes for late RTD measures, but changes in early RTD may be more difficult to distinguish from measurement error. Methods should be used to minimize variability between repetitions and sessions.

Combining Whey Protein Isolate with Eccentric Training Improved Quadriceps Strength in Patients with ACL Rupture (P12-024-19)

ObjectivesAnterior cruciate ligament (ACL) rupture results in significant quadriceps weakness, which will then cause abnormal gait and knee instability. Eccentric training (ET) can produce larger effects on muscle strength than concentric training, which may be further augmented by protein supplement. This study was to examine the effects of combining whey protein supplement with preoperative isokinetic ET on quadriceps strength and function after ACL rupture. MethodsThirty-seven male subjects aged 18–40 years with ACL rupture were randomly assigned to isokinetic ET (IET, N = 19) group or isokinetic ET with whey protein isolate (IET + WP, N = 18) group. Both groups received preoperative isokinetic ET for six weeks, containing 3–4 sets per day with 8–10 repetitions for each set, twice a week. Subjects in IET + WP consumed whey protein isolate 22 g per day. Cross-Sectional Area (CSA) of quadriceps was scanned by MRI, and strength and knee function were measured before and after the trials. ResultsAfter intervention, CSA of the involved quadriceps increased by 3.7% (NS) in IET and 7.6% (P = 0.012) in IET + WP. The ratio of side-to-side increased by 3.9% (NS) in IET and 4.8% (P = 0.002) in IET + WP. The peak torque of quadriceps during eccentric contraction at 60 degree/s, concentric contraction at 60, 180 and 300 degree/s increased by 27.9% (P < 0.001), 35.9% (P < 0.001), 34.3% (P = 0.002) and 27.3% (P = 0.003) in IET, and increased by 44.2% (P < 0.001), 42.3% (P < 0.001), 37.4% (P = 0.002) and 36.7% (P < 0.001) in IET + WP, respectively, with no differences between the two groups. Lysholm and IKDC2000 knee function score in IET + WP increased by 24.7% (P = 0.001) and 12.9% (P = 0.001). ConclusionsCombining whey protein supplement with ET tends to be more effective on improving CSA of quadriceps, knee function and quadriceps strength when compared to ET alone after ACL rupture, even though the results did not reach statistical differences. Funding SourcesThe research was supported by The National Key Research and Development Program (No.2016YFD0400603).

Effect of Blood Flow Restriction Training on Quadriceps Muscle Strength, Morphology, Physiology, and Knee Biomechanics Before and After Anterior Cruciate Ligament Reconstruction: Protocol for a Randomized Clinical Trial.

Despite best practice, quadriceps strength deficits often persist for years after anterior cruciate ligament reconstruction. Blood flow restriction training (BFRT) is a possible new intervention that applies a pressurized cuff to the proximal thigh that partially occludes blood flow as the patient exercises, which enables patients to train at reduced loads. This training is believed to result in the same benefits as if the patients were training under high loads. The objective is to evaluate the effect of BFRT on quadriceps strength and knee biomechanics and to identify the potential mechanism(s) of action of BFRT at the cellular and morphological levels of the quadriceps. This will be a randomized, double-blind, placebo-controlled clinical trial. The study will take place at the University of Kentucky and University of Texas Medical Branch. Sixty participants between the ages of 15 to 40 years with an ACL tear will be included. Participants will be randomly assigned to (1) physical therapy plus active BFRT (BFRT group) or (2) physical therapy plus placebo BFRT (standard of care group). Presurgical BFRT will involve sessions 3 times per week for 4 weeks, and postsurgical BFRT will involve sessions 3 times per week for 4 to 5 months. The primary outcome measure was quadriceps strength (peak quadriceps torque, rate of torque development). Secondary outcome measures included knee biomechanics (knee extensor moment, knee flexion excursion, knee flexion angle), quadriceps muscle morphology (physiological cross-sectional area, fibrosis), and quadriceps muscle physiology (muscle fiber type, muscle fiber size, muscle pennation angle, satellite cell proliferation, fibrogenic/adipogenic progenitor cells, extracellular matrix composition). Therapists will not be blinded. The results of this study may contribute to an improved targeted treatment for the protracted quadriceps strength loss associated with anterior cruciate ligament injury and reconstruction.

VALIDITY OF HAND-HELD DYNAMOMETRY IN MEASURING QUADRICEPS STRENGTH AND RATE OF TORQUE DEVELOPMENT

A hand-held dynamometer (HHD) offers a reliable and valid method to quantify quadriceps strength in a clinical environment. While measures of peak strength provide functional insights, most daily activities are performed quickly and do not require maximum strength. Rate of torque development (RTD) measures better reflect both the demands of daily activity and athletic movements. The capacity to obtain RTD measures in clinical settings is possible with an HHD, but the validity of RTD measures has not been quantified. To determine the validity of an HHD to measure quadriceps isometric strength metrics compared to isometric strength measures obtained on an isokinetic dynamometer. It was hypothesized that the HHD would be a valid measure of peak torque and RTD at all time intervals when compared to the isokinetic dynamometer. Descriptive laboratory study. Twenty healthy participants (12 male, 8 female) (age = 23.7 ± 2.9 years, height = 174.6 ± 10.1 cm, mass = 76.4 ± 15.9 kg, and Tegner = 6.7 ± 1.2) performed maximum isometric quadriceps contractions on an isokinetic dynamometer and with an HHD. Outcome measures included quadriceps peak torque and RTD at three intervals (0-100, 0-250 ms, and average). Pearson product-moment correlation coefficients and Spearman's rank correlation coefficient were used to determine relationships between devices. Bland-Altman Plots with Limits of Agreement (LOA) calculations were used to quantify systematic bias between measurement techniques. There was a significant correlation between the isokinetic dynamometer and the HHD for peak torque (p<.001, r = .894) and all RTD measurements (p<.002, r = .807; ρ = .502-.604). Bland-Altman plot LOA indicated the HHD overestimated peak torque values (19.4 ± 53.2 Nm) and underestimated all RTD measurements (-55.2 ± 190.7 Nm/s to -265.2 ± 402.6 Nm/s). These results show it is possible to obtain valid measures of quadriceps peak torque and late RTD using an HHD. Measures of early RTD and RTDAvg obtained with an HHD were more variable and should be viewed with caution. Diagnostic, Level 3.

How does acute pain influence biomechanics and quadriceps function in individuals with patellofemoral pain?

ObjectivesBeside pathophysiological factors, pain is believed to play a crucial role in the progression of patellofemoral pain (PFP). However, the isolated effect of pain on biomechanics and quadriceps function has not been investigated in PFP. Thus, this study aimed to investigate the effect of pain on quadriceps function and lower limb biomechanics in individuals with PFP. MethodsTwenty-one individuals with PFP (11 males and 10 females, age: 29.76 ± 6.36 years, height: 1.74 ± 0.09 m, mass: 70.12 ± 8.56 kg) were measured at two different occasions: when not and when experiencing acute pain. Peak quadriceps torque (concentric, eccentric and isometric) and arthrogenic muscle inhibition (AMI) were assessed. Three-dimensional motion analysis and surface electromyography of the quadriceps and hamstring muscles were collected during running, a single-leg-squat and step-down task. The normality was assessed using the Shapiro–Wilk test and a MANOVA was performed at the 95% confidence interval. ResultsAMI increased significantly in acute pain. The net muscle activation of the knee extensors and flexors decreased during running in acute pain. The lower limb biomechanics and the quadriceps torque did not change in acute pain. DiscussionIt appears that even if individuals with PFP experience pain they can still deliver maximal quadriceps contractions and maintain their moving patterns without biomechanical changes. However, the overall reduced activation of the quadriceps and the increased AMI indicate the presence of quadriceps inhibition in acute pain.

Effects of Recreational Ski Mountaineering on Cumulative Muscle Fatigue - A Longitudinal Trial.

Sport is known to have many positive effects on mental and physical health. High-intensity exercise is considered to decrease muscle strength and induce muscle fatigue, which is associated with a higher risk of injury. In recreational alpine skiers, a decrease of eccentric peak hamstring torque, as an indication of muscle fatigue, occurs even after 1 day of skiing. The popularity of ski mountaineering is increasing enormously, but no studies are available on its effects on muscle strength. Therefore, the present study examined the consequences of ski mountaineering on muscle fatigue of the concentric/eccentric quadriceps and/or hamstrings. In addition, a possible role of myofascial foam rolling in reducing muscle fatigue was evaluated. Fifty recreational ski mountaineers (27 males, 23 females) completed five consecutive tours of ski mountaineering within 1 week. After each day of skiing, participants underwent an isokinetic muscle test assessing the concentric and eccentric muscle strength of both thighs. One group completed an additional session of myofascial foam rolling. Right and left concentric quadriceps peak torque, left hamstrings peak torque, left eccentric quadriceps peak torque, as well as right and left hamstring peak torque, were reduced after a single day of ski mountaineering (p ≤ 0.016 for all). However, no cumulative muscle fatigue was detected and we could not demonstrate any effect of myofascial foam rolling. The results show conclusively that a single day of ski mountaineering leads to a significant decrease of concentric and eccentric quadriceps and hamstring strength. Therefore, in order to improve muscle strength for the ski mountaineering season, a physical training program including concentric and eccentric methods can be recommended.

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.

Participants at three months post-operative anterior cruciate ligament reconstruction (ACL-R) demonstrate differences in lower extremity energy absorption contribution and quadriceps strength compared to healthy controls

BackgroundThe purpose of this study was to compare hip and knee energy absorption contribution (EAC) during a double limb squat (DLS) and quadriceps strength in patients three months post-operative ACL-R versus matched healthy controls. MethodsTwenty-four ACL-R participants (Age = 15.5 ± 1.3 yrs; Ht = 1.66 ± .07 m; Mass = 66.3 ± 15.5 kg) were compared to 24 age, sex, limb, and activity-matched healthy controls (Age = 15.5 ± 1.2 yrs; Ht = 1.65 ± .08 m; Mass = 59.0 ± 9.8 kg). Lower extremity biomechanical data was collected at three months post-operative ACL-R during five consecutive DLS. EAC was calculated during DLS descent. Isokinetic quadriceps strength was collected at 60°/s. Normalized quadriceps peak torque (QUADS) was averaged across five trials. Independent t-tests examined differences in group hip and knee EAC during each task. Separate Pearson product–moment correlations examined the relationship between QUADS and hip and knee EAC during the DLS. ResultsACL-R demonstrated greater injured limb hip EAC (46.4 ± 16.0) than Healthy (31.7 ± 11.0) during a DLS (p = 0.001). ACL-R demonstrated less injured limb knee EAC (42.7 ± 14.6) than Healthy (60.6 ± 8.9) during DLS (p < 0.001). No differences were seen between uninjured limb hip (ACL-R = 0.0 ± 14.2; Healthy = 33.4 ± 9.1, p = 0.629) or knee (ACL-R = 56.9 ± 15.6; Healthy = 59.1 ± 9.8, p = 0.561) EAC and matched limbs. ACL-R injured limb QUADS was decreased compared to Healthy (ACL-R = 1.1 ± 0.5; Healthy = 2.0 ± 0.5, p < 0.001). No differences were seen in QUADS on the uninjured and matched limbs (ACL-R = 2.0 ± 0.6; Healthy = 1.9 ± 0.5, p = 0.894). There was a weak, negative correlation between injured limb QUADS and hip EAC (r = −0.471, p = 0.001) and moderate, positive correlation between injured limb QUADS and knee EAC (r = 0.615, p < 0.001). ConclusionsACL-R participants demonstrate different eccentric loading strategies during a DLS at three months postoperative compared to matched healthy controls.

Effects of Dance Exergaming on Depressive Symptoms, Fear of Falling, and Musculoskeletal Function in Fallers and Nonfallers Community-Dwelling Older Women.

The aim of this study was to evaluate the effects of a pop dance exergaming protocol on fall risk factors-depressive symptoms, fear of falling, and musculoskeletal function-in community-dwelling older female fallers and nonfallers. There were 47 community-dwelling older women assigned to the intervention group (IG) [fallers (n = 10, 69.8 ± 4.3 years); nonfallers (n = 12, 68.9 ± 3.3 years)] and the control group (CG) [fallers (n = 12, 73.6 ± 5.4 years); nonfallers (n = 13, 68.7 ± 4.8 years)]. The CG maintained their lifestyle and the IG performed a videogame dance training three times per week for 12 weeks. The Dance Central game for Xbox 360® and Kinect motion sensor were used. The primary outcomes were geriatric depressive symptoms, fear of falling, and concentric and eccentric isokinetic peak torque (PT) of quadriceps and hamstrings. Secondary outcomes included cross-sectional area of quadriceps and hamstring muscles, functionality (Timed Up and Go test, gait speed, the Five Times Sit-to-Stand test), and a fall circumstances and outcomes recording. The depressive symptoms decreased in the Intervention Fallers Group. The eccentric hamstrings PT at 180°/s increased in the Intervention Nonfallers Group. There were no significant differences between groups for the other variables analyzed. The training attendance was 83% for the Intervention Fallers Group and 88% for the Intervention Nonfallers Group. Dance exergaming can be indicated to decrease depressive symptoms in fallers and increase the PT in nonfallers among community-dwelling older women.

Maintenance of Health-Related Fitness Gains Following Underwater Treadmill Training in Adults with Type 2 Diabetes

PURPOSE: To document short- and long-term effects of a 12-week aquatic exercise walking program on components of health-related fitness in middle-aged adults with type 2 diabetes. METHODS: Thirteen adults with type 2 diabetes (age = 59.5 ± 4.5 yrs; 7 females, 6 males) completed 12 weeks of underwater treadmill training (UTT) (3d[BULLET OPERATOR]wk-1), followed by a 12-week follow-up period that involved no UTT. Exercise intensity and duration, which were initially set to 40-50% of heart rate reserve (HRR) and 30 minutes (three 10- min bouts) were systematically and progressively increased to 50-70% HRR and 60 minutes (three 20-min bouts) by week 12. During the follow-up period, study participants maintained their current diet and were given permission to perform any type or amount of physical activity except a formalized exercise program. Primary outcome variables included cardiovascular function [resting heart rate (RHR) and 6-min walk for distance (6MWFD)]; body composition [body mass (BM), body fat percentage (BF%), waist circumference (WC)]; and leg strength [hamstring and quadriceps isokinetic peak torque at 30°[BULLET OPERATOR]sec-1and 60°[BULLET OPERATOR]sec-1)]. Baseline, post-UTT, and post-follow-up scores were analyzed using 1-way repeated measures analysis of variance. RESULTS: Compared to baseline scores, significant (p < .05) improvements in cardiovascular function (decreased RHR, increased 6MWD), body composition (decreased BM, BF%, and WC), and leg strength (greater peak hamstrings torque at 60°[BULLET OPERATOR]sec-1, and peak quadriceps torque at 30°[BULLET OPERATOR]sec-1), were observed after UTT. Three months following completion of UTT, positive changes in nearly all HRF variables (6MWD, BM, BF%, WC, peak hamstrings torque at 60°[BULLET OPERATOR]sec-1, peak quadriceps torque at 30°[BULLET OPERATOR]sec-1) were maintained (p < .05) relative to baseline values. CONCLUSIONS: Our findings indicate that improvements in HRF resulting from 12 weeks of UTT persist three months after cessation of UTT in middle-aged adults with type 2 diabetes.

The Determination of the Relationship Between Isokinetic Leg Strengths and Agility and Speed Performance of Elite Handball Players

The aim of the study is to examine the relationship between isokinetic hamstring and quadriceps muscle strengths and agility and speed performance of elite male handball players. 15 male handball players participated in the study. The isokinetic leg forces of the handball players participating in the study were determined by isokinetic dynamometer, the agility performances by Ilionis and 505 agility test, and the speed performances by photocell. As a result of the analysis, there was no statistically significant relationship between isokinetic dominant and non-dominant leg hamstring and quadriceps peak torque forces and agility and speed performance at 60°s-1 and 400°s-1 angular speeds (p &lt;0.05). As a result, it can be stated that there is no relation between hamstring and quadriceps muscle strength and speed and agility performances of handball players. This may be related to the requirements and physical characteristics of the handball branch (tall height, high weight, high BMI).

Running fatiguing protocol affects peak torque joint angle and peak torque differently in hamstrings vs. quadriceps

The aim of the current study was to investigate the effects of a running fatiguing protocol on the peak torque joint angle and the peak torque in hamstrings vs. quadriceps. Twenty-one male runners underwent a running fatiguing protocol consisting of 40 min at a speed corresponding at first ventilatory threshold. Before and after the fatiguing protocol, isokinetic concentric and eccentric hamstrings and concentric quadriceps peak torque was measured at 60 and 300 deg s−1. The peak torque joint angle (i.e. the angle at which the peak torque was exerted) was recorded. The conventional Hconc:Qconc ratio and the functional Hecc:Qconc ratio were also calculated. The peak torque joint angle increased (i.e. shifted toward shorter muscle length) in hamstrings in eccentric at 60 deg s−1 (ES = 1.35) and at 300 deg s−1 (ES = 0.71) and in concentric modality at 300 deg s−1 (ES = 0.50) but not at 60 deg s−1 (ES = 0.23). No change occurred in quadriceps at 60 deg s−1 (ES = 0.15) and 300 deg s−1 (ES = 0.20). Peak torque deteriorated in both hamstrings and quadriceps, irrespective of the testing modality (ES 0.95–1.90) Functional Hecc:Qconc ratio decreased at 60 deg s−1 (ES = 0.74) and 300 deg s−1 (ES = 0.85). No change in conventional Hconc:Qconc ratio occurred at 60 deg s−1 (ES = 0.12) and 300 deg s−1 (ES = 0.14). The fatigue-induced changes in peak torque joint angle in hamstrings but not in quadriceps and the simultaneous decrements in the functional Hecc:Qconc ratio may point a reduced hamstrings resistive capacity, with implications for hamstrings strain injury risk.