scholarly journals Pre- and Post-Operative Limb Symmetry Indexes and Estimated Preinjury Capacity Index of Muscle Strength as Predictive Factors for the Risk of ACL Reinjury: A Retrospective Cohort Study of Athletes after ACLR

2021 ◽  
Vol 11 (8) ◽  
pp. 3498
Author(s):  
Martin Rudolf Zore ◽  
Nevenka Kregar Velikonja ◽  
Mohsen Hussein
Keyword(s):  
Muscle Strength ◽  
Cruciate Ligament ◽  
Knee Extensor ◽  
Peak Torque ◽  
Secondary Injury ◽  
Flexor Muscle ◽  
Acl Injuries ◽  
Secondary Injuries ◽  
Operative Limb ◽  
Torque Values

Long-term muscle weakness may increase the risk of knee reinjury after anterior cruciate ligament reconstruction (ACLR) and of osteoarthritis. The incidence of secondary injuries after ACLR and the predictive value of preoperative and postoperative limb symmetry index (LSI) and estimated preinjury capacity (EPIC) index were studied for predicting the risk of reinjury in a retrospective study. Sixty-three recreational and professional athletes after ACLR with hamstring autograft were followed for secondary injury in the period from 2012 to 2014, 5 years after ACLR. Peak torque values of knee extensor and flexor muscle strength of the involved and uninvolved limb were measured with an isokinetic dynamometer at 60 degrees per second before ACLR and 6 months after ACLR and were used to calculate LSI and EPIC index. The results suggest that the preoperative LSI and EPIC indexes predict a secondary ACL injury better than the postoperative LSI for extensor muscles which is often used as a criterion to determine the time for returning to normal sports activities. Individuals with secondary ACL injuries suffer greater loss of knee extensor muscle strength of the uninvolved limb between preoperative and postoperative ACLR testing compared to the individuals without secondary injury.

Hamstring Flexibility Is Not Correlated with Isokinetic Knee Muscle Strength in Female Modern Dancers

2018 ◽  
Vol 33 (2) ◽  
pp. 95-101 ◽  
Author(s):  
Ani Agopyan
Keyword(s):  
Muscle Strength ◽  
Knee Extensor ◽  
Peak Torque ◽  
Flexor Muscle ◽  
Work Production ◽  
University Level ◽  
Modern Dancers ◽  
Hamstring Flexibility ◽  
Knee Muscle ◽  
The Right

OBJECTIVE: To evaluate bilateral isokinetic knee extensor and flexor muscle strength relative to hamstring flexibility in female modern dancers. METHODS: 20 trained university-level female modern dance students (mean age 23.8±3.8 yrs) volunteered for the study. Concentric isokinetic peak torque (PT, in Nm), peak torque % of body weight (PT%BW, in Nm/kg), and total work (TW, in J) of the knee extensor and flexor muscles for each leg were measured with a dynamometer at a velocity of 60, 180, and 300°/s. Hamstring flexibility of both limbs was assessed by a goniometer with the subjects in a supine position using the active straight leg raise (SLR) test. Participants were divided into flexible (n=10) and highly flexible (n=10) groups based on their hamstring flexibility. RESULTS: The flexible and highly flexible groups had significant differences (p≤0.05) for the right (flexible, 119.7±4.3°; highly flexible, 137.7±2.6°) and left active SLR tests (flexible, 120.6±5.3°; highly flexible, 138.3±4.5°). No significant differences were found between the flexible and highly flexible dancers for concentric knee extensor and flexor muscle strength in all selected parameters (p≤0.05). There were also no significant correlations between flexibility and bilateral PT, PT%BW, and TW scores (60, 180, and 300°/s) of dancers at the concentric contraction (p≤0.05). CONCLUSION: These findings indicate that hamstring flexibility (for both the flexible and highly flexible groups) is not correlated with knee strength and has no impact on torque and work production during maximal concentric isokinetic knee muscle action in university-level female modern dancers.

scholarly journals Velocity-specific knee strength between professional and under-17 female volleyball player

2019 ◽  
Vol 75 (1) ◽  
Author(s):  
Alexandre R.M. Pelegrinelli ◽  
Laís F. Dela Bela ◽  
Mariana F. Silva ◽  
Lucas C.R. Rodrigues ◽  
João P. Batista ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Knee Extensor ◽  
Peak Torque ◽  
Total Work ◽  
Flexor Muscle ◽  
Mean Power ◽  
Cross Sectional ◽  
Significant Group ◽  
Surface Maps ◽  
Volleyball Players

Background: Many studies have investigated isokinetic performance in volleyball players but not through surface maps.Objectives: The goals of this study were to assess velocity-specific isokinetic knee extensor–flexor muscle strength and to compare the isokinetic knee extensor–flexor muscles between professional (PRO) and under-17 (U17) female volleyball players.Method: This cross-sectional laboratory study was developed with two groups: PRO (n = 12), medianage = 21.3 years, and U17 (n = 9), medianage = 15 years. Peak torque, total work, mean power, angle of peak torque, hamstring–quadriceps torque ratio (H–Q ratio) and torque–angle–velocity surface maps were analysed from knee extension–flexion at 60, 120 and 300 degrees per second (°/s).Results: Significant differences were identified for extensor peak torque between PRO x = 202.3 Newton metre (N·m) (standard deviation [SD] = 24.4) and U17 x = 141.6 N·m (30.1) at 60 °/s (p < 0.001; d = 2.21) as well as flexor peak torque (PRO x = 75.7 N·m [10.3] and U17 x = 57.7 N·m [11.4]) at 120 °/s (p < 0.001; d = 1.65) for the dominant limb. There were also significant group differences for total work and mean power at all velocities for extension and flexion. Surface maps demonstrated higher torque at lower speeds for both groups with smaller torque changes across velocities for flexion.Conclusion: Different groups of female volleyball players showed contrasting concentric knee muscle strength across isokinetic velocities.Clinical implications: These results demonstrate the importance of specific strength training for different age groups, even within the same sport, and provide insight into muscle strength.

scholarly journals ACTN3 genotype is associated with muscle phenotypes in women across the adult age span

2008 ◽  
Vol 105 (5) ◽  
pp. 1486-1491 ◽  
Author(s):  
Sean Walsh ◽  
Dongmei Liu ◽  
E. Jeffrey Metter ◽  
Luigi Ferrucci ◽  
Stephen M. Roth
Keyword(s):  
Muscle Strength ◽  
Knee Extensor ◽  
Peak Torque ◽  
Fat Free Mass ◽  
Isokinetic Dynamometry ◽  
Adult Age ◽  
Encoding Gene ◽  
Total Body ◽  
Torque Values ◽  
Adult Volunteers

The R577X polymorphism in the α-actinin-3 encoding gene ( ACTN3) has been associated with elite athletic performance, and recently with differences in isometric and dynamic muscle strength and power in the general population. In this study we sought to determine the association of ACTN3 R577X genotype with muscle strength and mass phenotypes in men and women across the adult age span. Eight hundred forty-eight ( n = 848) adult volunteers (454 men and 394 women) aged 22–90 yr were genotyped for ACTN3 R577X. Knee extensor (KE) shortening and lengthening peak torque values were determined using isokinetic dynamometry and fat-free mass (FFM) by dual-energy X-ray absorptiometry. Women deficient in α-actinin-3 (X/X; n = 53) displayed lower KE shortening peak torque (30°/s: 89.5 ± 3.5 vs. 99.3 ± 1.4 N·m, P = 0.011; 180°/s: 60.3 ± 2.6 vs. 67.0 ± 1.0 N·m, P = 0.019) and KE lengthening peak torque (30°/s: 122.8 ± 5.7 vs. 137.0 ± 2.2 N·m, P = 0.022; 180°/s: 121.8 ± 5.8 vs. 138.5 ± 2.2 N·m, P = 0.008) compared with R/X + R/R women ( n = 341). Women X/X homozygotes also displayed lower levels of both total body FFM (38.9 ± 0.5 vs. 40.1 ± 0.2 kg, P = 0.040) and lower limb FFM (11.9 ± 0.2 vs. 12.5 ± 0.1 kg, P = 0.044) compared with R/X + R/R women. No genotype-related differences were observed in men. In conclusion, our results indicate that the absence of α-actinin-3 protein (i.e., ACTN3 X/X genotype) influences KE peak torque and FFM in women but not men.

scholarly journals Isokinetic Performance of Knee Flexor and Extensor Muscles in American Football Players from Brazil

2017 ◽  
Vol 19 (4) ◽  
pp. 426 ◽  
Author(s):  
Lucas Severo-Silveira ◽  
Carolina Gassen Fritsch ◽  
Bruno Manfredini Baroni ◽  
Vanessa Bernardes Marques ◽  
Maurício Pinto Dornelles
Keyword(s):  
Cruciate Ligament ◽  
Production Capacity ◽  
Knee Extensor ◽  
Peak Torque ◽  
Primary Objective ◽  
American Football ◽  
Football Players ◽  
Thigh Muscles ◽  
Torque Values ◽  
Isokinetic Performance

DOI: http://dx.doi.org/10.5007/1980-0037.2017v19n4p426 The isokinetic performance of thigh muscles has been related to athletic performance and risk for non-contact injuries, such as anterior cruciate ligament ruptures and hamstring strains. Although isokinetic profile of American football players from United States (USA) is widely described, there is a lack of studies comprising players acting outside the USA. The primary objective of this study was to describe the isokinetic performance of thigh muscles in elite American football players in Brazil. Secondarily, we aimed to compare the playing positions and compare the Brazilian players with high-level athletes from USA. Knee extensor (KE) and flexor (KF) muscles of 72 Brazilian players were assessed through isokinetic tests at 60°·s-1. KE concentric peak torque was 276±56 N·m, while KF had concentric and eccentric peak torques of 151±37 N·m and 220±40 N·m, respectively. Offensive linemen players presented greater peak torque values than defensive lineman, halfbacks, and wide receivers (all comparisons are provided in the article). Brazilian players had lower scores than USA athletes for KE and KF peak torque values. In addition, a conventional torque ratio (concentric/concentric) lower than 0.6 was found in 76-83% of athletes, and a functional ratio (eccentric/eccentric) below to 1.0 in 94%. Bilateral asymmetry greater than 10% was verified in 26% and 43% of athletes for KE and KF muscles, respectively. Elite players in Brazil present high incidence of strength imbalance in thigh muscles, and they are below USA players in relation to torque production capacity of KE and KF muscles.

scholarly journals Evaluation of Physical Therapy Effectiveness after Anterior Cruciate Ligament Reconstruction

2018 ◽  
Vol 2 (85) ◽  
Author(s):  
Kęstutis Radžiūnas ◽  
Vytenis Trumpickas ◽  
Jonas Poderys
Keyword(s):  
Anterior Cruciate Ligament ◽  
Physical Therapy ◽  
Muscle Strength ◽  
Therapy Group ◽  
Cruciate Ligament ◽  
Knee Extensor ◽  
Flexor Muscle ◽  
Therapy Program ◽  
Physical Therapy Program ◽  
Anterior Cruciate

Research background and hypothesis. The aim of physical therapy after sports trauma is to help patients to restore physical activity as it was before injury. The participants who applied for intensive physical therapy after anterior cruciate ligament reconstructive surgery will achieve better leg muscle strength results.Research aim was to compare the effectiveness of intensive and traditional rehabilitation of the knee extensor and flexor muscle strength after the surgery for patients after anterior cruciate ligament reconstruction.Research methods. The method that we used was “Biodex Medical System 3 PRO” for the knee muscle strength. A total of 30 patients were enrolled in this study. The subjects were divided into two groups. The muscle strength was measured while leg was flexed and extended at the knee joint.Research results. The research results showed that participants who received intensive physical therapy program developed better muscle strength than in standard physical therapy group. Participant’s leg muscles recovered faster in intensive physical therapy group than in standard physical therapy group.Discussion and conclusions. The participants who received physical therapy before surgery, electrostimulation and intensive physical therapy program after surgery, achieved higher levels of knee extensor and flexor muscle strength after anterior cruciate ligament reconstructive surgery than those patients undergoing a traditional physical therapy program only after surgery.Keywords: anterior cruciate ligament, intensive physical therapy, muscle strength.

Isokinetic Strength After ACL Reconstruction: Influence of Concomitant Anterolateral Ligament Reconstruction

2021 ◽  
pp. 194173812110054
Author(s):  
Benoit Gillet ◽  
Yoann Blache ◽  
Isabelle Rogowski ◽  
Grégory Vigne ◽  
Bertrand Sonnery-Cottet ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Ligament Reconstruction ◽  
Knee Extensor ◽  
Anterolateral Ligament ◽  
Flexor Muscle ◽  
Knee Flexor ◽  
Strength Recovery ◽  
Flexor Muscles ◽  
Knee Muscle ◽  
Knee Muscle Strength

Background: To reduce the rate of anterior cruciate ligament (ACL) graft rupture, recent surgeries have involved anterolateral ligament reconstruction (ALLR). This reconstruction procedure harvests more knee flexor muscle tendons than isolated ACL reconstruction (ACLR), but its influence on knee muscle strength recovery remains unknown. This study aimed to assess the influence of ALLR with a gracilis graft on the strength of the knee extensor and flexor muscles at 6 months postoperatively. Hypothesis: The additional amount of knee flexor harvest for ALLR would result in impairment in knee flexor muscle strength at 6 months postoperatively. Study Design: Retrospective cohort study. Level of Evidence: Level 2. Methods: A total of 186 patients were assigned to 2 groups according to the type of surgery: ACL + ALLR (graft: semitendinosus + gracilis, n = 119) or isolated ACLR (graft: semitendinosus, n = 67). The strength of the knee extensor and flexor muscles was assessed using an isokinetic dynamometer at 90, 180, and 240 deg/s for concentric and 30 deg/s for eccentric contractions and compared between groups using analysis of variance statistical parametric mapping. Results: Regardless of the surgery and the muscle, the injured leg produced significantly less strength than the uninjured leg throughout knee flexion and extension from 30° to 90° for each angular velocity (30, 90, 180, and 240 deg/s). However, the knee muscle strength was similar between the ACL + ALLR and ACLR groups. Conclusion: The addition of ALLR using the gracilis tendon during ACLR does not alter the muscle recovery observed at 6 months postoperatively. Clinical Relevance: Although more knee flexor muscle tendons were harvested in ACL + ALLR, the postoperative strength recovery was similar to that of isolated ACLR.

scholarly journals Associations of the Stair Climb Power Test With Muscle Strength and Functional Performance in People With Chronic Obstructive Pulmonary Disease: A Cross-Sectional Study

2010 ◽  
Vol 90 (12) ◽  
pp. 1774-1782 ◽  
Author(s):  
Marc Roig ◽  
Janice J. Eng ◽  
Donna L. MacIntyre ◽  
Jeremy D. Road ◽  
W. Darlene Reid
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Muscle Strength ◽  
Functional Performance ◽  
Knee Extensor ◽  
Chronic Obstructive ◽  
Flexor Muscle ◽  
Cross Sectional ◽  
Obstructive Pulmonary Disease ◽  
Power Test ◽  
Muscle Torque

Background The Stair Climb Power Test (SCPT) is a functional test associated with leg muscle power in older people. Objective The purposes of this study were to compare the results of the SCPT in people with chronic obstructive pulmonary disease (COPD) and people who were healthy and to explore associations of the SCPT with muscle strength (force-generating capacity) and functional performance. Design The study was a cross-sectional investigation. Methods Twenty-one people with COPD and a predicted mean (SD) percentage of forced expiratory volume in 1 second of 47.2 (12.9) and 21 people who were healthy and matched for age, sex, and body mass were tested with the SCPT. Knee extensor and flexor muscle torque was assessed with an isokinetic dynamometer. Functional performance was assessed with the Timed “Up & Go” Test (TUG) and the Six-Minute Walk Test (6MWT). Results People with COPD showed lower values on the SCPT (28%) and all torque measures (∼32%), except for eccentric knee flexor muscle torque. In people with COPD, performance on the TUG and 6MWT was lower by 23% and 28%, respectively. In people with COPD, the SCPT was moderately associated with knee extensor muscle isometric and eccentric torque (r≥.46) and strongly associated (r=.68) with the 6MWT. In people who were healthy, the association of the SCPT with knee extensor muscle torque tended to be stronger (r≥.66); however, no significant relationship between the SCPT and measures of functional performance was found. Limitations The observational design of the study and the use of a relatively small convenience sample limit the generalizability of the findings. Conclusions The SCPT is a simple and safe test associated with measures of functional performance in people with COPD. People with COPD show deficits on the SCPT. However, the SCPT is only moderately associated with muscle torque and thus cannot be used as a simple surrogate for muscle strength in people with COPD.

scholarly journals Bridge-Enhanced Anterior Cruciate Ligament Repair Is Not Inferior to Autograft Anterior Cruciate Ligament Reconstruction at 2 Years: Results of a Prospective Randomized Clinical Trial

2020 ◽  
Vol 48 (6) ◽  
pp. 1305-1315 ◽  
Author(s):  
Martha M. Murray ◽  
Braden C. Fleming ◽  
Gary J. Badger ◽  
Christina Freiberger ◽  
Rachael Henderson ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Muscle Strength ◽  
Cruciate Ligament ◽  
Knee Laxity ◽  
Acl Injuries ◽  
Patient Reported ◽  
Subjective Score ◽  
Anterior Cruciate ◽  
Noninferiority Margin

Background: Preclinical studies suggest that for complete midsubstance anterior cruciate ligament (ACL) injuries, a suture repair of the ACL augmented with a protein implant placed in the gap between the torn ends (bridge-enhanced ACL repair [BEAR]) may be a viable alternative to ACL reconstruction (ACLR). Hypothesis: We hypothesized that patients treated with BEAR would have a noninferior patient-reported outcomes (International Knee Documentation Committee [IKDC] Subjective Score; prespecified noninferiority margin, –11.5 points) and instrumented anteroposterior (AP) knee laxity (prespecified noninferiority margin, +2-mm side-to-side difference) and superior muscle strength at 2 years after surgery when compared with patients who underwent ACLR with autograft. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: One hundred patients (median age, 17 years; median preoperative Marx activity score, 16) with complete midsubstance ACL injuries were enrolled and underwent surgery within 45 days of injury. Patients were randomly assigned to receive either BEAR (n = 65) or autograft ACLR (n = 35 [33 with quadrupled semitendinosus-gracilis and 2 with bone–patellar tendon–bone]). Outcomes—including the IKDC Subjective Score, the side-to-side difference in instrumented AP knee laxity, and muscle strength—were assessed at 2 years by an independent examiner blinded to the procedure. Patients were unblinded after their 2-year visit. Results: In total, 96% of the patients returned for 2-year follow-up. Noninferiority criteria were met for both the IKDC Subjective Score (BEAR, 88.9 points; ACLR, 84.8 points; mean difference, 4.1 points [95% CI, –1.5 to 9.7]) and the side-to-side difference in AP knee laxity (BEAR, 1.61 mm; ACLR, 1.77 mm; mean difference, –0.15 mm [95% CI, –1.48 to 1.17]). The BEAR group had a significantly higher mean hamstring muscle strength index than the ACLR group at 2 years (98.2% vs 63.2%; P < .001). In addition, 14% of the BEAR group and 6% of the ACLR group had a reinjury that required a second ipsilateral ACL surgical procedure ( P = .32). Furthermore, the 8 patients who converted from BEAR to ACLR in the study period and returned for the 2-year postoperative visit had similar primary outcomes to patients who had a single ipsilateral ACL procedure. Conclusion: BEAR resulted in noninferior patient-reported outcomes and AP knee laxity and superior hamstring muscle strength when compared with autograft ACLR at 2-year follow-up in a young and active cohort. These promising results suggest that longer-term studies of this technique are justified. Registration: NCT02664545 (ClinicalTrials.gov identifier)

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