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

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.

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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

Applied Sciences ◽

10.3390/app11083498 ◽

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.

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

Journal of Applied Physiology ◽

10.1152/japplphysiol.90856.2008 ◽

2008 ◽

Vol 105 (5) ◽

pp. 1486-1491 ◽

Cited By ~ 75

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.

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Peak Torque and Total Work Relationship in the Thigh Muscles After Anterior Cruciate Ligament Injury

Journal of Orthopaedic and Sports Physical Therapy ◽

10.2519/jospt.1988.10.3.97 ◽

1988 ◽

Vol 10 (3) ◽

pp. 97-101 ◽

Cited By ~ 12

Author(s):

Pekka Kannus

Keyword(s):

Anterior Cruciate Ligament ◽

Anterior Cruciate Ligament Injury ◽

Cruciate Ligament ◽

Peak Torque ◽

Ligament Injury ◽

Total Work ◽

Thigh Muscles ◽

Work Relationship ◽

Anterior Cruciate

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Return to High School– and College-Level Football After Anterior Cruciate Ligament Reconstruction

The American Journal of Sports Medicine ◽

10.1177/0363546512456836 ◽

2012 ◽

Vol 40 (11) ◽

pp. 2523-2529 ◽

Cited By ~ 174

Author(s):

Kirk A. McCullough ◽

Kevin D. Phelps ◽

Kurt P. Spindler ◽

Matthew J. Matava ◽

Warren R. Dunn ◽

...

Keyword(s):

High School ◽

Anterior Cruciate Ligament ◽

Acl Reconstruction ◽

Cruciate Ligament ◽

Performance Level ◽

American Football ◽

Return To Play ◽

Football Players ◽

Patient Reported ◽

Anterior Cruciate

Background: There is a relative paucity of data regarding the effect of anterior cruciate ligament (ACL) reconstruction on the ability of American high school and collegiate football players to return to play at the same level of competition as before their injury or to progress to play at the next level of competition. Purpose: (1) To identify the percentage of high school and collegiate American football players who successfully returned to play at their previous level of competition, (2) to investigate self-reported performance for those players able to return to play or reason(s) for not returning to play, and (3) to elucidate risk factors responsible for players not being able to return to play or not returning to the same level of performance. Study Design: Cohort study; Level of evidence, 3. Methods: This study was a retrospective analysis of prospective patients taken from the Multicenter Orthopaedic Outcomes Network (MOON) cohort who identified football as their primary or secondary sport. Identified patients were then questioned in a structured interview regarding their ACL injury, participation in football before their injury, and factors associated with returning to play. Data were analyzed for player position, concurrent meniscal/ligamentous/chondral injury, surgical technique and graft used for ACL reconstruction, and issues pertaining to timing and ability to return to play. Results: One hundred forty-seven players (including 68 high school and 26 collegiate) met our criteria and were contacted from the 2002 and 2003 MOON cohorts. Return to play rates for all high school and collegiate athletes were similar (63% and 69%, respectively). Based on player perception, 43% of the players were able to return to play at the same self-described performance level. Approximately 27% felt they did not perform at a level attained before their ACL tear, and 30% were unable to return to play at all. Although two thirds of players reported some “other interest” contributing to their decision not to return, at both levels of competition, fear of reinjury or further damage was cited by approximately 50% of the players who did not return to play. Analysis of patient-reported outcome scores at a minimum of 2 years after surgery between patients who returned to play and those who did not demonstrated clinically and statistically significant differences in the International Knee Documentation Committee form, Marx Activity Scale, and Knee injury and Osteoarthritis Outcome Score knee-related quality of life subscale in the collegiate players. Similar clinical differences were not statistically significant in the high school students. Player position did not have a statistically significant effect on the ability to return to play for high school players, and 41% of “skilled” position players and 50% of “nonskilled” position players were able to return to play at the same performance level. Conclusion: Return to play percentages for amateur American football players after ACL reconstruction are not as high as would be expected. While technical aspects of ACL reconstruction and the ensuing rehabilitation have been studied extensively, the psychological factors (primarily a fear of reinjury) influencing the ability to return to play after ACL surgery may be underestimated as a critical factor responsible for athletes not returning to play at any level of competition.

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ANTERIOR CRUCIATE LIGAMENT RECONSRUCTION IN CHILDREN: OUTCOMES OF QUADRICEPS VERSUS HAMSTRING AUTOGRAFTS

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967121s00068 ◽

2021 ◽

Vol 9 (7_suppl3) ◽

pp. 2325967121S0006

Author(s):

Joshua T. Bram ◽

Itai Gans ◽

Robert Parisien ◽

Elliot Greenberg ◽

Theodore J. Ganley

Keyword(s):

Pediatric Patients ◽

Cruciate Ligament ◽

Cohort Analysis ◽

Donor Site ◽

Peak Torque ◽

Patient Reported Outcome Measures ◽

Patient Reported Outcome ◽

Donor Site Pain ◽

Patient Reported ◽

Torque Values

Background: Emerging evidence has suggested reduced donor site pain and equivalent/improved functional outcomes in adults undergoing ACL reconstruction (ACLR) with quadriceps (QT) autograft versus hamstrings (HT) grafts. No studies in children comparing QT versus HT autografts have assessed postoperative strength or active range of motion (AROM) in addition to more commonly accepted patient-reported outcome measures (PROMs). Hypothesis/Purpose: The purpose of this study was to directly compare clinical and patient-reported outcomes of pediatric patients undergoing QT and HT autograft ACL reconstructions. We hypothesized that use of QT autografts would result in similar clinical and PROMs to HT autografts. Methods: A retrospective cohort analysis of pediatric patients (≤18 years) undergoing primary transphyseal ACLR from 1/2018-12/2019 without concomitant multiligamentous reconstruction was conducted. Outcomes at 3 and 6 months, including isokinetic strength testing, PROMIS and IKDC scores, and AROM were compared between patients receiving either HT or QT autografts. Hamstrings to quadriceps (H/Q) ratios were calculated using the ratio of the respective peak torque values normalized to body weight. Multiple imputation was utilized to minimize bias resulting from missed follow-up appointments. Results: 84 patients met inclusion criteria (Table 1). The 40 patients receiving QT were more often male (62.5% vs 34.1%, p=0.009). There were no differences in operative time (p=0.053) or proportion of patients requiring meniscus repair (p=0.958). At 3 months postoperative, those with HT had lower H/Q ratios (62.2 ± 15.8 vs 78.6 ± 19.9, p<0.001) and limb symmetry index (LSI) in flexion (86.1 ± 17.1 vs 94.3 ± 17.6, p=0.042), while patients with QT had lower LSI in extension (66.8 ± 13.2 vs 77.3 ± 12.6, p=0.001). The H/Q ratio was also lower at 6 months among patients receiving HT (59.7 ± 11.2 vs 66.3 ± 8.2, p=0.004). IKDC, PROMIS physical function, and PROMIS pain interference scores were not different between cohorts at either 3 or 6 months. There was no difference in AROM in flexion or extension between groups at all postoperative visits. Patients with QT were more likely to have a postoperative wound issue (20.0% vs 2.3%, p=0.012). Conclusion: Significant differences in quadriceps and hamstrings strength at 3 months were observed for ACLR patients by graft type. This contributed to higher H/Q ratios at 3 and 6 months postoperatively for patients receiving QT. QT grafts appear to have a higher rate of postoperative infection/wound issues. Tables/Figures: [Table: see text]

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Knee Muscles Isokinetic Evaluation after a Six-Month Regular Combined Swim and Dry-Land Strength Training Period in Adolescent Competitive Swimmers

Journal of Human Kinetics ◽

10.1515/hukin-2015-0121 ◽

2015 ◽

Vol 49 (1) ◽

pp. 195-200 ◽

Cited By ~ 4

Author(s):

Athanasios A. Dalamitros ◽

Vasiliki Manou ◽

Kosmas Christoulas ◽

Spiros Kellis

Keyword(s):

Strength Training ◽

Knee Extensor ◽

Peak Torque ◽

Knee Extension ◽

Training Period ◽

Similar Data ◽

Dry Land ◽

Isokinetic Testing ◽

Torque Values ◽

Competitive Swimmers

Abstract Previous studies demonstrated significant increases in the shoulder internal rotators’ peak torque values and unilateral muscular imbalances of the shoulder rotators after a competitive swim period. However, there are no similar data concerning the knee muscles. The purpose of the current study was to examine the effects of a six-month training period on knee flexor and extensor peak torque values, examine a possible bilateral strength deficit and evaluate the unilateral strength balance in competitive swimmers. Eleven male adolescent swimmers (age: 14.82 ± 0.45 years) were tested for concentric knee extension and flexion peak torque (60°/s) with an isokinetic dynamometer, before and after a regular combined swim and dry-land strength training period. A trend towards greater improvements in the knee extensor compared to flexor muscles peak torque was observed. Furthermore, the bilateral strength deficit remained almost unchanged, whereas unilateral strength imbalance was increased for both limbs. However, all results were nonsignificant (p > 0.05). According to the data presented, a six-month regular combined swim and dry-land strength training period caused non-significant alterations for all the parameters evaluated during isokinetic testing. This study highlights the fact that competitive adolescent swimmers demonstrated unilateral knee strength imbalances throughout a long period of their yearly training macrocycle.

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Video Analysis of Anterior Cruciate Ligament Tears in Professional American Football Athletes

The American Journal of Sports Medicine ◽

10.1177/0363546518756328 ◽

2018 ◽

Vol 46 (4) ◽

pp. 862-868 ◽

Cited By ~ 25

Author(s):

Jeffrey T. Johnston ◽

Bert R. Mandelbaum ◽

David Schub ◽

Scott A. Rodeo ◽

Matthew J. Matava ◽

...

Keyword(s):

Anterior Cruciate Ligament ◽

Lower Extremity ◽

Video Analysis ◽

External Rotation ◽

Cruciate Ligament ◽

Case Series ◽

American Football ◽

Football Players ◽

Acl Injuries ◽

Anterior Cruciate

Background: Anterior cruciate ligament (ACL) injuries are prevalent in contact sports that feature cutting and pivoting, such as American football. These injuries typically require surgical treatment, can result in significant missed time from competition, and may have deleterious long-term effects on an athlete’s playing career and health. While the majority of ACL tears in other sports have been shown to occur from a noncontact mechanism, it stands to reason that a significant number of ACL tears in American football would occur after contact, given the nature of the sport. Hypothesis/Purpose: The purpose was to describe the mechanism, playing situation, and lower extremity limb position associated with ACL injuries in professional American football players through video analysis to test the hypothesis that a majority of injuries occur via a contact mechanism. Study Design: Case series; Level of evidence, 4. Methods: A retrospective cohort of National Football League (NFL) players with ACL injuries from 3 consecutive seasons (2013-2016) was populated by searching publicly available online databases and other traditional media sources. Of 156 ACL injuries identified, 77 occurred during the regular season and playoffs, with video analysis available for 69 injuries. The video of each injury was independently viewed by 2 reviewers to determine the nature of the injury (ie, whether it occurred via a noncontact mechanism), the position of the lower extremity, and the football activity at the time of injury. Playing surface, player position, and time that the injury occurred were also recorded. Results: Contrary to our hypothesis, the majority of ACL injuries occurred via a noncontact mechanism (50 of 69, 72.5%), with the exception of injury to offensive linemen, who had a noncontact mechanism in only 20% of injuries. For noncontact injuries, the most common football activity at the time of injury was pivoting/cutting, and the most common position of the injured extremity included hip abduction/flexion, early knee flexion/abduction, and foot abduction/external rotation. There was no association between injury mechanism and time of injury or playing surface in this cohort. Conclusion: In this study of players in the NFL, the majority of ACL tears involved a noncontact mechanism, with the lower extremity exhibiting a dynamic valgus moment at the knee. These findings suggest that ACL injury prevention programs may reduce the risk of noncontact ACL tears in American football players.

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Isokinetic profile of subjects with the ruptured anterior cruciated ligament

Vojnosanitetski pregled ◽

10.2298/vsp141128067d ◽

2016 ◽

Vol 73 (7) ◽

pp. 631-635 ◽

Cited By ~ 1

Author(s):

Miodrag Drapsin ◽

Damir Lukac ◽

Predrag Rasovic ◽

Patrik Drid ◽

Aleksandar Klasnja ◽

...

Keyword(s):

Muscle Strength ◽

Cruciate Ligament ◽

Knee Injuries ◽

Peak Torque ◽

Acl Rupture ◽

Thigh Muscle ◽

Thigh Muscles ◽

Significant Difference ◽

Bilateral Differences ◽

High Level

Background/Aim. All changes in the knee that appear after anterior cruciate ligament (ACL) lesion lead to difficulties in walking, running, jumping especially during sudden changes of the line of movement. This significantly impairs quality of life of these subjects and leads to decrease in physical activity. Knee injuries make 5% of all most severe acute sport injuries. The aim of the study was to determine strength of the thigh muscles in persons with unilateral rupture of the ACL and to evaluate potential bilateral differences between healthy and injured leg. Methods. This study involved 114 male athletes of different sport specialities with the clinical diagnosis of ACL rupture. Each subject had unilateral ACL rupture and the other leg was actually the control for this research. An isokinetic device was used to evaluate the muscle strength of thigh muscles. Testing was performed for two testing speeds, 60?/s and 180?/s. Results. Data analysis showed a statistically significant difference (p < 0.01) between the ACL and the healthy leg in the following parameters: peak torque for thigh extensors (Ptrq_E), angle to peak torque during extension (Ang_E), power of extension (Pow_E) and work during extension (Work_E). Analysing hamstrings to quadriceps (H/Q) ratio we found the unilateral disbalance of thigh muscle strength in ACL leg. Conclusion. A high level of validity makes isokinetic dynamometry the method for evaluation of thigh muscles strength and leaves this field of research open for new studies in order to improve both diagnostic and rehabilitation of patients with the insufficient ACL.

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