CHANGES IN THE FLEXOR AND EXTENSOR MUSCLES AT DIFFERENT SPEEDS

2021 ◽  
Vol 27 (7) ◽  
pp. 686-688
Author(s):  
Rui Ma ◽  
Wenyan Li
Keyword(s):  
Knee Joint ◽  
Peak Torque ◽  
Muscle Group ◽  
Lower Limbs ◽  
Flexor Muscle ◽  
Level Of Evidence ◽  
Isokinetic Test ◽  
Extensor Muscles ◽  
Test Velocity ◽  
The Difference

ABSTRACT Introduction: Centrifugal strength is an important element for strength quality. Developing muscle centrifugal strength can effectively increase the stability of lower limbs and reduce the risk of injury. Objective: To explore the characteristics of contractile force of flexor ahods in strength training and rehabilitation training, and the extensor muscles of the knee joint in athletes with different speeds of centripetal force. Methods: The knee joint muscle group of 8 first-level male high jumpers and 8 second-level male high jumpers were tested by isokinetic centrifugal contraction; the angular test velocity was 60 °/s, 120 °/s, 240 °/s, and the indexes included peak torque, relative peak torque (peak torque/body weight), and the peak torque flexural extension ratio. Results: With the centrifugal contraction of the knee joint muscle group (P < 0.05), the second-level high jumpers should increase the ability of the knee flexor muscle group of the take-off leg. In the case of constant velocity centrifugal contraction (P < 0.01), taking off time must be reduced, that is, taking off speed must be accelerated. Conclusions: The difference in the knee joint muscle isokinetic test results is one of the reasons for the difference in knee joint flexor and extensor muscle contractility under the different speed forces of high jumpers. Level of evidence II; Therapeutic studies - investigation of treatment results.

scholarly journals Isokinetic assessment of the flexor-extensor balance of the knee in athletes with total rupture of the anterior cruciate ligament

1999 ◽  
Vol 54 (2) ◽  
pp. 35-38 ◽  
Author(s):  
Antonio Sérgio A. P. Terreri ◽  
Marco A. Ambrósio ◽  
André Pedrinelli ◽  
Roberto F.M. Albuquerque ◽  
Felix Andrusaitis ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Cruciate Ligament ◽  
Peak Torque ◽  
Muscle Group ◽  
Lateral Side ◽  
Flexor Muscle ◽  
Average Value ◽  
Significant Difference ◽  
Angular Velocities ◽  
Anterior Cruciate

The purpose of this study was to assess the flexor-extensor group of muscles of the knee in young athletes diagnosed with a total rupture of the anterior cruciate ligament (ACL). Eighteen knees of 18 athletes (14 men and 4 women) with an average age of 21.6 years (range 16-32 years) were assessed with a Cybex 6000 model isokinetic apparatus. The average interval between occurrence of the injury and assessment was 10.2 months (range 2 - 48 months). There was an associated meniscal injury in eight of the knees. Athletes with any other kind of associated injury, limitation, or blockage of the movement of the joint, significant pain during the exam, or interval between injury and exam of less than two months were excluded from the study. The parameters studied were the peak torque-velocity and flexor-extensor relationships at the constant angular velocities of 60°/sec and 240°/sec. Previous warming-up was done by means of an ergometric bicycle and adaptation with 3 submaximal repetitions. The contra-lateral side, which presented no injury, was used as control. Peak torque (PT) at the constant velocity of 60°/sec was greater than that at 240°/sec for knees with and without injuries. However, there was no significant difference between the injured and uninjured sides at 60°/sec or at 240°/sec. The average value for the flexor-extensor relationship at 60°/sec on the injured was 60% (( 6), compared to 57% (( 10) on the contra-lateral side. At 240°/sec, the average value was 75% ((10) on the injured side, and 65% ((12) on the contra-lateral side. In conclusion, despite the complete rupture of the ACL of one knee, the average values for the flexor-extensor relationship were similar on the injured and uninjured sides at the velocity of 60°/sec. As the velocity increased, an increase in the values for the flexor-extensor relationship of the knee also occurred, indicating a tendency of the performance of the flexor muscle group to approach that of the extensor muscle group, and this tendency was more pronounced on the side of the injury.

scholarly journals Ratio of maximum hamstring torque to maximum quadriceps torque in professional basketball and soccer players

2021 ◽  
Vol 7 (4) ◽  
pp. 8-18
Author(s):  
A. Kukrić ◽  
M. Joksimović ◽  
B. Petrović ◽  
F. Latino ◽  
R. Pavlović ◽  
...  
Keyword(s):  
Knee Joint ◽  
Peak Torque ◽  
Soccer Players ◽  
Football Players ◽  
Basketball Players ◽  
Professional Basketball ◽  
Professional Soccer ◽  
Lower Extremity Muscle ◽  
Significant Difference ◽  
The Difference

Purpose: The aim of the study was to determine the differences between football players and basketball players in the mean absolute values ​​of maximum torque flexors and extensors, ratio of maximum hamstring torque to maximum quadriceps torque dominant (DOM) non-dominant (ND) leg and differences in bilateral imbalance of flexor muscles and knee extensors. Material and methods: The research included a sample of 39 professional athletes. The first subsample included 19 professional basketball players while the second subsample included 20 professional soccer players. Results: Based on the results of the torques of the extensors in the knee joint of the DOM and ND legs, it was established that there is no statistically significant difference between basketball players and football players. However, a statistically significant difference was found in the torque flexors of the knee joint DOM (p≤0.01) and ND (p≤0.00) of the leg between basketball players and football players. On the other hand, the results of the research indicate that the difference between basketball players and football players in the ratio of Hamstrings peak torque to Quadriceps peak torque was recorded only in the ND leg (p≤0.02), while the difference in the DOM leg is not statistically significant. The results of our study indicate that basketball players have a higher percentage of imbalances compared to football players, especially in m. hamstrings. Conclusion: This study provides normative data on populations specific to soccer and basketball, but does not provide evidence of the ability of the isokinetic assessment of lower extremity muscle strength to predict injuries to football players and basketball players.

scholarly journals Biomechanical study on the stress distribution of the knee joint after residual rotation deformity of tibial fracture

2020 ◽  
Author(s):  
Ming Li ◽  
Yanbin Zhu ◽  
Ning Wei ◽  
Wenli Chang ◽  
Zeyue Jin ◽  
...  
Keyword(s):  
Stress Distribution ◽  
Knee Joint ◽  
Lower Limb ◽  
External Rotation ◽  
Biomechanical Study ◽  
Lower Limbs ◽  
Neutral Position ◽  
Lateral Stress ◽  
Significant Difference ◽  
The Difference

Abstract Objectives To investigate the effect of residual rotation deformity on the stress distribution of the knee joint after surgery to treat middle and upper tibial fractures. Methods Fourteen adult cadaver specimens that were preserved with formalin were included, and the tibias were randomly positioned at 0 degree, 5 degrees, 10 degrees, and 15 degrees from the line of force of the lower limb. These positions modeled deformities of 5 degrees, 10 degrees, and 15 degrees from the line of force. Low-pressure pressure-sensitive film technology measured the stress distribution of the knee joint under different degrees of rotation deformity. Results Under a vertical load of 400 N, the difference between the medial and lateral stress of the knee joint was significantly different between the different tibia deformities (P<0.05), and the medial stress of the knee joint was higher than the lateral stress. The current study showed that there were statistically significant differences in the medial stress on the knee joint at all angles (including the neutral position of 0 degrees) (F=89.753, P<0.001) . There was a statistically significant difference in the lateral stresses of the knee joint between different rotation deformities (including the neutral position of 0 degrees) (F=102.998, P<0.001). Conclusions Residual rotation deformity after fracture of middle and upper tibia can lead to poor alignment of lower limb force and change of articular contact characteristics of knee joint, especially external rotation of tibia.Therefore, orthopedic surgeons should correct the malalignment of lower limbs to the greatest extent and reduce the rotation deformity as far as possible.

scholarly journals The Effect of an 8-Week Hamstring Weight Training on H/Q ratio and H/Q FI of Male College Students

2021 ◽  
Vol 30 (3) ◽  
pp. 295-302
Author(s):  
Seung-Ri Kim ◽  
Hyun-Joo Kang
Keyword(s):  
College Students ◽  
Knee Joint ◽  
Weight Training ◽  
Statistical Significance ◽  
Peak Torque ◽  
Control Group ◽  
Significant Difference ◽  
Male College ◽  
The Difference ◽  
Male College Students

PURPOSE: This study aimed to examine the effects on the hamstring/quadriceps ratio (H/Q ratio) and H/Q ratio fatigue index (H/Q FI) of the knee joint of an 8-week weight training to improve the hamstring muscles of male college students.METHODS: Twenty male college students were divided into two groups: an exercise group (EG) and a control group (CG). The EG participated in an 8-week hamstring weight training program, working out twice a week, 60 min per session, with a 60–80% 1RM and 12–16 RPE intensity. The peak torque, H/Q ratio, and H/Q FI were measured, and a t-test was used to verify the statistical significance of the difference between the pre- and post-intervention results.RESULTS: The right flexor peak torque at 60°/sec increased by 14.10±9.60%BW in the EG and decreased by −9.00±16.55%BW in the CG, showing a significant difference between the groups (<i>p</i><0.01). The left flexor peak torque increased by 6.60±12.31%BW in the EG and decreased by −5.10±10.68%BW in the CG, showing a significant difference between the groups (<i>p</i><0.05). The left extensor peak torque decreased by −5.40±19.53%BW in the EG and by −28.40±25.70%BW in the CG, showing a significant difference between the groups (<i>p</i><0.05). The H/Q ratios tended to increase, but the difference was not significant.CONCLUSIONS: To prevent injuries and stabilize the knee joint, the central joint of the lower extremity that plays an important role in daily life and sports activities, hamstring weight training can be performed to maintain the H/Q ratio within the normal range.

scholarly journals RESEARCH ON STABILITY OF ATHLETE KNEE QULUS LIGTE RECONSTRUCTION

2021 ◽  
Vol 27 (8) ◽  
pp. 786-788
Author(s):  
Kuolin Zhang
Keyword(s):  
Anterior Cruciate Ligament ◽  
Knee Joint ◽  
High Speed ◽  
Cruciate Ligament ◽  
Acl Injury ◽  
Lower Limbs ◽  
Joint Stability ◽  
Level Of Evidence ◽  
Rehabilitation Training ◽  
Anterior Cruciate

ABSTRACT Introduction: ACL injury of the knee joint is common in sports. Due to the special characteristics of strong physical confrontation and high speed, basketball has a high risk of ACL injury. Objective: To investigate the stability of anterior cruciate ligament (ACL) reconstruction on knee injury in athletes. Methods: In the south, medical research selected 3 cases of unilateral injuries in men's basketball athletes with arthroscopic anterior cruciate ligament autogenous tendon revascularization. We started collecting and recording data of three players three days after rehabilitation training, at various stages in the process Results: At the end of rehabilitation training, 10 weeks after operation, the pain disappeared, the range of motion of the knee joint increased significantly, muscle atrophy of bilateral lower limbs diminished, knee joint stability improved, knee joint muscle strength of the affected leg strengthened, and the rehabilitation goal was basically accomplished. Conclusions: Early rehabilitation training can effectively restore the movement function of the patient's knee joint, improve the efficiency of rehabilitation and shorten the rehabilitation period, thus helping the injured individual recover from the injury and return to the game rapidly. Level of evidence II; Therapeutic studies - investigation of treatment results.

EVALUATION OF BLOOD OXYGEN SATURATION OF HIGH JUMPERS BASED ON ISOKINETIC TEST

2021 ◽  
Vol 27 (7) ◽  
pp. 722-724
Author(s):  
Qiang Yao
Keyword(s):  
Oxygen Saturation ◽  
Test System ◽  
Muscle Group ◽  
Extensor Muscle ◽  
Blood Oxygen ◽  
Flexor Muscle ◽  
Blood Oxygen Saturation ◽  
Test Speed ◽  
Isokinetic Test ◽  
Significant Difference

ABSTRACT Introduction: An isokinetic test refers to the test of the force of a muscle or muscle group during centripetal and centrifugal movements at a constant speed in the whole range of joint motion by means of a isokinetic force tester. Objective: To explore the application of the knee centripetal flexor and extensor muscle groups in the blood oxygen saturation of high jumpers. Methods: Eighteen teenage female high jumper athletes above level 2 in a city sports school were selected. Their ages was 16.89±1.02 years old; height, 168.31±6.32cm; weight, 55.36±6.75kg. Results: At 60° S and 120° S test speed, the peak moment of the extensor muscle group on the same side of the knee was significantly greater than that of the flexor muscle group (P<0.05), while at 240° S test speed, it was the opposite. There was a significant difference in the peak moment of the flexor muscle group on the left and right side of the knee (P<0.01). Conclusions: The function of the dynamic muscle strength test system is one of the methods of studying the human muscle function. and can be used to test and evaluate the general strength of athletes. Level of evidence II; Therapeutic studies - investigation of treatment results.

scholarly journals SPORTS MECHANICS REHABILITATION EFFECTS ON KNEE AND MUSCLE

2021 ◽  
Vol 27 (8) ◽  
pp. 807-809
Author(s):  
Aona Chen ◽  
Shuhua Qu ◽  
Xuejun Ma ◽  
Wenjiang Zhao ◽  
Chenggen Guo
Keyword(s):  
Anterior Cruciate Ligament ◽  
Knee Joint ◽  
Human Body ◽  
Cruciate Ligament ◽  
Weight Ratio ◽  
Peak Torque ◽  
Ligament Injury ◽  
Control Group ◽  
Level Of Evidence ◽  
Anterior Cruciate

ABSTRACT Introduction: The knee joint is a complex and important joint in the human body. It plays an active role in maintaining posture balance of the human body in sports, allowing one to bear a larger load and complete various complex technical movements. Objective: To investigate the stability and influence of kinemechanics in knee joint rehabilitation training. Methods: A total of 80 patients with anterior cruciate ligament injury who received treatment in Henan Provincial People's Hospital were selected and divided into control group and observation group according to the random number table method, with 40 cases in each group. Results: Six months after surgery, the peak torque (PT), peak torque to body weight ratio (PT/BWT), total work (TWT), Lysholm score and Tegner score, and knee circumference of the two groups were significantly improved compared with those before surgery (P <0.01). The degree of improvement was greater in the observation group:compared with the control group, the difference was highly statistically significant (P<0.01). Conclusions: Professional exercise rehabilitation has a definite effect on patients after anterior cruciate ligament reconstruction. It can significantly improve the muscle strength of quadriceps and hamstring, improve the function of knee joint and promote its recovery. Level of evidence II; Therapeutic studies - investigation of treatment results.

Lumbopelvic Control and the Development of Upper Extremity Injury in Professional Baseball Pitchers

2021 ◽  
pp. 036354652098812
Author(s):  
Kevin Laudner ◽  
Regan Wong ◽  
Daniel Evans ◽  
Keith Meister
Keyword(s):  
Upper Extremity ◽  
Lower Limbs ◽  
Group Differences ◽  
Professional Baseball ◽  
Extremity Injury ◽  
Level Of Evidence ◽  
Balance Task ◽  
Upper Extremity Injury ◽  
Baseball Pitchers ◽  
Extremity Injuries

Background: The baseball-throwing motion requires a sequential order of motions and forces initiating in the lower limbs and transferring through the trunk and ultimately to the upper extremity. Any disruption in this sequence can increase the forces placed on subsequent segments. No research has examined if baseball pitchers with less lumbopelvic control are more likely to develop upper extremity injury than pitchers with more control. Purpose: To determine if baseball pitchers who sustain a chronic upper extremity injury have less lumbopelvic control before their injury compared with a group of pitchers who do not sustain an injury. Study Design: Cohort study; Level of evidence, 2. Methods: A total of 49 asymptomatic, professional baseball pitchers from a single Major League Baseball organization participated. Lumbopelvic control was measured using an iPod-based digital level secured to a Velcro belt around each player’s waist to measure anteroposterior (AP) and mediolateral (ML) deviations (degrees) during single-leg balance with movement and static bridge maneuvers. During a competitive season, 22 of these pitchers developed upper extremity injuries, while the remaining 27 sustained no injuries. Separate 2-tailed t-tests were run to determine if there were significant differences in lumbopelvic control between groups ( P < .05). Results: There were no significant between-group differences for the stride leg (nondominant) during the bridge test in either the AP ( P = .79) or the ML ( P = .42) directions, or either direction during the drive leg bridge test ( P > .68). However, the injured group had significantly less lumbopelvic control than the noninjured group during stride leg balance in both the AP ( P = .03) and the ML ( P = .001) directions and for drive leg balance in both the AP ( P = .01) and the ML ( P = .04) directions. Conclusion: These results demonstrate that baseball pitchers with diminished lumbopelvic control, particularly during stride leg and drive leg single-leg balance with movement, had more upper extremity injuries than those with more control. Clinicians should consider evaluating lumbopelvic control in injury prevention protocols and provide appropriate exercises for restoring lumbopelvic control before returning athletes to competition after injury. Specific attention should be given to testing and exercises that mimic a single-limb balance task.

scholarly journals Concentric and eccentric isokinetic hamstring injury risk among 582 professional elite soccer players: a 10-years retrospective cohort study

2020 ◽  
Vol 6 (1) ◽  
pp. e000868
Author(s):  
Ricardo Lima Burigo ◽  
Robson Dias Scoz ◽  
Bruno Mazziotti de Oliveira Alves ◽  
Rubens Alexandre da Silva ◽  
Cesar Augusto Melo-Silva ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Cohort Study ◽  
Retrospective Cohort Study ◽  
Retrospective Cohort ◽  
Injury Risk ◽  
Peak Torque ◽  
Soccer Players ◽  
Complex Data ◽  
Isokinetic Test ◽  
Clinical Records

Background/AimDifferent authors have tried to correlate the peak isokinetic torque values with the incidence of soccer match injuries. However, due to the wide variety of assessment testing protocols, such an inference becomes difficult. This study aimed to verify the capacity of an isokinetic test to establish injury risk reference values for hamstring strain injuries.MethodsA retrospective cohort study based on isokinetic data and clinical records from the last 10 years was conducted in 582 Brazilian elite-professional soccer players, who were subjected to the same isokinetic test protocol, machine, and tester. A Multivariate Logistic Regression Analysis for Complex Data Sampling was used to generate injury risk statistical indexes.ResultsMultivariate regression analysis of both legs provided important data to identify the cut-off values of Concentric Peak Torque (181.82 Newton/*metres), Concentric Work (236.23 watts) and Concentric Power (130.11 joules).ConclusionsThe injury risk indexes indicate that an increase of just one Newton unit in CPT (Concentric Peak Torque) and CJ (Concentric Power) above those cut-off values, can reduce the risk of future injuries by 2% and 2.7%, respectively.

Arthroscopic Imaging Treatment and Clinical Rehabilitation of Knee Sports Injuries

2021 ◽  
Vol 11 (6) ◽  
pp. 1780-1788
Author(s):  
Habaxi Kaken ◽  
Shanshan Wang ◽  
Wei Zhao ◽  
Baoerjiang Asihaer ◽  
Li Wang
Keyword(s):  
Muscle Strength ◽  
Knee Joint ◽  
Sports Injuries ◽  
Cruciate Ligament ◽  
Quadriceps Muscle ◽  
Lower Limbs ◽  
Continuous Passive Motion ◽  
Control Group ◽  
Pressure Therapy ◽  
Quick Recovery

This article studies the effects of arthroscopic imaging treatment and clinical rehabilitation of knee sports injuries. Arthroscopy was used to perform meniscus trimming and resection for 40 patients with knee sports injuries. The ages of the patients ranged from 20 to 60 years old. All patients received routine rehabilitation training such as continuous passive motion of the knee joint, biofeedback of the lower limbs, and air pressure therapy of the lower limbs. In addition, the control group was given muscle strength training, and the training began after the patients received the quadriceps muscle strength test. The removal of the joint cavity and the joint debridement has achieved satisfactory treatment results. In the experiment, the test cases were divided into two groups, and the sensor test platform was used for signal collection. Normal activities can be resumed 2 weeks after the operation. After a follow-up of 6 to 24 months, the knee joint pain disappeared, the joint was free of swelling, and the knee function was normal up to 93%. Arthroscopic reconstruction of the anterior and posterior cruciate ligament joint repair/reconstruction of the medial and posterolateral ligament knots is safe and feasible for the treatment of multiple ligament injuries of the knee joint. It has the advantages of less trauma and quick recovery. Early postoperative systemic and standardized rehabilitation exercises can obtain good knee joint function.

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