Torque-angle-velocity Relationships and Muscle Performance of Professional and Youth Soccer Players

Isokinetic Training Program to Improve the Physical Function and Muscular Performance of an Individual with Partial Injury of the Medial Meniscus: A Case Report

Background and Purpose

One of the best alternatives for the treatment of meniscal injuries in relation to surgical procedures, is exercise. This case report aimed to describe the effects of isokinetic training and a neuromuscular/proprioceptive exercise program on muscle performance and physical function in an individual after a rupture of the posterior horn of the medial meniscus.

Study Design

Case report.

Case Description

A 40-year-old man injured his right knee during a soccer match, with a partial lesion of the medial meniscus confirmed by magnetic resonance imaging. He completed an isokinetic training program in addition to exercises that targeted proprioception (22 sessions, 11 weeks) to improve physical function and performance, which were assessed before and after treatment and at a six-month follow-up. An individual with similar anthropometric characteristics was chosen to be used as a control for understanding the patient's assessment values.

Outcomes

Muscular performance of the knee flexors and extensors was evaluated isokinetically using the Biodex System-4 in a concentric mode at angular velocities of 60, 120, and 300 °/s . The main results indicated that after 11 weeks, the peak torque normalized to body mass (PT/BM), at 60 °/s of the knee extensors remained unchanged (2.54 N.m/kg) (below the control value - 3.06 N.m/kg), and at the six-month follow-up, increased by approximately 20% (3.08 N.m/kg). For the hamstrings, at 60 °/s, an increase of 18 % occurred after intervention (1.98 N.m/kg) and by approximately 30 % at the six-month follow-up (2.12 N.m/kg) - values much higher than the control 1.55 N.m/kg). This increase in the PT/BM was also reflected in the Hamstrings:Quadriceps ratio (78 %) after treatment which improved at follow-up (68 %).

Discussion

The results showed that the isokinetic training and neuromuscular/proprioceptive exercises improved the muscle performance of the knee flexors and extensors, after eleven weeks of intervention, and remained (or continued to improve) at the six-month follow-up.

Level of evidence

5, single case report.

Comparison of hip abductor and adductor muscle performance between healthy and osteitis pubis professional footballers

OBJECTIVE

The study aimed to compare the concentric and eccentric muscle performance of the hip abductor and adductor muscles at a high angular velocity in football players with osteitis pubis and healthy players.

METHODS

A total number of 32 male football players with osteitis pubis and 20 healthy footballers were tested using an isokinetic dynamometer at a speed of 180°/s. Hip abductor and adductor peak torque/body weight, time to peak torque, acceleration, and deceleration times produced during concentric and eccentric muscle contraction modes were measured using a Biodex dynamometer.

RESULTS

Football players with osteitis pubis demonstrated a significantly higher time to peak torque, acceleration, and deceleration times (p < 0.05); however, when compared to healthy athletes, there was no significant change in muscle strength.

CONCLUSION

The present study showed that football players with osteitis pubis had a reduction in neuromuscular reaction. Therefore, the reaction time of these muscles is critical, and the reduction could result in magnified stresses and/or poorly distributed loads across the musculotendinous structure of the anterior pelvis, which presumably could lead to the development of osteitis pubis. Incorporate findings of the current study in clinical practice could afford critical information when evaluating the hip muscles in football players with osteitis pubis, for pre-screening, enhancing the rehabilitation programs, and guiding the decision of returning to sports after injury.

BIOMECHANICAL STUDY OF MUSCLE MOVEMENT IN THE PROCESS OF FOOTBALL TECHNICAL TRAINING

Study of biomechanical characteristics of muscles can provide an effective reference for the training of athletes. Football is a vigorous sport, and physical collision and damage are frequent during competition and training. In order to improve football skills and prevent sports injuries, 10 athletes from Sport College of Shaoyang University, Hunan, China, were tested for isokinetic muscle strength. The moment of flexors and extensors was measured when the flexion and extension angular speed of hip and knee joints was 50∘, 100∘, 150∘, 200∘, 250∘, 300∘, 350∘ and 400∘, respectively. Moreover the characteristics of force moment of flexor and extensor were verified by testing the electromyographic signal of the flexor and extensor of the hip and knee joints with isokinetic concentric exercise using piezoelectric sensor. The results showed that the electromyographic signal of the flexor and extensor of the hip and knee joint decreased with the increase of angular velocity of isokinetic concentric exercise; the electromyographic signal obtained by the piezoelectric sensor verified the law that the output of the flexor and extensor decreased, the extensor of the hip joint had incoordination during rapid movement, and the output of the extensor was always larger than that of the flexor no matter how fast the extensor moved.