Background and aim:  For the rehabilitation program of the anterior cruciate ligament reconstructed patients (ACLR) strength and functional assessment and comparing with the uninvolved side is in great importance. Strength plays an important role in performing vertical jump moreover. It is performed in closed kinetic chain. Despite this importance, no information exists regarding the relationship on peak force of linear isokinetic and vertical jump score. The purposes of this study were1- To determine correlation between isokinetic squat and vertical jump in healthy and ACLR patients. 2- Comparing the peak force and vertical jump between the involved and uninvolved side of the ACLR patients.   
Materials and Methods: Twenty two ACLR patients with 6 months post-surgery and 16 healthy men participated in this study. Their isokinetic squat strength at the testing velocity of 25.4 cm/sec and vertical jump was measured.
Results: ACLR patients' peak force and vertical jump were significantly different between the involved and uninvolved side P≤0.05. The findings showed low relationship )r=0.425)  at the involved side between the vertical jump and peak force of squat, however, there was no relationship in the uninvolved side and the control group.
Conclusion: Findings of  this study indicate no relationship between vertical jump and peak force of squat. Both testing methods should be used since strength not always correlate strongly with physical performance.   Closed kinetic chain isokinetic testing should be used for testing lower extremity strength, while vertical jump should be used to determine performance levels.

Background and aim: Knee joint has a major role in various lower extremity activities. Among different elements of knee joint complex more interest was seen to anterior cruciate ligament because of its alignment, structural complications, more nerve receptors and susceptibility to injury. After injury of this ligament, knee extensor torque decreases but it is believed that this decrease compensated for by muscles of hip and ankle joints. This suggestion has not investigated by isokinetic studies. Therefore, the aim of this research was that if quadriceps muscle torque decreases in spite of rehabilitation process and if this decrease compensated for by hip extensors and ankle plantar flexors?

Materials and methods: 10 healthy men (age: 22-35 years old) and 10 patients with ACL deficiency (age: 23-42 years old) participated in this study. Plantar flexor muscle strength, quadriceps muscle strength and hip extensor muscle strength were tested by Isokinetic Biodex System 3 at 60 and 180 degrees of angular velocities. Also functional vertical jump test was done for each lower extremity.
Results: Will coxson test and Spearman correlation coefficient were used. Results showed that there was no significant difference between mean strength of gastrosoleus, hip extensors and sum of mean strength of gastrosoleus, quadriceps and hip extensors of patient's injured and sound limbs (P>0.05). Results showed that there was significant difference between mean strength of quadriceps of injured and sound limbs (P> 0.01). There was no relationship between gastrosoleus, quadriceps and hip extensor summation and vertical jump functional test in the patients and normal subjects (P>0.05).
Conclusion: The results show that compensation occurs in the ankle plantar flexors and hip extensors of injured lower extremity. Thus in spite of significant decrease in quadriceps strength in the injured limb, sum of mean strength of gastrosoleus, quadriceps and hip extensor muscles between injured and sound limbs was not statistically significant. Also there was no relationship between functional test and isokinetic parameters. Thus functional vertical jump test can not be used instead of isokinetic test.

Abstract

Background and Aim: Patients with anterior cruciate ligament (ACL) deficiency are divided to coper and noncoper groups. The purpose of this study was to compare the efficacy of perturbation training with traditional rehabilitation on functional tests of lower extremity and knee muscles isokinetic peak torque ratio in two groups of patients with ACL-deficient: coper and noncoper

Materials and Methods: In this clinical trial study, 24 patients with ACL-deficient were divided to two groups: coper and noncoper. They participated in a management plan for 4 weeks, three times a week, including perturbation exercises and traditional rehabilitation (stretching, strengthening, and endurance exercises). Lower extremity functional tests through hop tests and knee muscles isokinetic peak torque ratio were evaluated.

 Results: After 4 weeks, all the functional tests improved significantly in both groups and timed 6-meter hop test showed significant improvement in coper group with respect to noncoper grouop (p< 0.05). There was no significant difference between two groups in knee flexors to extensors isokinetic peak torque ratio but this ratio was lower and close to normal values in coper group.

Conclusion: Perturbation training with traditional rehabilitation improves functional abilities of lower extremity in both groups of coper and noncoper of the patients with ACL-deficient. Probably, the patients of noncoper ACL-deficient have chance to return in some daily activities too.

Keywords: anterior cruciate ligament, perturbation training, functional tests, knee isokinetic peak torque

Background and Aim : Athletes from different sport fields are needed to lower extremity dynamic balance for their specific skills. The question can be raised is whether athletes from different sport fields are different in lower extremity dynamic balance? The aim of this study was to compare the dynamic balance of lower extremity of football, handball and taekwondo athletes with functional tests.

Material and Methods : Ten football, 10 handball, and 10 taekwondo healthy male athletes with the mean age of 23.83±0.06 years participated voluntarily in this study . The lower extremity dynamic balance was assessed by Shuttle Run test (SR), figure of 8 Hop test (FEH), Side to Side Hop test(SSH) and Agility Hop test (AH). All analyses were conducted using SPSS version 19.

Results : The scores of SR, FEH and AH tests were higher in taekwondo players compared to football and handball players (7.11± 0.26, 9.86±1.09 and 9.2 ±1.31, respectively). Football players gained the highest score in SSH test (7.52±0.84). The FEH test score in handball players was higher than football players (9.59±0.94). Statistical analysis showed significant differences between three groups on two tests (SR P=0/03 and AH P=0/01).

Conclusion : This study showed that lower extremity function of athletes from different fields of sport may be different. It seems that football and handball players need more agility and speed than taekwondo players for doing their own skills. This issue should be considered in designing the sport specific training protocol for athletes.

Key words : Functional test, Football, Handball, Taekwondo