Bachground and Aim:The anterior cruciate ligament(ACL) has both mechanical and sensory function. Knee joint proprioception has been tested utilizing either reproduction of position or threshold to detection of passive motion in non-weight bearing positions. It has been suggested that more functional and dynamic/active tests of proprioception may clarify the effect of injury and reconstruction on the proprioceptive function of the ACL at the knee.

 The purpose of this study was assessment of knee joint position sense (JPS) following ACL reconstruction in functional position.

Material and Method:12 patients who had undergone ACL reconstruction and 12 healthy control subjects participated in the study.

JPS was evaluated by reproduction of the angles in weight-bearing position with limb movement into flexion and extension.

The dominant-limb knee of healthy subjects and reconstructed and normal knee of the patients were selected for evaluation.

The knee angles were measured  by using a system comprised of digital photography, non-reflective markers and AutoCAD software. Absolute error was considered as a dependent variable.

Results:There were no significant differences between the operated and normal knee of the patients and between the patients and healthy control subjects. These results were observed in two tasks of limb movement into flexion and extension. The position had no significant effect on the absolute error in both groups.

Conclusion and Discussion: The result of this study suggest that subjects who have undergone ACL reconstruction do not have a deficit in knee JPS when tested under functional weight bearing conditions. Knee JPS  is maintained by muscle-tendon receptors providing primary and accurate sensory information for normal proprioceptive function, along with remaining capsular and ligamentous mechanoreceptors which provide additional and/or complimentary proprioceptive information.

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.

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: Anterior Cruciate Ligament (ACL) is responsible for physical and somatosensory function. It is expected that additional sensory information improves dynamic balance of ACL reconstruction patients. This study is aimed to determine the effect of sensory information on knee dynamic balance after ACL reconstruction in comparison with normal people.

Materials and Methods: The study was designed as a randomized clinical trial. Thirty two men (16 men with unilateral ACL reconstruction and 16 healthy men), assigned in three groups: ACLR, reconstructed knee ACLR, non-reconstructed knee and normal. All participants received tactile information during functional tests. Dynamic postural stability was assessed by two functional tests including: Star Excursion Balance test and Cross over Hop for distance. The functional tests scores were conducted both pre and post applying sensory information in ACLR and normal people.

Results: The data showed that tactile information improves functional performance of ACLR patients. There were significant difference in reconstructed knee’s SEBT scores in medial (p=0.005) and posteromedial (p=0.034) directions by adding touch information. Significant difference in dynamic balance by addition of touch sense, in COH scores of ACLR people and normal population was found.

Conclusion: The findings of this study showed that additional sensory information improves dynamic balance in ACLR patients. The positive effect of tactile information supports to apply additional sensory information as a new method for increasing dynamic balance.

Key words: Anterior cruciate ligament, Sensory information, Dynamic balance.

Background and Aim: ACL injury is one of the most common sport injuries which undergo reconstructive surgery. Electromyography or recording of muscles’ electrical activity is a suitable means to assess changes in motor control system output. The goal of this study is to compare the lower limb muscles EMG activity during drop landing in individuals after ACL reconstruction and healthy subjects.

Materials and Methods: Eleven men who had undergone ACL reconstruction 6 to 24 months ago (Age 29±6 years old) and 11 healthy men (Age 28±2 years old) participated in the study. Amount of electrical activity for tibialis anterior, vastus medialis, vastus lateralis, semitendinosus and biceps femoris muscles was recorded using surface electrodes during drop landing and calculated for two time intervals. The amount of activity was measured in -150 to +50 and +50 to +180 intervals in relation to the landing moment. Subjective IKDC questionnaire and cross-over hop functional test were used to determine the subjective and objective functional level.  Independent t test was used to determine between-group statistical differences.

Results: Feed forward activity of semitendinosus (P=.041) and biceps femoris (P=.008) muscles were significantly higher in ACLR group and feedback activity of vastus medialis (P=.03) muscles was significantly lower in ACLR group. Healthy individuals showed higher score on both the functional test and IKDC questionnaire. (P<.0005)

Conclusion: Individuals who had undergone reconstructive surgery of ACL showed different muscular activity compared to healthy subjects and closer to ACL deficient individuals 6 months after surgery and routine rehabilitation.

Keywords: Anterior cruciate ligament reconstruction, Electromyography, Neuromuscular control