Background and Aim : The aim of this study was to determine the effects of fatigue due to plyometric training on vertical jump ability and activity pattern of rectus femoris of dominant leg of high jump of active girls .

Materials and Methods : Seventeen females , mean age (21.5 ± 0.76 years ) were randomly assigned to two experimental (n = 10 ) and control ( n = 7) groups. Experimental group performed plyometric training and control group had no activity. Before and after training , vertical jump test using Ergo jump and electrical activity of rectus femoris muscle of dominant leg using electromyography were tested . The results of vertical jump test showed a decrease in performance (p: 0.04, F: 4.5) and fatigue process was confirmed . The raw EMG signal based on deep jump phases was divided in three phases and only 2 phases of the first were analyzed . In every phase, the maximum activity , amplitude and total time were obtained .respectively. M ultivariate analysis of variance (2×2) was used to compare of post-test of two groups.

Results : After one session training , rectus femoris maximum activity of the experimental group showed a significant decrease in pre-activation phase of motor program .

Conclusion : This study showed that neural fatigue due to plyometric training can occur in motor program (especially in pre-activation phase of motor program ).

Keywords : Deep jump, Plyometric training, Vertical jump, Electromyography, Rectus femoris muscle.

Background and Aim: Proprioception is a type of feedback from limbs to CNS which defines a sensory tools to contribute position sense and movement sense.

Precise and controlled movements are important sections of sports and activity daily living which needs to accurate information of proprioception.

High concentration of proprioceptors are reported in cervical spine, sacroiliac and ankle joint. The purpose of this study was to compare repositioning error of cervical spine on high level badminton and basketball players and healthy subjects.

Materials and Methods: Twenty female basketball players (23.40 years old), 20 female badminton players (24.81years old) and 20 healthy female (24,95years old) subjects were recruited to participate in this study. Cervical total range of motion (ROM) and repositioning error in target angle (30% of full ROM in each movement) of flexion, extension, right and left lateral flexion and rotation were measured by CROM apparatus.

Results : Our results indicate that two groups of athletes has significant differences with non-athletic subjects in flexion, extension, left lateral flexion and ro tation and there were significant differences in right lateral flexion and right rotation between badminton players and non-athletic subjects (P<0.005).

Conclusion : Cervical proprioception may improve with specific sport movements. Basketball and badminton are non-contact sports that needs to eye and hand coordination, as our results showed that the cervical repositioning error was decreased in athletics related to non-athletic subjects, the mentioned sports may improve proprioception.

Key Words: Proprioception, Cervical, Repositioning error, Basketball, Badminton

Background and Aim: Proprioception is a component of somatosensory system. One of the most important somatosensory receptors is muscle spindles. Neck area with high density of muscle spindle, plays a significant role in providing this sense. With repeated contact sports, with high trauma on head and neck region, it is likely that proprioception will be impaired. The present study was conducted to compare proprioception between wrestlers, taekwondo players and non-athlete subjects to determine the effect of trauma on proprioception of craniocervical region.

Material and Methods: This study was a case-control study of 75 male with the age range of 18-30 years (Including: 25 professional wrestlers, 25 professional taekwondo players and 25 non-athlete subjects). Participants were selected through simple non-probability sampling. To assess proprioception of craniocervical region, angular repositioning of two positions (neutral and 50% of range of motion) was evaluated by using the cervical range of motion device (CROM device). The statistical method which used in this study was one way ANOVA.

Results: Accuracy of target repositioning (50% of range of motion) of extension, right and left rotation were significantly different between three groups (p<0.05). Returning to neutral position from mentioned movement was associated with a significant error (p<0.05).

Conclusion: It is assumed that proprioception of craniocervical region has been affected by trauma in wrestlers and taekwondo players, so that the accuracy of head repositioning for both neutral and target positions were reduced in wrestlers. However, taekwondo players had more errors in repositioning of target angle.

Keywords: Proprioception, Repositioning error, Craniocervical, Wrestlers, Taekwondo players