مجله بیومکانیک ورزشی
سال یکم شماره 3 (زمستان 1394)

This study aims to predict basketball shooting ability on the basis of anthropometric characteristics, wrist range of motion, and strength of upper extremity in elite female basketball players.
The sample of the study included 34 female basketball players invited to attend the national team trainings. 15 subjects were playing in center and 19 subjects in guard and forward positions. Measuring tapes and standard method (ISAK) were used to measure the length of segments of dominant or shooting upper extremity. Digital dynamometer and goniometer were used to measure muscular strength and the wrist range of motion, respectively. Shooting ability of players was assessed by standard tests of free throw, three pointer and elbow shot. The research data was statistically analyzed using linear regression analysis.
Results showed that only forearm length variable is significantly effective on free throw shot. However, according to measures and regression coefficient, this effect was low.
When choosing players for the guard and forward positions, coaches can necessarily ignore the stature and length of upper limb issue, and pay more attention to the other factors such as their shooting technique.

pesplanus is one of the changes that brings about changes in muscle activation patterns. Being aware of muscles activity changes in various standing positions among pesplanus patients provides insights into preventing lower extremity injuries in this population. The aim of this study was to compare leg muscles electromyography during various standing positions in pesplanus and normal subjects.
60 healthy male university students, 30 subjects with pesplanus deformity (with average age 23/54±3/57 year, average height 175/34±7/62 cm, average weight 74/87±10/72 kg ) and 30 normal subjects (with average age 22/97±2/38 year, average height 176/6±5/59 cm, average weight 73/58±8/36 kg ) participated in this comparative study. Deformity of pesplanus was assessed with navicular drop test. Each subject performed single-leg landing dropping from 30cm height onto a force platform where muscles activity was recorded with EMG device. For data analysis, Matlab and Spss softwares were used and independent sample t-test was used to compare the dependent variables at a significance level of P &le 0/05.
Significant differences were observed between the two groups for the activities of the longus peroneus and anterior tibialis muscles ( p&le0/05) while no significant differences were observed in other muscles.
The changes in the normal structure of the foot might affect muscle activities during standing, which can cause changes in the injury patterns. Therefore, it is proposed that focusing on corrective exercises and therapy plan can reduce these risks.

The present paper reports on program of work undertaken to evaluate the effect of real time visual feedback on kinematics of prosthetic gait.
A total of 6 below-knee male amputees were included in the study. Each individual underwent three trials of self-selected speed treadmill walking, in which real time visual feedback was provided from forward, backward, and lateral views, together with a control trial without any visual feedback. Kinematic reference values were captured via VICON motion analysis system, and one-minute slots of data sets were processed by its Workstation software (Plug in Gait), which were than statistically analyzed running Wilcoxon Signed-Rank Test.
Statistical analyses revealed significant differences in stance phase (Z=0.923, p=0.031) and stride length (Z=-1.807, p=0.043) between normal and affected sides in front visual feedback mode. Stance phase was generally extended on normal legs, and there appeared to be reductions in hip joint range of motion on affected limbs. Stride time followed relatively comparable patterns in both sides across all trials.
The results suggest that providing visualization in the context of amputee gait rehabilitation may provide an effective way to help subjects correct gait patterns and thereby it may improve the outcome of rehabilitation.

Balancing is the most basic function of the neuromuscular system in performing all simple and complex activities that contribute to health-related physical fitness. Core stability may be a contributing factor to static and dynamic balance. The aim of this study was to investigate the relationship between core stability muscle endurance and static and dynamic balance in basketball players.
100 basketball players (50 female and 50 male players) were selected randomly based on the including criteria.To evaluate core stability muscle strength, a set of tests from core stability exercises was used. Static and dynamic balance were evaluated by Bass Stick and Y balance test respectively. Normality of the data was evaluated using the Kolmogorov Smirnoff test. Data analysis was performed by Spearman product moment coefficient test and independent samples t test. Significant level of p&le0/05 was used in all statistical analyses.
Results of t-test showed no significant difference between static balance in boys and girls, while significant differences were observed between dynamic balance and core stability in males and females. In other words, core stability and dynamic balance in boys were more than girls. Also, the results of correlation analysis showed a significant relationship between core stability and dynamic balance (p=0.00) However, no significant relationship was observed between core stability and static balance (p=0.451).
Due to the correlation between muscle endurance and dynamic balance in the present study, it can be implied that core stability exercises can improve balance.

The aim of this study was comparing the ground reaction forces, center of pressure and body center of mass changes in voluntary, semi-voluntary and involuntary gait termination in healthy young men.
In this study, 12 young men performed termination of gait in three different patterns. The variable of peak antero-posterior and vertical forces in two directions at both limbs, the time to reach peak and average forces in every limb in both directions, the center of pressure displacement of medio-lateral and antero-posterior direction for each limb and the net center of pressure and the displacement of the center of mass motion in all three motion plates were recorded using motion analysis system and force plate.The repeated measurements test was used to compare three patterns of gait termination at significance level of p&le0.5.
The results showed a significant difference in variables of peak antero-posterior force, the time to reach peak antero-posterior force and mean antero-posterior forces of the leading limb, the peak antero-posterior force of the trialing limbs, the depth force of leading limbs, medio-lateral cop of leading limbs displacement and vertical displacement of the center of mass, among different patterns of gait termination.
While walking, the probability of a fall or collision damage, when a sudden or unexpected stop is required, increases. Therefore, more coordination between neuromuscular systems is required.

Cerebral palsy is the most common chronic motor disability in children and can have negative effect on motor functions. The purpose of this study was to investigate the effect of eight weeks resistance training on gross motor ability, balance and walking speed in a group of such children.
21 cerebral palsy boys with spastic diplegia, aged between 12 and 16 years (mean, 13.66 years), participated in this study. A pre-test, involving walking, sitting, standing and walking up stairs. They were randomly divided into an experimental and control groups. Then, the experimental group participated in 8 weeks of resistance training. The data was attained from a 10 meter walk test, Berg Balance Test, gross motor ability Section E, D and GMFCS tests. Kolmogorov-Smirnov test, sample t-test were used for analyzing the data.
The results showed a significant improvement in the performance of experimental group in gross motor abilities section E and D, balance and walking speed after 8 weeks of resistance training (P The results showed that resistance training improves gross motor ability, balance and gait in children with cerebral palsy hence, it is recommended that resistance exercise be used as a therapeutic modality for children with cerebral palsy.