During locomotion, human subjects navigate in their environment and choose the direction by means of the internal representation of space that is continuously updated by sensory input. The aim of this study was to assess whether LEG proprioceptive information plays a role in the definition of the reference frame for orientation. Eleven male young healthy rights–handed subjects volunteered in these experiments. Unilateral LEG vibration muscle was applied during locomotion a long a straight path in these subjects. Vibration was administered either from the onset or in the middle of a seven- step task, under eyes–open (OE) or blindfolded condition. The deviation of the walking trajectory was quantified by the distance of the seventh from the first foot print along the medio–lateral axis. Foot angles and stride lengths were computed for all foot all foot–falls. All deviations from the straight–ahead were accompanied by coherent changes in foot orientation on the ground. Vibration produced a clear–cut deviation from the straight–ahead direction when delivered in the middle of blindfolded locomotion. With EO the deviation was much smaller. A mild deviation was obtained in blindfolded condition when vibration started at the onset of locomotion. LEG proprioceptive plays a major role in the definition of loco motor trajectory.

Shock absorption and reducing the Rate of Loading (ROL) during daily activities are considered as a reason for reducing the rate of injuries. Since, skeletal MUSCLES utilize as shock absorber during weight bearing tasks, the purpose of this study was to examine the relationship between the maximum torques of lower extremity MUSCLES with the ROL during single LEG drop landing. 33 men subjects (23±2years and 73±3 Kg) from Tarbiyat Moallem University of Tehran volunteered in this study. Maximum torque of lower extremity MUSCLES and the Ground Reaction Forces (GRF) were measured by the Biodex system and force plate (AMTI), respectively. The Pearson correlation used to analyses the data at the a£0.05 threshold. The mean torque of the quadriceps, hamstring, plantar flexors, dorsi flexors, invertors and evertors muscled were 2.70, 1.75, 0.77, 0.43, 0.43, 0.40 Nm respectively, and the mean ROL was 519/60 N/ms. Significant correlations wasn't seen between maximum torque of lower extremity MUSCLES with ROL. Due to results of this study it seem that quadriceps, hamstring, plantar flexors, dorsiflexors, invertors and evertors MUSCLES have no role in decreasing the ROL in single LEG drop landing.

Background and aim: To investigate the effect of the light touch, vision and dual task interference on the surface electromyography (sEMG) activity of ankle MUSCLES Participants: Thirty persons (12 male, 18 Female), right hand without any neuro-musculo-skeletal disorder and in healthy condition, participated in this study.Methods and Materials: Participants stood in upright and semi tandem position. There was a high sensitivity sensor on the right side in direction of femur greater trochanter. They should press the sensor less than 50 gr. Also we examined the rate of activity in 3 MUSCLES (Tibialis Anterior, Proneus Longuse, Soleuse) on both lower limbs by Biometrix sEMG device. 4 positions were experimented in semi tandem standing: No Touch, No Counting; No Touch, Counting; Light Touch, No Counting; Light Touch, Counting. Each of the above positions was tested in 2 conditions: Eyes Open, Eyes Closed.Results: Our findings detect that light touch contact especially during vision, resulted in reducing the rate of sEMG activity in the LEG postural MUSCLES. No touch and closed eyes, raise the rate of sEMG activity to maximum.conclusion: On basis of findings, it seems that following skin receptors stimulation, some complicated mechanisms will be begun and in order to the orders of Central Nervous System (CNS), these MUSCLES will make the hole body, stable. So it can reduce the entered pressure on LEG postural MUSCLES. Therefore, we can see the lesser rate in sEMG activity of LEG postural MUSCLES.

The purpose of this study was to compare the EMG activity of Vastus Medialis Oblique (VMO) and Vastus Lateralis (VL) MUSCLES in the single- joint knee extension (KE) and the multi- joint LEG press (LP). Subjects performed two maximal voluntary isometric contractions (MVC) and LP and KE actions subsequently performed at individual load, equal 80% of MVC in each exercise modality. 15 healthy men, (mean age 31.93 ± 7.08 yrs, mean height 176.6 ± 5.93 cm, mean weight 72 ± 12.62 kg) with no previous of knee pain, trauma, surgery, or other joint disease participated in the study. The EMG signal of VMO and VL MUSCLES was recorded bilaterally during both exercises. Results showed no significant difference between LP and KE. However when EMG activity of VMO and VL MUSCLES were compared whit each other, a significant difference was found (p £ 0.05), and in both action the activity of VMO was more than VL. Regardless of the exercise model this suggests the increased demand of involvement may not be equally shared among MUSCLES possessing different anatomical origin and insertion. Motor control plays an important role in rehabilitation in general and patellofemoral joint problems in particular.

Objective: Active straight LEG raising (SLR) test is advocated as a valid diagnostic method in diagnosis of sacroiliac joint (SIJ) dysfunction that can assess the quality of load transfer between trunk and lower limb. The aim of this study is Comparison of changes in tonicity and activity of pelvic stabilizer MUSCLES during active SLR, between healthy individuals and patients with sacroiliac joint pain.Materials and Methods: A case-control study was designed in 26 women (19-50 years old). With use of simple sampling, surface electromyography from rectus abdominis, external oblique, internal oblique, adductor longus, erector spine, gluteus maximus and biceps femoris was recorded in 26 subjects (15 healthy females and 11 females with sacroiliac pain) in resting position and during active SLR test. Resting muscle tonicity and rms during ramp time and hold time in active SLR test were assessed by non parametric-two independent sample test.Results: Biceps femoris activity in resting position was significantly larger in patients group (P<0.05). During the active SLR, the women with sacroiliac joint pain used much less activity in some pelvic stabilizer MUSCLES compared to the healthy subjects (P<0.05).Conclusion: The increased resting tonicity of biceps femoris and decreased activity of pelvic stabilizer MUSCLES in subjects with sacroiliac joint pain, suggests an alteration in the strategy for lumbopelvic stabilization that may disrupt load transference through the pelvis.

Introduction: pesplanus is considered that makes muscle activation changes. Being aware of MUSCLES activity changes in various standing positions among pesplanus patients, provide insight to prevent lower extremity injuries in this population. This study is undertaken to compare the electromyography of the LEG MUSCLES in various standing positions between young healthy and pesplanus men male individuals.Materials and Methods: 40 healthy male university students, 20 normal and 20 subjects with pesplanus deformity participated in this semi-experimental study. Deformity of pesplanus was assessed with navicular drop test. Each subject stood in five different positions and MUSCLES activity was recorded with emg device. For data analysis, Matlab and Spss software applied and Mixed variance analysis test (Mixed ANOVA) was used to compare the dependent variables at a significance level of P£0.05.Results: Significant differences were observed between the two groups for MUSCLES activity of the longus peroneus and anterior tibialis (at single LEG with closed eye and upward head postions) (p£0.05); while no significant differences was observed in other MUSCLES.Conclusion: The changes in the normal structure of the foot might affect muscle activities during standing that can cause changes in the injury patterns. It is proposed focusing on corrective exercises and therapy plan can reduce these risks.

Purpose: Core stability training (CST) has increased among athletes. The study hypothesis is that neuromuscular training and exercises of central area of trunk, pelvis and hip can reduce injury risk, and specifically peak vertical ground reaction forces in drop landing task. Therefore, the objective of this study was to evaluate kinetics during single LEG drop landing test following a CST intervention.Methods: The present research was a quasi-experimental study with pretest/posttest and a control group. After giving their informed written consent, 30 athletes (15 in the experimental group, and 15 in the control group) volunteered to participate in the training program consisting of CST sessions, 3 times per week for 8 weeks. Training group was performed the CST during 8 weeks but control group did not perform these exercises. Kinetics variables in pretest and posttest during single-LEG drop landing were measured by motion analysis and force plate device. To compare the obtained data, mixed ANOVA repeated measure at significance level of P<0.05 was used. All analyses were done by SPSS 22.Results: The results revealed that the peak vertical ground reaction forces, loading rate, and average loading rate significantly reduced following 8 weeks CST intervention (P<0.05).Conclusion: This study shows evidence that core stability training improves landing kinetics, and may reduce lower extremity injury risk in athletes.

Background and Aims: Although volleyball is a contact sport, there are a high number of injuries in volleyball during training or competitions. Since many jumps are performed during training, it is not surprising that a high number of injuries are caused by jumping and landing. The present study aims to investigate the effect of taping on the feedforward activity of non-dominant LEG MUSCLES during single-LEG jump-landing in professional volleyball players with chronic ankle instability. Methods: In this study, participants were 13 volleyball players with chronic ankle instability who were selected by a purposive sampling method. Electromyographic activity of peroneus longus, anterior tibialis, gastrocnemius, vastus lateralis, gluteus medius, and rectus femoris MUSCLES of the non-dominant LEG during a single-LEG jump-landing task following a spike shot before and after taping was evaluated. Root mean square was used to calculate muscle activity before and after taping. The data were analyzed using paired t-test. The significance level was set at 0. 05. Results: The findings showed the significant effect of taping only on maximum feedforward activity (P=0. 02) and average feedforward activity (P=0. 03) of the peroneus longus muscle. The effect was not statistically significant for other MUSCLES (P>0. 05). Conclusion: It seems that taping is not useful for improving the feedforward activity of MUSCLES in volleyball players with chronic ankle instability during single-LEG jump-landing. Hence, other exercises or methods are recommended for these players during recovery or training.