Background and Aim: In this study, we investigated : 1) The effect of diferent lengths of Abd. policis brevis muscle on variations EMG frequency spectrum. 2) The effect of muscle contractions on frequency spectrum and 3) The effect of different lengths of muscle on local muscle fatigue.

Material and Method: 20 normal subjects participated in this study. (with range of 20 - 34 years old). Each test carried out in four steps. Every person performed 3 minutes of isometric contraction in Abd. policis brevis muscle and EMG signals were saved for 5 seconds before and after the test. Then the  same procedure was performed while individual did 6 minutes free dynamic contraction and 6 minutes high speed dynamic contraction and 6 minutes forceful dynamic contraction respectively.

Results:This study showed that when the individual performed muscle contraction in short length, median and mean frequency increased (P = % 0) and fatigue test caused a decrease in frequency charactristics that was more in dynamic contractions in compare with isometric contraction (it was more obvious in forceful dynamic contraction). These parameters didn't change in different lengths (P = %9, P = %4, P= %3 for 0 - 45, 0 -90 and 45 - 90 degrees respectively).

Conclusion and discussion:This study showed that different muscle lengths and muscle contractions affect on frequency spectrum and it also showed the effect of different muscle lengths and muscle contractions on local muscle fatigue.

Background and Aim: In recent years, introducing the quantitative methods for diagnosing the joints injuries and its level of severity, surveying the recovery progress and effectiveness of rehabilitation methods are important for clinical practice. Using the inertial sensors is one of the custom methods for quantifying joints motion. The purpose of this study is to quantify injuries in ankle joint.

Materials and Methods: By setting the Sharif-HMIS inertial sensors on the leg and ankle of patients and control subjects, the motion of their ankle was evaluated and the amount of velocity and acceleration in 8 distinct motions were measured.

Results: Using the gathered data from the sensors in different motions and by implementing the assumed criterions, several parameters are calculated that can give a rather precise and quantitative distinction between injured people and control subjects. The results showed that RAV, M and P scores indicate the differences between patients and control subjects clearly, although their performance as a parameter for qualifying the level of ankle injuries is not good.

Conclusion: Motion analysis of ankle and comparing the results of patients and control subjects showed that the assumed criterions are valid and can be used for diagnosing the ankle injury. Also, this method is utilized to measure the ankle motion of both elderly and young groups and the results showed that this method is suitable for indicating the ankle motion differences between two groups.

Key words: Ankle sprain, Motion measurement, Arthritis, Inertial sensors.

Background and Aim:: Muscular shortness is one of the most common musculoskeletal impairments. It may occur as a result of trauma or even a sedentary life style and cause clinical symptoms. Hamstring muscle, due to its functional roles, is prone to injuries during physical activities. Research has shown that decreased hamstring muscle flexibility may lead to lower extremity injury. The goal of this study is to compare the effects of myofascial release (MFR) and muscle energy technique (MET) effects on hamstring muscle flexibility. 

Materials and Methods: Twenty four non-athlete healthy subjects (means ± SD= 26/12 ± 5.4 Years) were randomly assigned to two groups; myofascial release group and muscle energy technique group. Passive range of motion (ROM) of knee extension was measured using a digital goniometer before and immediately after the intervention.

Results: There was a significant increase in the knee passive range of motion immediately after both interventions (in MFR group p=0.000 and in MET Group p=0.000).The amount of knee extension increase was greater in myofascial release group (p=0.023).

Conclusion: Both MFR and MET can increase hamstring muscle flexibility; however, in this study MFR has shown to be more effective than MET.

Keywords: Flexibility, Muscle energy technique,  Myofascial release technique,  Hamstring muscle