---

Background and Objective: There are relations between rate of loading, osteoarthritis and genu varum result in osteoarthritis. This study was done to compare the peak vertical ground reaction forces and the rate of loading during single leg drop landing between men with genu varum deformity and normal knee from three heights. Methods: This quasi-experimental studywas carried out on 20 male students with genu varum deformity and 20 male students with normal knee. Genu varum deformity was measured and recorded by collis and goniometer. Subjects performed single-leg landing dropping from three heights (20, 40, 60 Centimeter) on a force platform. Results: The peak vertical ground reaction force in calcaneus contact and the rate of loading between groups significantly were different (P<0.05). No significant difference was found in the peak vertical ground reaction during toe contact. Conclusion: Frontal knee angle affect on loading rate. Maybe one of the reasons for higher injury risk and knee arthritis in genu varum population might be due to higher ground reaction forces and the rate of high loading.

---

Background and Objective: Genuvarum is considered as one of the risk factors for the incidence of osteoarthritis. This study was done to compare the knee joint muscles activity during single leg drop landing from different heights among men with genu varum and men with normal knee.

Methods: This case – control study was done on 20 male students with genu varum deformity and 20 male students with normal knee. Genu varum deformity was measured by a kolis and goniometer. Muscle activity of lower limb was recorded with electromyography.

Results: There was significant difference in muscles activity of medialis gastrucnemius, peroneus longus, biceps femoris and gluteus medius in cases and controls (P<0.05), while no significant difference was observed in other muscles.

Conclusion: The changes in the knee normal structure might affect daily activities and possibly lead to in injuries due to physical training.

---

Background and Objective: Genu varus deformity is associated with changes of lower limb muscle co-contraction and running economy. This study was done to evaluate the effect of using of brace in three different knee flexion angles on running economy and lower limb muscular co-contraction in individuals with genu varus.
Methods: This quasi-experimental study was done on active soccer male students including 15 healthy subjects (average age of 22.86±1.55 years) and 15 subjects with genu varus (average age of 22.13±1.80 years). The amount of electrical activity of the muscles (tibialis anterior, medial gastrocnemius, vastus medialis, vastus lateralis, rectus femoris, biceps femoris, semi-tendinosus) were recorded by electromyography system during four conditions of with and without using knee brace. After that, directed and general co-contraction was computed during running. The angles of brace were 15, 30, and 60 degrees. The values of VO2 max were recorded using of gas analyzer system to compute running economy.
Results: The ratio of respiratory exchange was significantly more in the genu varus group than healthy group (P<0.05). However, the acute effect of brace was not significant on running economy and ratio of respiratory exchange. The main effect of brace was significant for general co-contraction of knee joint during the loading phase (P<0.05). Paired wise comparison revealed significant greater general knee co-contraction during brace conditions (P<0.05). However, the general knee co-contraction during loading phase reduced while using brace 15 degree. The main effect of “brace” for ankle joint general co-contraction during the push-off phase was significant (P<0.05). Paired wise comparison revealed significant greater general ankle co-contraction during brace conditions at push-off phase (P<0.05).
Conclusion: Knee brace did not change running economy. However, the using of brace 15 degree improved general knee joint co-contraction during loading phase.

---

Background and Objective: Genu varus is a deformity in frontal plane that in weight bearing position whiles the medial malleolus’s touch each other, the medial knee epicondyles far from each other. Genu varus is very prevalent in soccer players. This study was done to evaluate the effect of using knee brace and lateral wedge on muscular activity amplitude in male soccer players with genu varus during running.
Methods: This quasi-experimental study was done on 15 right-footed male soccer players with genu varus and 15 healthy soccer players. A wireless electromyography system with eight pairs of bipolar Ag/AgCl surface electrodes (20 mm center-to-center distance; input impedance of 100 MΩ; and common-mode rejection ratio of >110 dB) was used to record the activity of the tibialis anterior, gastrocnemius medialis, biceps femoris, semitendinosus, vastus lateralis, vastus medialis, and rectus femoris, and gluteus medius muscles of the right leg. Electromyography data were recorded by sampling rate of 1000 Hz in selected muscles during running at five conditions including: control, 10 degrees lateral wedge, 15 degrees lateral wedge, simultaneous using 30 degrees brace and 10 degrees lateral wedge, and simultaneous using 30 degree brace and 15 degrees lateral wedge.
Results: Treatment intervention had reduction effect on muscular amplitude of biceps femoris and vastus lateralis during push-off phase (P<0.05). Muscular amplitude of biceps femoris and vastus lateralis during loading phase was reduced due to Treatment intervention (P<0.05).
Conclusion: Simultaneous using of lateral wedge and knee brace reduce the electromyography activity of vastus lateralis and biceps femoris muscles. This reduction may be associated with passive support of knee brace that in result could decrease the external knee adductor mowment.

---

Background and Objective: Genu varum is a lower limb deformity. This study was done to evaluate the effects of shoe aging on the general and directional contraction of ankle muscles during running in females with genu varum.
Methods: This case-control study was done on 30 female students (15 individuals with genu varum degree 2 and 15 healthy individuals) using new and old sneakers for 6 months in the sports biomechanics laboratory of the University of Mohaghegh Ardabili, Iran. Each subject was given a new pair of sneakers, and after the initial data collection, the subjects were asked to use them in their daily activities for at least an hour a day for 6 months. Electrical muscle activity was recorded using surface electromyography.
Results: There was no significant difference in the general and directional contractions if ankle muscles during the running phases.
Conclusion: Shoe aging has no effect on ankle joint co-contractions.