Comparison of lower leg muscle strength and grip strength for diagnosing slower gait speed in the elderly

OBJECTIVES: Sarcopenia, decreased muscle volume and muscle weakness in the elderly is a serious risk of various adverse outcomes. Current diagnostic procedure for sarcopenia includes gait speed, grip strength, and percentage of skeletal muscle volume. However, lower leg muscle strength decreases much faster than grasp power, and we have evaluated the usefulness of its measurement using a recently developed instrument (Locomoscan). METHODS: Forty-three institutionalized elderly subjects were evaluated for their anthropometrical parameters, body composition, grasp and lower leg muscle strength, and gait speed. They were categorized into 2 groups; gait speed equal to or higher than 0.8 m/s and that below 0.8 m/s. RESULTS: Leg muscle strength per body weight was significantly greater in those with their gait speed equal to or higher than 0.8 m/s, whereas there was no significant difference in other parameters. Receiver operator characteristics analysis has shown that leg muscle alone significantly predicted the greater gait speed. CONCLUSIONS: Lower leg muscle strength can be useful for predicting gait speed.

The Effect of Visual Information Provision on the Changes of Electromyogram Activity in Trunk and Lower Leg Muscles during Dynamic Balance Control / 대한스포츠의학회지

The purpose of this study was to investigate the changes of electromyogram activity of trunk and lower leg muscles during dynamic balance control in 20 healthy adult subjects when various experimental visual conditions were applied. Surface electromyography system was used for recording of any signals produced by muscles. Muscle activity was recorded from muscles, of which left and right sides of rectus abdominis, external obliques, longissimus thoracis, multifidus, vastus medialis, biceps femoris, gastrocnemius medialis, and tibialis anterior, and then normalized as percentage of maximum voluntary isometric contraction. All data obtained from experiment were analyzed using SPSS ver. 20.0, and two-way analysis of variance were used to determine statistical significance between two factors (3x2 factorial analysis, visual conditions vs. leg conditions). Statistical significance levels were set at alpha=0.05. There were significant different in biceps femoris and external obliques muscle's activities between right and left leg, showing more prominent reduction in left leg when blind vision condition was given. Significantly higher muscle activities were shown in both sides of multifidus (p<0.05), vastus medialis (p<0.001), tibialis anterior (p<0.001) and gastrocnemius medialis (p<0.001) with sighted vision and blanking vision compared to the condition of blind vision. These results confirmed that muscle activity is prominently stimulated by visual information provision, and this implies that visual input may be a major factor for maintaining of the body's balance control.

Electromyographic Analysis of Left Leg Muscle Activity during Golf Driver Swing

OBJECTIVE: To analyze activities of left lower extremity muscles throughout phases of the golf swing, using surface electromyography. METHOD: We evaluated muscle activities during the golf swing of 5 amateur and 5 professional golfers using surface electromyography. Surface electrodes were placed in the left gluteus medius, gluteus maximus, biceps femoris, gastrocnemius, rectus femoris, peroneus longus, and tibialis anterior. RESULTS: Muscle activities of professional golfers in the left gluteus medius, gluteus maximus, biceps femoris, tibialis anterior, rectus femoris abruptly increased from top-swing phase to impact phase but muscle activities of amateur golfers in these muscles increased to top-swing phase and decreased at follow swing phase. Muscle activities of professional golfers in left peroneus longus, gastrocnemius abruptly increase from forward swing to impact but muscle activity of amateur golfers in these muscles continuously increase to impact and abruptly increase at follow swing. CONCLUSION: Our findings demonstrate the importance of the muscles in the golfer's swing.

The Cross-Leg Gastrocnemius Muscle Flap for Leg Reconstruction of the Difficult and Unfavorable Conditions

PURPOSE: In the cases of a vascular compromised condition in an injured lower extremity, soft tissue coverage with free tissue transfer presents a challenging problem to the reconstructive surgeon. For this reason, cross-leg flaps are still used in unusual circumstances. Advances in surgical technique has made the cross-leg free flap possible although it may require long operation time along with significant donor site morbidity. Therefore, a pedicled cross-leg muscle flap may be an alternative treatment modality when local flap or free flap is not possible. METHODS: Twelve patients(9 males and 3 females) underwent the operation from October 2001 to December 2008. The patients' age ranged from 6 to 82 years. The unusual defects included the regions such as the knee, popliteal fossa, distal third of the tibia, dorsal foot, and the heel. Indications for the cross-leg gastrocnemius flap are inadequate recipient vessels for free flap(in eight cases), extensive soft tissue injuries(in three cases) and free flap failure(in one case). The muscle flap was elevated from contralateral leg and transferred to the soft tissue defect on the lower leg while both legs were immobilized with two connected external fixator systems. Delay procedure was performed in 2 weeks postoperatively, and detachment was done after the establishment of the adequate circulation. The average period from the initial flap surgery to detachment was 32 days(3 to 6 weeks). Mean follow-up period was 4 years. RESULTS: Stable coverage was achieved in all twelve patients without any flap complications. Donor site had minimal scarring without any functional or cosmetic problems. No severe complications such as deep vein thrombosis or flap necrosis were noted although mild to moderate contracture of the knee and ankle joint developed due to external fixation requiring 3 to 4 weeks of physical treatment. All patients were able to walk without crutches in 3 months postoperatively. CONCLUSION: Although pedicled cross-leg flaps may not substitute free flap surgery, it may be an alternative method of treatment when free flap is not feasible. Using this modification of the gastrocnemius flap we managed to close successfully soft tissue defects in twelve patients without using free tissue transfers.