Lower Extremity Muscle Activity Research Articles

Walking beyond preferred transition speed increases muscle activations with a shift from inverted pendulum to spring mass model in lower extremity

BackgroundThe triggers for the transition of gait from walking to running during increasing speed locomotion have been attributed to an energy conservation strategy or a relief of excessive muscle activation. Walking beyond the preferred transition speed (PTS) has been proposed as an exercise protocol for boosting energy consumption. However, the biomechanical factors involved while this protocol is used have not been investigated. Thus, this study investigated the difference between walking and running below, during, and beyond the PTS from a biomechanical perspective. MethodsSixteen healthy male participants were recruited. After determination of their PTS, five speeds of walking and running were defined. Kinematic data, including center-of-mass (COM) displacement, COM acceleration, and electromyography (EMG) data of rectus femoris (RF), biceps femoris, gastrocnemius (GAS), and tibialis anterior were collected at the five speeds for both walking and running. ResultThe vertical COM displacement and acceleration in running were significantly larger than those in walking at all five speeds (p<0.05). EMG signals of the two antigravity muscles, RF and GAS, demonstrated a significant higher activation in walking than that in running at the speed beyond PTS (p<0.05). ConclusionThe larger energy consumption in walking than that in running beyond the PTS may be attributed to the high activation of lower-extremity muscles. The smaller vertical COM displacements and accelerations exhibited when participants walked beyond the PTS rather than ran did not indicate adverse effects of using walking beyond the PTS as an exercise prescription for boosting energy consumption.

Dynamic Frequency Analyses of Lower Extremity Muscles during Sit-To-Stand Motion for the Patients with Knee Osteoarthritis

ObjectiveMuscle activities during the sit-to-stand motion (STS) are characterized by coordinated movements between hip extensors and knee extensors. However, previous reports regarding the STS and lower extremity muscle activities have focused on some quantitative assessment, but little qualitative research. This study aimed to examine the muscle activities of the lower extremity both quantitatively and qualitatively.MethodsStudy participants included 13 patients with knee osteoarthritis (knee OA) and 11 age-matched asymptomatic controls. The task was STS from a chair with a height-adjustable seat. EMG activities were acquired using surface electromyogram. The root mean square signals normalized as a percentage of maximum voluntary isometric contraction values (RMS%MVC) and the mean power frequency (MPF) were calculated.ResultsDuring STS, knee OA patients had increased RMS%MVC of the vastus medialis and raised MPF of the rectus femoris before buttocks-off.ConclusionThese findings suggest that STS of knee OA patients not only increased relative muscle activity of the vastus medialis, but also enlisted the rectus femoris in knee extension to improve muscle contraction force by activating more type II fibers to accomplish buttocks-off.

A comparative study of the electromyographic activities of lower extremity muscles during level walking and Pedalo riding.

[Purpose] To analyze the electromyographic (EMG) activities of several lower extremity muscles during ground walking and pedaling using the Pedalo Reha-Bar device. [Subjects and Methods] Fifteen healthy adults aged 20–29 year participated in this study. The subjects’ surface EMG signals while walking and Pedalo Reha-Bar riding were recorded. The subjects performed 20 steps on flat ground and 20 cycles on the Pedalo Reha-Bar. During the tasks, EMG signals of the rectus femoris, biceps femoris, tibialis anterior, soleus, and gastrocnemius within a 20-second period were recorded. The mean EMG signals within the 10 seconds from 6 to 15 seconds were used for the data analysis. [Results] There was a significant increase in the bilateral use of the rectus femoris and a significant decrease in the use of the left tibialis anterior and left soleus in pedaling using the Pedalo Reha-Bar device compared to ground walking. [Conclusion] Level walking and the Pedalo Reha-Bar riding utilize different types of muscles activities. These results suggest that Pedalo Reha-Bar riding may be used for neuromuscular activation, especially of the rectus femoris.

The effect of virtual reality-based eccentric training on lower extremity muscle activation and balance in stroke patients.

[Purpose] The purpose of this study was to examine the effect of virtual reality-based eccentric training on lower extremity muscle activity and balance in stroke patients. [Subjects and Methods] Thirty stroke patients participated, with 15 patients allotted to each of two eccentric training groups: one using a slow velocity (group I) and one using a fast velocity (group II). The virtual reality-based eccentric training was performed by the patients for 30 minutes once a day, 5 days a week, for 8 weeks using an Eccentron system. Surface electromyography was used to measure the lower extremity muscle activity, while a BioRescue was used to measure balancing ability. [Results] A significant difference in lower extremity muscle activation and balance ability was observed in group I compared with group II. [Conclusion] This study showed that virtual reality-based eccentric training using a slow velocity is effective for improving lower extremity muscle activity and balance in stroke patients.

The effects of hip external rotator exercises and toe-spread exercises on lower extremity muscle activities during stair-walking in subjects with pronated foot.

[Purpose] The purpose of the present study was to examine the effects of toe-spread (TS) exercises and hip external rotator strengthening exercises for pronated feet on lower extremity muscle activities during stair-walking. [Subjects and Methods] The participants were 20 healthy adults with no present or previous pain, no past history of surgery on the foot or the ankle, and no foot deformities. Ten subjects performed hip external rotator strengthening exercises and TS exercises and the remaining ten subjects performed only TS exercises five times per week for four weeks. [Results] Less change in navicular drop height occurred in the group that performed hip external rotator exercises than in the group that performed only TS exercises. The group that performed only TS exercises showed increased abductor hallucis muscle activity during both stair-climbing and -descending, and the group that performed hip external rotator exercises showed increased muscle activities of the vastus medialis and abductor hallucis during stair-climbing and increased muscle activity of only the abductor hallucis during stair-descending after exercise. [Conclusion] Stair-walking can be more effectively performed if the hip external rotator muscle is strengthened when TS exercises are performed for the pronated foot.

Life Quality Increase Using Locomotion in Students with Disabilities

The aspects of the bioelectrical muscular activity of lower extremities, motor coordination and balance in football players with musculoskeletal disorders when performing a ball shot have been studied. The study has demonstrated that football players with musculoskeletal disorders while performing a ball shot experienced movement linearity disorders, manifested as motor coordination disorders, possibly related to the displacement of the general centre of gravity. However, these disorders in student football players were compensated by decrease of the general centre of gravity range and the fluctuation rate in sagittal and frontal planes, thus promoting an increase of the balance quality. The student football players with musculoskeletal disorders while performing a ball shot experienced simultaneous restructure in the activity of lower extremity muscles: an increase of lower leg muscle activity was accompanied by a hip muscle activity decrease. The results would help us to correct the training program for football players with musculoskeletal disorders, by adding physical exercises, aimed at strengthening hip muscles and the inclusion of additional coordination and balance exercises.

The effects of performing a one-legged bridge with hip abduction and use of a sling on trunk and lower extremity muscle activation in healthy adults.

[Purpose] This study investigated the changes in the muscle activities of the trunk and lower limbs of healthy adults during a one-legged bridge exercise using a sling, and with the addition of hip abduction. [Subjects and Methods] Twenty-seven healthy individuals participated in this study (14 males and 13 females). The participants were instructed to perform the bridge exercises under five different conditions. Trunk and lower limb muscle activation of the erector spinae (ES), external oblique (EO), gluteus maximus (GM), and biceps femoris (BF) was measured using surface electromyography. Data analysis was performed using the mean scores of three trials performed under each condition. [Results] There was a significant increase in bilateral EO and contralateral GM with the one-legged bridge compared with the one-legged bridge with sling exercise. Muscle activation of the ipsilateral GM and BF was significantly less during the one-legged bridge exercise compared to the one-legged bridge with sling exercise, and was significantly greater during the one-legged bridge with hip abduction compared to the one-legged bridge exercise. The muscle activation of the contralateral GM and BF was significantly greater with the one-legged bridge with hip abduction compared to the general bridge exercise. [Conclusion] With the one-legged bridge with hip abduction, the ipsilateral EO, GM and BF muscle activities were significantly greater than those of the one-legged bridge exercise. The muscle activation of all trunk and contralateral lower extremity muscles increased with the bridge with sling exercises compared with general bridge exercises.

The effects of gluteus maximus and abductor hallucis strengthening exercises for four weeks on navicular drop and lower extremity muscle activity during gait with flatfoot.

[Purpose] The purpose of the present study is to examine the effects of abductor hallucis and gluteus maximus strengthening exercises on pronated feet. [Subjects and Methods] The present study was conducted with 18 adults without no history of surgery on the foot or ankle. One group performed both gluteus maximus strengthening exercises and abductor hallucis strengthening exercises, while the other group performed only abductor hallucis strengthening exercises five times per week for four weeks. [Results] The group that performed both gluteus maximus and abductor hallucis strengthening exercises showed smaller values in the height of navicular drop than the group that performed only abductor hallucis strengthening exercises. The muscle activity of the gluteus maximus and the vastus medialis increased during heel-strike in the group that added gluteus maximus exercises, and the muscle activity of the abductor hallucis significantly increased in both groups. [Conclusion] Given the results of the present study, it can be suggested that strengthening the gluteus maximus while also performing exercises to correct the pronated foot is an effective method for achieving normal gait.

Effect of rain boot shaft length on lower extremity muscle activity during treadmill walking.

[Purpose] This study aimed to determine the extent of lower extremity muscle activity before and after walking based on rain boot shaft length. [Subjects and Methods] The subjects, 12 young and healthy females, were divided into three groups based on rain boot shaft length (long, middle, and short). They walked on a treadmill for 30 minutes. Activity of the rectus femoris, vastus lateralis, semitendinosus, tibialis anterior, peroneus longus, and gastrocnemius was measured using electromyography before and after walking. Two-way repeated measures analysis of variance was performed to compare the muscle activities of each group. [Results] There were no significant differences in terms of the interactive effects between group and time for all muscles, the main effects of group, or the main effects of time. [Conclusion] The results of this study may indicate that movement of the lower extremities was not significantly limited by friction force based on the characteristics of the boot material or the circumference of the boot shaft. Thus, it may be helpful instead to consider the material of the sole or the weight of the boots when choosing which rain boots to wear.

The effects of a pelvic belt on trunk and lower extremity muscles in the bridge position.

[Purpose] The purpose of this study was to investigate the effects of a pelvic belt on the activities of trunk and lower extremity muscles in normal adults. [Subjects and Methods] The subjects were 20 normal individuals without a history of orthopedic problems. The pelvic compression belt (The Com-Pressor, OPTP, Minneapolis, MN, USA) was an adjustable body belt with four elastic compression bands that provide stabilizing pressure and was designed to adjust the amount of force applied and to alter sites of compression. The body belt was placed below the anterior superior iliac spine, and stabilizing pressure was applied to the belt using the elastic compression bands in the bridge position after confirming the site of compression. [Results] The subjects showed a significant decrease in muscle activation in the erector spinae, oblique internus abdominis, rectus femoris, and biceps femoris while wearing the pelvic belt. [Conclusion] The use of a pelvic compression belt with external pelvic compression might improve pelvic joint stability and alter neuromotor control of the lumbopelvic and thigh muscles.

Multicenter survey analysis of satisfaction according to actual utilization of rehabilitation services.

[Purpose] Most such studies have been limited to evaluating the muscle activity patterns of lower extremity muscles using surface electromyograms, but studies of muscle activity patterns according to chair types are lacking. [Subjects and Methods] In the present study, 52 university students in their 20s (26 males, 26 females) were selected in order to analyze the activity of five lower extremity muscles (vastus lateralis, rectus femoris, vastus medialis, tibialis anterior, and gastrocnemius). The selected subjects had sufficient muscle strength for the experiment and normal joint range of motion. [Results] To examine the sociodemographic variables of the study subjects, the frequencies and percentages of individual items were presented as follows Table 3. [Conclusion] Differences in lower extremity muscle activity levels during standing and sitting were identified, and differences between genders were also seen. There was no significant difference in lower extremity muscle activity levels between use of fixed and wheeled chairs.

The Effects of Water-Based Exercise on Muscle activity and Gait Ability in Stroke Patients

Purpose: This study attempts to determine the effects of water-based exercise performed on stroke patients in their muscle activity of lower extremity and gait ability tests. Methods: The subjects were 20 stroke patients, who were randomly divided into a water-based exercise group and a land-based exercise group, each including 10 patients. Both exercises were performed 3 days per week, for 40 minutes a day, for a period of eight weeks. Results: The water-based exercise group showed a greater increase in muscle activity of lower extremity compared to the land-based exercise group. The water-based exercise group showed a greater increase in gait ability than the land-based group, showing a significant difference and better efficiency of water-based exercise when compared to land-based exercise. Conclusion: From the result of this study, we found that water-based exercises are more effective in improving muscle activity of lower extremity and gait ability. The patient is considered to be used by itself to involve the treatment and the risk of falling from the lowered state into the treatment method for the intensive treatment of stroke patients to be useful in improving the strength and ability to walk.

The activation of lower-extremity muscles during walking in different stage of Parkinson's disease

The activation of lower-extremity muscles during walking in different stage of Parkinson's disease

Lower extremity muscle activation onset times during the transition from double-leg stance to single-leg stance in anterior cruciate ligament injured subjects

The goal of this study was to evaluate muscle activation onset times (MAOT) of both legs during a transition task from double-leg stance (DLS) to single-leg stance (SLS) in anterior cruciate ligament injured (ACLI) (n=15) and non-injured control subjects (n=15) with eyes open and eyes closed. Significantly delayed MAOT were found in the ACLI group compared to the control group for vastus lateralis, vastus medialis obliquus, hamstrings medial, hamstrings lateral, tibialis anterior, peroneus longus and gastrocnemius in both vision conditions, for gluteus maximus and gluteus medius with eyes open and for tensor fascia latae with eyes closed. Within the ACLI group, delayed MAOT of tibialis anterior with eyes open and gastrocnemius with eyes closed were found in the injured leg compared to the non-injured leg. All other muscles were not significantly different between legs. In conclusion, the ACLI group showed delayed MAOT not only around the knee, but also at the hip and ankle muscles compared to the non-injured control group. No differences between both legs of the ACLI group were found, except for tibialis anterior and gastrocnemius. These findings indirectly support including central nervous system re-education training to target the underlying mechanisms of these altered MAOT after ACL injury.

Simulator study of young driver's instinctive response of lower extremity to a collision

ABSTRACTObjective: A driver's instinctive response of the lower extremity in braking movement consists of two parts, including reaction time and braking reaction behavior. It is critical to consider these two components when conducting studies concerning driver's brake movement intention and injury analysis. The purposes of this study were to investigate the driver reaction time to an oncoming collision and muscle activation of lower extremity muscles at the collision moment. The ultimate goal is to provide data that aid in both the optimization of intervention time of an active safety system and the improvement of precise protection performance of a passive safety system.Method: A simulated collision scene was constructed in a driving simulator, and 40 young volunteers (20 male and 20 female) were recruited for tests. Vehicle control parameters and electromyography characteristics of eight muscles of the lower extremity were recorded. The driver reaction time was divided into pre-motor time (PMT) and muscle activation time (MAT). Muscle activation level (ACOL) at the collision moment was calculated and analysed.Results: PMT was shortest for the tibialis anterior (TA) muscle (243∼317 ms for male and 278∼438 ms for female). Average MAT of the TA ranged from 28-55 ms. ACOL was large (5∼31% for male and 5∼23% for female) at 50 km/h, but small (<12%) at 100 km/h. ACOL of the gluteus maximus was smallest (<3%) in the 25 and 100 km/h tests. ACOL of RF of men was significantly smaller than that of women at different speeds.Conclusions: Ankle dorsiflexion is firstly activated at the beginning of the emergency brake motion. Males showed stronger reaction ability than females, as suggested by male's shorter PMT. The detection of driver's brake intention is upwards of 55ms sooner after introducing the electromyography. Muscle activation of the lower extremity is an important factor for 50 km/h collision injury analysis. For higher speed collisions, this might not be a major factor. The activations of certain muscles may be ignored for crash injury analysis at certain speeds, such as gluteus maximus at 25 or 100 km/h. Furthermore, the activation of certain muscles should be differentiated between males and females during injury analysis.

Effects of Game Based Weight-Bearing Training on Lower Extremity Muscle Activation and Balance in Stroke Patients

The objective of this study was to determine the effects of game based weight-bearing training (GBWBT) on lower extremity muscle activation and balance in stroke patients.

Effects of Isokinetic Eccentric Training on Lower Extremity Muscle Activation and Walking Velocity in Stroke Patients

Effects of Isokinetic Eccentric Training on Lower Extremity Muscle Activation and Walking Velocity in Stroke Patients

Effects of Game Based Weight-Bearing Training on Lower Extremity Muscle Activation and Balance in Stroke Patients

Purpose: The objective of this study was to determine the effects of game based weight-bearing training (GBWBT) on lower extremity muscle activation and balance in stroke patients. Methods: Thirty subjects were randomly divided into two groups: experimental group I (n=15) and control group II (n=15). Each group was provided intervention under two conditions, as follows: in the Game based weight-bearing training (group I), 30 minutes per day, five times per week, with physical therapy for 30 minutes, and in the functional weight-bearing training (group II), 30 minutes per day, five times per week, with physical therapy for 30 minutes The training program was conducted for a period of eight weeks. Subjects were measured on lower extremity muscle (rectus femoris, biceps femoris, tibialis anterior, gastrocnemius) by electromyography and balance by Biorescue. ANCOVA was performed for comparison of lower extremity muscle activation and balance between different intervention methods. All patients were evaluated at baseline and at the end of the treatment protocol. Statistical significance was tested between the patients before and after treatment by t-test. Results: Significant difference in lower extremity muscle activation was observed in experimental group I compared with control group II (p<0.05). Significant difference in balance was observed in experimental group I compared with control group II (p<0.001). Conclusion: Findings of this study suggest that game based weight-bearing training may have a beneficial effect on improvement of lower extremity muscle activation and balance in stroke patients.

Effects of Isokinetic Eccentric Training on Lower Extremity Muscle Activation and Walking Velocity in Stroke Patients

Effects of Isokinetic Eccentric Training on Lower Extremity Muscle Activation and Walking Velocity in Stroke Patients

Changes in lower extremity peak angles, moments and muscle activations during stair climbing at different speeds

Stair climbing is a common daily activity, yet there is no basic knowledge on how lower extremity joint angles, moments or muscle activations are affected by stair climbing speed. This information will determine whether speed matching is necessary for stair climbing studies. Moreover, changes in lower extremity biomechanics during stair climbing at different speeds will aid in the clinical interpretation of a patient’s maximal stair climbing speed.Thirty healthy participants provided consent. Kinematics, kinetics, and muscle activations were collected on a three step staircase. Subjects climbed the staircase at normal, slow and fast self-selected speeds. Linear mixed models for repeated measures were used to study the associations between speed and the lower extremity peak joint angles and moments, and muscle activations.The peak hip flexion and extension moments increased with increasing speed, while peak knee flexion moment did not vary consistently with speed. The peak muscle activations varied consistently with respect to the sagittal plane kinetics.These results suggest that in healthy subjects, the hip is the greatest contributor when modulating stair climbing speed, while additional knee contributions do not appear necessary to increase speed. Further stair studies should consider speed matching in order to accurately assess biomechanical differences.