Extremity Muscle Activity Research Articles

Lower limbs kinematic analysis during a jump landing task in soccer players with unilateral anterior cruciate ligament reconstruction

BackgroundFatigue leads to an acute decline in muscle strength, altered patterns of lower extremity muscle activation, changes in hip and knee kinematics. In terms of the effects of fatigue on knee joint kinematics during plyometric training, there is still a lack of knowledge regarding kinematic differences between athletes who passed the ACL reconstructions rehabilitation period and healthy athletes. Therefore, this study aimed to compare lower limb joint kinematic parameters between reconstructed cruciate ligament and healthy control soccer players during jump landing in a fatigued setting.MethodsLower limb kinematic parameters were recorded in 20 professional soccer players (age, 24.95 ± 2.92 years; body mass, 77.20 ± 12.88 kg; height, 1.77 ± 3.19 m) during jump landing task before and after the fatigue protocol. The control group consisted of healthy subjects and the experimental group consisted of subjects with ACL reconstruction by thigh transplantation. Kinematic data was recorded with 4 cameras to measure lower limb angles at first foot contact and maximum range of motion.ResultsThe results showed that before fatigue, there was only a significant difference between the two groups in the maximum range of motion of the non-involved hip joint (P = 0.022) and angle of the involved hip at first contact (P = 0.049). In other data on joint range of motion or initial contact angle, no significant difference was observed between the two groups (P > 0.05). After fatigue protocol, there was a significant difference in initial foot contact in non-involved (P = 0.030), and involved (P = 0.020) hip joint angles between the two groups. However, no significant difference in initial contact angle or range of motion of other joints was observed between the groups.ConclusionsThis study shows that plyometric fatigue does not contribute to numerous changes in contact angles and range of motion in lower extremity joints in healthy soccer players and those with a history of cruciate ligament repairs.

The effect of squats on muscle activity in standing, kneeling, and half-kneeling positions: A cross-sectional study.

Kneeling and half-kneeling training are common positions used in physical therapy. however, research on lower extremity muscle activity is lacking compared to the ergonomic aspects and trunk muscle activity. The purpose of this study is to investigate the effects on lower extremity muscle activity during squats in kneeling and half-kneeling positions. The study was designed as a cross-sectional study with a single group of healthy adults. Participants were instructed to perform squats while assuming 3 positions (standing, kneeling, and half-kneeling). Surface electromyography data were recorded 3 times from the rectus femoris (RF), gluteus maximus (GMax), gluteus medius (GMed), and biceps femoris (BF) on the participant's dominant side, and the mean values were analyzed. The participants performed squats for 9 seconds, with 4 seconds of the descent phase, 1 second of the maintenance phase, and 4 seconds of the ascent phase. A metronome was used to ensure precise timing. The study included 30 participants (19 males and 11 females). The muscle activities of the RF, GMed, and BF showed statistically significant differences among the 3 positions, being highest in the half-kneeling position (HKP), followed by the standing position (SP) and kneeling position (KP). The muscle activity of the GMax was significantly higher in the HKP than in the SP and KP (P < .05). The co-contraction ratio was significantly higher with KP than with the SP and HKP (P < .05). In the SP and KP, there were statistically significant differences between the ascent and descent phases of the RF, GMax, GMed, and BF (P < .05). In the HKP, there were statistically significant differences between the ascent and descent phases of the RF, GMax, and GMed (P < .05). The results of this study indicate that squats in the HKP (especially during the ascent phase) require the highest muscle activity, whereas squats in the KP (especially during the descent phase) can be performed with the lowest muscle activity. It can be concluded that these findings could serve as selective indicators for squat exercises and in enhancing postural control, muscle strength, and lower extremity stabilization.

Differences In Lower Extremity Muscle Activation Are Characteristic Between Curves And Straight Paths In Older Adults

Differences In Lower Extremity Muscle Activation Are Characteristic Between Curves And Straight Paths In Older Adults

Trunk And Lower Extremity Muscle Activation During Yoga

Trunk And Lower Extremity Muscle Activation During Yoga

Lower extremity muscle activity during reactive balance differs between adults with chronic traumatic brain injury and controls.

Control of reactive balance is key to achieving safe independent walking and engagement in life activities. After traumatic brain injury (TBI), motor impairments and mobility challenges are persistent sequelae. To date, no studies have explored muscle activity of individuals with chronic TBI during a task that requires reactive control of balance. To investigate lower extremity muscle activity during a reactive balance test performed by adults with chronic severe TBI and matched controls. We hypothesized that abnormal activity of lower extremity muscles would be related with poorer reactive balance performance. Also, we performed an exploratory analysis for those with TBI investigating the impact of unilateral versus bilateral lower extremity involvement in the control of reactive balance. Ten adults with chronic severe TBI who were independent community ambulators and ten matched controls performed the computerized reactive balance test (Propriotest®) while lower extremity muscle activity was recorded. Electromyographic (EMG) activity was contrasted (Mann-Whitney U Test) between groups across each 10 s epoch of the 120 s test. Additionally, test scores were correlated (Spearman) with lower extremity composite EMG activity to distinguish muscle activity patterns related with reactive balance performance. Lastly, reactive balance test scores were correlated with reactive balance test scores and clinical functional measures only for the TBI group. Although the TBI group exhibited greater EMG activity across the entire test compared with the control group, significant differences were not observed. Greater composite EMG activity correlated significantly with poorer reactive balance performance across most of the 10 s windows of the test. Greater muscle activity exhibited during the reactive balance test by individuals with chronic severe TBI compared to those without disabilities, particularly at small unexpected perturbations, highlights the greater physiologic effort required to control reactive balance even after independent ambulation is achieved.

Effects of Weight-Bearing Posture During Heel Raise on Lower Extremity Muscle Activation in Adults with Chronic Ankle Instability

Effects of Weight-Bearing Posture During Heel Raise on Lower Extremity Muscle Activation in Adults with Chronic Ankle Instability

"The Effect of Upper Limb Resistance Directional Changes Using an Elastic Tubing Band on Lower Extremity Muscle Activities during Squat Exercise"

"The Effect of Upper Limb Resistance Directional Changes Using an Elastic Tubing Band on Lower Extremity Muscle Activities during Squat Exercise"

Balance Training With Stroboscopic Glasses and Neuromechanics in Patients With Chronic Ankle Instability During a Single-Legged Drop Landing.

Therapeutic interventions for individuals with chronic ankle instability (CAI) are recommended to improve muscle strength, postural control, and range of motion. However, their effects on neuromechanics during a drop landing remain unclear. In addition, even though therapeutic interventions with stroboscopic glasses appear to effectively improve postural control, how they affect landing neuromechanics remains unclear. To identify the effect of balance training with stroboscopic glasses on neuromechanics during a single-legged drop landing in patients with CAI. Randomized controlled clinical trial. Laboratory. A total of 50 participants with CAI were randomly assigned to 1 of 2 groups: strobe (n = 25; age = 22 ± 3 years, height = 174.7 ± 8.2 cm, mass = 71.8 ± 12.2 kg) or control (n = 25; age = 21 ± 2 years, height = 173.1 ± 8.3 cm, mass = 71.1 ± 13.5 kg). The 4-week rehabilitation (3 sessions per week) included hop-based tasks and single-legged stance. The strobe group wore stroboscopic glasses during the training, whereas the control group did not. Ankle-, knee-, and hip-joint kinematics and 4 lower extremity muscle activations 150 milliseconds before and after initial contact during a single-legged drop landing in the 2 groups. The strobe group showed greater eversion (from 150 milliseconds before to 30 milliseconds after initial contact) and dorsiflexion (from 30 to 96 milliseconds after initial contact) angles and peroneal longus (from 35 milliseconds before to 5 milliseconds after initial contact) and tibialis anterior (from 0 to 120 milliseconds after initial contact) activation in the posttest than the pretest. Patients with CAI who underwent a 4-week rehabilitation with stroboscopic glasses demonstrated changes in neuromechanics, including increased ankle-dorsiflexion and -eversion angles and tibialis anterior and peroneus longus activation, during a single-legged drop landing. This finding suggests that use of stroboscopic glasses during rehabilitation could help patients with CAI develop safe landing mechanics.

Biomechanical Comparison of Pediatric Female Ballet Dancers With and Without Pain

BACKGROUND: Across all genres of dance, studies have reported musculoskeletal injury in 20-84% of dancers with 95% reporting a history of musculoskeletal pain. Compared to other dance styles, ballet dancers specifically are most affected by musculoskeletal injuries. The purpose of this study is to compare movement patterns and muscle activity in pediatric female pre-professional dancers with and without self- reported pain, using the Patient-Reported Outcomes Measurement Information System pediatric numeric rating scale. We hypothesize dancers reporting pain will exhibit compensatory strategies, such as asymmetrical movement patterns and muscle activity, across a series of ballet movements. METHODS: A total of 55 female ballet dancers who train en pointe were seen for testing (age 14.4±1.9 years), with 34 dancers (62%) self-reported pain in the 7 days preceding testing. Biomechanical testing, performed in pointe shoes, included performance of static (5 classical ballet positions) and dynamic ballet movements (développé, arabesqué and grand jeté) while instrumented with surface electromyography (EMG) to capture muscle activity and inertial measurement (IMU) dual sensors on the trunk and lower extremities to capture movement patterns. The experimental setup allowed for measurement of trunk and lower extremity muscle activity, as well as trunk, hip, knee, and ankle joint angles in the sagittal, coronal, and transverse planes. Student’s t-test was used to compare the pain and no pain groups across all variables with statistical significance set to α=0.05. RESULTS: Movement patterns and EMG differences were seen between groups. During first and third positions, the right (non-barre sided) leg demonstrated less external knee rotation in the pain group (p≤0.05). In fifth position, the left (barre-sided) leg exhibited increased ankle flexion (p=0.048), reduced hip abduction (p=0.027), and reduced knee adduction (p=0.026) in the pain group. The pain group exhibited decreased trunk flexion/extension range-of-motion during the grand jeté (p=0.004), and increased trunk rotation range-of-motion when performing the arabesqué en pointe (p=0.034). Rectus femoris activation was reduced for the pain group on the left leg in fifth position (p&lt;0.03). The up leg in the pain group during the développé (flat) showed increased hamstring activation (p=0.04). CONCLUSION: Ballet dancers with pain exhibited differences in movement patterns while performing certain ballet movements, notably during fifth position, grand jeté, and arabesqué (en pointe). Additionally, dancers with pain exhibited reduced rectus femoris activation in fifth position and increased hamstring activation on the working leg during the développé (flat). Future work should investigate how movement patterns and muscle activation in ballet dancers vary by location and severity of reported pain.

Driver’s instinctive response and it’s influence of lower extremity injury

Instinctive response was produced for protecting drivers from injury when facing incoming collisions. For better understanding it’s influence of lower extremity injury, this study proposed an approach to analyze the collision injury considering the instinctive response posture and musculoskeletal characteristics. 20 male drivers were recruited for an instinctive response test in driving simulator and their lower extremity postures and muscle activation of 8 major ones at the collision moment were collected. The difference between different postures and muscles were analyzed and their influence on injuries were investigated by collision simulation. Results showed that increased possibility for the right leg holding on the air or even on the accelerator pedal with increased emergency level at the collision moment. Significant difference existed in different muscles between different postures. The introduction of instinctive response changed the driving posture and musculoskeletal characteristics, which further influence the lower extremity injury. This study help understanding the accurate behavioral and injury procedure and providing support for design a better restraint systems.

External focus instruction using a paper balloon: impact on trunk and lower extremity muscle activity in isometric single-leg stance for healthy males.

Core stability is crucial for preventing and rehabilitating lumbar spine injuries. An external focus instruction using a paper balloon is an effective way to activate the trunk muscles. However, the degree of trunk and lower extremity muscle activation during single leg stance with external focus instruction using a paper balloon is unknown. This study aimed to investigate the core muscle involving activity in the trunk and lower extremities on both the support and non-support sides with or without using external focus instruction using a paper balloon during isometric single-leg stance. Thirteen healthy males aged 20-28 years volunteered to take part in this study and performed a single leg stance task with and without an external focus instruction, pressing their non-supporting foot onto a paper balloon without crushing it. The participant's muscle electrical activity was recorded during the single leg task using surface EMG and intramuscular EMG for six trunk muscles (transversus abdominis, internal oblique, external oblique, rectus abdominis, multifidus, and lumbar erector spinae) and five lower extremity muscles (gluteus maximus, gluteus medius, adductor longus, rectus femoris, and biceps femoris). Compared to the normal single leg stance, the external focus instruction task using a paper balloon showed significantly increased transversus abdominis (p < 0.001, p < 0.001), internal oblique (p = 0.001, p < 0.001), external oblique (p = 0.002, p = 0.001), rectus abdominal (p < 0.001, p < 0.001), lumbar multifidus (p = 0.001, p < 0.001), lumbar erector spinae (p < 0.001, p = 0.001), adductor longus (p < 0.001, p < 0.001), rectus femoris (p < 0.001, p < 0.001), and biceps femoris (p < 0.010, p < 0.001) muscle activity on the support and non-support sides. In conclusion, external focus instruction using a paper balloon significantly activates the trunk and lower extremities muscles on both the support and non-support sides. This finding provides insights for designing programs to improve coordination and balance. The benefits extend to diverse individuals, encompassing athletes, tactical professionals, and the general population, mitigating the risk of injury or falls linked to inadequate lower limb balance.

Effects of the walking independence on lower extremity and trunk muscle activity during straight-leg raising following incomplete cervical cord injury

The purpose of this study was to compare the acceleration and surface electromyography (EMG) of the lower extremity and trunk muscles during straight-leg raising (SLR) in patients with incomplete cervical cord injury according to their levels of walking independence. Twenty-four patients were measured acceleration and EMG during SLR held for 10 s. Data were analyzed separately for the dominant and nondominant sides and compared between the nonindependent (NI) and independent (ID) groups based on their levels of walking independence. Frequency analysis of the EMG showed that the high-frequency (HF) band of the contralateral biceps femoris (BF) in the ID group and bands below the medium-frequency (MF) of the BF and the HF and MF bands of the rectus abdominis in the NI group were significantly higher during dominant and nondominant SLR. During the nondominant SLR, the low-frequency band of the internal oblique and the MF band of the external oblique were significantly higher in the NI group. The ID group mobilized muscle fiber type 2 of the BF, whereas the NI group mobilized type 1 of the BF and types 2 and 1 of the trunk muscles to stabilize the pelvis. This result was more pronounced during the nondominant SLR.

The effect of marathon running on the lower extremity kinematics and muscle activities during walking and running tasks

ABSTRACT Patellofemoral pain syndrome (PFPS) is a common injury among runners, and it is thought that abnormal lower extremity biomechanics contribute to its development. However, the relationship between biomechanical changes after a marathon and PFPS injury remains limited. This study aims to investigate whether differences in knee and hip kinematics and lower extremity muscle activities exist in recreational runners before and after a marathon. Additionally, it aims to explore the relationship between these biomechanical changes and the development of PFPS injury. 12 recreational runners participated in the study. Kinematics and muscle activities of the lower extremity were recorded during walking (5 km/h) and running (10 km/h) tasks within 24 hours before and within 5 hours after a marathon. After the marathon, there was a significant decrease in peak knee flexion (walking: p = 0.006; running: p = 0.006) and an increase in peak hip internal rotation (walking: p = 0.026; running: p = 0.015) during the stance phase of both walking and running compared to before the marathon. The study demonstrates a decrease in knee flexion and an increase in hip internal rotation during the stance phase of gait tasks after completing a marathon, which may increase the risk of developing PFPS injury.

Postural balance disorders in sarcopenia based on surface electromyography

BackgroundSarcopenia is an intrinsic factor that leads to balance disorders and falls in older adults. However, the characterization of sarcopenia-related postural balance deficits remains unclear. AimsThis study aimed to explore the balance performance and postural control strategy in older adults with sarcopenia during static stance tasks using force platforms and surface electromyography. MethodsOlder adults with right-sided dominance were recruited, including 27 adults with sarcopenia and 27 healthy counterparts. Postural sway was measured with eyes open/closed on rigid/compliant surfaces. The time- and frequency-domain indexes of bilateral lower extremity muscle activity were simultaneously recorded. ResultsThe postural sway and activity of multiple lower extremity muscles in the sarcopenia group were increased (P < 0.05). The amplitude contribution ratio of the right tibialis anterior muscle (larger in sarcopenia), co-contraction ratio of right ankle dorsiflexion (smaller in sarcopenia), and mean power frequency and median frequency of the left gluteus maximus muscle (smaller in sarcopenia) had main effects of grouping (P < 0.001, η2p = 0.06–0.10). All of them had discrimination for sarcopenia (area under the curve = 0.639–0.657, P < 0.001) and were correlated with balance function measurement in sarcopenia (|rs| = 0.22–0.44, P < 0.05). ConclusionThe results of this study suggest that older adults with sarcopenia have decreased balance function and increased cost of electrophysiology. They were found to prefer the postural strategy of dominant ankle dorsiflexion and demonstrated overactivity of the dominant tibialis anterior muscles and fatigue vulnerability of the nondominant gluteus maximus. Improvements in these postural features may have balance benefits.

Effect of Corrective Exercises on Posture, Upper Extremity Muscle Activity, and Shoulder Kinematics in Male Handball Players With Upper Cross Syndrome

Background and Aims Abnormal posture and alterations in movement and muscle activity patterns have been reported in people with upper cross syndrome (UCS). These changes can lead to imbalance in muscle activation, altered movement patterns, and biomechanical changes. The present study aims to investigate the effect of corrective exercises on posture, upper extremity muscle activity, and shoulder kinematics in male handball players with UCS. Methods This quasi-experimental study was conducted on 30 male handball players with UCS who were randomly divided into exercise (n=15) and control (n=15) groups. The variables including upper extremity muscle activation patterns, shoulder kinematics, forward head posture, forward shoulder posture, and kyphosis were evaluated before and after intervention. Should kinematics and activation patterns of upper extremity muscles (supraspinatus, lumbar erector spinae, upper trapezius, middle trapezius, latissimus dorsi, pectoralis major) were recorded using electromyography and motion analyzer. The angles of forward head and forward shoulder were assessed using photographic method taken from lateral view, and Kyphosis angle was measured using a flexible ruler before and after exercises. The exercise group performed the comprehensive corrective exercises for 8 weeks (3 sessions per week), but the control group did not receive any intervention. To analyze the data, two-way analysis of variance and Bonferroni test were used. The significant level was set at 0.05. Results Forward head posture (P=0.001), forward shoulder posture (P=0.003), and kyphosis (P=0.002) showed significant improvements in the exercise group compared to the control group from pretest to post-test phase. In the preparatory and throw phases (slow and fast throwing), higher activities of supraspinatus, lumbar erector spinae, upper trapezius, middle trapezius, latissimus dorsi, and pectoralis major were observed in the exercise group compared to the control group (P=0.05). Moreover, in the preparatory and throw phases, higher range of motion of shoulder flexion, forward flexion of shoulder, internal rotation of shoulder, external rotation of shoulder, and shoulder abduction were observed in the exercise group compared to the control group (P=0.05). Conclusion Corrective exercises can significantly alter shoulder kinematics and upper extremity muscle activity patterns in male handball players with UCS, which can be used in future studies to prevent UCS in handball players during throwing the ball.

Effect of blood flow restriction training according to pressure level on lower extremity muscle activity in adult males

Effect of blood flow restriction training according to pressure level on lower extremity muscle activity in adult males

가상현실 운동 프로그램이 뇌성마비 아동의 균형과 하지 근활성도에 미치는 영향

가상현실 운동 프로그램이 뇌성마비 아동의 균형과 하지 근활성도에 미치는 영향

Visual Disruption and Neuromechanics During Landing-Cutting in Individuals With Chronic Ankle Instability.

Individuals with chronic ankle instability (CAI) demonstrate altered movement patterns when their vision is disturbed during simple tasks, such as single-legged standing and walking. However, it remains unclear whether visual disruption by stroboscopic glasses alters movement patterns during landing-cutting movements, considered highly demanding sport maneuvers that mimic a typical athletic movement. To identify altered lower extremity kinematics and muscle activation when vision is disrupted by stroboscopic glasses during landing-cutting tasks in individuals with CAI. Case-control study. Laboratory. A total of 18 individuals with CAI (age = 22.3 ± 2.3 years, height = 1.75 ± 0.1 m, mass = 72.5 ± 9.8 kg) and 18 matched healthy controls (age = 21.7 ± 2.3 years, height = 1.75 ± 0.1 m, mass = 71.9 ± 10.3 kg). All participants performed 5 trials of a landing-cutting task with (SV) and without (NSV) stroboscopic glasses. Frontal- and sagittal-plane lower extremity kinematics and 6 lower extremity muscle activations during the stance phase of a landing-cutting task in the SV and NSV conditions. Individuals with CAI demonstrated more ankle-inversion angle from 18% to 22% and from 60% to 100% of the stance phase and more peroneus longus activation from initial contact to 18% of the stance phase under the SV condition than under the NSV condition. We observed no differences in knee- and hip-joint angles between the visual conditions for both groups. When wearing stroboscopic glasses, individuals with CAI showed altered movement patterns, including increased ankle-inversion angle and peroneus longus activation during the stance phase of a landing-cutting task. The results suggest that they may lack the ability to reweight sensory information to adapt their movement to visual disruption.

Effect of sports shoe weight on lower limb muscle activities in athletes with ACL reconstruction during walking

Background. Different shoe weights affect walking mechanics. Therefore, the purpose of this study was to determine the effect of sport shoe weight on lower extremity muscle activities in athletes with anterior cruciate ligament reconstruction during walking. It was hypothesized that reduced shoe weight results in decreased frequency content of selected muscles during walking. Methods. Twenty healthy males and athletes with ACL reconstruction volunteered and gave their written informed consent to participate in this study. Participants were male and physically active. Each participant performed three walking trials in each of the light (mass per shoe: 150 ± 18 g), medium (300 ± 18 g), and heavy (450 ± 18 g) conditions in a randomized order and electromyography were analyzed during shod walking. Results. EMG results showed that the increase in shoe weight was directly related to the increase in electrical activity of the muscles, but only in the swing phase was the electrical activity of the TA muscle decreased. Conclusion. Different shoe weights affect the electrical activity of the muscles and the walking speed. Therefore, lighter weight shoes are recommended for patients with ACL. Practical Implications. The results of this study show that light shoes are useful for patients with anterior cruciate ligament rupture and the use of lightweight shoes is recommended for people with anterior cruciate ligament rupture.

The Effects of Structural Characteristics of the Rollator on the Elderly’s Gait Strategies in Various Walking Environments

A rollator, one of the most widely used among walking assistance devices, can assist the elderly with stable walking in their daily lives. In this study, we investigated how the structural characteristics of two types of rollators affect the upper and lower extremity muscle activity and plantar pressure of the elderly in various walking environments. We quantified muscle activity (upper and lower limbs) and plantar pressure (mean force, peak pressure, and contact area) of 11 older adults walking in various environments (flat, obstacle, uneven, and sloped terrain) using two types of rollators. Upper extremity muscle activity was highest in the obstacle terrain and the uneven terrain, and a significant difference was found due to the structural differences of the rollator. Additionally, it was observed that lower extremity muscle activity and plantar pressure patterns appeared in accordance with the gait strategy to maintain stability in an unstable or inclined walking environment. In other words, it was confirmed that the weight of the rollator, the size of the wheel, grip type, and the auxiliary tools had a great effect on the upper and lower extremity muscle activity and plantar pressure of the elderly during walking. From the results of this study, it can be suggested that it is absolutely necessary to consider the biomechanical characteristics of the elderly and the structure of the rollator, which appear differently depending on the walking environment, in the development of walking aids. In the future, more clinical data will be collected, and based on this a rollator that can safely assist the elderly in various walking environments will be developed.