Lower Extremity Muscle Activity Research Articles

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.

Dual-Task Interference Effects on Lower-Extremity Muscle Activities during Gait Initiation and Steady-State Gait among Healthy Young Individuals, Measured Using Wireless Electromyography Sensors.

To maintain a healthy lifestyle, adults rely on their ability to walk while simultaneously managing multiple tasks that challenge their coordination. This study investigates the impact of cognitive dual tasks on lower-limb muscle activities in 21 healthy young adults during both gait initiation and steady-state gait. We utilized wireless electromyography sensors to measure muscle activities, along with a 3D motion capture system and force plates to detect the phases of gait initiation and steady-state gait. The participants were asked to walk at their self-selected pace, and we compared single-task and dual-task conditions. We analyzed mean muscle activation and coactivation in the biceps femoris, vastus lateralis, gastrocnemius, and tibialis anterior muscles. The findings revealed that, during gait initiation with the dual-task condition, there was a decrease in mean muscle activation and an increase in mean muscle coactivation between the swing and stance limbs compared with the single-task condition. In steady-state gait, there was also a decrease in mean muscle activation in the dual-task condition compared with the single-task condition. When participants performed dual-task activities during gait initiation, early indicators of reduced balance capability were observed. Additionally, during dual-task steady-state gait, the knee stabilizer muscles exhibited signs of altered activation, contributing to balance instability.

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.

Effects of gait training with weight support feedback walker on walker dependence, lower limb muscle activation, and gait ability in patients with incomplete spinal cord injury: A pilot randomized controlled trial

Background Spinal cord injury (SCI) is a devastating condition affecting an individual’s life, particularly through lower extremity paralysis, which limits walking and daily activities. Objectives This study investigated the effects of weight support feedback walker (WSFW) gait training on walker dependence, lower limb muscle activation, and gait ability in patients with incomplete SCI (ISCI). Methods Eleven subjects capable of walking > 20 m with and without a walker were randomly assigned to WSFW gait training (n = 6) or conventional walker (CW) gait training groups (n = 5). All subjects underwent standard physical therapy for 4 weeks. Additionally, the WSFW group participated in WSFW gait training, whereas the CW group participated in CW gait training conducted for 30 min per day, thrice per week, for 4 weeks. Walker dependence (the average force pressing WSFW with the user's arm during walker gait), lower extremity muscle activity (rectus femoris, biceps femoris, and medial gastrocnemius), and gait ability (gait elements: velocity, cadence, step length, and step length asymmetry) were measured to investigate the effects of training. Results The WSFW group showed significant decrease in walker dependence compared to the CW group (P < 0.05). Some lower extremity muscle activation (left side biceps femoris) and velocity of the gait elements were increased in the WSFW group compared with those in the CW group (P < 0.05). Conclusion WSFW gait training could help patients with ISCI transfer their body weight to the paralyzed lower extremity. However, a randomized controlled trial with several subjects is essential to verify the effects of WSFW training.

Systematic Evaluation of the Effects of Voluntary Activation on Lower Extremity Motor Thresholds.

The purpose of this investigation was to elucidate the relationship between the resting motor threshold (rMT) and active motor threshold (aMT). A cross-sectional comparison of MTs measured at four states of lower extremity muscle activation was conducted: resting, 5% maximal voluntary contraction (MVC), 10%MVC, and standing. MTs were measured at the tibialis anterior in the ipsilesional and contralesional limbs in participants in the chronic phase (>6 months) of stroke (n = 11) and in the dominant limb of healthy controls (n = 11). To compare across activation levels, the responses were standardized using averaged peak-to-peak background electromyography (EMG) activity measured at 10%MVC + 2SD for each participant, in addition to the traditional 0.05 mV criterion for rMT (rMT50). In all participants, as muscle activation increased, the least square mean estimates of MTs decreased (contralesional: p = 0.008; ipsilesional: p = 0.0015, healthy dominant: p < 0.0001). In healthy controls, rMT50 was significantly different from all other MTs (p < 0.0344), while in stroke, there were no differences in either limb (p > 0.10). This investigation highlights the relationship between rMT and aMTs, which is important as many stroke survivors do not present with an rMT, necessitating the use of an aMT. Future works may consider the use of the standardized criterion that accounted for background EMG activity across activation levels.

Comparison of Muscle Activity and Muscle Thickness According to Knee Flexion Angle during Supine Bridge Exercises using the Abdominal Drawing-in Maneuver on an Unstable Surface.

This study evaluated changes in deep trunk muscle thickness and lower extremity muscle activities during bridge exercises with the abdominal drawing-in maneuver. Bridge exercises were conducted on an unstable surface at different knee flexion angles (60º, 90º and 120º), with the aim of identifying more effective angles for bridge exercises. This study included 21 healthy adults, aged 20-27 years. Biceps femoris (BF), rectus abdominis, and rectus femoris activity was measured using surface electromyography. The thicknesses of the transverse abdominis (TrA), external oblique (EO) and internal oblique (IO) muscles were measured. BF (p = 0.000, partial η2 = 0.670) activity increased considerably as the knee flexion angle decreased. TrA (p = 0.000, partial η2 = 0.883) and IO (p = 0.000, partial η2 = 0.892) thickness significantly increased, while EO (p = 0.000, partial η2 = 0.893) thickness decreased as the knee flexion angle decreased. When performing bridge exercises using the abdominal drawing-in maneuver on an unstable surface, the knee flexion angles should be at 120º and 60º to increase trunk stability and lower extremity muscle activity, respectively.

Musculoskeletal simulation of professional ski jumpers during take-off considering aerodynamic forces.

Introduction: Musculoskeletal simulation has been widely used to analyze athletes' movements in various competitive sports, but never in ski jumping. Aerodynamic forces during ski jumping take-off have been difficult to account for in dynamic simulation. The purpose of this study was to establish an efficient approach of musculoskeletal simulation of ski jumping take-off considering aerodynamic forces and to analyze the muscle function and activity. Methods: Camera-based marker-less motion capture was implemented to measure the take-off kinematics of eight professional jumpers. A suitable full-body musculoskeletal model was constructed for the simulation. A method based on inverse dynamics iteration was developed and validated to estimate the take-off ground reaction force. The aerodynamic forces, which were calculated based on body kinematics and computational fluid dynamics simulations, were exerted on the musculoskeletal model as external forces. The activation and joint torque contributions of lower extremity muscles were calculated through static optimization. Results: The estimated take-off ground reaction forces show similar trend with the results from past studies. Although overall inconsistencies between simulated muscle activation and EMG from previous studies were observed, it is worth noting that the activation of the tibialis anterior, gluteus maximus, and long head of the biceps femoris was similar to specific EMG results. Among lower extremity extensors, soleus, vastus lateralis, biceps femoris long head, gluteus maximus, and semimembranosus showed high levels of activation and joint extension torque contribution. Discussion: Results of this study advanced the understanding of muscle action during ski jumping take-off. The simulation approach we developed may help guide the physical training of jumpers for improved take-off performance and can also be extended to other phases of ski jumping.

The Effect of Elastic Tape on Lower Extremity Muscle Activity in Squats of Young Female Adults: A Cross-sectional Pilot Study

The Effect of Elastic Tape on Lower Extremity Muscle Activity in Squats of Young Female Adults: A Cross-sectional Pilot Study

The Effects of Whole-Body Vibration Training with Blood Flow Restriction on Lower Extremity Muscle Activity and Hemodynamic Variables

The Effects of Whole-Body Vibration Training with Blood Flow Restriction on Lower Extremity Muscle Activity and Hemodynamic Variables

The Effects of Whole-Body Vibration Training with Blood Flow Restriction on Lower Extremity Muscle Activity and Hemodynamic Variables

The Effects of Whole-Body Vibration Training with Blood Flow Restriction on Lower Extremity Muscle Activity and Hemodynamic Variables

EFFECTS OF A NORDIC WALKING INTERVENTION ON WALKING IN NORMAL ADULTS

The purpose of this study was to compare and examine gait parameters, hip joint angle, and lower extremity muscle activity during normal walking before and after Nordic walking (NW) intervention. Nineteen healthy male participants (age 26.3 ± 2.4 years) were included in the study. During walking, we measured gait parameters using the footprint-measuring gait analysis system. Аngular changes of the hip joint were measured with an IMU-type portable three-dimensional motion analyzer and the EMG activity of each muscle. The measurements above were performed before and after a one-hour NW training course. The hip joint angle, muscle activity, and gait parameters were compared before and after the intervention with the same participants. In gait parameters, the stride length and walking speed were significantly greater after the intervention, while the cadence decreased significantly. Both hip flexion and extension angles were significantly greater after the intervention. In terms of muscle activity, the rectus abdominis, the tibialis anterior, and the gastrocnemius were very different after the intervention. According to previous reports, employing a large stride length during NW would affect the normal gait after the training. The use of the Nordic pole may have stimulated a substantial forward movement in the lower extremities using the large range of motion of the hip joints. The benefits of NW include enhanced forward propulsion during gait and additional stability during the stance phase due to the greater support surface provided by the poles.

Immediate Effects of Ankle Mobilization on Range of Motion, Balance, and Muscle Activity in Elderly Individuals with Chronic Ankle Instability: A Pre-Post Intervention Study.

BACKGROUND This study aimed to identify the immediate effect of applying ankle mobilization to the elderly with chronic ankle instability on the range of joint motion, balance, and lower extremity muscle activity. MATERIAL AND METHODS This study, the Cumberland Ankle Instability Tool (CAIT) was used to evaluate chronic ankle instability, and as a result, 65-year-olds with a score of 24 or less were conducted. In this study, the grade III of Maitland mobilization was used to increase the range of joint motion in older people with chronic ankle instability. And four joint mobilizations were administered for a total of 40 minutes, 10 minutes per run. In the pre-examination, the range of motion of ankle joints, balance, and lower extremity muscle activity in the Limit of Stability (LOS) position prior to ankle mobilization. The reexamination was taken a right after the intervention to see the immediate effect of applying joint mobilization. This study was conducted after receiving the approval of the Institutional Review Board of the Korea National University of Transportation. RESULTS The study results show that, as a result of applying the ankle mobilization intervention, the range of dorsi flexor and plantar flexor motion increased, resulting in the improvement of balance and an immediate effect on the lower extremity muscle activity when measuring the Limit of Stability. CONCLUSIONS The conclusion of this study is ankle mobilization may be a useful intervention method in preventing falls and improving balance in older adults with chronic ankle instability.

Investigation of Maximum Voluntary Contraction Activity during Robotic Gait

The purpose of this study is to investigate healthy people’s and patients’ lower extremity muscle activities during robotic gait using kinesiology analysis. Initially, muscle signals were taken from 6 paraplegic patients such as spinal cord injury (SCI) and stroke patients, 2 hemiplegic patients and 4 healthy persons. Then, signals were analyzed by using signal processing techniques such as filtering, rectifying, Root Mean Square (RMS) and also by calculating the Max Voluntary Contraction (MVC). As a result, it was seen that hip muscles such as the Gluteus Maximus (GMA), Gluteus Medius (GM) and Iliopsoas (ILP) had lower MVC values in the hemiplegic patients than those of the SCI patients and the healthy persons. Additionally, when the signals that were obtained were analyzed, it was found that the activity of the Medial Gastrocnemius (MG) muscle could be used in determination of movement path and movement intention. Moreover, the EMG results of gait motion may be helpful in applying accurate amplitude and frequency stimulation in epidural stimulation (ES) therapy.

Unexpected inversion perturbation during a single-leg landing in patients with chronic ankle instability

ABSTRACT It remains unclear how unexpected perturbations during single-leg landings affect lower extremity kinematics and muscle activations in patients with chronic ankle instability (CAI). The purpose of this study was to identify the differences in lower extremity movement patterns among CAI subjects, copers, and healthy controls. Sixty-six people including 22 CAI subjects, 22 copers, and 22 healthy controls volunteered to participate in the study. Lower extremity joint kinematics and EMG activations from 200-ms pre to 200-ms post the initial contact during unexpected tilted landings were measured. Functional data analysis was used to evaluate between-group differences for outcome measures. Relative to copers and healthy controls, CAI subjects showed more inversion from 40-ms to 200-ms after initial contact. Relative to healthy controls, CAI subjects and copers showed more dorsiflexion. Relative to healthy controls, CAI subjects and copers showed more muscle activation in tibialis anterior and peroneus longus, respectively. In conclusion, CAI subjects demonstrated greater inversion angles and muscle activation before initial contact compared to LAS copers and healthy controls. This suggests that CAI subjects and copers prepare for their landing with protective movements, but the prepared movements shown by CAI subjects may be insufficient to reduce risk of recurrent injury.

Lower Extremity Muscle Activation during the Star Excursion Balance Test in Patients with Chronic Ankle Instability and Copers.

Background and Objectives: The aim of this study was to assess the impact of ankle muscles on performance of the Star Excursion Balance Test (SEBT) among individuals with stable ankles, a history of ankle sprain, and chronic ankle instability (CAI). Materials and Methods: Sixty subjects (twenty per group) performed the SEBT in each of the anterior (A), posteromedial (PM), and posterolateral (PL) directions. Normalized maximum reach distance (NMRD) and normalized mean amplitude of the tibialis anterior (NMA_TA), fibularis longus (NMA_FL), and medial gastrocnemius (NMA_MG) were measured during performance of the SEBT. Results: Copers have greater NMRD than subjects with stable ankles and those with CAI, and subjects with stable ankles also have greater NMRD than those with CAI in only the PL direction. Subjects with stable ankles and those with CAI showed greater NMA_TA than copers. The A direction showed greater NMA_TA than the PM and PL directions. Copers showed greater NMA_FL than subjects with stable ankles. Subjects with CAI showed greater NMA_MG than copers and subjects with stable ankles. The A and PL directions showed greater NMA_MG than the PM direction. Conclusions: Overall, copers and/or subjects with CAI demonstrated altered neuromuscular function by compensating for their ankle muscles when compared to subjects with stable ankles due to a history of ankle sprain.

Effect of load carriage on joint kinematics, vertical ground reaction force and muscle activity: Treadmill versus overground walking

BackgroundPrevious studies have investigated the effect of either different load or different surface conditions, such as overground or treadmill walking, on human biomechanics. However, studies combining these two aspects are scarce. Research questionThe purpose of this study was to quantify the difference in spatiotemporal parameters, lower extremity joint kinematics, vertical ground reaction forces (vGRF) and muscle activity between normal bodyweight (100 %BW) and 20 % increased bodyweight (120 %BW) during overground and treadmill walking. MethodsTen healthy young adults walked overground at self-selected speed and on an instrumented treadmill set to the overground speed. Spatiotemporal parameters, 3-dimensional lower extremity kinematics, vGRF and muscle activity were measured and compared between conditions. ResultsThe stance phase was longer for 120 %BW than 100 %BW in both overground and treadmill walking. Further, the stance phase was longer and cadence higher in treadmill than overground walking for both load conditions. Knee flexion angles were more than 3° greater in the second half of swing in treadmill than in overground walking. The vGRF was higher for 120 %BW compared to 100 %BW on both surfaces (treadmill, first peak: +18.6 %BW; second peak: +13.5 %BW; overground, first peak: +22.2 %BW; second peak: +19.8 %BW). Differences between conditions greater than 20 % were observed in short periods during the gait cycle for vastus medialis, vastus lateralis and semitendinosus. SignificanceResults regarding the effects of carrying additional load using a weight vest on joint kinematics during treadmill walking may be translated to overground walking but some changes in muscle activation can be expected.

External Focus Reduces Accuracy and Increases Antagonist Muscle Activation in Novice Adolescent Soccer Players.

Instep kick is one of the most effective kicking techniques in soccer. Lower extremity muscles and joints play a crucial role during instep kick. However, external (EF) and internal focus and their effect on the muscles are still ambiguous. In this study, 13 male adolescent soccer players were included and aimed to hit the targets in internal and EF conditions. Lower extremity muscle activations were measured with surface electromyography, and kinematics were measured with a high-speed video camera. Muscle activations and movement latencies were analyzed in four different phases (backswing, leg cocking, acceleration, and follow-through) of kicking. While 10 out of 13 participants kicked accurately in internal focus, only five out of 13 in EF kicked accurately. Gastrocnemius muscle activations increased significantly in EF in all phases except acceleration. Movement latencies were found 0.07 ± 0.002s for accurate and 0.05 ± 0.004s for inaccurate kicks in EF. A correlation has been found between accuracy and movement latency in EF (R = .67). Our results suggest that novices cannot yet coordinate their muscles in EF, cocontraction ratio increases. Therefore, training strategies that aim to reduce the cocontraction ratio can help the athlete increase performance through better motor coordination. Moreover, better motor coordination may be beneficial in preventing injuries (joint stiffness, etc.) caused by increased cocontraction ratio.

바드라가즈 링 기법이 만성 뇌졸중 환자의 몸통 조절과 다리 근육의 근활성도에 미치는 효과

바드라가즈 링 기법이 만성 뇌졸중 환자의 몸통 조절과 다리 근육의 근활성도에 미치는 효과

Comparison of Lower Extremity Muscle Activity According to Ankle Angle during Sling Bridge Exercise in Patients with Patellofemoral Pain Syndrome

Comparison of Lower Extremity Muscle Activity According to Ankle Angle during Sling Bridge Exercise in Patients with Patellofemoral Pain Syndrome