RESUMEN
An abundance of degrees of freedom (DOF) exist when executing a countermovement jump (CMJ). This research aims to simplify the understanding of this complex system by comparing jump performance and independent functional DOF (fDOF) present in CMJs without (CMJNoArms) and with (CMJArms) an arm swing. Principal component analysis was used on 39 muscle forces and 15 3-dimensional joint contact forces obtained from kinematic and kinetic data, analyzed in FreeBody (a segment-based musculoskeletal model). Jump performance was greater in CMJArms with the increased ground contact time resulting in higher external (p = 0.012), hip (p < 0.001) and ankle (p = 0.009) vertical impulses, and slower hip extension enhancing the proximal-to-distal joint extension strategy. This allowed the hip muscles to generate higher forces and greater time-normalized hip vertical impulse (p = 0.006). Three fDOF were found for the muscle forces and 3-dimensional joint contact forces during CMJNoArms, while four fDOF were present for CMJArms. This suggests that the underlying anatomy provides mechanical constraints during a CMJ, reducing the demand on the control system. The additional fDOF present in CMJArms suggests that the arms are not mechanically coupled with the lower extremity, resulting in additional variation within individual motor strategies.
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Brazo , Músculo Esquelético , Humanos , Fenómenos Biomecánicos , Brazo/fisiología , Masculino , Músculo Esquelético/fisiología , Adulto , Adulto Joven , Articulación de la Cadera/fisiología , Articulación del Tobillo/fisiología , Movimiento/fisiología , Rango del Movimiento Articular/fisiología , FemeninoRESUMEN
The accurate estimation of lower-limb joint angles and moments is crucial for assessing the progression of orthopedic diseases, with continuous monitoring during daily walking being essential. An inertial measurement unit (IMU) attached to the lower back has been used for this purpose, but the effect of IMU misalignment in the frontal plane on estimation accuracy remains unclear. This study investigated the impact of virtual IMU misalignment in the frontal plane on estimation errors of lower-limb joint angles and moments during walking. Motion capture data were recorded from 278 healthy adults walking at a comfortable speed. An estimation model was developed using principal component analysis and linear regression, with pelvic accelerations as independent variables and lower-limb joint angles and moments as dependent variables. Virtual IMU misalignments of -20°, -10°, 0°, 10°, and 20° in the frontal plane (five conditions) were simulated. The joint angles and moments were estimated and compared across these conditions. The results indicated that increasing virtual IMU misalignment in the frontal plane led to greater errors in the estimation of pelvis and hip angles, particularly in the frontal plane. For misalignments of ±20°, the errors in pelvis and hip angles were significantly amplified compared to well-aligned conditions. These findings underscore the importance of accounting for IMU misalignment when estimating these variables.
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Pelvis , Caminata , Humanos , Caminata/fisiología , Masculino , Femenino , Adulto , Pelvis/fisiología , Fenómenos Biomecánicos/fisiología , Extremidad Inferior/fisiología , Articulación de la Cadera/fisiología , Aceleración , Adulto Joven , Rango del Movimiento Articular/fisiología , Articulación de la Rodilla/fisiología , Marcha/fisiologíaRESUMEN
BACKGROUND: Anterior cruciate ligament injuries are serious conditions encountered in volleyball players and occur frequently during spike jump landings. During spike jumps, the lower limb kinematics and kinetics during landing may be altered in relation to the ball position. RESEARCH QUESTION: Does the ball position have an effect on lower-limb kinematics and kinetics during spike jumps? METHODS: We measured the lower limb kinematics and kinetics of 20 healthy female college volleyball athletes during a spike jump using a three-dimensional motion analysis system. The ball positions were set to normal, dominant, and non-dominant positions. A repeated analysis of variance was used to compare the lower limb kinematics and kinetics at the initial contact and the maximum knee flexion during jump landing. Additionally, statistical parametric mapping analysis was used to analyze changes over time during the spike jumps. RESULTS: At the initial contact of the spike jump landing, the knee valgus angle, trunk lateral bending angle, and maximum knee valgus moment when the ball was set at the non-dominant position increased compared to those at the dominant position. Statistical parametric mapping analysis showed no significant change in knee valgus angle and moment of jump landing. CONCLUSION: Knee valgus angle, trunk lateral bending angle, and maximum knee valgus moment increased with the non-dominant position; furthermore, the risk of ACL injury may also be increased. SIGNIFICANCE: The posture at ball impact may influence the landing kinematics and kinetics. Therefore, it is necessary to pay close attention to movements during and prior to landing.
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Articulación del Tobillo , Articulación de la Cadera , Articulación de la Rodilla , Torso , Voleibol , Humanos , Voleibol/fisiología , Fenómenos Biomecánicos , Femenino , Adulto Joven , Articulación de la Rodilla/fisiología , Articulación del Tobillo/fisiología , Articulación de la Cadera/fisiología , Torso/fisiología , Lesiones del Ligamento Cruzado Anterior/fisiopatología , Movimiento/fisiología , Rango del Movimiento Articular/fisiologíaRESUMEN
BACKGROUND: Anterior cruciate ligament (ACL) injuries may correlate with lower limb angles and biomechanical factors in both dominant and non-dominant legs at initial contact (IC) post-landing. This study aims to investigate the correlation between ankle angles in three axes at IC and knee and hip joint angles during post-spike landings in professional volleyball players, both pre- and post-fatigue induction. RESEARCH QUESTION: To what extent does fatigue influence lower limb joint angles, and what is the relationship between ankle joint angles and hip and knee angles at IC during the landing phase following a volleyball spike? METHODS: Under conditions involving the peripheral fatiguing protocol, the lower limb joint angles at IC following post-spike landings were measured in 28 professional male volleyball players aged between 19 and 28 years, who executed the Bosco fatigue protocol both before and after inducing fatigue. A paired t-test was utilized to compare the joint angles pre- and post-fatigue in both dominant and non-dominant legs. Furthermore, Pearson's correlation test was conducted to explore the relationship between ankle angles at IC and the corresponding knee and hip joint angles. RESULTS: The findings of the study revealed that fatigue significantly increased hip external rotation and decreased knee joint flexion and external rotation in both the dominant and non-dominant legs (p < 0.05). Additionally, correlation analysis demonstrated that the ankle joint's positioning in the frontal and horizontal planes was significantly associated with hip flexion and external rotation at the IC, as well as with knee flexion and rotation (0.40 < r < 0.80). CONCLUSION: Fatigue increased hip external rotation and ankle internal rotation, weakening the correlation between these joints while strengthening the ankle-knee relationship, indicating a reduced hip control in jumps. This suggests a heightened ACL injury risk in the dominant leg due to the weakened ankle-hip connection, contrasting with the non-dominant leg.
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Articulación del Tobillo , Lesiones del Ligamento Cruzado Anterior , Articulación de la Cadera , Articulación de la Rodilla , Voleibol , Humanos , Masculino , Articulación de la Cadera/fisiopatología , Articulación de la Cadera/fisiología , Lesiones del Ligamento Cruzado Anterior/fisiopatología , Articulación del Tobillo/fisiopatología , Articulación del Tobillo/fisiología , Adulto Joven , Adulto , Fenómenos Biomecánicos , Articulación de la Rodilla/fisiopatología , Voleibol/fisiología , Rango del Movimiento Articular/fisiología , Fatiga Muscular/fisiología , RotaciónRESUMEN
Overuse injuries are often caused by pronated foot and the associated abnormal lower-extremity kinematics during dynamic activities. Various patterns of foot kinematics are observed among individuals with pronated feet during dynamic activities, resulting in different dynamic kinematics of the proximal joint. This study aimed to identify the foot kinematic patterns during gait among individuals with pronated feet and evaluate the relationship between these foot kinematic patterns and the hip and knee kinematics. A three-dimensional motion capture system was used to collect data regarding the foot, knee, and hip kinematics during the stance phase of gait of 42 individuals with pronated feet. A hierarchical cluster analysis method was used to identify the optimal number of clusters based on the foot kinematics, including navicular height (NH) at initial contact and dynamic navicular drop (DND). The differences in the cluster and demographic variables were examined. One-dimensional statistical parametric mapping was used to evaluate the differences in the time histories of the NH, knee, and hip kinematics during the stance phase. Three subgroups were identified on the basis of the NH and DND: Cluster 1, moderate NH at initial contact and larger DND; Cluster 2, highest NH at initial contact and smaller DND; and Cluster 3, lowest NH at initial contact and smaller DND. The hip adduction angle of Cluster 1 was significantly higher than that of Cluster 3 from the 0% to 51% stance phases. Further longitudinal studies are needed to clarify the relationship between identified subgroups and the development of overuse injuries.
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Pie , Marcha , Articulación de la Rodilla , Humanos , Masculino , Femenino , Fenómenos Biomecánicos , Pie/fisiología , Pie/fisiopatología , Marcha/fisiología , Articulación de la Rodilla/fisiopatología , Articulación de la Rodilla/fisiología , Adulto , Articulación de la Cadera/fisiopatología , Articulación de la Cadera/fisiología , Pronación/fisiología , Adulto JovenRESUMEN
OBJECTIVES: To investigate the intra-rater reliability and validity of belt-stabilized and tension dynamometry to assess hip muscle strength and power. DESIGN: Repeated measures. SETTING: Biomechanics laboratory. PARTICIPANTS: Seventeen uninjured adults (age = 22.0 ± 2.3y; 13 females). MAIN OUTCOMES MEASURES: Peak torque (strength) and rate of torque development (RTD; power) were measured for hip abduction, internal rotation, external rotation and extension using an isokinetic dynamometer, and belt-stabilized and tension dynamometry. RESULTS: For peak torque assessment, belt-stabilized and tension dynamometry showed good (Intraclass Correlation Coefficient [ICC] = 0.848-0.899) and good-to-excellent (ICC = 0.848-0.942) reliability, respectively. For RTD, belt-stabilized dynamometry showed fair reliability for abduction (ICC = 0.524) and good reliability for hip internal rotation, external rotation, and extension (ICC = 0.702-0.899). Tension dynamometry showed good reliability for all motions when measuring RTD (ICC = 0.737-0.897). Compared to isokinetic dynamometry, belt-stabilized and tension dynamometry showed good-to-excellent correlations for peak torque assessment (r = 0.503-0.870), and fair-to-good correlations for RTD (r = 0.438-0.674). Bland-Altman analysis showed that measures from belt-stabilized and tension dynamometry had clinically meaningful disagreement with isokinetic dynamometry. CONCLUSION: Tension dynamometry is reliable for assessing hip strength and power in all assessed motions. Belt-stabilized dynamometry is reliable for assessing internal rotation, external rotation, and extension. Validity of both methods is questionable, considering the lack of agreement with isokinetic dynamometry.
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Dinamómetro de Fuerza Muscular , Fuerza Muscular , Torque , Humanos , Femenino , Masculino , Fuerza Muscular/fisiología , Reproducibilidad de los Resultados , Adulto Joven , Adulto , Cadera/fisiología , Articulación de la Cadera/fisiología , Rango del Movimiento Articular/fisiología , Músculo Esquelético/fisiologíaRESUMEN
In this study, we investigated the combined effects of age, dual-tasking (DT) and a passive hip exoskeleton on gait patterns among senior (SA) and young adults (YA). It was hypothesized that SA will be more affected by DT and that wearing the exoskeleton will improve gait patterns for both groups during DT. Twenty-two SA and twenty-six YA performed a single task (normal walking) and DT walking at their preferred speed with an exoskeleton (EXO), without (noEXO), and a sham version (SHAM) in a randomized and balanced order. Speed, cadence, double support time (DST), step length, hip joint power, range of motion (ROM), and moments (mom), as well as DT performance, were extracted using mocap, force plates (1000 Hz), and a voice recorder. Three-way MANOVA with group × device × condition was conducted (p < .05, inferred significance). Results showed a predominantly significant main effect of group for step length, speed, DST, ROM, and mom (p ≤ .01), main effect of condition for cadence, DST, speed, and mom (p < .01) and a main effect of the device for ROMz and mom (p < .05). Age-related changes were seen by decreased walking speed and step length, independent of DT and use of exoskeleton. Wearing the EXO aided the SA group to maintain similar levels of cadence from single to DT and decreased the hip internal rotation mom by 65%. There was no difference in DT performance between groups. In conclusion, SA showed a decline in gait patterns during DT that was somewhat mitigated by wearing an EXO.
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Dispositivo Exoesqueleto , Marcha , Caminata , Humanos , Fenómenos Biomecánicos , Masculino , Adulto Joven , Femenino , Caminata/fisiología , Marcha/fisiología , Adulto , Anciano , Rango del Movimiento Articular , Cognición , Articulación de la Cadera/fisiología , Velocidad al CaminarRESUMEN
Texting while walking (TWW) is a dual-task activity that young adults perform in their everyday lives. TWW has been reported to affect gait characteristics such as gait speed, stride length, and cadence. However, the influence of TWW on lower extremity gait function has not been investigated. Therefore, the purpose of this study was to quantify gait function by examining gait symmetry and using a time series analysis. Twenty-eight young adults (14 males, 14 females) walked at their preferred speed for 10 m as a baseline condition and a 10 m TWW task. Three-dimensional segment tracking was achieved utilizing a lower extremity and trunk marker set and the Model Statistic was used to test for statistical differences between the hip, knee, and ankle angular joint positions. The hip yielded the most asymmetries (25 out of 101 points) throughout the gait cycle, while asymmetries for the knee and ankle joints yielded 16 out of 101 points and 11 out of 101 points, respectively. The outcomes of this study suggest there are differences between baseline and TWW gait symmetry, however, the percentage of the gait cycle affected was less than 25 % - indicating gait function is not strongly influenced by texting while walking in young adults.
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Marcha , Extremidad Inferior , Envío de Mensajes de Texto , Caminata , Humanos , Masculino , Femenino , Adulto Joven , Marcha/fisiología , Caminata/fisiología , Fenómenos Biomecánicos , Adulto , Extremidad Inferior/fisiología , Articulación del Tobillo/fisiología , Velocidad al Caminar/fisiología , Articulación de la Rodilla/fisiología , Articulación de la Cadera/fisiologíaRESUMEN
The purpose was to determine the impact of both cognitive constraint and neuromuscular fatigue on landing biomechanics in healthy and chronic ankle instability (CAI) participants. Twenty-three male volunteers (13 Control and 10 CAI) performed a single-leg landing task before and immediately after a fatiguing exercise with and without cognitive constraints. Ground Reaction Force (GRF) and Time to Stabilization (TTS) were determined at landing in vertical, anteroposterior (ap) and mediolateral (ml) axes using a force plate. Three-dimensional movements of the hip, knee and ankle were recorded during landing using a motion capture system. Exercise-induced fatigue decreased ankle plantar flexion and inversion and increased knee flexion. Neuromuscular fatigue decreased vertical GRF and increased ml GRF and ap TTS. Cognitive constraint decreased ankle internal rotation and increased knee and hip flexion during the flight phase of landing. Cognitive constraint increased ml GRF and TTS in all three axes. No interaction between factors (group, fatigue, cognitive) were observed. Fatigue and cognitive constraint induced greater knee and hip flexion, revealing higher proximal control during landing. Ankle kinematic suggests a protective strategy in response to fatigue and cognitive constraints. Finally, these two constraints impair dynamic stability that could increase the risk of ankle sprain.
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Articulación del Tobillo , Cognición , Inestabilidad de la Articulación , Extremidad Inferior , Fatiga Muscular , Humanos , Masculino , Inestabilidad de la Articulación/fisiopatología , Fenómenos Biomecánicos , Adulto Joven , Articulación del Tobillo/fisiopatología , Articulación del Tobillo/fisiología , Fatiga Muscular/fisiología , Extremidad Inferior/fisiología , Extremidad Inferior/fisiopatología , Cognición/fisiología , Rodilla/fisiología , Rodilla/fisiopatología , Adulto , Ejercicio Pliométrico , Tobillo/fisiología , Tobillo/fisiopatología , Estudios de Tiempo y Movimiento , Movimiento/fisiología , Traumatismos del Tobillo/fisiopatología , Articulación de la Rodilla/fisiología , Articulación de la Rodilla/fisiopatología , Articulación de la Cadera/fisiología , Articulación de la Cadera/fisiopatologíaRESUMEN
Humans exhibit unique skeletal muscle morphologies that are known to matter in upright bipedalism. However, their relevance to the ease of leg swing, which limits locomotion performance, remains unclear. Here, we aimed to examine muscle mass distribution within the human leg and the effect of each muscle on the ease of leg swing. We calculated the mass, center of mass position, and moment of inertia around the hip extension-flexion axis for all leg muscles by using a publicly available dataset of the 3D reconstruction of the musculoskeletal components in human male and female legs. The leg muscles showed a top-heavy-bottom-light tapering trend; muscles far from the hip joint tended to have smaller masses. Interestingly, however, the soleus exhibited sizable mass for its location. Consequently, the moment of inertia of the soleus was exceptionally greatest, accounting for approximately one-quarter of that of all muscles. These results indicate that compared to the other muscles the soleus muscle has a much larger effect on the leg moment of inertia and uniquely makes humans difficult to swing the leg, although the leg muscles basically show the top-heavy bottom-light tapering trend favoring the leg swing. Our findings highlight a novel functional consequence of human body evolution, suggesting that muscular enlargement for postural stability and endurance capacity has compromised the locomotion speed during the adaptation to bipedalism.
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Pierna , Músculo Esquelético , Humanos , Músculo Esquelético/fisiología , Masculino , Femenino , Pierna/fisiología , Pierna/anatomía & histología , Articulación de la Cadera/fisiología , Articulación de la Cadera/anatomía & histología , Adulto , Fenómenos Biomecánicos , Caminata/fisiología , Locomoción/fisiologíaRESUMEN
Gait monitoring using hip joint angles offers a promising approach for person identification, leveraging the capabilities of smartphone inertial measurement units (IMUs). This study investigates the use of smartphone IMUs to extract hip joint angles for distinguishing individuals based on their gait patterns. The data were collected from 10 healthy subjects (8 males, 2 females) walking on a treadmill at 4 km/h for 10 min. A sensor fusion technique that combined accelerometer, gyroscope, and magnetometer data was used to derive meaningful hip joint angles. We employed various machine learning algorithms within the WEKA environment to classify subjects based on their hip joint pattern and achieved a classification accuracy of 88.9%. Our findings demonstrate the feasibility of using hip joint angles for person identification, providing a baseline for future research in gait analysis for biometric applications. This work underscores the potential of smartphone-based gait analysis in personal identification systems.
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Marcha , Articulación de la Cadera , Teléfono Inteligente , Humanos , Masculino , Femenino , Articulación de la Cadera/fisiología , Marcha/fisiología , Adulto , Acelerometría/instrumentación , Acelerometría/métodos , Algoritmos , Aprendizaje Automático , Análisis de la Marcha/métodos , Análisis de la Marcha/instrumentación , Caminata/fisiología , Adulto JovenRESUMEN
Boots are widely used by many people for various purposes, but their impact on gait biomechanics and injury risk is not well understood. This study investigated the effects of boots on walking biomechanics, compared to casual footwear. The lower limb joint kinematics and kinetics of 20 healthy male participants aged 20 to 30 years old were compared during self-paced walking with boots and shoes. The results showed that walking with boots is associated with greater hip extensor (P = 0.009) and ankle dorsiflexor (P < 0.001) moments in early stance, hip power generation (P < 0.001) and knee power absorption (P < 0.001) in early swing phase, hip abductor (P < 0.001) and knee adduction (P < 0.001) moments in the entire stance, net concentric work for the hip joint in sagittal (13.9%, P = 0.001) and frontal (21.7%, P = 0.002) planes. In contrast, the subtalar supinator moment in the entire stance (P < 0.001), ankle angular velocity in late stance (P < 0.001), and net concentric (- 42.7%, P < 0.001) and eccentric (- 44.6%, P = 0.004) works of subtalar joint were significantly lower in the boot condition. The compensatory adjustments in the hip and knee joints may result from ankle restrictions. While boots may aid those with ankle disorders, lower limb loading and the risk of musculoskeletal injuries and osteoarthritis could be increased. This study offers new perspectives on the biomechanical impact of boots on gait, potential prevention and treatment strategies of related injuries, and advancing footwear design.
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Articulación del Tobillo , Marcha , Articulación de la Cadera , Zapatos , Caminata , Humanos , Masculino , Adulto , Fenómenos Biomecánicos , Caminata/fisiología , Adulto Joven , Marcha/fisiología , Articulación de la Cadera/fisiología , Cinética , Articulación del Tobillo/fisiología , Articulación de la Rodilla/fisiología , Extremidad Inferior/fisiologíaRESUMEN
INTRODUCTION: Measuring rate of torque development (RTD) and peak torque (PT) for hip muscle performance presents challenges in clinical practice. This study investigated the construct validity of a handheld dynamometer (HHD) versus an isokinetic dynamometer (IKD), and intra-rater repeated reliability for RTD and PT and their relationship in hip joint movements. METHODS: Thirty healthy individuals (mean age = 30 ± 8 years, 13 males) underwent two test sessions in a single day. RTD (0-50, 0-100, 0-150, 0-200ms) and PT normalised to body mass in maximal voluntary isometric contractions were measured using a HHD and an IKD in hip flexion, extension, abduction, adduction, internal and external rotation. RESULTS: For validity between the devices, RTD0-50 exhibited the largest significant systematic bias in all hip movements (3.41-11.99 Nm·s-1 kg-1) and widest limits-of-agreement, while RTD0-200 had the lowest bias (-1.33-3.99 Nm·s-1 kg-1) and narrowest limits-of-agreement. For PT, agreement between dynamometers was observed for hip flexion (0.08 Nm·kg-1), abduction (-0.09 Nm·kg-1), internal (-0.01 Nm·kg-1), and external rotation (0.05 Nm·kg-1). For reliability, intra-rater intraclass correlation coefficient (ICC2,1) ranged from moderate to good in RTD0-50 and RTD0-100 (0.5-0.88), and good to excellent in RTD0-150 and RTD0-200 (0.87-0.95) in all movements. The HHD displayed excellent intra-rater, relative reliability values (ICC2,1) in all movements (0.85-0.95). Pearson's correlation revealed good linear correlation between PT and RTD0-150 and RTD0-200 in all movements (r = .7 to .87, p = < .001). CONCLUSION: Validity analysis demonstrated significant systematic bias and lack of agreement in RTD measures between the HHD and IKD. However, the HHD displays excellent to moderate intra-rater, relative reliability for RTD and PT measures in hip movements. Clinicians may use the HHD for hip muscle PT assessment but note, late phase RTD measures are more reliable, valid, and relate to PT than early phase RTD. Additionally, the correlation between RTD and PT at various time epochs was examined to better understand the relationship between these measures.
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Articulación de la Cadera , Contracción Isométrica , Dinamómetro de Fuerza Muscular , Torque , Humanos , Masculino , Adulto , Femenino , Articulación de la Cadera/fisiología , Reproducibilidad de los Resultados , Contracción Isométrica/fisiología , Rango del Movimiento Articular/fisiología , Adulto Joven , Músculo Esquelético/fisiologíaRESUMEN
BACKGROUND: Voluntary stepping tasks are used to measure the ability of an individual to step and has been associated with fall risk in older adults. Although electromyography (EMG) amplitude is measured during stepping tasks, there is no consensus about the reference EMG value that should be used to normalize the signal. The purpose of the present study was to 1) investigate the impact of using different EMG parameters as a reference to normalize the rate of activation (RoA) of the hip abductor muscles across lateral voluntary step trials and the differences between trials, and 2) to investigate the reliability among trials of the reference EMG values. METHODS: Nineteen older adults (>65 years of age) performed ten lateral choice reaction stepping test (CRST), while the gluteus medius and tensor fascia latae EMG were recorded. Three reference EMG values were calculated and used to normalize RoA during the stepping task. A repeated-measures ANOVA was used (normalized RoA[3] x trial[3]) to compare normalized EMG across trials, and an intraclass correlation coefficient and coefficient of variation were used for the inter-trial reliability of the reference EMG values. RESULTS: The present study showed that gluteus medius and tensor fascia latae RoA normalized values from the stance and stepping leg (right or left side) measured during CRST are different according to the reference EMG value(P<0.001), with no differences across trials. Overall, the EMG procedures showed high inter-trial reliability, with a few exceptions. SIGNIFICANCE: Therefore, after careful examination of our results, the peak and mean EMG amplitudes showed consistently higher intraclass correlation coefficients; however, the former may provide a more intuitive reference value.
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Electromiografía , Músculo Esquelético , Humanos , Anciano , Femenino , Masculino , Músculo Esquelético/fisiología , Reproducibilidad de los Resultados , Articulación de la Cadera/fisiología , Anciano de 80 o más Años , Valores de ReferenciaRESUMEN
BACKGROUND: Obesity is a crucial factor that increases the risk of initiating and advancing knee osteoarthritis. However, it remains unclear how obesity directly impacts the biomechanical experience of the lower limb joints, potentially triggering or exacerbating joint degeneration. This study investigated the interactive effects of BMI augmentation on lower limb kinematics, kinetics, and muscle activations during walking. METHODOLOGY: A group of 60 participants underwent a three-dimensional gait analysis. These individuals were categorized into three groups based on their body mass index (BMI): those with a BMI below 25 were classified as having a healthy weight, those with a BMI between 25 and 30 were categorized as overweight, and those with a BMI exceeding 30 were considered obese. This study analyzed the gait of 60 participants categorized by BMI. During walking trials, they recorded ground reaction forces electromyography of leg muscles like the gastrocnemii, hamstrings, and quadriceps. Lower limb joint angles and net moments were also calculated. Statistical mapping identified variations in kinematic, kinetic, and muscle activation patterns across the stance phase between BMI groups. RESULTS: The results displayed distinct biomechanical patterns in obese individuals. Notably, there was a significant increase in flexion observed in the hip and knee joints (P < 0.001) during the initial stance phase and an increase in hip and knee adduction angles and moments throughout the entire stance phase (P < 0.001). Additionally, muscle activations underwent significant changes (P < 0.01), with a positive correlation noted with the BMI factor. This correlation was most pronounced during the early stance phase for the quadriceps and hamstring muscles and the late stance phase for the gastrocnemius. CONCLUSION: These findings represent a comprehensive picture that contributes to understanding how excess weight and obesity influence joint biomechanics, highlighting the associated risk of joint osteoarthritis.
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Índice de Masa Corporal , Electromiografía , Articulación de la Rodilla , Músculo Esquelético , Obesidad , Sobrepeso , Caminata , Humanos , Fenómenos Biomecánicos , Obesidad/fisiopatología , Masculino , Femenino , Sobrepeso/fisiopatología , Adulto , Caminata/fisiología , Articulación de la Rodilla/fisiología , Articulación de la Rodilla/fisiopatología , Músculo Esquelético/fisiología , Articulación de la Cadera/fisiología , Articulación de la Cadera/fisiopatología , Marcha/fisiología , Extremidad Inferior/fisiología , Adulto Joven , Rango del Movimiento Articular/fisiología , Análisis de la MarchaRESUMEN
OBJECTIVES: To determine normal hip adduction- and abduction strength and range of motion (ROM) values for youth and adult female national team football players, and evaluate if increasing age, playing position and leg dominance were associated with these strength and ROM values. DESIGN: Cohort study. SETTING: National football center. PARTICIPANTS: 344 unique asymptomatic female football players. MAIN OUTCOME MEASURES: Hip internal/external rotation (°), Bent Knee Fall Out test (cm), hip adduction/abduction strength(N) and ratio, and normalised hip adduction/abduction torque (Nm/kg). RESULTS: A total of 504 assessments were performed. A total of 107 players underwent two (n = 67), three (n = 27) or four (n = 13) assessments. Mean peak hip adduction strength was 39% greater in 20 + Y old players 170 (±53 N) than in 13Y old players 122 (±28 N). Normalised hip adduction torque was 9% greater: 2.5 (±0.8Nm/kg) versus 2.3 (±0.5Nm/kg). A positive association between age and all strength measurements was found, while a negative association between age and hip external rotation and total hip rotation was found. No clinically relevant differences were found for the associations between playing position, leg dominance and hip strength- and ROM values. CONCLUSION: Normal values for hip strength and range of motion in youth and adult female national football players are presented that can be used as clinical reference values.
Asunto(s)
Articulación de la Cadera , Fuerza Muscular , Rango del Movimiento Articular , Humanos , Rango del Movimiento Articular/fisiología , Femenino , Fuerza Muscular/fisiología , Adolescente , Adulto Joven , Adulto , Articulación de la Cadera/fisiología , Torque , Fútbol Americano/fisiología , Factores de Edad , Rotación , Estudios de Cohortes , Fútbol/fisiología , Cadera/fisiologíaRESUMEN
BACKGROUND: Biomechanical evaluations of sport-specific jump-landing tasks may provide a more ecologically valid interpretation compared to generic jump-landing tasks. For accurate interpretation of longitudinal research, it is essential to understand the reliability of biomechanical parameters of sport-specific jump-landing tasks. RESEARCH QUESTION: How reliable are hip, knee and ankle joint angles and moment curves during two volleyball-specific jump-landing tasks and is this comparable with the reliability of a generic jump-landing task? METHODS: Three-dimensional (3D) biomechanical analyses of 27 male volleyball players were performed in two sessions separated by one week. Test-retest reliability was analyzed by calculating integrated as well as 1D intraclass correlation coefficient (ICC) and integrated standard error of measurement (SEM) for hip, knee and ankle angles and moments during a spike and block jump (volleyball-specific tasks), and during a drop vertical jump (generic task). RESULTS: Reliability of joint angles of volleyball-specific and generic jump-landing tasks are similar with excellent-to-good integrated ICC for hip, knee and ankle flexion/extension (ICC= 0.61-0.89) and hip and knee abduction/adduction (ICC=0.61-0.78) but fair-to-poor ICC for ankle abduction/adduction (ICC=0.28-0.52) and hip, knee and ankle internal/external rotation (ICC=0.29-0.53). Reliability of hip, knee and ankle joint moments was good-to excellent (ICC= 0.62-0.86) except for hip flexion moment during spike jump and drop vertical jump (ICC=0.43-0.47) and knee flexion moment during both volleyball-specific tasks (ICC=0.56-0.57). For all tasks, curve analysis revealed poorer reliability at start and end of the landing phase than during the midpart. SIGNIFICANCE: Our data suggests that kinematic evaluations of volleyball-specific jump-landing tasks are reliable to use in screening programs, especially in the sagittal plane. Notably, reliability is poorer at the beginning and end of the landing phase, requiring careful interpretation. In conclusion, the results of this study indicate the potential for integration of sport-specific jump-landing tasks in screening programs, which will be more ecologically valid.
Asunto(s)
Articulación del Tobillo , Articulación de la Rodilla , Rango del Movimiento Articular , Voleibol , Humanos , Voleibol/fisiología , Masculino , Fenómenos Biomecánicos , Reproducibilidad de los Resultados , Adulto Joven , Articulación del Tobillo/fisiología , Articulación de la Rodilla/fisiología , Rango del Movimiento Articular/fisiología , Articulación de la Cadera/fisiología , Extremidad Inferior/fisiología , AdultoRESUMEN
This study compared the joint kinematics between the front squat (FS) conducted in the upright (natural gravity) position and in the supine position on a short arm human centrifuge (SAHC). Male participants (N = 12) with no prior experience exercising on a centrifuge completed a FS in the upright position before (PRE) and after (POST) a FS exercise conducted on the SAHC while exposed to artificial gravity (AG). Participants completed, in randomized order, three sets of six repetitions with a load equal to body weight or 1.25 × body weight for upright squats, and 1 g and 1.25 g at the center of gravity (COG) for AG. During the terrestrial squats, the load was applied with a barbell. Knee (left/right) and hip (left/right) flexion angles were recorded with a set of inertial measurement units. AG decreased the maximum flexion angle (MAX) of knees and hips as well as the range of motion (ROM), both at 1 and 1.25 g. Minor adaptation was observed between the first and the last repetition performed in AG. AG affects the ability to FS in naïve participants by reducing MAX, MIN and ROM of the knees and hip.
Asunto(s)
Centrifugación , Ejercicio Físico , Articulación de la Rodilla , Rango del Movimiento Articular , Humanos , Masculino , Rango del Movimiento Articular/fisiología , Fenómenos Biomecánicos , Adulto , Articulación de la Rodilla/fisiología , Ejercicio Físico/fisiología , Adulto Joven , Articulación de la Cadera/fisiología , Postura/fisiología , Gravedad AlteradaRESUMEN
BACKGROUND: This study investigated the effects of changes in motor skills from an educational video program on the kinematic and kinetic variables of the lower extremity joints and knee ligament load. METHODS: Twenty male participants (age: 22.2 ± 2.60 y; height: 1.70 ± 6.2 m; weight: 65.4 ± 7.01 kg; BMI: 23.32 ± 2.49 [Formula: see text]) were instructed to run at 4.5 ± 0.2 m/s from a 5 m distance posterior to the force plate, land their foot on the force plate, and perform the cutting maneuver on the left. The educational video program for cutting maneuvers consisted of preparatory posture, foot landing orientation, gaze and trunk directions, soft landing, and eversion angle. The measured variables were the angle, angular velocity of lower extremity joints, ground reaction force (GRF), moment, and anterior cruciate ligament (ACL) and medial collateral ligament (MCL) forces through musculoskeletal modeling. RESULTS: After the video feedback, the hip joint angles increased in flexion, abduction, and external rotation (p < 0.05), and the angular velocity increased in extension (p < 0.05). The ankle joint angles increased in dorsiflexion (p < 0.05), and the angular velocity decreased in dorsiflexion (p < 0.05) but increased in abduction (p < 0.05). The GRF increased in the anterior-posterior and medial-lateral directions and decreased vertically (p < 0.05). The hip joint moments decreased in extension and external rotation (p < 0.05) but increased in adduction (p < 0.05). The knee joint moments were decreased in extension, adduction, and external rotation (p < 0.05). The abduction moment of the ankle joint decreased (p < 0.001). There were differences in the support zone corresponding to 64â87% of the hip frontal moment (p < 0.001) and 32â100% of the hip horizontal moment (p < 0.001) and differences corresponding to 32â100% of the knee frontal moment and 21â100% of the knee horizontal moment (p < 0.001). The GRF varied in the support zone at 44â95% in the medial-lateral direction and at 17â43% and 73â100% in the vertical direction (p < 0.001). CONCLUSIONS: Injury prevention feedback reduced the load on the lower extremity joints during cutting maneuvers, which reduced the knee ligament load, mainly on the MCL.
Asunto(s)
Articulación de la Rodilla , Destreza Motora , Soporte de Peso , Humanos , Masculino , Adulto Joven , Soporte de Peso/fisiología , Articulación de la Rodilla/fisiología , Fenómenos Biomecánicos/fisiología , Destreza Motora/fisiología , Grabación en Video , Articulación de la Cadera/fisiología , Articulación del Tobillo/fisiología , Adulto , Carrera/fisiología , Extremidad Inferior/fisiologíaRESUMEN
The commonly used finite-state-machine (FSM) impedance control for powered prostheses deploys diverse control parameters according to different gait phases, resulting in dozens of parameter adjustments and possible gait phase misrecognition. In contrast, this study presents a straightforward, continuous, and speed-adaptive control approach based on hip-knee motion-lagged coordination mapping (MLCM). The mapping, featured by the motion lag, can effectively generate the prosthetic knee's goal gait within a second-order polynomial. It is also verified from extensive gait analysis that the motion lag and polynomial coefficients evolve linearly with respect to walking speed and gait period, promising a simple real-time deployment for prosthesis control. Experimental validation with two non-disabled subjects and two transfemoral amputees wearing a prosthesis demonstrates the MLCM controller's ability to reduce the hip compensatory behavior, generate biomimetic knee kinematics, stance phase time, stride length, and hip-knee motion coordination across various speeds. Furthermore, compared to the benchmark FSM impedance controller, the MLCM controller reduces the number of control parameters from 17 to 7 and avoids misrecognition during gait phase transitions.