RESUMEN
Fifteen military personnel performed 30-cm drop landings to quantify how body borne load (light, â¼6 kg, medium, â¼20 kg, and heavy, â¼40 kg) impacts lower limb kinematics and knee joint energy absorption during landing, and determine whether greater lower limb flexion increases energy absorption while landing with load. Participants decreased peak hip (P = 0.002), and knee flexion (P = 0.007) posture, but did not increase hip (P = 0.796), knee (P = 0.427) or ankle (P = 0.161) energy absorption, despite exhibiting greater peak hip (P = 0.003) and knee (P = 0.001) flexion, and ankle (P = 0.003) dorsiflexion angular impulse when landing with additional load. Yet, when landing with the light and medium loads, greater hip (R(2) = 0.500, P = 0.003 and R(2) = 0.314, P = 0.030) and knee (R(2) = 0.431, P = 0.008 and R(2) = 0.342, P = 0.022) flexion posture predicted larger knee joint energy absorption. Thus, military training that promotes hip and knee flexion, and subsequently greater energy absorption during landing, may potentially reduce risk of musculoskeletal injury and optimize soldier performance.
Asunto(s)
Pierna/fisiología , Personal Militar , Postura/fisiología , Soporte de Peso/fisiología , Fenómenos Biomecánicos/fisiología , Articulación de la Cadera/fisiología , Humanos , Articulación de la Rodilla/fisiología , Masculino , Movimiento/fisiología , Adulto JovenRESUMEN
STUDY DESIGN: Data were collected from 27 patients who were participating in a rehabilitation program for chronic low back pain. The patients were tested on day 2 and day 11 of a 2-week rehabilitation program. OBJECTIVES: To determine specific characteristics of trunk motion associated with long-term dysfunction caused by low back pain of various origin, to determine if a neural network analysis system can be effective in distinguishing between patterns, and to determine if the rehabilitation has an effect on range and pattern of motion. SUMMARY OF BACKGROUND DATA: There is a lack of objective measures for evaluating the efficacy of rehabilitation programs. Numerous studies have established the difficulty of evaluating low back pain. Existing techniques, such as imaging methods, are in many cases either very rough and inaccurate or expensive and ineffective. A technique for evaluation of motion patterns in low back pain was developed based on analysis of dynamic motion features such as shape, velocity, and symmetry of movements. METHODS: Dynamic motion data were collected before and after rehabilitation from 27 patients with low back pain by using a triaxial goniometer. Range of motion and features of the movement, such as shape, velocity, and repetitiveness, were extracted for analysis. RESULTS: Motion features showed significant improvement after the rehabilitation program. CONCLUSIONS: A neural network based on kinematic data is an excellent model for classification of low back pain dysfunction. Such a system could markedly improve the management of low back pain for an individual patient.
Asunto(s)
Dolor de la Región Lumbar/fisiopatología , Dolor de la Región Lumbar/rehabilitación , Región Lumbosacra/fisiopatología , Movimiento/fisiología , Rango del Movimiento Articular/fisiología , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Redes Neurales de la Computación , Recuperación de la Función/fisiología , Rotación , Resultado del TratamientoRESUMEN
The purpose of this study was to perform a biomechanics-based assessment of body borne load during the walk-to-run transition and steady-state running because historical research has limited load carriage assessment to prolonged walking. Fifteen male military personnel had trunk and lower limb biomechanics examined during these locomotor tasks with three different load configurations (light, â¼6 kg, medium, â¼20 kg, and heavy, â¼40 kg). Subject-based means of the dependent variables were submitted to repeated measures ANOVA to test the effects of load configuration. During the walk-to-run transition, the hip decreased (P=0.001) and knee increased (P=0.004) their contribution to joint power with the addition of load. Additionally, greater peak trunk (P=0.001), hip (P=0.001), and knee flexion (P<0.001) moments and trunk flexion (P<0.001) angle, and reduced hip (P=0.001) and knee flexion (P=0.001) posture were evident during the loaded walk-to-run transition. Body borne load had no significant effect (P>0.05) on distribution of lower limb joint power during steady-state running, but increased peak trunk (P<0.001), hip (P=0.001), and knee (P=0.001) flexion moments, and trunk flexion (P<0.001) posture were evident. During the walk-to-run transition the load carrier may move joint power production distally down the kinetic chain and adopt biomechanical profiles to maintain performance of the task. The load carrier, however, may not adopt lower limb kinematic adaptations necessary to shift joint power distribution during steady-state running, despite exhibiting potentially detrimental larger lower limb joint loads. As such, further study appears needed to determine how load carriage impairs maximal locomotor performance.
Asunto(s)
Rango del Movimiento Articular/fisiología , Carrera/fisiología , Caminata/fisiología , Soporte de Peso/fisiología , Adaptación Fisiológica/fisiología , Adolescente , Adulto , Tobillo/fisiología , Fenómenos Biomecánicos , Pie/fisiología , Cadera/fisiología , Humanos , Rodilla/fisiología , Extremidad Inferior , Masculino , Personal Militar , Postura , Valores de Referencia , Torso/fisiología , Adulto JovenRESUMEN
Whiplash motion of the neck is characterized by having an extension-flexion motion of the neck. It has been previously assumed that muscles do not play a role in the injury. Eight healthy males were seated in a car seat mounted on a sled. The sled was accelerated by a spring mechanism. Muscle electromyographic (EMG) activity was measured by wire electrodes in semi-spinalis capitis, splenius capitis, and levator scapulae. Surface EMG activity was measured over trapezius and sternocleidomastoideus. Wavelet analysis was used to establish the onset of muscle activity with respect to sled movement. Shorter reaction times were found to be as low as 13.2 ms from head acceleration and 65.6 ms from sled acceleration. Thus the muscles could influence the injury pattern. It is of interest that clinical symptoms are often attributed to muscle tendon injuries.