| dbo:abstract
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- The function of the lower limbs during walking is to support the whole-body against gravitational forces while generating movement patterns which progress the body forward. Walking is an activity that is primarily confined to the sagittal plane, which is also described as the plane of progression. During one gait cycle, there are two major phases: stance and swing. In a healthy individual walking at a normal walking speed, stance phase makes up approximately 60% of one gait cycle and swing makes up the remaining 40%. The lower limbs are only in contact with the ground during stance phase which is typically subdivided into 5 events: heel contact, foot flat, mid-stance, heel off, and toe off. The majority of stance phase (~40%) takes place in single-limb support where one limb is in contact with the ground and the contralateral limb is in swing phase. During this time interval, the lower limb must support constant changes in alignment of body weight while propelling forward. The hip, knee, and ankle joints move through cyclical kinematic patterns that are controlled by muscles which cross these joints. As postural changes occur, the body adapts by motor tuning an efficient muscular pattern that will accomplish the necessary kinematics required to walk. Kinetic and kinematic measures together, are powerful tools that help infer joint patterns and understand how patterns may alter in the presence of physical or environmental changes. In kinetic measures of ground reaction force, the shape of the vertical ground-reaction force is consistent and well known. Researchers have spent decades trying to establish a direct connection between kinetic patterns and muscle activity. Since the musculoskeletal system is complex, identifying all individual muscle contributions is challenging, therefore net joint moments are most commonly examined. In 1980, a principle called the support moment was introduced. It described a total lower-limb pattern occurring at the hip, knee, and ankle during stance. According to this principle, the basic function of the lower limbs during stance phase is to resistant collapse; and to prevent this collapse, vertical support of the body requires net extensor activity at the hip, knee, and ankle joints. Other reports suggest that the necessary amount of force generated by a muscle to produce a given moment about the axes of rotation at a joint, is dependent on limb position. (en)
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| rdfs:comment
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- The function of the lower limbs during walking is to support the whole-body against gravitational forces while generating movement patterns which progress the body forward. Walking is an activity that is primarily confined to the sagittal plane, which is also described as the plane of progression. During one gait cycle, there are two major phases: stance and swing. In a healthy individual walking at a normal walking speed, stance phase makes up approximately 60% of one gait cycle and swing makes up the remaining 40%. The lower limbs are only in contact with the ground during stance phase which is typically subdivided into 5 events: heel contact, foot flat, mid-stance, heel off, and toe off. The majority of stance phase (~40%) takes place in single-limb support where one limb is in contact (en)
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