In this study, the three-dimensional (3D) asymmetric maximum weight lifting is predicted using an inverse-dynamics-based optimization method considering dynamic joint torque limits. The limits are functions of angles and angular velocities, imposed on hip, knee, ankle, wrist, elbow, shoulder, lumbar spine joints. 3D model has 40 degrees freedom (DOFs) including 34 physical revolute joints 6 glo...

Muscle atrophy (sarcopenia) in the elderly is associated with a reduced rate of muscle protein synthesis. The purpose of this study was to determine if weight-lifting exercise increases the rate of muscle protein synthesis in physically frail 76- to 92-yr-old women and men. Eight women and 4 men with mild to moderate physical frailty were enrolled in a 3-mo physical therapy program that was fol...

Limits to flight performance at high altitude potentially reflect variable constraints deriving from the simultaneous challenges of hypobaric, hypodense and cold air. Differences in flight-related morphology and maximum lifting capacity have been well characterized for different hummingbird species across elevational gradients, but relevant within-species variation has not yet been identified i...

Activation of premotor cortex during the observation and imitation of human actions is now increasingly accepted, but it remains unclear how the CNS is able to resolve potential conflicts between the observation of another person's action and the ongoing control of one's own action. Recent data suggest that this overlap leads to a systematic bias, where lifting a box influences participant's pe...

Objective: To determine the net moments on the glenohueral joint and elbow joint during wheelchair activities. Design: Kinematics and external forces were measured durng wheelchair activities of daily living (level propulsion, iding on a slope, weight-relief lifting, reaching, negotiating a urb) and processed in an inverse dynamics biomechanic odel. Setting: Biomechanics laboratory. Participant...

AIMS To investigate the use of a worker based methodology to assess the physical stresses of lifting tasks on effort expended, and to associate this loading with musculoskeletal outcomes (MO). METHODS A cross sectional study was conducted on 217 male manual handling workers from the Hong Kong area. The effects of four lifting variables (weight of load, horizontal distance, twisting angle, and...

Theories of weight illusions have traditionally emphasised either the primary contribution of low-level sensory cues or the role of expectation based on knowledge and past experience. Current models of weight illusions lean quite strongly towards sensory-based interpretations. The current experiment raises a problem for such approaches by generating a weight illusion that is difficult to explai...

The flow set with partial order is a mixed-integer set described by a budget on total flow and a partial order on the arcs that may carry positive flow. This set is a common substructure of resource allocation and scheduling problems with precedence constraints and robust network flow problems under demand/capacity uncertainty. We give a polyhedral analysis of the convex hull of the flow set wi...