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A six-accelerometer inertial tracking package currently in intensive use in measuring living human and human surrogate response to impact acceleration is presented and discussed. The discussion includes an enumeration of the various requirements imposed upon the package as well as its design and fabrication. The on-site calibration facility is described, including a discussion of the procedures for routine calibration of the packages. Accounts of the data acquisition link from the packages through the sled borne amplifiers to the hybrid computer are also included. Particular attention is devoted to the theoretical aspects of this system. A statement of errors is developed and compared to the various precision parameters of this system and to a general estimation of the dynamic response envelope demonstrating the overall feasibility of this approach.

Overexertion injuries comprise the largest category of nonfatal injuries among construction workers. These injuries typically occur when the biomechanical stresses associated with tasks such as lifting, carrying, pushing, etc., exceed the worker’s strength capacity. Two studies were conducted to measure the whole-body isometric strength capability of 56 construction workers. The first study examined the effect of four typical postures (2 symmetric lifts and 2 asymmetric lifts) associated with scaffold end frame disassembly. The effect of posture on isometric strength capability was significant; the strength capability ranged from 366 N to 676 N. The second study evaluated the effect of hand separation distance (46 cm, 86.4 cm, and 116.8 cm) and vertical hand placement (knuckle, elbow, and acromial heights) on isometric force during symmetric lifting postures. The interaction effect of hand separation distance - vertical hand placement on isometric strength capability was significant.