Objective assessment of knife sharpness over a working day cutting meat.

Knife sharpness is one of multiple factors involved in musculoskeletal disorders in industrial meat cutting. The aim of this study was to objectively evaluate, in real working situations, how knife sharpness changed over a working day cutting meat, and to analyse the impact of sharpening, steeling and meat-cutting activities on these variations. Twenty-two meat-cutting workers from three different companies participated in the study.

Physiological consequences of using an upper limb exoskeleton during manual handling tasks.

This study aimed to assess the physiological consequences of using an upper limb exoskeleton during manual handling task, as muscle activity, upper limb kinematics, postural balance and cardiac cost. Participants performed three tasks (load lifting (LIFT), carrying (WALK) and stacking-unstacking (STACK)) with (EXOS) and without (FREE) an exoskeleton. During LIFT and STACK, the activity of the deltoid anterior muscle was significantly lower for EXOS than for FREE.

Upper Limb Kinematics Using Inertial and Magnetic Sensors: Comparison of Sensor-to-Segment Calibrations.

Magneto-Inertial Measurement Unit sensors (MIMU) display high potential for the quantitative evaluation of upper limb kinematics, as they allow monitoring ambulatory measurements. The sensor-to-segment calibration step, consisting of establishing the relation between MIMU sensors and human segments, plays an important role in the global accuracy of joint angles. The aim of this study was to compare sensor-to-segment calibrations for the MIMU-based estimation of wrist, elbow, and shoulder joint angles, by examining trueness ("close to the reference") and precision (reproducibility) validity criteria.

A technique to determine friction at the fingertips.

This article proposes a technique to calculate the coefficient of friction for the fingertip- object interface. Twelve subjects (6 males and 6 females) participated in two experiments. During the first experiment (the imposed displacement method), a 3-D force sensor was moved horizontally while the subjects applied a specified normal force (4 N, 8 N, 12 N) on the surface of a sensor covered with different materials (sandpaper, cotton, rayon, polyester, and silk).

A device for testing the intrinsic muscles of the hand.

Testing intrinsic function in the past has been primarily via coordination tests such as the Minnesota Rate of Manipulation Tests, Purdue Pegboard Test, Valpar Work Sample, The Crawford, to name a few. Typically as therapists we will use exercise putty and various techniques in the clinic to strengthen these important functional muscles of the hand. However, measuring the strength of these muscles has been very limited and time-consuming.