Motor Skills in Work Settings

Introduction

Despite the fact that work is increasingly mechanized and automatized, motor skills are still the main vehicles by which tasks in industrial settings are performed. The literature in this area is vast, originating from psychology, engineering, biology, neuroscience, kinesiology, and physical education. Within the present limited framework, only a few topics can be dealt with to provide some understanding of the basic concepts and a flavour for the field.

First some classificatory schemas and definitions will be provided, and a brief overview is given of the major motor control theories. Then a short description of how movement speed and movement accuracy is formalized in Fitts' law is followed by some methods of observation applied in work settings.

Motor Skills

A motor skill is defined by Jensen, Schulz, and Bangerter (1983) as the ability to use the correct muscles with the exact force necessary to perform the desired response with proper sequence and timing. Some conceive motor skill also as the capacity to adapt to changing environmental conditions and the consistency of action across repetitions; this is called motor equivalence (Rosenbaum, 1991).

Types of Movement Classifications

Capturing the wide repertoire of physical activities requires some ordering principles. A frequently applied classification distinguishes discrete, serial, and continuous movements (e.g. Sanders & McCormick, 1993; Schmidt, 1988). Discrete movements involve a single aiming movement to a stationary target with a clearly defined start and end, such as reaching for a control knob or pointing to a command field on a computer display. Serial movements involve a series of discrete movements. When similar discrete movements are repeated, like tapping a cursor key on a keyboard or hammering on a nail, they are mostly called repetitive movements, while the term sequential movements applies to a series of discrete movements carried out to a number of stationary targets that are regularly or irregularly spaced, e.g. playing the piano, typewriting, or reaching for parts in various stock bins. Continuous movements refer to a class of movements of which the beginning and the end must be arbitrarily defined, as with swimming and steering a car. An additional distinguishing [Page 596]feature is that these movements need muscular control adjustments during the movement, as in guiding a piece of fabric through a sewing machine. Though not strictly a movement, maintaining posture or a static positioning for a period of time might be considered as an additional movement class.

Assessment of motor skills in work settings can be approached also from a process perspective: the preparation and execution processes involved in motor skills. In that case one describes motor skills, respectively, in terms of the involved information processes and the cognitive load emerging from preparatory and controlling demands, as well as in terms of maintaining the spatio-temporal trajectory, speed or force of the movement. Another level of description concerns the quality of movement outcome, both in qualitative (jerky, good) and quantitative (numbers expressing spatial accuracy, produced force) measures. A last classification schema addresses the predictability of the environment: a movement might belong to the class of open skills (football, soccer) or closed skills (darting, most machine operating skills).

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