Ann Rehabil Med.  2023 Dec;47(6):468-482. 10.5535/arm.23055.

Comprehensive Physical Work Capacity Evaluations for Korean Farmers Assessed in Healthy Volunteers

• Jeong S
• Kim G
• Park Hw
• Baek S

• KMID: 2549728
• DOI: http://doi.org/10.5535/arm.23055

Abstract

Objective
To establish the lower limits of normative values of the physical work capacity for Korean farmers in healthy working individual.
Methods
We developed a comprehensive set of physical work capacity evaluation items that encompass common farming tasks. These items include measurements of trunk flexion/extension angles, strength (hand grip, trunk flexion/extension, leg/back lifting, and pushing/pulling), and positional tolerances. We calculated the normative values for the items and defined the normal range in 124 healthy volunteers aged 20–79 years. We calculated the intraclass correlation coefficient (ICC) to validate the test-retest reliability of the measurements protocol.
Results
The normal values for each measurement item were as follows: trunk flexion and extension angle (65.3°±11.6° and 29.6°±6.6°), dominant hand grip strength (32.2±10.5 kgf), trunk flexion and extension strength (288.4±119.0 N and 297.3±129.9 N), leg and back lifting strength (452.9±233.5 N and 349.2±166.7 N), pushing and pulling strength (214.7±75.1 N and 221.7±63.3 N), and positional tolerance time (squat: 76.8±9.0 seconds, front: 73.8±7.7 seconds, twist: 82.2±8.8 seconds, upward: 71.9±11.3 seconds). Regarding test-retest reliability, all strength measurements demonstrated excellent absolute agreement (ICC, 0.91–0.96). However, positional tolerance showed poor-to-moderate absolute agreement (ICC, 0.37–0.58).
Conclusion
We conducted measurements of muscle strength and positional tolerance in healthy participants of various ages, focusing on tasks commonly performed by Korean farmers. The outcomes hold significant value as they offer a pertinent instrument for assessing the appropriateness of workers, thereby carrying implications for rehabilitation objectives, legal evaluations, and work capacity assessments within the agricultural domain.

Keyword

Work capacity evaluation; Physical fitness; Occupational health services; Agriculture; Low back pain

Figure

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  Fig. 1. Hand grip strength measured using a hydraulic hand dynamometer (SH5001®; Saehan Corporation). (A) The subject was seated with the shoulder adducted and neutrally rotated, the elbow flexed at 90°, and the forearm and wrist in a neutral position. (B) The handle bars are set on the second notch (arrow) for the second handle position.

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  Fig. 2. Range of trunk flexion and extension. (A) Trunk flexion angle. (B) Trunk extension angle. (C) Digital inclinometer.

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  Fig. 3. Isometric strength of trunk flexion and trunk extension. (A) Trunk flexion strength. (B) Trunk extension strength. (C) PrimusRS (BTE Technologies Inc.).

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  Fig. 4. Isometric strength of leg lifting (A), back lifting (B), pushing (C), and pulling (D) are displayed. (A, B) For lifting strengths, the vertical and horizontal distance of from the hand-held static force gauge dynamometer from the midpoint of the ankle were predetermined. The vertical distance between the midpoint of the hand grasp and the floor was 15 inches (38.1 cm) in both leg lifting (A) and back lifting (B), indicated by the vertical dotted line. The horizontal distance between the midpoint of the hand grasp and the midpoint of the ankle is represented by the horizontal solid line. The horizontal adjustment was set at 0 cm for leg lifting (A), while the horizontal distance was 15 inches (38.1 cm) in back lifting indicated in solid line (B). (C, D) For pushing and pulling strengths, the height of a handle was adjusted to align with the level of the anterior superior iliac spine.

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  Fig. 5. Positional tolerance of squat, front, twist, and upward reaching tasks. (A) Squat task. (B) Front reaching task. (C) Twist reaching task. (D) Upward reaching task.

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