Related Experiment Video
Updated: Oct 2, 2025

The Impact of Motor Task Conditions on Goal-Directed Arm Reaching Kinematics and Trunk Compensation in Chronic Stroke Survivors
Published on: May 2, 2021
[Positioning the hand to act-Validation of the 8-point reaching range test]
Sonja Krupp1, Theresa Petersen2, Friedrich Balck2,3
1Forschungsgruppe Geriatrie Lübeck, Krankenhaus Rotes Kreuz Lübeck - Geriatriezentrum, Marlistr. 10, 23566, Lübeck, Deutschland. krupp@geriatrie-luebeck.de.
Background:
The standardized geriatric assessment of the upper extremities is often limited to measurement of hand strength. The only other instrument mentioned in the S1 guidelines on level 2 geriatric assessment is the 20 cents test (20-C-T); however, in addition to strength and fine motor skills, successful hand placement is a prerequisite for self-care.
Objective:
The 8‑point reaching range test (8P-GRT) was developed for standardized separate testing of sides in a seated person concerning hand positioning relevant to daily living. The purpose of the study was to determine quality criteria of the 8P-GRT in geriatric hospital patients.
Material And Methods:
Between 31 July 2019 and 23 September 2019, a total of 82 inpatients were examined at the Hospital Red Cross Lübeck Geriatrics Center using the 8P-GRT, shoulder pain and disability index (SPADI), a questionnaire on self-care activities corresponding to the hand positions of the 8P-GRT, hand strength measurement and the 20-C‑T.
Results:
The interrater reliability was 0.99 and the retest reliability was 0.95 for the right side and 0.90 for the left side. On the individual level a ceiling effect (both sides score 8) occurred in 4.1% (n = 3) but no floor effect was observed. The internal consistency (Cronbach's alpha) of the two-factorial test according to factor analysis was 0.78 (right) and 0.76 (left). Each of the other tests correlated more closely with the 8P-GRT on the right side, whereby the correlation was highest with the abovenamed questionnaire (-0.72), followed by the SPADI (-0.60).
Conclusion:
A standardized survey of hand strength, fine motor skills and active positioning of the hand (e.g., 8P-GRT) synthesizes the main aspects of upper extremity functioning into an overall picture.

