Comparison between Two Different Handgrip Systems and Protocols on Force Reduction in Handgrip Assessment

Area of Science:

• Gerontology
• Musculoskeletal Physiology
• Clinical Assessment

Background:

• Fatigue resistance (FR) is typically measured by grip strength (GS) decline during sustained maximal voluntary contraction.
• Previous research has not compared different handgrip systems or validated briefer FR test protocols.

Purpose of the Study:

• To compare force-time characteristics of the FR test between pneumatic and hydraulic handgrip systems.
• To investigate age- and clinical-related differences in FR using a briefer protocol (100% to 75% GS drop).
• To determine if a briefer FR test protocol is sufficiently informative for clinical use.

Main Methods:

• Participants included young, middle-aged, older healthy adults, and hospitalized geriatric patients.
• The FR test was performed using both pneumatic (Pneu) and hydraulic (Hydr) handgrip systems.
• Force-time curves were analyzed for strength decay from 100% to 75% and 75% to 50% of maximal GS.

Main Results:

• Both systems showed significant associations between 100-50% and 100-75% FR measures.
• A significant age-related difference in grip work (GW)/body weight was found in the first 25% strength decay for the Pneu system between middle-aged and older adults.
• The Pneu system identified differences in strength decay between older adults and hospitalized patients, unlike the Hydr system.

Conclusions:

• A brief FR test protocol (100% to 75% GS drop) is valid and informative for appraising muscle fatigability.
• The pneumatic handgrip system is more effective than the hydraulic system for detecting age- and clinical-related differences in muscle fatigability with a brief protocol.