Abstract
Date Presented 4/8/2016
This study established norms by gender and age groups for the Baseline® digital dynamometer and pinch gauge. Norms specific to the Baseline instruments will control for variability associated with using norms published in 1985 for the Jamar hydraulic dynamometer and the B&L® hydraulic pinch gauge.
Primary Author and Speaker: Melissa Gilbert
Additional Authors and Speakers: Julie Jepsen Thomas, Amanda Pinardo,
RESEARCH PURPOSE: To establish specific normative data for the Baseline® digital pinch gauge and Baseline digital dynamometer.
RATIONALE: The purpose of assessing hand strength is to make comparisons relative to normative data, monitor individual progress, and collect information regarding the effectiveness of occupational therapy interventions. Digital strength instruments, such as the Baseline digital dynamometer and pinch gauge, are recent options for measuring hand strength. They offer advantages, such as automatically calculating the mean of three trials and accuracy of reading a digital output, versus the needle gauge output found on hydraulic devices. However, the Baseline digital devices lack specific norms and rely on the 1985 norms published by Mathiowetz et al. for the Jamar and B&L® hydraulic devices.
Previous studies have documented differences between the readings taken with different brands of strength devices and the Jamar and B&L devices. There is a need for norms specific to the Baseline digital devices to ensure the most accuracy in reporting patients’ strength in relation to age- and gender-matched norms.
DESIGN: Cross-sectional, descriptive study with computer randomization of instruments, hand (right vs. left), and type of pinch (lateral, tip, and three-jaw chuck).
PARTICIPANTS: We recruited 318 men and 316 women representing 12 age categories from 20 to ≥75 yr in 5-yr increments. Those between 20 and 59 yr reported that they were free from upper-extremity injury and/or conditions affecting hand strength. Those ≥60 yr reported no acute pain in arms/hands, a minimum of 6 mo posthospitalization, and currently living a lifestyle unrestricted by health problems.
METHOD: University- and community-based sites from a Midwestern state. Positioning and instructions were consistent with American Society of Hand Therapy standardized protocol. Instruments were independently calibrated at start and points throughout data collection.
ANALYSIS: Descriptive statistics for demographics (handedness, ethnicity). Mean of three trials for each strength type measured, standard deviations, and standard errors. We compared our results descriptively with the 1985 Mathiowetz et al. study.
RESULTS: Grip strength: For both men and women, the Baseline measured higher values than the Jamar in a strong majority of comparisons. More than 50% of the differences were 5 lb or more, and more than 35% of the differences for men were 10 lb or more.
Pinch strength: For men and women, across pinch types, 92.3% of mean measurements were greater for the B&L hydraulic pinch gauge compared with the Baseline digital pinch gauge. Of these differences, 52% were 2 lbs. or more. The B&L measured 5 lb higher values in 33% of the comparisons. Age of peak grip and pinch strength differed from the values Mathiowetz et al. reported, but we found a similar inverse relationship between strength and age. Men were stronger than women across age groupings, and the majority of right hands were stronger than left hands.
IMPACT STATEMENT: Because of the differences among the norms produced by the Baseline, Jamar, and B&L devices, we recommend that occupational therapists use the norms we produced when testing strength with the Baseline digital dynamometer and pinch gauge.
References
Mathiowetz, V., Kashman, N., Volland, G., Weber, K., Dowe, M., & Rogers, S. (1985). Grip and pinch strength: Normative data for adults. Archives of Physical Medicine and Rehabilitation, 66, 69–74.
