GripAble: An accurate, sensitive and robust digital device for measuring grip strength

Interrater Reliability and Precision of a Novel Hand Strength Assessment and Treatment Device: The GripAble

IMPORTANCE

Occupational therapy practitioners need modern tools for the assessment of maximal grip strength in clinical and remote settings.

OBJECTIVE

To establish the (1) interrater reliability and (2) precision of the GripAble among three raters with different expertise in occupational therapy when testing healthy participants, and to (3) evaluate the relative reliabilities of different approaches to estimating grip strength (i.e., one trial, mean of two trials, and the mean of three trials).

DESIGN

Measurement study.

SETTING

Minnesota Translational Musculoskeletal and Occupational Performance Research Lab, University of Minnesota, Minneapolis.

PARTICIPANTS

Thirty volunteers, age ≥18 yr, without any hand problems.

OUTCOMES AND MEASURES

Using GripAble, three occupational therapy raters with varied experience measured the maximal grip strength of the dominant and nondominant hands of all participants. Using the mean of three trials when testing grip strength with GripAble adds precision.

RESULTS

GripAble has excellent interrater reliability (i.e., intraclass correlation coefficient > .75) and acceptable precision (minimal detectable change < 15%) among healthy adults.

CONCLUSIONS AND RELEVANCE

GripAble allows occupational therapy practitioners with different experiences to assess grip strength in healthy hands quickly, precisely, and with excellent reliability. Additional research is needed on its psychometrics in clinical populations and capacities in remote monitoring and exergaming. Plain-Language Summary: The results of this study show that grip strength, an important biomarker and commonly assessed construct in occupational therapy, can be evaluated reliably, precisely, and rapidly with GripAble. The use of GripAble by occupational therapy practitioners in clinical settings may help to build an infrastructure for remote measurements and exergaming interventions in the future.

[Digital medicine in neurological research-Between hype and evidence]

BACKGROUND

The rapid advancement of digital medicine and health technologies in neurology offers both significant potential and challenges. This article outlines fundamental aspects of digital medicine related to neurological research and highlights application examples of digital technologies in neurological research.

AIM

To provide a comprehensive overview of current digital developments in neurology and their impact on neurological research.

MATERIAL AND METHODS

In this narrative review articles from various sources and references related to digital medicine and health technologies in neurology were compiled and analyzed.

RESULTS AND DISCUSSION

The data presented indicate that digital health technologies and digital therapeutics have the potential to decisively shape neurological care and research; however, it is emphasized that a critical evaluation and evidence-based approach to these technologies are essential to determine their actual value in neurology.

A Metamaterial Computational Multi-Sensor of Grip-Strength Properties with Point-of-Care Human-Computer Interaction

Grip strength is a biomarker of frailty and an evaluation indicator of brain health, cardiovascular morbidity, and psychological health. Yet, the development of a reliable, interactive, and point-of-care device for comprehensive multi-sensing of hand grip status is challenging. Here, a relation between soft buckling metamaterial deformations and built piezoelectric voltage signals is uncovered to achieve multiple sensing of maximal grip force, grip speed, grip impulse, and endurance indicators. A metamaterial computational sensor design is established by hyperelastic model that governs the mechanical characterization, machine learning models for computational sensing, and graphical user interface to provide visual cues. A exemplify grip measurement for left and right hands of seven elderly campus workers is conducted. By taking indicators of grip status as input parameters, human-computer interactive games are incorporated into the computational sensor to improve the user compliance with measurement protocols. Two elderly female schizophrenic patients are participated in the real-time interactive point-of-care grip assessment and training for potentially sarcopenia screening. The attractive features of this advanced intelligent metamaterial computational sensing system are crucial to establish a point-of-care biomechanical platform and advancing the human-computer interactive healthcare, ultimately contributing to a global health ecosystem.

Study of Reliability and Validity of the Load Cell-Type Hand Dynamometer Compared to the Jamar Dynamometer and the Number of Reliable Grip Strength Measurements

Background: Standardised measurement protocols for grip strength remained unclear due to variations in values depending on the device and measurement method. The load cell hand dynamometer has recently been developed. This study aims to investigate the reliability of the load cell dynamometer by comparing it to the Jamar dynamometer, which is considered the gold standard, and to identify a reliable and practical measurement method. Methods: This study included 80 healthy hospital workers (mean age of 40.1 years). All measurements were performed seated, with the elbow flexed 90° and the grip span at the second handle (approximately 50 mm) for the Jamar dynamometer, and with the elbow extended and the grip span fixed at 55 mm for the load cell dynamometer. Grip strength was measured three times on each hand using two dynamometers, and the same tests were repeated on different days. Test-retest reliability, the association between the two devices and the agreement between the two measurement methods were assessed using the intraclass correlation coefficient (ICC), Pearson correlation and the Bland-Altman analysis. Results: The ICC of the one measurement was lower than that of three measurements for both dynamometers, but was above 0.858 in all groups, indicating sufficient reliability with one-time measurement. Additionally, the ICC for different days revealed good reliability (Jamar: >0.830, load cell: >0.772). The load cell dynamometer showed significantly lower values in all measurements despite the excellent correlation (r > 0.70) and the agreement between the two dynamometers. Conclusions: This study revealed sufficient reliability of the load cell dynamometer with the standardised measurement method, but it should be noted the lower values compared to the Jamar dynamometer. Additionally, one-time measurement reliability is adequate for practical use by standardising the measurement methods for both dynamometers. Level of Evidence: Level III (Diagnostic).

Usability of Two New Interactive Game Sensor-Based Hand Training Devices in Parkinson's Disease

This pilot cross-sectional study aimed to evaluate the usability of two new interactive game sensor-based hand devices (GripAble and Smart Sensor Egg) in both healthy adults as well as in persons with Parkinson's Disease (PD). Eight healthy adults and eight persons with PD participated in this study. Besides a standardised usability measure, the state of flow after one training session and the effect of cognitive abilities on flow were evaluated. High system usability scores (SUS) were obtained both in healthy participants (72.5, IQR = 64.375-90, GripAble) as well as persons with PD (77.5, IQR = 70-80.625, GripAble; 77.5, IQR = 75-82.5, Smart Sensor Egg). Similarly, high FSSOT scores were achieved after one training session (42.5, IQR = 39.75-50, GripAble; 50, IQR = 47-50, Smart Sensor Egg; maximum score 55). Across both groups, FSSOT scores correlated significantly with SUS scores (r = 0.52, p = 0.039). Finally, MoCA did not correlate significantly with FSSOT scores (r = 0.02, p = 0.9). The present study shows high usability for both interactive game sensor-based hand training devices, for persons with PD and healthy participants.

Modernising grip dynamometry: Inter-instrument reliability between GripAble and Jamar

INTRODUCTION

Maximum grip strength (MGS) is a reliable biomarker of overall health and physiological well-being. Therefore, an accurate and reliable measurement device is vital for ensuring the validity of the MGS assessment. This paper presents GripAble, a mobile hand grip device for the assessment of MGS. GripAble's performance was evaluated using an inter-instrument reliability test against the widely used Jamar PLUS+ dynamometer.

METHODS

MGS data from sixty-three participants (N = 63, median (IQR) age = 29.0 (29.5) years, 33 M/30 F) from both hands using GripAble and Jamar PLUS+ were collected and compared. Intraclass correlation (ICC), regression, and Bland and Altman analysis were performed to evaluate the inter-instrument reliability and relationship in MGS measurements between GripAble and Jamar PLUS+ .

RESULTS

GripAble demonstrates good-to-excellent inter-instrument reliability to the Jamar PLUS+ with ICC3,1 = 0.906 (95% CI [0.87-0.94]). GripAble's MGS measurement is equivalent to 69% (95% CI [0.67-0.71]%) of Jamar PLUS+'s measurement. There is a proportional difference in mean MGS between the two devices, with the difference in MGS between GripAble and Jamar PLUS+ increasing with MGS.

CONCLUSION

The GripAble is a reliable tool for measuring grip strength. However, the MGS readings from GripAble and Jamar PLUS+ should not be interchanged for serial measurements of the same patient, nor be translated directly from one device to the other. A new normative MGS data using GripAble will be collected and accessed through the software for immediate comparison to age and gender-matched subpopulations.