Estimation of grip force using the Grip-ball dynamometer.

The Grip-ball is an innovative device that has been designed to measure grip strength. The Grip-ball consists of an airtight ball that contains a pressure sensor and Bluetooth communication system. The Grip-ball can be inflated to different initial pressures, with data available continuously in real time. The aim of this study was to build a model to predict the force applied to the Grip-ball dynamometer based only on the pressure measured by the Grip-ball and its initial pressure. Forces ranging from 2 to 70 kg were applied to a hybrid version of the device for 10 different initial pressures, ranging from atmospheric pressure of 100 kPa through to 190 kPa. A model was constructed to predict applied force, with force as a function of the initial pressure and the pressure measured. The error of the model was calculated as 1.29 kg across all initial pressures and forces applied. The results of the study are comparable with the errors observed for the gold standard in grip force measurement, the Jamar dynamometer. The best results for force prediction were obtained over the range in which frailty is typically detected. The Grip-ball will now be tested using a large population in order to establish clinical norms.

[1]  Elaine Ewing Fess,et al.  Clinical assessment Recommendations , 1981 .

[2]  V. Mathiowetz,et al.  Reliability and validity of grip and pinch strength evaluations. , 1984, The Journal of hand surgery.

[3]  Wan Ariffin Bin Abdullah.  Singapore Med J , 1993 .

[4]  Thomas J. Armstrong,et al.  Investigation of Grip Force, Normal Force, Contact Area, Hand Size, and Handle Size for Cylindrical Handles , 2008, Hum. Factors.

[5]  M J Botte,et al.  Analysis of pinch and grip strength after carpal tunnel release. , 1989, The Journal of hand surgery.

[6]  N. Incel,et al.  Grip strength: effect of hand dominance. , 2002, Singapore medical journal.

[7]  L. Fried,et al.  Frailty in older adults: evidence for a phenotype. , 2001, The journals of gerontology. Series A, Biological sciences and medical sciences.

[8]  V. Mathiowetz,et al.  Grip and pinch strength: normative data for adults. , 1985, Archives of physical medicine and rehabilitation.

[9]  Virgil G Mathiowetz,et al.  Effects of three trials on grip and pinch strength measurements , 1990 .

[10]  Ren G Dong,et al.  Development of a new dynamometer for measuring grip strength applied on a cylindrical handle. , 2009, Medical engineering & physics.

[11]  J. Parker,et al.  Measurement of joint inflammation in rheumatoid arthritis with indium-111 chloride. , 1990, Annals of the rheumatic diseases.

[12]  David J. Hewson,et al.  Domo-Grip: functional evaluation and rehabilitation using grip force , 2010, 2010 Annual International Conference of the IEEE Engineering in Medicine and Biology.

[13]  E. Haker,et al.  A comparative study of continuous ultrasound, placebo ultrasound and rest in epicondylalgia. , 1988, Scandinavian journal of rehabilitation medicine.

[14]  J. Schulzke,et al.  Hand grip strength: outcome predictor and marker of nutritional status. , 2011, Clinical nutrition.

[15]  D. Hewson,et al.  Reliability and validity of the Grip-Ball dynamometer for grip-strength measurement , 2012, 2012 Annual International Conference of the IEEE Engineering in Medicine and Biology Society.

[16]  D. Kuh,et al.  Objectively measured physical capability levels and mortality: systematic review and meta-analysis , 2010, BMJ : British Medical Journal.

[17]  R. Härkönen,et al.  Accuracy of the Jamar dynamometer. , 1993, Journal of hand therapy : official journal of the American Society of Hand Therapists.

[18]  Rana Jaber,et al.  Design and validation of the Grip-ball for measurement of hand grip strength. , 2012, Medical engineering & physics.

[19]  E. Rousseau,et al.  Measurement of Adult Hand Strength: A Comparison of Two Instruments , 1982 .

[20]  J. Desrosiers,et al.  Comparison of the Jamar dynamometer and the Martin vigorimeter for grip strength measurements in a healthy elderly population. , 1995, Scandinavian journal of rehabilitation medicine.

[21]  L. Richards,et al.  Grip Strength Measurement: A Critical Review of Tools, Methods, and Clinical Utility , 1996 .