Isometric Hand Grip Strength Measured by the Nintendo Wii Balance Board

A Reliable New Method

A. W. Blomkvist; S. Andersen; E. D. de Bruin; M. G. Jorgensen


BMC Musculoskelet Disord. 2016;17(56) 

In This Article


Muscle function is pivotal to overall physical fitness and a change in muscle strength is an important risk factor for functional decline, independent of disease processes.[1] Hence, the assessment of muscle function is an important measure in many situations. It may be assessed by proxies such as muscle mass or muscle strength. Compared to muscle mass, it is easier and more reliable to measure muscle function in terms of strength, particularly hand grip strength (HGS).[2,3] Accordingly, HGS is a strong predictor of future disability[4] and mortality[2,3,5–7] in the old and middle-aged.[4,7,8] In addition to being a marker for nutritional status,[9,10] low HGS is also associated with increased risk of postoperative complications, extended hospitalisation, higher re-submission rates and increased short-term mortality following acute admission.[9–11]

In clinical settings, there are several methods for assessing muscle strength. Manual muscle testing (using a subjective scale from 0 to 5) is one of the most commonly used methods because of its simplicity and speed, however, a serious drawback is its crudeness.[12,13] Another way of evaluating HGS is by using an objective handgrip dynamometer, which can be hydraulic, pneumatic, mechanical or electrical. The handgrip dynamometer has shown high reliability and validity when appropriately calibrated[14–16] and it can be useful for identifying individuals at high risk of poor disease outcomes.[17] The gold standard by which other dynamometers are evaluated is the Jamar hand dynamometer (JD).[16]

Most handgrip dynamometers are primarily found in the hands of health care professionals as they only measure HGS and prices range from 250 to 1484 USD. In contrast, the Nintendo Wii Balance Board (WBB) is widely available globally and it sells at approximately 60 USD. Moreover, the WBB has been demonstrated to be a reliable and valid instrument for the assessment of other physical characteristics such as balance[18] and reaction-time.[19] In 2014, an American research group demonstrated that both new and used WBB recorded static forces accurately in a laboratory setting.[20] Inspired by these findings, researchers at Aalborg University Hospital have developed software that enabled isometric strength recordings to be performed using the WBB. This software has shown high reproducibility and concurrent validity for measuring isometric muscle strength in the lower limbs.[21] Next, we want to establish whether this software can be used for isometric HGS testing. Hence, the aim of this study was (1) to explore both relative and absolute reproducibility of the WBB to measure HGS in the dominate and the non-dominate hand and (2) to explore concurrent validity when compared to the gold standard, the JD.