upa - home page JUS - Journal of usability studies
An international peer-reviewed journal

A System in the Wild: Deploying a Two Player Arm Rehabilitation System for Children With Cerebral Palsy in a School Environment

Raymond Holt, Andrew Weightman, Justin Gallagher, Nick Preston, Martin Levesley, Mark Mon-Williams, and Bipinchandra Bhakta

Journal of Usability Studies, Volume 8, Issue 4, August 2013, pp. 111 - 126

Article Contents


Cerebral palsy (CP) is the most common cause of severe disability among children in Europe, affecting 2.1/1,000 live births (Johnson, 2002). CP is an umbrella term covering a range of permanent movement and postural disorders arising from non-progressive brain injury prior to birth or during infancy. The effects can vary greatly between individuals, depending in part on which parts of the brain have been affected (Rosenbaum, Paneth, Leviton, Goldstein, & Bax, 2007). Effects may be restricted to a single limb, several limbs, or the entire body. Effects can also include hypertonia (muscle stiffness causing restricted movement), involuntary movement, impaired coordination, and sensory deficits (such as impaired vision or hearing). While CP is not progressive, the impairments it causes can adversely affect the trajectory of child development by restricting opportunities to develop social and motor skills. CP can create problems in later life as strategies used to compensate for impairments can place undue strain on other parts of the body (Cox, Weze, & Lewis, 2005). There are a range of organizations whose aim is to support people with CP, such as Scope in the UK (www.scope.org.uk) or United Cerebral Palsy in the US (www.ucp.org). These organizations provide a good range of resources on the condition and its varied effects and support available to address them.

Where the condition affects one or both upper limbs, the ability to reach and manipulate objects is affected. Movements in an arm affected by CP exhibit slower and more variable movements (Jaspers et al., 2011; Utley & Sugden, 1998), which combined with weakness and sensory deficits, can significantly impair the ability of individuals with CP to carry out daily activities and can create significant social barriers (Imms, 2008). It is clearly desirable to improve upper limb function in children with CP, but the best strategy remains an open question, with many proposed treatment modalities demonstrating improvements in upper limb function (Boyd, Morris, & Graham, 2001). A common adjunct to all of these treatment modalities is the recommendation that children practice appropriate arm exercises. Use of the affected limbs has been shown to significantly offset the impact of CP (Kluzik, Fetters, & Coryell, 1990). However, a lack of physiotherapy resources means that such exercise is often delivered through a self-managed home exercise program with only occasional expert supervision. Exercises are frequently dull and repetitive, and children often lack the motivation to carry out these regimes, leading to poor compliance with the prescribed plan (Chappell & Williams, 2002).

There has been little research on how much exercise is required for therapeutic benefits to show, but it is generally agreed that the affected limb needs to be pushed to the point of fatigue for this to happen. Successful programs have required children to exercise for 20 to 45 minute sessions three times a week (McBurney, Taylor, Dodd, & Graham, 2003) and 75 minute sessions three times a week (Knox & Evans, 2002), representing a significant time commitment.

One solution to the problem of a lack of motivation is the use of interactive computer play-based therapy (Sandlund, McDonough, & Hager-Ross, 2009), where therapy is delivered as a game through a computer interface. This approach has been growing in popularity due to the increased popularity of video gaming as a pastime in the last few decades. The development of consoles that use movement-based interaction with videogames, most notably the Nintendo WiiTM, has led to great interest in their use as a means of encouraging physical activity among children and making rehabilitation enjoyable (Anderson, Annett, & Bischof, 2010; Chang, Chen, & Huang, 2011; Deutsch, Borbely, Filler, Huhn, & Guarrera-Bowlby, 2008). The use of off-the-shelf videogame consoles in rehabilitation has many benefits: The consoles are mass produced and do not require specialist development, and the games are designed first and foremost to be enjoyable. However, the game systems have some limitations that reduce their effectiveness as therapeutic devices. First, such systems may be unusable and frustrating for individuals with significant arm impairments. Some systems do not verify whether the actions performed are therapeutically useful, and while one could argue that any use of an affected limb is potentially beneficial, systems such as the Wii are easily operated with small sharp movements rather than the smooth coordinated movements required for therapy (Levac et al, 2012). Second, hands-on therapy from a physiotherapist provides support to push reaching motions to their limit and extend reach beyond that which the individual could achieve on their own, compensating for the weight of the individual’s arm.

An alternative to the existing commercial, unassisted technologies are assisted movement devices (AMDs), a term that encompasses any rehabilitation technology that applies assistive force while promoting therapeutically beneficial movements. Such treatment devices offer benefits not only to children with CP, but also to stroke patients (Jackson et al., 2007) and children with developmental coordination disorder (Snapp-Childs, Mon-Williams, & Bingham, 2013). While this requires the development of more complex specialist devices than existing games consoles, the devices are able to promote adherence to desirable trajectories—controlling both spatial and temporal components through the application of force (at either an endpoint or around the upper and lower limbs to control joint position). A conventional force-feedback joystick (i.e., those available commercially) is not appropriate for this purpose, as its control is based around fine wrist movements rather than the wide workspace needed for these sort of exercises (ensuring full arm movement). Moreover, the force-feedback available in commercial joysticks is not sufficient to provide the forces needed by an AMD. Such systems also require knowledge of target points to be reached in order to calculate the appropriate force and trajectory, and it is important to ensure that the ordering of these target points (and the motions required to reach them) are therapeutically appropriate. Accordingly, this means developing not only specialist hardware, but also specialist games that reflect these characteristics rather than using existing commercial games.

Such technology has been utilized in clinical settings (Fluet et al., 2010, Jackson et al., 2007; Krebs, Ladenheim, Hippolyte, Monterroso, & Mast, 2009) and home environments (Weightman et al., 2011). In response to feedback gathered from the Weightman et al. (2011) project, we developed a two-player system with the aim of deploying it in a school environment. Social interaction (such as cooperation and competition) in games has long been identified as a motivator for playing (Malone & Lepper, 1987) and continues to be recognized as an important aspect of making games enjoyable (Sweetser & Wyeth, 2005). However, it does raise significant challenges in computer play-based therapy, as different players will have different levels of impairment (and in some cases, none at all), making it difficult to create a level playing field. It also means deploying a system in an environment where time and space are constrained, and where teachers supervising the use of the system have little expertise in therapy and robotics. The goal of the research presented here was to determine whether such a complex system could be deployed under the “real life” conditions of a school environment. This paper represents the first reported deployment of such a system. In this paper we discuss the results of deploying the system in terms of the usage it received and the barriers encountered during its use.


Previous | Next