The application of commercial wearable technology and smartphone rehabilitation applications for enhancing individuals’ level of activity after hip replacement surgery.

Abstract

Total hip replacement (THR) is one of the most common and successful orthopaedic operations worldwide that offers pain relief, even at week one post-surgery. However, many studies suggested that the aim should not only be to improve pain, but also lead to improving daily activity which currently does not follow the same positive trend. Commercially available activity monitoring wearables and smartphone apps have the potential to engage patients as advocates in their personalised care, but the systematic review conducted in this integrated thesis identified that the evidence of their use in THR population is limited. Furthermore, findings from Patient and Public Involvement (PPI) study, showed that, in the absence of pain post-surgery, a major motivator for individuals undergoing THR surgery is their desire to participate in walking activities. Given the importance of walking to this group, an assessment of gait data 6-month post-surgery was carried out using a self-paced instrumented treadmill. Data indicated that despite gradual improvement from pre surgery to up to 6 months post-surgery, the walking speed and step length of the THR group remain statistically significantly different from that of the control group 3 months after surgery. In contrast, the cadence is improved and recovers, when compared to the control group, as early as the 6 weeks stage post-surgery. Indeed, it might even be earlier than that, but intervening measurements were not made. It then remains constant up to the 6-month assessment. However, it is important to note that, the step length and walking speed do not recover so quickly and only become closer to that of the control group over the first 6 months. This could be interpreted that as the patients rehabilitate, their range of movement only gradually improves and that although the number of steps might rapidly get back to the levels of the control group, the distance walked, and walking efficiency does not recover so quickly. Therefore, step count which has readily been identified as an indicator of walking ability and reported as a parameter for enhancing long-term activity levels and subsequently returning to walking freely, may not be the best indicator. Meanwhile, studies reported that an ability to walk even a short distance outdoors can be meaningful for successful and independent living at home among the THR group as well as enhancing their physical function. On the other hand, despite commercial wearable activity monitors having been suggested as a possible motivator to enhance individuals’ compliance to self-care and increase the chance of long-term quality of life, there was no evidence which activity monitor is most suitable for this population. Therefore, an exhaustive screening of the most popular wearable activity monitor with the most suitable interface was carried out. The Fitbit Charge 4 (FC4) activity monitor was selected as the most appropriate wearable activity monitor. The findings prompted a mixed-method feasibility study to evaluate the feasibility of personalised outdoor walking which was referred to as a ‘purposeful walk’ intervention. The findings from this study suggested that the intervention was feasible and that it encouraged all participants to increase their daily activity. Outcome measures were also streamlined in order to inform a follow up study that aimed to evaluate the effectiveness of such an intervention. Designed as a randomised pilot trial, the final study aimed to determine the effect of an intervention where outdoor walking distance was used as a goal to increase daily activity of older adults, using a commercial activity monitor, at 3 to 6 months post THR. The final study results suggested that the participants in the intervention group had higher activity levels after THR, compared to those in the control group. The Cohen’s effect size was larger for the changes in the gait, HOOS, and PIADS data in the intervention group in contrast to the control group. However, further research with a larger sample size is suggested to provide tangible evidence on the significance of the effect of the purposeful walk in contrast to step count.