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Sports injury prevention in your pocket?! Prevention apps assessed against the available scientific evidence: a review
  1. Daan M van Mechelen,
  2. Willem van Mechelen,
  3. Evert A L M Verhagen
  1. Department of Public and Occupational Health, EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, The Netherlands
  1. Correspondence to Dr Evert Verhagen, Department of Public and Occupational Health, EMGO Institute for Health and Care Research, VU University Medical Center, Van der Boechorststraat 7  Amsterdam 1081 BT, The Netherlands; e.verhagen{at}vumc.nl

Abstract

Background High costs and personal burden follow sports and physical activity-related injuries (SPRI). The last decades’ knowledge on how to prevent SPRIs has grown. Past years’ eHealth is emerging and mobile applications (apps) helping to prevent SPRIs are appearing.

Aim To review the content of iPhone and iPad apps containing a claim to prevent sports and physical activity-related injuries and to appraise this claim against best available scientific evidence.

Methods The US iTunes App Store was searched using the keywords ‘injury’, ‘prevention’ and ‘rehabilitation’. Apps within the categories ‘health & fitness’, ‘sports’ and ‘medical’ containing a preventive claim in the app name, description or screenshots were included. Claims were extracted and a search for best available evidence was performed.

Results Eighteen apps met our inclusion criteria. Four of these apps contained claims for which evidence was available: three apps covered ankle sprains and provided information on taping or neuromuscular training. Of these three apps, one app also provided information on prevention of dental injury with mouth guards. One app provided a routine to prevent anterior cruciate ligament injury. The main focus of the five apps was running injury prevention; for their content evidence of absence of efficacy was found. For nine apps no evidence supporting their content was found.

Conclusions f 18 apps included, only four contained claims that could be supported by available literature and five apps contained false claims. This lack of scientifically sound apps provides an opportunity for caretakers to develop apps with evidence-based claims to prevent SPRIs.

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Introduction

Regular participation in physical activity and sports increases the individual's exposure to injury. This threatens ongoing, healthy physical activity behaviour. Moreover, there are substantial direct and indirect costs of sports and physical activity-related injuries (SPRIs), also making these injuries a societal problem. As such, safety is an essential corollary of our global effort to promote sports and physical activity. Over the past two decades the knowledge about the prevention and treatment of various SPRIs within different sports has grown exponentially.1 Fortunately, based on the current available evidence it is reasonable to state that we are able to significantly reduce the risk of SPRIs for most participants in a wide array of sports and physical activities.

However, wide-scale implementation of (cost-)effective intervention measures and treatment protocols under real life conditions proves to be an ongoing challenge.2–4 In an attempt to bridge this implementation gap (social) media is believed to be a way forward, providing an attractive interactive and mobile medium for information transfer. With contemporary technology, online platforms are able to provide tailored information with ease of self-monitoring.5–7 Added to this, mobile platforms have the additional appeal of portability and all-round availability, making such mobile solutions particularly interesting for the dissemination of information on prevention and treatment of SPRIs which are generally encountered in a sports setting and which demand instant information.

Access to mobile platforms is no limiting factor, as it has been estimated that about 80% of the world's population now has a mobile phone.8 This equals over five billion mobile phones worldwide, of which about one billion are smartphones. Nearly 90% of all smartphone users use their phone throughout the day.8 Although the Android platform has the largest market share, iOS users download the highest number of different apps per month. Likely, this is due to the abundance of controlled apps that are available through the App Store which over 700 000 readily available apps.9

Although formal implementation of knowledge on SPRI prevention and treatment through apps is still lacking, several (semi) commercial activities have found their way to the App Store. A similar trend was found previously for weight-loss initiatives, for which commercially available weight-loss programmes were transferred to mobile platforms.7 However, a review of these apps found that they only, in part, adhere to evidence-informed practices.7 With regards to apps that advocate to inform on the prevention and treatment of SPRIs little is known about the types of apps that are publicly available, the features they contain and the degree to which apps incorporate evidence on efficacious preventive measures or treatment protocols. Therefore, the aim of this review was to summarise the content of available SPRI prevention apps and to evaluate their preventive claims against the available evidence.

Methods

Selecting apps for review

The US App Store was searched using iTunes 10.7 (31 October 2012). The categories ‘health & fitness’, ‘sports’ and ‘ medical’ were searched for apps on injury prevention and rehabilitation, using the keywords ‘injury’, ‘prevention’ and ‘rehabilitation’. Searches were conducted for both iPhone and iPad apps. Apps that included a basic (free) and paid version, or apps that included an iPhone or iPad version, were considered as equal apps when the preventive claim was equal. The iTunes description page for each app was used to select potentially relevant apps. An iTunes description page consists of an overall description of the app, a list of included features, user ratings, customer reviews and one to four screenshots of what the app looks like when downloaded. An app was deemed of potential relevance when it was, according to the iTunes description page, SPRI related and when a preventive claim was made in the name, description or screenshot. This methodology is similar to a previous review on weight-loss apps.7 Apps that allowed users only to keep a sports diary and apps that acted as a reference (eg, an anatomy atlas and physical therapy exercises) were excluded. Some apps met more than one exclusion criterion.

Assessing available best evidence

App content was reviewed by the first author and preventive claims were summarised. For each preventive claim Cochrane reviews were searched first to provide information on the best available evidence. If no recent Cochrane reviews were available, other systematic reviews were sought through PubMed, followed by randomised controlled trials or position statements.

Ratings and price

Prices and average user ratings of apps ascertained were collected through their respective iTunes description page. Apps that did not have a user rating were coded as ‘not rated.’ Among those rated, the ratings were in increments of 0.5 and ranged from 1 (lowest) star to 5 (highest) stars, reflecting the extent to which users liked the app. Appsfire scores were also noted.10 The Appsfire score is based on, among other features, the rating and ranking performance over time, developer's track record and online reviews for that app. The Appsfire score also identifies apps engaging in suspicious rating/review behaviour for current and publisher's previous apps in the App Store. Appsfire score increases by 1, ranging from one till 100, where 25 is categorised as ‘Crappy’, 55 as ‘Hmmm’, 65 as ‘Promising’, 75 as ‘Good Stuff’, 85 as ‘Super’ and 95 as ‘Red Hot’. Apps that did not have an Appsfire score were coded as ‘no score’. Average iTunes user rating or Appsfire score was calculated when an app was available for both platforms, iPhone and iPad.

Results

The initial search yielded 482 potential apps meeting the keywords, out of a total of 64 873 apps available within the searched categories (figure 1). After exclusion of non-SPRI apps (n=340), reference apps (n=89), activity diaries (n=14) and duplicates (n=115) a total of 18 apps remained available for further review. Costumers rated eight apps, with an average rating of 4.3. The average Appsfire score of all apps was 59 (table 1). Average price for all apps was US$2.49.

Table 1

Characteristics of apps meeting the inclusion criteria

Figure 1

Flowchart of iTunes store search leading to the identification of 18 apps eligible for further analysis.

Evidence-based apps

Of the 18 apps included, four apps contained claims for which evidence was found (table 2).

Table 2

Apps reviewed for sport and injury, with preventive statement extracted and available evidence

Two of those apps dealt with ankle injury prevention, suggesting to apply tape or to perform neuromuscular training to prevent ankle sprains. For this claim evidence is available.11 A third ankle app advocating the use of tape, that is, the ‘Elastoplast’-app produced by Beiersdorf Australia, contained two additional claims. This app also informed people to use properly fitted mouth guards to prevent dental injury. This evidence-based advice is substantiated by a report of the council of scientific affairs of the American Dental Association.12 ‘Elastoplast’ also advocated to apply a knee tape to prevent medial collateral ligament sprain, a claim for which no evidence is available.

A fourth app that is, the ‘iPrevent ACL injuries’-app, consisted of a narrated video only. In this video it was stated that a combination of exercises will prevent anterior cruciate ligament (ACL) sprains. The video routine shown, included a warm-up and cool-down, and stretching, strengthening, plyometrics and agility exercises. The app did not target a specific age or gender. A study by Gilchrist et al13 has shown that a 20 min warming-up intervention reduced the risk of ACL injuries in female college soccer players. A meta-analysis by Yoo et al14 showed that a neuromuscular training routine, with an emphasis on plyometrics and strengthening exercises, was effective in preventing ACL injuries in young female athletes.

Average price for the evidence-based apps was US$1.67 and average Appsfire score was 52. Only two apps had a customer rating, that is, ‘Elastoplast’ 3 and ‘Medical iRehab Anklesprain’ 4.5. The other two apps were not rated.

Non-evidence-based apps: running apps

Five apps contained strategies to prevent running injuries. These strategies included the use of proper shoes, warming-up and stretching before starting a workout and the implementation of strengthening routines into a workout, as well as a cooling-down. According to a systematic review by Yeung et al15 there is evidence that none of these strategies reduce injury (ie, evidence of absence). Difference between the free and the paid version of the app ‘RunInjuryFree’ was the availability of training schedules for which also no evidence was found related to the prevention of injuries. ‘Kangarun’ claimed that excessive vertical bouncing while running may increase the risk of injury. However, no evidence was found to back up this statement.

Non-evidence-based apps: other apps

For nine apps addressing a variety of preventive claims neither supporting evidence nor evidence of absence was found (table 2). Three of these apps did not state a preventive measure within the app. Three apps concerned the prevention of different shoulder injuries, one app on the prevention of plantar fasciitis and one app advocated myofascial relief through foam rolling to prevent not further specified injuries. For none of these apps supporting evidence was found. One app referred to delayed onset of muscle soreness (DOMS). This app offered a strategy on how to prevent DOMS in general, without mentioning a specific sport. Their preventive strategy was based on a limitation of a10% increase in exercise intensity. For the preventive claim in this app no supporting evidence was available. For running, the prevention of DOMS has been subject of scientific evaluation,16–18 but it is not clear whether the application of the 10% rule prevents running injuries.19 For other sports the 10% rule has not been evaluated.

Discussion

Out of 64 873 apps in the categories we searched, 482 apps were found with the keywords used. Eighteen apps met our inclusion criteria and for only four apps with supporting evidence were found in the scientific literature.

Although we performed our search for apps as systematic as possible, we must assume that our search did not include all apps of potential interest. The iTunes search engine is not built for a rigorous scientific search, but for user comfort. It is unknown how the iTunes search engine fetches apps and arranges results after a search. Furthermore, relevant apps might not have been included because they may not have been tagged with the keywords we used for our search. App developers are required to provide a limited number of self-selected keywords when submitting an app to the iTunes Store. Apps of potential interest may have been tagged with other keywords.

Out of 18 included apps, we found four apps with a certain level of evidence-based information. The use of this evidence was different for these apps. The neuromuscular balance intervention presented in the app ‘Ankle’ was based on the outcome of a cost-effective randomised controlled trial. This app was developed specifically to implement this evidence-based exercise programme. The app ‘Ankle’ clearly stated its scientific source. ‘Elastoplast’ was produced as a commercial app, with the goal to familiarise the public with common applications of tape and—arguably—by coincidence contained some evidence-based statements. ‘Elastoplast’ also holds statements, for which no evidence was found and no reference to literature was provided within the app. The ‘iPrevent ACL injuries’ home screen contained the sentence ‘ACL injury prevention techniques’ and only contained the option to play a narrated video. This 18 min video showed a warming-up, stretching, strengthening, plyometrics, agility and cool-down routine. Although the app clearly stated a preventive measure in the app name, it was difficult to find preventive advice within the app, since there was only the option to play the video. When used, the narrated referral to a preventive measure can be overlooked easily. The medical iRehab series are apps with the same functional layout for different injuries, not all covering SPRIs. All iRehab apps contained a section on ‘prevention strategies’. Within this sections 3–4 omnipresent, but mostly not evidence-based, preventive tips were provided. It seems as if some of the preventive claims stated in the medical iRehab series were evidence based by coincidence.

While our main goal was to review the app content, we think that user experience is equally important for an app to reach its goal. In our opinion user experience consists of, but is not limited to, multiple factors including price, presence of bugs, the need to retrieve videos or information online, the presence of advertorials and substantiating to the statement made in the app name, description or content. We included paid apps that gave proven untrue information, crashed when playing a video and contained advertorials. We also included apps, which announced a preventive measure before downloading, but when app content was analysed the preventive measure could not be retrieved. This reduces the user satisfaction and might decrease the app use. We think it is not only important to provide evidence-based content, but also a user-friendly app. An app stating measures to prevent SPRIs should contain evidence-based content and should have a good form and function.

The app ‘How to prevent DOMS’ contained a preventive claim and directed the user to literature that should support their claim. However, when the cited literature was reviewed, the claim could not be extracted. In our opinion, this app tried to create a false sense of security, by citing literature that can be difficult to understand by the untrained reader.

The iTunes App Store provides its costumers the possibility to rate the apps through the ‘costumer rating’ system. We found that only nine of 18 apps had a costumer rating. With half the apps not rated we could not use this rating to compare the apps. Also the rating did not reflect the scientific base for the app content, since average user App Store rating for all apps was higher than for evidence-based apps. Also, user App Store ratings are gameable by marketers, and are therefore less reliable. We tried to overcome this by also including the Appsfire score. This score is not directly based on user critics, but claims to implement more objective data. Although the build-up of the Appsfire score is not completely transparent and its intentions are commercial, it provided an opportunity to compare all apps on an equal basis. Amplitude of the Appsfire score did not reflect the availability evidence and, thus, the content quality of reviewed apps. From this we conclude that there is a discrepancy between user experience and quality of content. Here we have a lot of ground to cover by generating apps that include high-quality content in a useable and appealing package. Simply providing evidence in an app is apparently insufficient to grasp the full potential of implementation of evidence in this way.

The apps containing evidence-based advices were, on average, lower priced and had a lower user rating. It seems that developers produce apps, which despite the lack of supporting evidence, are still downloaded by costumers. This might be because they are found easier and/or because commercial app developers understand the iTunes search engine better than scientists. Most developers seem to be driven more by a commercial than a scientific goal. This commercial goal can be achieved through developing an app that has to be paid for by the costumer. Another way to gain profit from an app is by propagating certain products. For instance, ‘Elastoplast’ was produced by ‘Beiersdorf’, which is a worldwide producer of medical dressings.

While conducting the search for apps in the iTunes store, we found apps that did not strictly meet our inclusion criteria, but did give the impression that they will help the costumer to prevent SPRIs. An example was an app that stated to contain content which a novice barefoot runner should read before commencing. When the content was reviewed no SPRI preventive tips were available.

Also, some apps that appeared to help prevent SPRIs, did not cover a SPRI. For instance, one app covered a golfer’s elbow and another app covered a tennis elbow. People playing golf or tennis are not more likely to develop a golfer's or tennis’ elbow than the normal population. Development of a golfer’s and tennis elbow is associated with movements of the elbow that incorporate force, repetition and vibration,20 and are common also among working age adults.21

The key strength of this study is that it is the first study to review apps claiming to contain content to prevent SPRIs. Mobile app use has increased from 43 min daily in June 2009 to 94 min daily in December 2011.22 Therefore, it is important that this review was done rigorously, so that a foundation can be made for the implementation of strategies to prevent SPRIs through mobile applications.

A limitation of the study is that the App Store search engine is not made for a rigorous scientific search as needed for this review. After each search query each app had to be checked for category since it is not possible to arrange search results by category. Therefore, it is likely that we did not include all the apps that state preventive measures. Another limitation is the absence of evidence for some preventive claims. It is possible that the preventive claims and accompanying sports injuries have not been scientifically evaluated and therefore there is absence of evidence.

Conclusion

The aim of this review was to summarise the content of available SPRI prevention apps and to evaluate their preventive claim against the available evidence. Out of 64 873 apps within the app categories of interest only 18 addressed the prevention of SPRI. Our main finding is that only four out of 18 apps contained evidence-based statements. These apps provided information about the prevention of ankle sprains, dental injury and ACL injury. Overall it can be concluded that there is a dearth of evidence-based apps on the prevention of SPRI. In addition, there is a need for a recognised independent quality ‘label’ to rate apps based upon content.

What are the new findings?

  • Numerous (n=64 873) mobile apps for iPhone or iPad within the categories ‘health and fitness’, ‘sports’ and ‘medical’ are available.

  • Only a fraction of those (=18) relate to the prevention of SPRIs.

  • Four apps contain an evidence-based advice.

  • Five apps, all referring to the prevention of running injuries, contain injury prevention advices of which it is known that these advices do not reduce injury risk.

  • Nine apps address a variety of preventive claims, for which neither supporting evidence nor evidence of absence was found.

View Abstract

Footnotes

  • Contributors DMvM has performed app and literature search and has written the draft of the paper. WvM and EALMV have supervised the review and have provided input to the draft paper. All authors have approved the final manuscript.

  • Competing interests None.

  • Provenance and peer review Not commissioned; internally peer reviewed.

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