This study aimed to offer a systematic review of apps for smartphones validated for body position measurement pertinent to physical medicine and rehabilitation. A literature search was conducted on relevant articles indexed by PubMed before April 15, 2014. We selected only research papers published in English. Papers related to apps not relevant to physical medicine and rehabilitation or unavailable on the market were excluded. Two independent reviewers screened the articles (full text). The researchers analyzed the following information for all apps: target population, object of the measure, body segment evaluated, modality of use, operating platform system, and validation results. The literature search yielded 27 papers, 17 of which met the inclusion criteria for our review. The included papers featured 12 apps validated for angle measurement: 7 were validated exclusively for upper and lower limb joint angles, 4 for spine measurements, ie, cervical or lumbar range of motion and curvature, Cobb angle on radiographs, and the scoliotic distortions of the torso, and 1 for both upper limb and spine measurement. The 12 apps used the inbuilt smartphone magnetometer, accelerometer, or camera to produce angle measurements. Most of the studies assessed the smartphone-apps’ reliability (calculating the intraclass correlation coefficients) and validity (showing the limits of agreement).
This review highlights the validated goniometer apps that physiatrists and other health care practitioners can employ with confidence in research and clinical practice. 12 apps corresponding to these criteria were found, but there is a need for validation studies on available or new apps focused on goniometric measurement in dynamic conditions; during gait or when performing therapeutic exercises, for instance.