Detecting Shoulder Range of Motion Changes Following Breast Reconstruction Using a Novel Smartphone App

Breast reconstruction following mastectomy can restore body image and confer psychosocial benefits but can also result in lasting functional deficits in shoulder range of motion (SROM). Early identification of these deficits is crucial for guiding rehabilitation and improving long-term outcomes, but traditional assessment tools are often costly or impractical for routine clinical use. This longitudinal observational study examined the feasibility and validity of an app-based shoulder mobility assessment (MotionDetect) for detecting post-operative changes in SROM compared to traditional inertial measurement units (IMU)-derived measurements among breast cancer patients undergoing reconstruction. Twenty female participants undergoing bilateral mastectomy with immediate breast reconstruction performed at-home SROM assessments before surgery and once at 6-12 weeks post-operatively using both wearable IMUs and the MotionDetect iPhone application. Maximum shoulder abduction and flexion angles were recorded at each time point. Structured interviews gathered patient feedback on app usability. Statistical analyses assessed changes over time, correlation between measurement modalities, and repeatability. Significant reductions in abduction ROM after surgery were observed using both IMU and iPhone app assessments (both p < 0.031), with strong correlations between modalities (r > 0.80). Both approaches demonstrated excellent intra-class coefficients (ICC) repeatability (ICC > 0.89). Patient interviews indicated high feasibility and acceptability, with minor logistical challenges. Overall, this study indicates MotionDetect is a valid and feasible tool for remotely identifying post-operative SROM limitations in breast cancer patients, enabling early referral for rehabilitation to improve long-term quality of life.