Effects of Proprioceptive and Craniocervical Flexor Training on Static Balance in University Student Smartphone Users with Balance Impairment: A Randomized Controlled Trial

PURPOSE: University student smartphone users adopt flexed neck postures during smartphone use, creating an increased compressive load on their neck structures. This study was conducted to compare the effects of proprioceptive and craniocervical flexor training with a control group on static balance in a group of university student smartphone users with balance impairment. METHODS: A double-blinded, randomized controlled trial was conducted involving 42 university students (19.67±1.68 years old) with balance impairment. Participants were randomized into a proprioceptive training (ProT) group (n=14), a craniocervical flexor training (CCFT) group (n=14), and a control group (CG; n=14) for a 6-week intervention. The balance error scoring system (BESS), cervical joint position sense (CJPS), craniocervical flexion (CCF) test, and visual analog scale (VAS) for neck pain were evaluated using univariate analysis of covariance (ANCOVA). RESULTS: After 6 weeks of intervention, the ProT group showed significantly greater improvement of CJPS than the CG (p=0.000) and the CCFT group significantly improved of CCF test than CG (p=0.002). Findings, at 4 weeks after intervention, were (i) the ProT group had significantly more improvement in BESS than the CCFT group (p=0.014) and CG (p=0.003), (ii) the ProT group had significantly more improvement of CJPS than the CG (right and left rotate) (p=0.001, p=0.016, respectively) and CCFT group (right rotate) (p=0.004), (iii) the CCFT group had significantly more improvement of craniocervical flexor strength than CG (p=0.004), and (iv) the ProT group and CCFT group had significantly more decreased pain than CG (p=0.015, p=0.033, respectively). No adverse effects occurred during or after training in any group. CONCLUSION: ProT is important for regaining static balance and CJPS, while CCFT improved craniocervical flexor strength. Moreover, both ProT and CCFT can reduce neck pain. We recommend performing ProT to improve static balance, CJPS and to reduce neck pain in smartphone users with static balance impairment. CLINICAL TRAIL REGISTRATION NUMBER: TCTR20190909003.