Background Low back pain patients suffer from balance disturbance. Balance allows a person to interact with the surrounding environment and to do his daily activities. As recent technology has facilitated patient monitoring and enhanced our ability to monitor patients remotely, smartphone apps have been developed to achieve this goal. There are various balance assessment instruments used nowadays. It may be subjective or objective assessments. This study was applied to verify if the measurements of balance Y-MED smartphone applications are valid and reliable compared to the HUMAC balance board in order to offer easy, fast, cost-effective, and time-effective valid and reliable balance assessment that can be used in a clinical setting. Methods Fifty-four patients (12 males and 42 females) with chronic mechanical low back pain for more than 3 months was volunteered to participate in the current study with an age range of 25–60 years and BMI range of 18–34 kg/m2. Compared with the HUMAC balance board, the validity of the balance Y-MED smartphone application is evaluated, and the test-retest reliability of the balance Y-MED smartphone application is obtained by the same examiner 3 times. Results For concurrent validity, the correlations between balance measurements by Y-MED smartphone application and HUMAC balance board were not significant in both eyes open (r = − 0.12, p = 0.38) and eyes closed (r = 0.26, p = 0.054). The smartphone application showed poor test-retest reliability measurement of balance with eyes open; (ICC was 0.279, with 95% CI − 0.117–0.554) and with eyes closed (ICC was − 0.159, with 95% CI − 0.814–0.287). Conclusions According to the evaluation scheme selected in this study, the researchers were unable to confirm the validity of the balance Y-MED smartphone application in the balance assessment of patients with mechanical chronic low back pain. More than that, the balance Y-MED smartphone application has been shown poor score reliability. This makes it inaccurate for use in assessment balance.

Objective: To compare the effectiveness of the slider, tensioner neurodynamic mobilization techniques and stretching exercises on pain, ROM, and functional disability in patients with chronic discogenic sciatica.Design: A pre-test post-test three-armed comparative study designSetting: Outpatient clinics, faculty of physical therapy, Kafrelsheikh UniversityParticipants: 36 patients with unilateral chronic discogenic sciatica were randomly allocated into three equal groups: Group (A) slider neurodynamic mobilization Group (B) tensioner neurodynamic mobilizationGroup (C) stretching exercises of back extensors, hamstrings, and gastrocnemius musclesTreatment was given three sessions per week for two weeks.Outcome measures: all patients were examined by Visual Analogue scale (VAS) for pain intensity, Modified-Modified Schober test (MMST) for lumbar flexion ROM, Goniometer for hip flexion and knee extension ROM, and Oswestry Disability Index (ODI) for functional assessment. Results: there were no statistically significant differences between groups at baseline (p<0.05). There were statistically significant differences in the slider and tensioner groups compared to the stretching group for all variables. Furthermore, statistically significant differences were found in the slider technique as compared to the tensioner technique regarding ROM of lumbar flexion (p = 0.03), hip flexion (p = 0.004), and knee extension (p = 0.005). Conclusion: Slider and tensioner neurodynamic mobilization techniques are more effective than stretching exercises in terms of reducing pain, increasing ROM, and improving function. Slider technique is more effective in ROM improvement.