Smartphone Versus Back Range of Motion: Validity and Reliability in Lumbar Range of Motion Assessment

Clinimetric Properties of Smartphone Application as a Suitable Alternative to Back Range of Motion Device in Assessing the Back Range of Motion

This study aims to investigate the clinimetric properties of the iPhone Level application as a suitable alternative to the Back Range of Motion device in assessing lumbar range of motion, including flexion, extension, and lateral flexion.

Study Overview

• Status: Completed
• Conditions: Lumbar Pain Syndrome
• Intervention / Treatment: Device: easement tool 1 - BROM device; Device: Measurement tool 2 - iPhone level application

Detailed Description

Range of motion measurement is vital in physiotherapy for assessing deficits, establishing diagnoses, and planning interventions. Digital advancements now allow Range of motion assessment through devices and applications, such as the back range of motion, which is a gold standard for measuring lateral flexion due to its validity. Furthermore, studies indicate that the iPhone Level app effectively measures Range of motion in various joints, demonstrating good reliability and validity. This study aims to evaluate the reliability and concurrent validity of the iPhone Level application specifically for measuring lumbar flexion, extension, and side bending Range of motion.

• Study Type: Observational
• Enrollment (Actual): 120

Contacts and Locations

Study Locations

• Egypt
  • Giza, Egypt, 12613
    • Cairo University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Probability Sample

Study Population

Healthy University Students with normal BMI Healthy Male university students

Description

Inclusion Criteria:

1. Age 18-25 years old
2. Healthy Male university students
3. All participants have normal BMI

Exclusion Criteria:

1. Recent back, pelvic, or abdominal surgeries, traumatic injury to the back .
2. Lower limb deformities, e.g., leg length discrepancy.
3. Adolescent idiopathic scoliosis
4. Any overweight or obese participants

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
assessment of flexion and extension range of motion using inclinometer	During lumbar flexion and extension measurements using the Back Range of Motion (BROM) device, patients stand upright with extended knees and feet approximately 17 centimeters apart. For flexion, they bend forward to touch the floor, while for extension, they bend backward with crossed arms. An inclinometer is secured over the sacrum, and its position is centered to record readings in degrees. An L-shaped slide arm measures the distance between the T12 and S1 spinous processes. The device isolates lumbar motion from pelvic motion, and the stationary flexion/extension unit minimizes errors, enhancing measurement accuracy.	at baseline
assessment of lateral flexion range of motion using inclinometer	For measuring lumbar lateral flexion, the subject's sides are parallel to a wall to prevent compensatory forward trunk flexion. An inclinometer is secured over the sacral region at S1, using a belt for stability. A gravity goniometer is placed on the upper thoracic region to capture trunk angular displacement during side bending. The inclinometer is levelled and zeroed before movement, allowing for precise measurement of lateral lumbar movement while reducing thoracic and pelvic compensations. Accurate placement of the device is essential for reliable results. The subject slides their hand down the thigh, keeping weight on the opposite leg to ensure the measurement reflects true lateral flexion.measures]	at baseline

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
assessment of flexion and extension range of motion using smartphone	To measure lumbar flexion range of motion (ROM) using the iPhone Level app, participants are positioned standing upright with feet shoulder-width apart. T12-L1 and S1-S2 spinal levels are identified through palpation and marked on the skin. The iPhone is placed at these levels to record angles during maximum lumbar flexion. Total lumbar flexion ROM is calculated by subtracting the angle at S1-S2 from T12-L1. Subjects perform maximum lumbar flexion and extension with straight knees, and measurements are taken across three trials.	at baseline
assessment of lateral flexion range of motion using smartphone	During the measurement of lumbar side bending using the iPhone Level application, the subject will stand in a neutral upright position with feet shoulder-width apart and hands placed on the hips to prevent arm movement from influencing the measurement. The spinous processes of T12 and S2 are identified and marked on the skin. The iPhone is first placed and zeroed at the T12 level, and the subject is instructed to bend sideways (toward one side) as far as possible without lifting the heels or rotating the trunk. The device remains aligned at T12 to capture the angular displacement. The same procedure is repeated with the device positioned at S2, and the final lumbar side bending range of motion is calculated by subtracting the angle at S2 (pelvic movement) from that at T12 (trunk movement). This method isolates lumbar lateral flexion and has shown good reliability and validity in clinical settings	at baseline

Collaborators and Investigators

• Sponsor: Cairo University
• Collaborators: October University for Modern Sciences and Arts

Study record dates

Study Major Dates

• Study Start (Actual): December 1, 2025
• Primary Completion (Actual): March 1, 2026
• Study Completion (Actual): May 12, 2026

Study Registration Dates

• First Submitted: June 14, 2026
• First Submitted That Met QC Criteria: June 29, 2026
• First Posted (Actual): July 2, 2026

Study Record Updates

• Last Update Posted (Actual): July 2, 2026
• Last Update Submitted That Met QC Criteria: June 29, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Mental Disorders; Somatoform Disorders
• Other Study ID Numbers: P.T.REC/012/006199

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No