Effects of a Wearable Postural Feedback Device on Scapular Muscle Endurance, Trunk Proprioception and Postural Awareness in Sedentary Office Workers

Effects of a Wearable Postural Feedback Device on Scapular Muscle Endurance, Trunk Proprioception and Postural Awareness in Sedentary Office Workers: Randomized Controlled Trial

This study aims to investigate the effects of a wearable postural feedback device on scapular muscle endurance, trunk proprioception, thoracic kyphosis angle, and postural awareness in sedentary office workers. A total of 70 sedentary office workers aged 25-45 years will be randomly allocated to either the wearable postural feedback device group or the control group using block randomization. Participants in the intervention group will use the wearable postural feedback device for 12 weeks (5 days per week, 60 minutes per day), while the control group will maintain their usual working routine without receiving any intervention. Outcome assessments will be performed at baseline, immediately after the 12-week intervention, and at the end of a 4-week follow-up period (Week 16).

The primary outcome measures are scapular muscle endurance, trunk proprioception, thoracic kyphosis angle, and postural awareness. The primary research question is whether the use of a wearable postural feedback device improves these outcomes in sedentary office workers compared with no intervention. It is hypothesized that participants using the wearable postural feedback device will demonstrate greater improvements in scapular muscle endurance, trunk proprioception, thoracic kyphosis angle, and postural awareness than those in the control group.

Study Overview

• Status: Active, not recruiting
• Conditions: Sedentary Behavior; Postural Disorders
• Intervention / Treatment: Device: Wearable Postural Feedback Device

Detailed Description

Sedentary behavior and prolonged office work have become increasingly common with the widespread use of computers and desk-based occupations. Prolonged sitting and sustained poor posture are associated with musculoskeletal disorders, particularly forward head posture, rounded shoulders, and increased thoracic kyphosis. These postural alterations may contribute to reduced scapular muscle endurance, impaired trunk proprioception, decreased postural awareness, and altered spinal alignment, ultimately affecting physical function and quality of life.

Wearable postural feedback devices have emerged as a promising strategy for promoting correct posture by providing real-time vibrotactile feedback whenever the user deviates from a predefined neutral posture. Previous studies have demonstrated that these devices may improve postural behavior and increase postural awareness. However, most published studies have been conducted in laboratory settings or have primarily focused on subjective outcomes and short-term postural changes. Evidence regarding their effects on objective neuromuscular outcomes, including scapular muscle endurance, trunk proprioception, and thoracic spinal alignment, in sedentary office workers remains limited.

This study is designed as a single-blind, randomized controlled trial to investigate the effects of a wearable postural feedback device on scapular muscle endurance, trunk proprioception, thoracic kyphosis angle, and postural awareness in sedentary office workers. 64 participants aged 25-45 years will be randomly assigned to either the intervention group or the control group using block randomization. Participants in the intervention group will use the wearable postural feedback device for 12 weeks (5 days per week, 60 minutes per day), while participants in the control group will continue their usual work routine without receiving any intervention.

Outcome measures will be assessed at baseline, immediately after the 12-week intervention, and following a 4-week follow-up period (Week 16). Scapular muscle endurance will be evaluated using the Scapular Muscle Endurance Test, trunk proprioception will be assessed using the Active Trunk Reposition Sense Test with the GYKO inertial sensor, thoracic kyphosis angle will be measured using the Commander® Echo Wireless Inclinometer device, and postural awareness will be assessed using the Postural Awareness Scale.

This study aims to provide high-quality evidence regarding the effectiveness of wearable postural feedback technology in improving neuromuscular function and spinal posture among sedentary office workers. The findings may contribute to the development of evidence-based workplace rehabilitation and ergonomic intervention strategies for the prevention and management of posture-related musculoskeletal disorders.

• Study Type: Interventional
• Enrollment (Estimated): 64
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Ankara, Turkey (Türkiye)
    • Faculty of Physiotherapy and Rehabilitation, University of Health Sciences Ankara

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

Aged between 25 and 45 years. Sedentary lifestyle (<600 MET-min/week) determined using the International Physical Activity Questionnaire-Short Form (IPAQ-SF).

Working in a desk-based occupation for at least 6 hours per day. Willing to use the wearable postural feedback device (intervention group). Able to provide written informed consent.

Exclusion Criteria:

History of scapular or spinal surgery or trauma. Presence of neurological or vestibular disorders. Spinal deformity. Dermatological conditions preventing the use of a wearable device. Chronic systemic diseases affecting posture or musculoskeletal function. Inability or unwillingness to provide written informed consent.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Wearable Postural Feedback Device Group; Device: Wearable Postural Feedback Device Participants will use a wearable postural feedback device for 12 weeks, 5 days per week, 60 minutes per day during working hours. During the first week, device use will be gradually increased (20, 30, 40, 50, and 60 minutes/day) to improve adherence, followed by 60 minutes/day for the remaining 11 weeks. The device provides real-time vibrotactile feedback when participants deviate from their calibrated neutral posture. Outcome measures, including scapular muscle endurance, trunk proprioception, thoracic kyphosis angle, and postural awareness, will be assessed at baseline, immediately after the 12-week intervention, and at the end of the 4-week follow-up period (Week 16).	Device: Wearable Postural Feedback Device; Participants assigned to the intervention group will use a wearable postural feedback device for 12 weeks, 5 days per week, 60 minutes per day during working hours. During the first week, device use will be gradually increased (20, 30, 40, 50, and 60 minutes/day) to facilitate adaptation, followed by 60 minutes/day for the remaining 11 weeks. The device is individually calibrated to each participant's neutral posture and provides real-time vibrotactile feedback whenever a deviation from the calibrated posture is detected, promoting immediate postural correction during daily work activities.
No Intervention: No Intervention: Control Group; Participants assigned to the control group will continue their usual work routine without receiving the wearable postural feedback device or any additional intervention. Outcome measures, including scapular muscle endurance, trunk proprioception, thoracic kyphosis angle, and postural awareness, will be assessed at the same time points as the intervention group (baseline, Week 12, and Week 16).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Scapular Muscle Endurance	Scapular muscle endurance will be assessed using the Scapular Muscle Endurance (SME) Test. Participants will stand with both shoulders and elbows positioned at 90° of flexion while maintaining the scapulae in a neutral position. A handheld dynamometer will be used to apply a constant force of 1 kg (10 N). Participants will maintain the test position as long as possible. The test will be terminated if the force cannot be maintained, the upper extremity position changes, the supporting bar falls, or the participant reports pain. Performance will be recorded in seconds, with longer durations indicating greater scapular muscle endurance.	Baseline, immediately after the 12-week intervention (Week 12), and at the end of the 4-week follow-up period (Week 16).
Trunk Proprioception	Trunk proprioception will be assessed using the Active Trunk Reposition Sense Test with the GYKO inertial sensor. The sensor will be positioned at the thoracolumbar region according to the standardized protocol. Participants, with their eyes closed, will actively reproduce a previously demonstrated trunk position. The absolute repositioning error will be recorded in degrees (°). Lower values indicate better trunk proprioception.	Baseline, immediately after the 12-week intervention (Week 12), and at the end of the 4-week follow-up period (Week 16).
Thoracic Kyphosis Angle	Thoracic kyphosis angle will be assessed using the Commander® Echo Wireless Inclinometer (JTECH Medical, USA). Measurements will be performed according to a standardized thoracic spine assessment protocol. Thoracic kyphosis angle will be recorded in degrees (°). Lower values indicate a reduction in thoracic kyphosis and improved thoracic spinal alignment.	Baseline, immediately after the 12-week intervention (Week 12), and at the end of the 4-week follow-up period (Week 16).
Postural Awareness	Postural awareness will be assessed using the Postural Awareness Scale (PAS). The PAS is an 11-item self-reported questionnaire with a total score ranging from 11 to 77. Higher scores indicate greater postural awareness	Baseline, immediately after the 12-week intervention (Week 12), and at the end of the 4-week follow-up period (Week 16).

Collaborators and Investigators

• Sponsor: Saglik Bilimleri Universitesi

Study record dates

Study Major Dates

• Study Start (Actual): February 20, 2026
• Primary Completion (Estimated): August 20, 2026
• Study Completion (Estimated): September 5, 2026

Study Registration Dates

• First Submitted: August 6, 2026
• First Submitted That Met QC Criteria: August 6, 2026
• First Posted (Actual): August 11, 2026

Study Record Updates

• Last Update Posted (Actual): August 11, 2026
• Last Update Submitted That Met QC Criteria: August 6, 2026
• Last Verified: August 1, 2026

More Information

Terms related to this study

• Keywords: Office Workers; Thoracic Kyphosis; Scapular Muscle Endurance; Postural Awareness; Wearable Postural Feedback Device; Trunk Proprioception
• Additional Relevant MeSH Terms: Behavior; Sedentary Behavior
• Other Study ID Numbers: 2025-301

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: There is no plan to share individual participant data (IPD) at this time.

Drug and device information, study documents

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