Chronic Adaptations to Spinal Flexion Exposure

Not Applicable

Completed

• Conditions: Occupational Exposure
• Interventions: Other: Repeated trunk flexion

• Registration Number: NCT05752006
• Lead Sponsor: University of Primorska

Brief Summary

An experimental study, which will aim to compare changes of trunk mechanical properties and neuromuscular control following spinal flexion exposure in crane operators and control subjects.

Detailed Description

Our experimental study will include 40 participants, more specifically 15 crane operators and 15 control subjects. All participants will complete a 60-min protocol of intermittent trunk flexion. Measurements of trunk mechanical properties and neuromuscular control will be performed prior to and following the 60-min protocol.

Study Timeline

• Study First Submitted: 2023-02-20
• Study First Submitted QC: 2023-02-20
• Study First Posted: 2023-03-02
• Study Start: 2023-08-05
• Status Verified: 2023-10
• Primary Completion: 2023-10-30
• Study Completion: 2023-11-15
• Last Update Submitted: 2024-03-26
• Last Update Posted: 2024-03-28

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Male
• Target Recruitment: 30

Inclusion Criteria

• Crane operators: employed as crane operators for more than 3 years
• Occupational workers with a predominantly non static job (e.g. combination of sitting and standing)

Exclusion Criteria

• History of chronic low back pain
• Episode of acute low back pain
• Hip injury in the past six months
• Previous spine, pelvis or hip surgery
• Hypermobility, diagnosed with the Beighton score
• High intensity resistance training (> 75 % of 1 repetition maximum) more than two times a week
• Control group: sporting or recreational activities, that include repetitive spinal flexion or maintenance of a flexed posture (for example cycling or rowing).

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Control subjects	Repeated trunk flexion	Individuals who spend more than half of their occupation time standing.
Crane operators	Repeated trunk flexion	Individuals employed as crane operators in Port of Koper.

Primary Outcome Measures

Name	Time	Method
Change in muscle stiffness	90 minutes	Muscle stiffness will be measured using ultrasound-based shear wave elastography during prone lying and forward stooping. Erector spinae and multifidus muscle stiffness will be expressed as the shear modulus value in kilopascals.

Secondary Outcome Measures

Name	Time	Method
Change in trunk extension maximal strength	90 minutes	Isometric trunk extension peak torque will be assessed on a trunk dynamometer.
Change in range of motion	90 minutes	Trunk flexion range of motion will be evaluated using Spinal Mouse in maximal trunk flexion while standing.
Change in muscle activity	90 minutes	Muscle activity will be measured using electromyography during standing, a forward stoop hold and during maximal trunk flexion.
Change in length of the spine	90 minutes	The length of spine will be measured on a custom-developed stadiometer, with the participants in a seated position.
Change in lumbar lordosis angle	90 minutes	The lumbar lordosis angle will be evaluated using Spinal Mouse during upright standing.

Trial Locations

Locations (1)

University of Primorska, Faculty of Health Sciences; 🇸🇮 Izola, Primorska, Slovenia