Chronic Adaptations to Spinal Flexion Exposure

Chronic Adaptations to Spinal Flexion Exposure in Crane Operators

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.

Study Overview

• Status: Completed
• Conditions: Occupational Exposure
• Intervention / Treatment: Other: Repeated trunk flexion

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 Type: Interventional
• Enrollment (Actual): 30
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Slovenia
  • Primorska
    • Izola, Primorska, Slovenia, 6310
      • University of Primorska, Faculty of Health Sciences

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 25 years to 65 years (Adult)
• Accepts Healthy Volunteers: Yes

Description

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 Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Crane operators; Individuals employed as crane operators in Port of Koper.	Other: Repeated trunk flexion; A 60-min intermittent trunk flexion protocol. Participants will sit on a standard height sit, with their knees bent at approximately 90° with their hands crossed on their chest. They will perform 40 sets of 60 s of maintaining a flexed position, interspersed with 30 s of rest. Participants will achieve the flexed position by tilting the pelvis posteriorly and leaning forward. During rest, participants will sit up straight without leaning on the support.
Active Comparator: Control subjects; Individuals who spend more than half of their occupation time standing.	Other: Repeated trunk flexion; A 60-min intermittent trunk flexion protocol. Participants will sit on a standard height sit, with their knees bent at approximately 90° with their hands crossed on their chest. They will perform 40 sets of 60 s of maintaining a flexed position, interspersed with 30 s of rest. Participants will achieve the flexed position by tilting the pelvis posteriorly and leaning forward. During rest, participants will sit up straight without leaning on the support.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in muscle stiffness	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.	90 minutes

Secondary Outcome Measures

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

Collaborators and Investigators

• Sponsor: University of Primorska
• Investigators: Principal Investigator: Matej Voglar, PhD, University of Primorska, Faculty of Health Sciences

Study record dates

Study Major Dates

• Study Start (Actual): August 5, 2023
• Primary Completion (Actual): October 30, 2023
• Study Completion (Actual): November 15, 2023

Study Registration Dates

• First Submitted: February 20, 2023
• First Submitted That Met QC Criteria: February 20, 2023
• First Posted (Actual): March 2, 2023

Study Record Updates

• Last Update Posted (Actual): March 28, 2024
• Last Update Submitted That Met QC Criteria: March 26, 2024
• Last Verified: October 1, 2023

More Information

Terms related to this study

• Other Study ID Numbers: SWE_Flexion2_Crane

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Coded individual data will be uploaded on public scientific data repository.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL

Drug and device information, study documents

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