Reliability of Ultrasonography to Assess Spinal Compression During Heavy Load Carriage.

Area of Science:

• Biomechanics
• Musculoskeletal imaging
• Occupational health

Background:

• Back pain and spinal injuries are major causes of early retirement in physically demanding jobs.
• Practical spinal assessment methods are crucial for evaluating interventions that reduce spinal loading and injury risk.
• While ultrasonography is used for disc height, its reliability for measuring inter-transverse process distances under load is unproven.

Purpose of the Study:

• To establish the reliability of ultrasonography for measuring lumbar inter-transverse process distances under various loading conditions.
• To determine if loaded standing affects lumbar spine geometry as measured by ultrasonography.

Main Methods:

• Eleven healthy adults underwent ultrasonography to measure lumbar inter-transverse process distances (L1-L5) under four conditions: unloaded standing, unloaded standing for 15 minutes, loaded standing (25kg vest) for 15 minutes, and loaded standing for 30 minutes.
• Measurements were repeated over 1-7 days to assess inter-rater, within-visit, and between-visit reliability using intraclass correlation coefficients (ICCs) and coefficients of variation (CVs).
• A one-way ANOVA analyzed the effect of loading conditions on inter-transverse process distances.

Main Results:

• Ultrasonography demonstrated good to excellent reliability for inter-rater, within-visit, and between-visit measurements (ICCs: 0.81-0.99; CVs: 5.24%-13.0%).
• Loaded standing for 15 and 30 minutes significantly reduced inter-transverse process distances at L2/3, L3/4, and total lumbar distance (p < 0.05).

Conclusions:

• Ultrasonography is a reliable and cost-effective tool for quantifying lumbar spine geometric changes during loaded standing.
• This technique shows potential for assessing spinal compression in response to mechanical load in occupational and clinical environments.