Two methods for determining trunk extensor endurance. A comparative study.

Area of Science:

• Biomechanics
• Exercise Physiology
• Occupational Health

Background:

• Epidemiological studies indicate a correlation between reduced trunk extensor muscle endurance and the prevalence of low back pain.
• Trunk extensor muscles play a crucial role in spinal stability and posture, making their endurance capacity a significant factor in musculoskeletal health.

Purpose of the Study:

• To compare the efficacy and practicality of two distinct methods for assessing trunk extensor endurance.
• To identify the most suitable method for evaluating trunk extensor endurance, particularly for ergonomic applications.

Main Methods:

• Method I involved subjects maintaining a prone position with their iliac crest at the couch edge, measuring the time to hold the upper body horizontal (max. 240s).
• Method II required standing subjects to exert a 60% maximal voluntary contraction (MVC) isometric pull on a strain gauge, measuring time to exhaustion.
• Both methods were tested on healthy adult populations, including postmenopausal women, men, and young male students.

Main Results:

• Method II demonstrated superior practicality and ease of implementation compared to Method I.
• Method II yielded reliable, statistically viable results that were not confounded by anthropometric variations.
• The study found Method II to be more suitable for ergonomic assessments and general clinical use.

Conclusions:

• Method II is the preferred method for assessing trunk extensor endurance due to its practicality, reliability, and independence from anthropometric factors.
• The findings suggest that Method II can be effectively utilized in ergonomic evaluations and clinical settings to assess risk factors for low back pain.
• Further research could explore the application of Method II in diverse populations and its predictive value for low back pain incidence.