Related Experiment Video
Updated: Feb 8, 2026

Author Spotlight: Enhancing Small Animal Bone Compression Testing for Research
Published on: December 1, 2023
Effects of cognitive loading on lumbar flexion relaxation phenomenon in healthy people
Mohammad Pouretezad1, Reza Salehi1,2, Hossein Negahban3,4
1Musculoskeletal Rehabilitation Research Center, Ahvaz Jundishapur University of Medical Sciences: Golestan St, Ahvaz 6135733133, Iran.
Abstract:
[Purpose] The objective of this research was to examine the impact of cognitive load on the flexion relaxation phenomenon (FRP) during trunk flexion and return from flexion task. [Subjects and Methods] Twenty-two healthy subjects (18 males, 4 females) participated in the study. Each participant was exposed to 3 experimental conditions: no cognitive task, easy cognitive task and difficult cognitive task. Surface electromyography was used to measure lumbar erector spinae muscles activity level. Flexion relaxation ratio (FRR) was compared in order to assess the differences between the three experimental conditions during flexion and extension (FLX FRR and EXT FRR). [Results] The FRR was decreased with increase in cognitive difficulty; the difficult cognitive task was associated with significant lower value of FLX FRR in both sides. However, these changes were not significant in easy cognitive task. In addition, the EXT FRR was decreased in cognitive task conditions, but these results were not statistically significant except for difficult cognitive task condition in comparison to no cognitive task condition in left side. [Conclusion] These findings suggest that cognitive loading can affect FRP in healthy subjects.
Related Concept Videos
Skeletal Muscle Relaxants: Adverse Effects
Unlike...
Tip-of-the-Tongue Phenomenon
Cognitive Dissonance
Relaxation of Skeletal Muscles
When an action potential reaches the axon terminal, it depolarizes the membrane and opens voltage-gated sodium channels. Sodium ions enter the cell, further depolarizing the presynaptic membrane. This depolarization causes voltage-gated calcium channels to open....
Framing Effects
Classification of Skeletal Muscle Relaxants
Peripherally acting skeletal muscle relaxants interfere with the neurotransmission at the neuromuscular end plate to induce paralysis during...

