Investigation of the Putative Correlation Between Involuntary Psoas Activity During Passive Flexion of the Trunk at the Hips

University Hospital, Strasbourg, France90 enrolled

Overview

Passive flexion of the trunk (relative to the legs) may be accompanied by contraction of the psoas muscles, even when the subject has been told not to contract any muscles. The psoas contraction is involuntary and cannot be controlled by the subject. This lack of passivity might be concomitant with lower back pain: the impairment may be present when lower back pain is present and/or absent when lower back pain is absent. The study's primary objective is thus to determine the sensitivity and/or specificity of a clinical test for impaired hip flexor passivity in cases of lower back pain during passive flexion of the trunk (from the supine position,). The secondary objective is to show that a negative test (after administration of correcting measures) is correlated with a decrease in pain (i.e. pain intensity and the functional repercussions of pain).

Study Type

INTERVENTIONAL

Allocation

Purpose

PREVENTION

Masking

NONE

Enrollment

Conditions

Lower Back Pain

Interventions

Description of the test: the subject lies in the supine position on an exercise mat with his/her feet together. The subject is told to let his/her arms rest loosely by his/her side (as if they were ropes) and to keep the head aligned with the back. The examiner pulls the subject into the sitting position by pulling on the subject's wrists, with passive flexion of the trunk until the hip joint is fully flexed..

Eligibility

Sex: ALLMin age: 18 YearsMax age: 30 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Age between 18 and 30 * Social security coverage * Ability to understand the study's objectives, procedures and risks and to provide informed, written consent * Having been informed about the results of the prior clinical examination. Exclusion Criteria: * Past or concomitant infectious or cancerous diseases of the spine * Vertebral osteosynthesis * Acute neck or arm pain (recurrent dislocations of the glenohumeral joint, trauma in the previous 12 months, etc.) * Lower back pain with irradiation of pain below the buttocks * Known specific lower back pain or pain for which a differential diagnosis suggests an inflammatory, traumatic, cancerous or infectious cause * Subjects under legal guardianship * Known pregnancy * Simultaneous participation in another biomedical research study of a drug or medical device.

Outcomes

Primary Outcomes

Qualitative evaluation of impaired psoas muscle passivity during passive flexion of the trunk at the hips (while sitting).

Time frame: Visit 1 (Day 0)

Secondary Outcomes

- A visual analog scale for pain

Time frame: - Visit 0 (Day 0: inclusion visit)