Straight leg raise test high reliability is not a motor memory artefact

Area of Science:

• Orthopedics
• Neurology
• Physical Therapy

Background:

• The straight leg raise (SLR) test is a common clinical assessment for lower back pain and sciatica.
• Concerns exist regarding the test-retest reliability of the SLR, with potential confounding factors like motor memory.
• Understanding the factors influencing SLR reliability is crucial for accurate diagnosis and treatment planning.

Purpose of the Study:

• To investigate if the established test-retest reliability of the straight leg raise (SLR) test is influenced by motor memory.
• To determine if systematic variations in test conditions affect the reliability of SLR pain provocation angles.
• To validate the reliability of the SLR procedure as a diagnostic tool.

Main Methods:

• Six straight leg raise (SLR) measurements were conducted by a single therapist on 16 subjects experiencing symptomatic SLR.
• Distance cues were manipulated by systematically altering the starting position for each test to mitigate motor memory effects.
• Pain provocation angles (P1) were measured using a gravitational goniometer.

Main Results:

• No significant effect on the P1 angle was found due to variations in the starting position.
• Repeated testing did not significantly alter the P1 angle.
• The SLR procedure demonstrated high reliability, evidenced by an intraclass correlation coefficient (ICC) of 0.95.

Conclusions:

• The high reliability of the straight leg raise (SLR) test is not an artifact of motor memory.
• The SLR test provides a reliable measure of pain provocation, independent of starting position variations or repeated testing.
• The findings support the use of the SLR test as a dependable clinical assessment tool.