Reliability of measuring trunk motions in centimeters

Area of Science:

• Physical Therapy
• Biomechanics
• Musculoskeletal Assessment

Background:

• Physical therapists developed a novel method using a tape measure and stepstool for trunk motion assessment.
• Existing methods for measuring trunk motion may lack reliability or practicality.

Purpose of the Study:

• To evaluate the inter-rater and intra-rater reliability of a new physical therapy measurement technique for trunk and related motions.
• To identify specific motions with reliable and unreliable measurement characteristics.

Main Methods:

• Three physical therapists (raters) measured six different motions (forward bending, backward bending, side bending, rotation, straight leg raising, prone knee bending) on 24 subjects.
• Each motion was measured three times per subject, with measurements repeated on two separate days.
• Reliability, standard deviation, standard error, and analysis of variance were calculated for each motion.

Main Results:

• Only forward bending demonstrated good single-measurement reliability.
• Reliability improved when using the average of three measurements or when measurements were taken by the same rater on successive days.
• Motions such as rotation and straight leg raising consistently showed low reliability despite improvements.

Conclusions:

• The developed physical therapy measurement method exhibits limited reliability, particularly for rotational and leg-raising movements.
• Averaging multiple measurements or using consistent raters across days can enhance reliability but does not fully resolve issues for all motions.
• Further refinement of the measurement technique is needed to improve accuracy and consistency for clinical application.