Reproducibility of trunk and lower extremities alignment in subjects with abnormal head posture using photogrammetry

Evaluation of the alignment of the trunk and lower limbs in people with forward head posture (FHP)assumes critical importance due to biomechanical connection. The present study aimed to assess the reliability of trunk, pelvis, and lower limb posture assessment in people with FHP by the photogrammetric method.

This observational study was conducted on 60 male and female participants, 32 with FHP and 28 without FHP, from students of Tabriz University of Medical Sciences. The mean age of participants was 23.30±2.66 years. A craniovertebral angle of 48 degrees or less is known as FHP. To evaluate intratester reliability, postural evaluation was repeated one week apart by the first examiner and one hour apart by the second examiner to assess intertester reliability. The measured angles included vertical and lateral alignment of the body, vertical alignment of the trunk and lower limbs, the horizontal alignment of the pelvis, as well as the angle of the hip and ankle joints.

The results of the intraclass correlation coefficient based on Munro's scale demonstrated that in the FHP group, the vertical straight angle of the body had the lowest (0.73), and the hip joint angle had the highest intertester reliability coefficient (0.96). Considering intertester reliability in the FHP group, the lower limb alignment was the lowest (0.88), and the hip joint angle had the highest reliability coefficient (0.97).

The evaluation of trunk and lower limb posture in people with FHP by photogrammetry can be used as a quantitative method with high reliability