ABSTRACT
Background: Four empirical studies have measured the impact of head-loading on female African porters posture using expensive radiography and manual kin anthropometry and goniometry. The reliability of cheaper, pragmatic smartphone goniometric technology as an alternate clinical tool to assess posture is needed. Objectives: This study was designed to test the inter-rater reliability of smartphone goniometry technology against manual goniometry in measuring selected sagittal postural angles in South African female youth who habitually head-load. Methods: Female South African youth who habitually headload voluntarily participated in the study (N = 100) and were randomly allocated into experimental (n = 50) and control (n = 50) groups. An observational randomized control design involving a pre-test post-test crossover was used, after which the control group crossed over into the experimental group and vice versa. The control group stood in the unloaded phase without a head load, while the experimental group carried the head load. The daily head loads and body mass were measured on an electronic scale. Demographic characteristics (age, body mass, and stature) were recorded and selected biomechanical angles were measured on the right side. Results: The mean age of the study participants was 12.3 ± 2.5 years; average body mass was 44.5 ± 13.7 kg. The average head load habitually carried was 8.0 ± 2.5 kg. The inter-rater reliability between the smartphone goniometry technology and manual goniometry was 0.9. Conclusion: The findings support the use of smartphone goniometry as a pragmatic method for assessing sagittal plane postural changes among rural South African youth who habitually head-load. Further studies are needed to validate these findings.