Original scientific paper
https://doi.org/https://doi.org/10.65241/wh.9.1.3
Comparison of manual goniometry and Kinovea-based photogrammetry for infrasternal angle assessment
Sonja Ostojic
; Faculty of Dental Medicine and Health Osijek, J. J. Strossmayer University Osijek, Osijek, Croatia
Ivan Jurak
orcid.org/0000-0001-7682-6077
; University of Applied Health Sciences Zagreb, Department of Physiotherapy, Zagreb, Croatia; Alma Mater Europaea University – European Centre Maribor, Maribor, Slovenia
*
* Corresponding author.
Abstract
Background: The infrasternal angle (ISA) has recently
gained attention as a potentially relevant clinical and
kinematic parameter due to its associations with breathing
patterns, abdominal muscle function and thoracic–
pelvic interaction. However, the lack of a standardised
measurement protocol and the variability of manual
techniques limit its broader clinical and research
application. Photogrammetry using Kinovea software
may represent a practical and objective alternative,
although its application to ISA measurement has not
yet been systematically investigated. This study aimed
to compare manual goniometry and Kinovea-based
photogrammetry to assess their agreement for ISA
measurement in healthy young adults, assuming a high
level of inter-method agreement.
Methods: ISA was measured in 94 healthy young adults
using manual goniometry and frontal photographs
analysed in Kinovea. Continuous data were summarised
using descriptive statistics; normality was assessed via
the Shapiro–Wilk test. Systematic differences between
methods were evaluated using a paired-samples t-test.
Absolute agreement at the individual level was quantified
using a two-way single measure intraclass correlation
coefficient (ICC). Measurement error was characterised
by the standard error of measurement (SEM) and minimal
detectable change at the 95% confidence level (MDC95).
Agreement was further examined using Bland–Altman
analysis.
Results: The ICC (2,1) for absolute agreement was 0.955
(95% CI 0.941–0.970). SEM was 2.54°, and MDC95 was
7.04°. Bland–Altman analysis showed a mean bias of
1.63° with 95% limits of agreement from –4.84° to 8.09°
with most values falling within these bounds.
Conclusions: Kinovea photogrammetry demonstrates
excellent agreement with manual goniometry with small
and consistent inter-method differences that fall below
the MDC95 threshold. These findings indicate that Kinovea
represents a reliable and methodologically consistent
alternative to manual goniometry for ISA assessment,
offering advantages such as objective documentation,
reduced examiner dependency and suitability for research,
education and large-scale data collection.
Keywords
Infrasternal angle; goniometry; photogrammetry.
Hrčak ID:
349701
URI
Publication date:
31.5.2026.
Visits: 2 *