Reliability of hip and knee angle measurement in Modified Thomas test, distance in Sign of four and palpation of quadratus lumborum and psoas muscles and sacrotuberous ligament

Abstract

Objective: To study the inter-rater and intra-rater reliabilities of hip angle measurement and knee flexion in Modified Thomas test, the distance measurement between head of fibular to the couch in Sign of 4 test and quadratus lumborum (QL), psoas muscle and Sacrotuberous ligament (ST ligament) palpation.

Material and Method: Five subjects both left and right legs (10 lower extremities) were randomized. Two researchers assessed the abduction and flexion of hip angle measurements in Modified Thomas test, the distance measurement between head of fibular to the couch in Sign of 4 test. Afterwards, the researchers palpated twice for QL, psoas at the lumbar spine; L4-5, L3-4, L2-3 and ST ligament. The invisible ink pen was used by the researchers (two times per a subject) to mark the area on the muscles and ligament then used black light to present the agreement area. The level of acceptance was 50% of the agreement area of palpation between the two researchers. Test-retest reliability was used to determine the outcome measurements.

Results: Intra-rater reliability of the two researchers in abduction and flexion of hip angle measurements were (0.971, 0.904), (0.945, 0.953), knee flexion angle measurements were 0.989, 0.988 and the distance between head of fibular to the couch in Sign of 4 test were 0.901, 0.947. Inter-rater reliability of the two researchers in abduction and flexion of hip and knee flexion angle measurements were 0.867, 0.942, 0.992 and the distance between head of fibular to the couch was 0.867. The 80-100% of the agreement area was shown in QL, psoas and ST ligament palpation.

Conclusion: Excellent intra-rater reliability was presented in abduction, flexion of hip and knee extension angle measurement in Modified Thomas test including the distance of head of fibular to the couch measurement in Sign of 4 test. The agreement of palpated area of QL, psoas and ST ligament between two researchers were 80-100%.