Clinical and Instrumented Measurements of Hip Laxity and Their Associations With Knee Laxity and General Joint Laxity

Abstract

Context: Hip-joint laxity may be a relevant anterior cruciate ligament injury risk factor. With no devices currently available to measure hip laxity, it is important to determine if clinical measurements sufficiently capture passive displacement of the hip.Objective: To examine agreement between hip internalexternal-rotation range of motion measured clinically (HIER ROM ) versus internal-external-rotation laxity measured at a fixed load (HIER LAX ) and to determine their relationships with knee laxity (anterior- Conclusions: Although HIER ROM and HIER LAX differed in magnitude, they were measured with similar consistency and precision and were similarly correlated with knee laxity and GJL measures. Individuals with greater GJL also had greater hip laxity. These findings are relevant to clinicians and investigators conducting prospective risk factor studies, given the need for accessible, efficient, and low-cost alternatives for characterizing an individual's laxity profile.Key Words: anterior cruciate ligament injuries, risk factors, lower extremity Key PointsDifferences between measures of hip internal-external-rotation range of motion and laxity were large and systematic, even though the measures demonstrated comparable precision and were strongly correlated in relative magnitude. Measures of hip internal-external-rotation range of motion and laxity were strongly correlated with measures of knee laxity and general joint laxity. Clinical measurement of hip internal-external-rotation range of motion may be a reliable, efficient, and low-cost measure of passive hip-joint displacement.

Passive Hip Range-of-Motion Values Across Sex and Sport

“…For instance, greater ROM TOT has been associated with generalized joint laxity (r ¼ 0.57), 10 a prospectively identified ACL injury risk factor in females. 11 Although passive hip ROM during functional activity has been empirically linked to dynamic knee valgus during functional activity 6,12 and females have been reported to differ from males in passive hip ROM, 10 literature quantifying normative ranges of motion by sex is lacking. This gap can be particularly problematic considering that females may exhibit different injury mechanisms than males.…”

“…3 Previous reports of transverse-plane hip ROM values are presented in Table 1. Researchers who examined sex differences in ROM IR and ROM ER have suggested that females possess more ROM IR than ROM ER and more ROM IR than males in a healthy population 10 and elite tennis players. 16 However, as a result of the limited data on athletic populations, these sex comparisons may not be generalizable to individuals participating across a variety of sports.…”

Differential Effects of Hip Rotation Range on Knee Abduction Biomechanics during Double-Legged Landing between Males and Females

“…Compared with males, females likely display greater dynamic knee valgus during those activities [9]. Females differ from males in passive hip ROM [14]. Ranges of hip IR and external rotation (ER) are highly correlated with radiographic measures of femoral anteversion [15].…”

The Effects of Gluteal Strength and Activation on the Relationship Between Femoral Alignment and Functional Valgus Collapse During a Single-Leg Landing

“…[10][11][12] Femoral anteversion is characterized by a medially-torsioned femoral neck and is developmental. 13 In contrast, passive hip RoM is a pliable soft tissue restraint which may be influenced by other factors such as general joint laxity, 14 that has been shown to remain constant throughout maturation, 15 and has been retrospectively associated with ACL injury. 16 Though these factors cannot be directly modified through training interventions, it may be possible to design more effective intervention strategies to counteract non-modifiable anatomical factors.…”