Investigation of the Changing of Quadriceps Angle in Static and Dynamic Postures in Healthy Adults and Its Relation With Physical Parameters

The Q angle is a very important tool in evaluating the function of the knee joint and describing the biomechanical alignment and function of the lower extremity (5). Abnormal values may cause joint problems later on, and in some cases, may affect the quadriceps reflex time, causing subluxation of the patella or an increased risk of developing anterior cruciate ligament ACL injury (5). For this reason, the Q angle is routinely and regularly used as an evaluation parameter when diagnosing many knee-related problems, including anterior knee pain, osteoarthritis, and degenerative knee disorders. When evaluated correctly, it provides very useful information about the alignment of the pelvis, legs and feet (6-8).

Therefore, determining the Q angle is very important, especially for athletic and physically active patients (9). In most studies, the Q angle was measured using a goniometer or with a modified goniometer (10-12). Biedert et al. by radiography (3). Braz et al. determined the Q angle with digital photogrammetry (13). In the literature, the q angle was generally evaluated in the supine or standing position (14). Higher Q angle values have been reported when transitioning from the supine position to the standing position (15). The increased Q angle while standing has been attributed to changes in lower extremity alignment due to weight bearing. In studies in the literature, the q angle was generally evaluated in static postures. In an ideal postural alignment, there should be a dynamic balance between muscles, joints and skeletal structures (16-17). Not only static structures but also dynamic structures are responsible for problems related to the alignment of the patella. For this reason, it is important to know the changes in the q angle not only in static postures but also in dynamic postures. Evaluation in correct postures is essential for diagnosis, planning and follow-up of the development and results of physical therapy (16).

The primary aim of this study was to report the prevalence and normative reference values of the q angle in the midstance phase of gait using 2D analysis (video).

The secondary aim of this study is to examine the variation of q angles during the midstance phase gait with Q angle values in static postures.

The tertiary aim of this study is to examine the relationship of q angles with different parameters such as age, gender, BMI, lower extremity strength, and hypermobility.