Q. A diagnosis of "Bilateral positive FABER test" indicates left and right hip/SIJ mobility dysfunction -
From a client: "Does this just mean I need to increase my hip mobility and range of motion?"
Yes, in general. The test tells us to look further into the hip and SIJ area. Together with the test below, the modified thomas test, which also tells us about the hip, we are led to try to improve whatever is limiting the hip from being mobile enough. In your case, your quads (and the tissue that wraps around it, the fascia) is pretty tight - it has adapted that way with your training and lifestyle. That contributes to tightness around the hip area. The hip joint ITSELF was compressed - meaning the subtle "accessory" glides were limited. Accessory glides are the small movements that you CAN NOT do yourself, such as glides and slides from anterior to posterior direction, medial to lateral direction and traction/compression. Accessory glides, when they are limited, will limit the "physiological" mobility. Physiological mobility is the range of motion that you CAN produce, ie hip flexion, extension, external and internal rotations. So, when your physiological range of motion is limited, as shown by these two tests, then.....hip mobility drills like stretching into the limited direction may not work......if they were going to work, they might have already (unless you don't stretch). So, regaining accessory slides and glides often restores physiological range of motion, or improves it at least - then the stretches work better. The thing about accessory glides and slides is that since you can't actively produce them, you need someone skilled to reset them by hand. And....often when the quads, hamstrings and glutes, with all their fascia, are tight also, regaining accessory glides needs help from soft tissue therapy and stretching to limit the negative effect of muscle-fascia tissue extensibility issues. In some individuals, being tight can be beneficial, but if you want to squat, lunge and deadlift fully, under load, being tight only limits the freedom of movement, limits your end-range positions, and can mess with your patterns and power. Think of the three P's - positions, patterns, power. Positions require mobility to at least minimum so you can get into the start position and end position. Patterns is the motor control required to move you between the start and end position. And power is the force production to express the pattern under load. Your strength training aims to increase more and more force production, but if you lack being able to get into the position, that alters motor control and your nervous system struggles to express power. Make sense?