Patient Sensation During Hip Joint Mobilization
Patients should not typically feel the femoral head moving away from the acetabulum during joint mobilization techniques, as the actual displacement is minimal (0.57-1.52 mm on average) and occurs within the joint capsule rather than as a gross separation that would be perceptible to the patient. 1
Normal Biomechanics of Hip Joint Mobilization
The hip joint allows only very limited translational movement during mobilization procedures:
- Posterior-anterior glide of the femoral head produces displacement ranging from 0.04 mm to 2.90 mm maximum, even with forces up to 356 Newtons applied. 1
- Mean femoral head displacement is approximately 0.57 mm with 89 N of force and 1.52 mm with 356 N of force. 1
- This movement is highly variable between individuals, with some hips demonstrating minimal displacement even with substantial mobilizing forces. 1
What Patients Actually Feel
The sensation patients experience during hip mobilization should be stretch, pressure, or mild discomfort in surrounding soft tissues—not a feeling of the joint "coming apart" or the femoral head separating from the socket. 1
Key considerations:
- The hip is a ball-and-socket joint that "sacrifices stability for mobility" but still maintains substantial structural integrity through the joint capsule and surrounding ligaments. 2
- Any perception of gross joint separation would indicate either excessive force application or potential joint instability requiring immediate cessation of the technique. 2
Clinical Implications and Safety
If a patient reports feeling the femoral head moving away from the socket, this warrants immediate discontinuation of the mobilization and clinical reassessment. 2
This sensation could indicate:
- Excessive mobilization force beyond therapeutic range 1
- Potential joint instability or capsular laxity 2
- Patient misinterpretation of normal soft tissue stretch as joint separation 1
- Contraindication to continued mobilization requiring multidisciplinary consultation 2
Proper Mobilization Technique
Therapeutic hip mobilization should involve:
- Controlled forces that produce millimeter-level displacement within the joint capsule, not gross separation of joint surfaces 1
- Patient positioning that maintains hip flexion within comfortable limits, generally not exceeding 90 degrees 3, 4
- Monitoring for changes in patient comfort, with any distress reported by the patient serving as a criterion to stop the session 2
The therapeutic goal is to improve range of motion through gentle capsular stretching and neuromuscular facilitation, not to create perceptible joint distraction. 5, 6