Walking Patterns and Hip Impingement
One of the easiest ways to determine if someone is in pain is to watch the way they move. And perhaps the most commonly observed and universal movement pattern is gait. From a subtle loss of trunk rotation or pelvic translation to a gross loss of reciprocal gait, a dynamic assessment of walking is a very valuable tool in the physical therapist’s toolbox.
In evaluation of the hip, gait assessment is a critical element of the physical therapy exam. Pain-free ambulation is an essential part of measuring a person’s quality of life (QOL) and is a clinically significant functional outcome measure. Loss of hip extension and knee hyperextension prior to or at heel strike are part of several self-limiting patterns that arise from intra-articular hip injury. Dynamic gait assessment can give the therapist distinct clues as to hip pathophysiology etiology.
It was previously assumed that surgery to correct intra-articular pathology, such as in CAM-based femoracetabular impingement (FAI) [see the photo at left], would result in correction of deficiencies in gait patterning. CAM FAI limits and creates pain in the direction of hip (osteokinematic) flexion, adduction, and internal rotation range of motion and is caused by a lack of sphericity (roundness and symmetry) of the femoral head and neck, causing impingement of the labrum and/or chondral contact at the acetabulum.
A recent study published in 2013 in Gait and Posture, shows that previous assumptions about gait are incorrect. The study compared the gait of healthy controls to those with FAI and hypothesized that gait abnormalities would resolve status post surgery.
Gait measures were obtained both preoperatively and postoperatively. Researchers were surprised to find that gait abnormalities found presurgically did not automatically resolve postsurgically. Another pertinent finding is that the surgical patients not only retained their old faulty antalgic gait patterns and habits, they also adopted new abnormalities that resulted from surgical intervention, such as those arising from scar tissue, soft tissue pathology, neuromuscular patterning, or loss of arthrokinematic motion in the hip. These findings underscores the importance of early intervention via physical therapy for both operative and nonoperative patients if we want our patients to enjoy or return to a high quality of life.
Although the patients in the study who underwent FAI surgery did demonstrate decreased pain, nonoptimal preoperative gait patterns that persist postoperatively can put these patients at risk for reinjury (e.g. labral retears) or related cobmorbidities like pelvic pain, back pain, or sacroiliac joint dysfunction.
Further, a separate study published in 2009 established the presence of altered hip and pelvic biomechanics during gait, finding that those with hip FAI had decreased peak hip abduction, attenuated pelvic frontal ROM or translation, and less sagittal ROM than controls. Soft tissue restriction including scar tissue from previous or current surgeries, myofascial restriction, or neuromuscular patterning problems are, again, all important variables which must be differentially diagnosed for their possible contribution to the loss of ROM and function. Other considerations that can alter gait pattern and increase injury or reinjury risk assessment of capsular mobility, ligamentous integrity, and sacroiliac joint contributions to limited hip ROM and excursion.
For health care professionals: To learn more about nonoperative and operative hip labral and FAI management, check out faculty member Ginger Garner’s continuing education course on Extra-Articular Pelvic and Hip Labrum Injury: Differential Diagnosis and Integrative Management. The next opportunity to take the course is March of 2015 in Houston.