Women with posterior tibial tendon dysfunction have diminished ankle and hip muscle performance. J Orthop Sports Physical Therapy. (2011)

Abstract
STUDY DESIGN:
Controlled laboratory study using a cross-sectional design.

OBJECTIVES:
To characterize ankle and hip muscle performance in women with posterior tibial tendon dysfunction (PTTD) and compare them to matched controls. We hypothesized that ankle plantar flexor strength, and hip extensor and abductor strength and endurance, would be diminished in women with PTTD and this impairment would be on the side of dysfunction.

BACKGROUND:
Individuals with PTTD demonstrate impaired walking abilities. Walking gait is strongly dependent on the performance of calf and hip musculature.

METHODS:
Thirty-four middle-aged women (17 with PTTD) participated. Ankle plantar flexor strength was assessed with the single-leg heel raise test. Hip muscle performance, including strength and endurance, were dynamometrically measured. Differences between groups and sides were assessed with a mixed-model analysis of variance.

RESULTS:
Females with PTTD performed significantly fewer single-leg heel raises and repeated sagittal and frontal plane non-weight-bearing leg lifts, and also had lower hip extensor and abductor torques than age-matched controls. There were no differences between sides for hip strength and endurance measures for either group, but differences between sides in ankle strength measures were noted in both groups.

CONCLUSION:
Women with PTTD demonstrated decreased ankle and hip muscle performance bilaterally.

My comments:

In the study the authors reported ankle plantar flexion (calf muscle) strength in those with posterior tibial tendinitis reduced 63% of normal, hip extension reduced 33.8%, and hip abduction 28.4%.  These results of calf and hip muscle weakness being associated with foot and ankle pain are in near complete agreement the other studies on hip, knee, ankle, and foot injuries, and would explain why they are so resistant to healing. Many physician, podiatrist, and physical therapy programs focusing on the site of injury, or treating with passive modalities do little to affect either the underlying cause or symptom of the condition, or worse with a cortisone injection which makes the involved tissue weaker and much more likely to tear.  While not measured in this study I would be surprised if the injured subjects didn’t have intrinsic foot muscle weakness as well.

My way of thinking is that it is much better to start patients off on a good progressive resistance exercise program that restores strength at the same time it reduces pain.  I generally start with lighter exercises, and electric muscle stimulation, at the site of injury to prevent exacerbation of symptoms but more aggressive exercise elsewhere else to get foot, hip and thigh strength back up to normal ASAP, which in turns help to normalize forces when walking and running, in this case at the ankle.