Impact of Plantar Massage and Ankle Mobilization on Visual Reliance in Those With Chronic Ankle Instability: A Randomized Controlled Trial.

CONTEXT

Those with chronic ankle instability (CAI) rely more on visual information to maintain postural control. Plantar massage and ankle joint mobilization are moderately successful at improving CAI-associated postural control impairments. Manual therapies may have a larger influence on the underlying sensory strategy used to maintain postural control, but their effect on these strategies remains unknown.

OBJECTIVE

To evaluate the effects of separate 2-week plantar massage and ankle joint mobilization interventions on estimates of visual reliance during single-limb stance in those with CAI and determine whether changes in visual reliance estimates were driven by concurrent changes in peripheral- or spinal-level sensorimotor function.

DESIGN

Randomized controlled clinical trial.

SETTING

Research laboratory.

PATIENTS

Sixty participants with CAI.

INTERVENTIONS

Participants were equally randomized into plantar massage, ankle joint mobilization, and control (no intervention) groups. The manual therapy groups received six 5-minute treatments of their respective interventions over a 2-week period.

MAIN OUTCOME MEASURE

A percentage modulation outcome quantified an individual's reliance on visual information by estimating the weight given to visual information during eyes-open stance based on the magnitude of postural instability that occurs with vision removed. Secondary measures included joint position sense, plantar light-touch thresholds, and the H-reflex. Outcomes were captured before (baseline), immediately after (post), and 1-month (follow-up) after the 2-week intervention.

RESULTS

Plantar massage resulted in significant percentage modulation changes in sagittal (P ≤ .046) but not frontal plane outcomes (P ≥ .069) relative to the control group. Joint mobilization did not alter percentage modulation changes (P ≥ .413). Significant correlations between percentage modulation changes and peripheral sensorimotor function were noted primarily at the 1-month follow-up.

CONCLUSIONS

A 2-week plantar massage but not an ankle joint mobilization intervention alters sagittal plane percentage modulation values during single-limb stance in those with CAI. These changes may be driven by changes in peripheral sensorimotor function.