Shoe Lifts for Leg Length Inequality in Adults With Knee or Hip Symptoms

Limb length inequality is when a person has one leg that is longer than the other. This research will look at correcting limb length inequality in adults with knee or hip symptoms. This study will examine whether ways of measuring leg length inequality in the clinic are valid and reliable, determine whether foot posture (flat foot, normal, and high arch) is related to leg length inequality, and determine whether shoe lifts are a helpful treatment for leg length inequality and knee/hip symptoms.

The purpose of this study is to examine the optimal clinical assessment method(s) for leg length inequality (LLI), determine if there is an association between foot posture (flat foot, normal, and high arch) and LLI, and gather preliminary data on lift therapy as a treatment for LLI and knee/hip symptoms. The specific aims of the project are as follows: Specific Aim 1: Determine the validity and reliability of 4 clinical methods for assessing LLI. Specific Aim 2: Determine differences in static and dynamic foot postures between longer and shorter limbs. Specific Aim 3: Assess the feasibility of conducting a specific lift therapy intervention among individuals with a LLI and knee or hip pain, refining procedures as needed. Public Health Impact: Results from the proposed research will be used to: 1) improve diagnosis of LLI by providing evidence on the various assessment methods for the clinicians who most frequently use clinical methods (i.e., physical therapists, chiropractors, podiatrists, and primary care physicians), and 2) develop and test new non-pharmacologic/non-invasive intervention strategies aimed at reducing pain and improving function in individuals with osteoarthritis and LLI.

This group will not receive shoe lifts during the first 3 months after baseline. At 3 months, they will begin the shoe lift correction for leg length inequality.

Lift therapy will be administered by a physical therapist. Heel lifts and full length inserts used inside participants' shoes will be constructed on-site. If an external shoe lift is required for a participant, a local shoe repair shop will construct the lifts and add them to the outside of the shoe. Participants will be required to wear the lift in their shoes when they are walking or standing while enrolled in the study; participants will keep a daily diary to record their compliance (number of hours lift worn per day, amount of lift used, type of shoes worn, general symptoms experienced, and activities performed). They will be contacted weekly to be reminded to increase their lift height and identify when they have achieved their optimal lift height.

Western Ontario and McMasters Universities Osteoarthritis Index pain subscale is a 5 item questionnaire that asks participants to rate their pain during walking, using stairs, in bed, sitting or lying, and standing. Each item is rated by the participant as 0-4 (no pain to extreme pain). Total scores on the pain subscale range from 0 to 20 (no pain to extreme pain).

For self-reported lower extremity physical function: Western Ontario and McMasters Universities Osteoarthritis Index physical function subscale. The physical function subscale includes 17 items that ask about difficulty with stair use, rising from sitting, standing, bending, walking, getting in / out of a car, shopping, putting on / taking off socks, rising from bed, lying in bed, getting in / out of bath, sitting, getting on / off toilet, heavy household duties, and light household duties. Participants rate each item on a scale of 0-4 (no difficulty to extreme difficulty. Totals scores for this subscale range from 0-68 (no difficulty to extreme difficulty).

Inclusion Criteria: participants from the Johnston County Osteoarthritis Project who have been previously identified to have a LLI and knee or hip symptoms Exclusion Criteria: hospitalized for stroke, myocardial infarction, coronary artery revascularization, or diagnosis of metastatic cancer in the past 3 months terminal illness rheumatoid arthritis, severe fibromyalgia, or other systemic rheumatic disease