Gait Modification Treatment for Knee Osteoarthritis

Effects of Toe-out Gait Modification on Clinical and Biomechanical Measures in People With Knee Osteoarthritis

Knee osteoarthritis (OA) is a costly health condition affecting more than 10% of Canadian adults. Excessive and unbalanced loads passing through the knee joint have been implicated in the progression of OA. Typical conservative treatment of OA has focused on increasing daily activity, without consideration for the underlying joint loading. This study aims to compare a 4-month walking program that aims to increase the angle of the foot (toe-out angle) during walking - a measure shown to reduce joint loading and OA disease progression - while increasing walking time/distance, with a standard walking program that aims to increase walking time/distance. It is predicted that the walking program focusing on increasing toe-out will provide greater reductions in self-reported knee pain and a greater reduction in unfavorable knee joint loading.

Participants will complete 4 months of a home-based progressive walking program with toe-out gait modification aimed at improving physical activity level. This group will perform continuous treadmill walking during regular sessions with a study therapist and will be instructed to perform a toe-out gait, with the aid of a mirror during walking. Focus will also be on increasing the time and distance of walking. These goals will be emphasized for the home-based portion of the intervention as well.

Participants will complete 4 months of a home-based progressive walking program aimed at improving physical activity level. This group will perform continuous treadmill walking during regular sessions with the study therapist with focus on increasing the time and distance of walking. This goal will be emphasized for the home-based portion of the intervention as well.

Participants in this study group will perform continuous treadmill walking for a minimum of 30 minutes at each session, but the emphasis will be to increase toe-out angle by 10 degrees over that exhibited at baseline. A mirror will be provided for biofeedback and participants will be instructed on its use for achieving the target toe-out angle. Increased walking time and distance will be encouraged the same as for the control group.

At each scheduled visit, participants will perform treadmill walking for a minimum of 30 minutes depending on the individual's baseline activity level and the stage of the intervention. Emphasis will be solely on increasing walking time and distance to achieve the target of a 40% increase in daily activity.

Change From Baseline to Week 17 and From Baseline to Week 21 in Pain as Measured by Numerical Rating Scale

Average pain over the previous week will be assessed using an 11-point numerical rating scale (0 = no pain; 10 = maximum pain). Higher scores mean a worse outcome. Change was calculated as the value at 17 weeks and at 21 weeks minus the value at baseline.

Change From Baseline to Week 17 and From Baseline to Week 21 in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Pain Subscale.

Lower-limb impairments will be measured using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). The WOMAC is a 24-item self-report questionnaire that quantifies pain (5 items), stiffness (2 items), and physical function (17 items). It is a valid, reliable, and responsive disease-specific self-report instrument and has been used in many knee OA studies. Minimum value of the WOMAC pain subscale is 0 and maximum value is 20. Higher scores mean a worse outcome.

Change From Baseline to Week 17 and From Baseline to Week 21 in Knee Joint Loading: First Peak Knee Adduction Moment

Participants will undergo a gait analysis, where 10-15 trials of walking will be collected. Participants will walk in bare feet and at their own, self-selected speed while analyzed using three-dimensional motion analysis. Kinematic (joint angle) and kinetic (joint loading) data will be collected synchronously using high-speed digital cameras and floor-mounted force platforms. A total of 5 "acceptable" (clean force platform strikes and no observable deviation in walking characteristics) will be analyzed.

Change From Baseline to Week 17 and From Baseline to Week 21 in Knee Joint Loading: Second Peak Knee Adduction Moment

Participants will undergo a gait analysis, where 10-15 trials of walking will be collected. Participants will walk in bare feet and at their own, self-selected speed while analyzed using three-dimensional motion analysis. Kinematic (joint angle) and kinetic (joint loading) data will be collected synchronously using high-speed digital cameras and floor-mounted force platforms. A total of 5 "acceptable" (clean force platform strikes and no observable deviation in walking characteristics) will be analyzed.

Change From Baseline to Week 17 and From Baseline to Week 21 in Knee Joint Loading: Knee Adduction Moment Impulse

Participants will undergo a gait analysis, where 10-15 trials of walking will be collected. Participants will walk in bare feet and at their own, self-selected speed while analyzed using three-dimensional motion analysis. Kinematic (joint angle) and kinetic (joint loading) data will be collected synchronously using high-speed digital cameras and floor-mounted force platforms. A total of 5 "acceptable" (clean force platform strikes and no observable deviation in walking characteristics) will be analyzed.

FPA indicates orientation of the foot with respect to the forward progression of the body. Positive values correspond to a toe-in orientation, whereas negative values correspond to a toe-out orientation. Therefore, a positive change value indicates more toe-in versus a negative change value indicates more toe-out.

Change From Baseline to Week 17 and From Baseline to Week 21 in Self-reported Physical Function as Measured by Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Physical Function Subscale.

Lower-limb impairments will be measured using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). The WOMAC is a 24-item self-report questionnaire that quantifies pain (5 items), stiffness (2 items), and physical function (17 items). It is a valid, reliable, and responsive disease-specific self-report instrument and has been used in many knee OA studies. The WOMAC physical function subscale minimum value is 0 and maximum value is 68. Higher scores mean a worse outcome.

Change From Baseline to Week 17 and From Baseline to Week 21 in Objective Physical Function as Measured by Timed Stair Climb.

Participants were instructed to ascend 12 stairs "as quickly as possible", and the fastest time from two attempts was recorded.

Change From Baseline to Week 17 and From Baseline to Week 21 in Knee Joint Loading: Knee Flexion Moment

Participants will undergo a gait analysis, where 10-15 trials of walking will be collected. Participants will walk in bare feet and at their own, self-selected speed while analyzed using three-dimensional motion analysis. Kinematic (joint angle) and kinetic (joint loading) data will be collected synchronously using high-speed digital cameras and floor-mounted force platforms. A total of 5 "acceptable" (clean force platform strikes and no observable deviation in walking characteristics) will be analyzed.

Inclusion Criteria: aged 50 years and older radiographically confirmed medial compartment tibia-femoral knee osteoarthritis available for weekly training sessions in the Vancouver British Columbia Canada region able to safely perform treadmill walking under therapist supervision Exclusion Criteria: articular cartilage degradation in the lateral tibiofemoral compartment greater than the medial inflammatory arthritic condition history of knee replacement or arthroscopic knee surgery recent use of corticosteroids (oral or via injection) inability to ambulate without a gait aid non-English speaking planning to commence a new treatment approach within the next 4 months

Hunt MA, Charlton JM, Krowchuk NM, Tse CTF, Hatfield GL. Clinical and biomechanical changes following a 4-month toe-out gait modification program for people with medial knee osteoarthritis: a randomized controlled trial. Osteoarthritis Cartilage. 2018 Jul;26(7):903-911. doi: 10.1016/j.joca.2018.04.010. Epub 2018 Apr 27.