The Effect of Lateral Wedge Insoles on Lower Limb Biomechanics, Muscle Activity and Knee Adduction Moment During Walking and Running

The Effect of Lateral Wedge Insoles on Lower Limb Biomechanics, Muscle Activity and Knee Adduction Moment During Walking and Running

The aim of this prospective, randomized, single-group interventional study is to use quantitative methods to investigate the acute effects of using lateral-wedge insoles on lower extremity biomechanics, muscle activation patterns, and knee adduction moment during walking and running activities in healthy individuals aged 18-40. The primary research questions it seeks to answer are as follows:

• Do lateral wedge insoles cause a significant change in knee adduction moment?
• Do lateral wedge insoles change lower extremity biomechanics during walking and running?
• Do lateral wedge insoles change the activation patterns of lower extremity muscles during walking and running? To compare the effectiveness of lateral wedge insoles, participants will randomly use insoles with 0 (neutral), 5, and 10-degree angles.

Participants will do the following:

• Put on the shoes and insoles provided to you in the motion analysis laboratory and complete the walking and running protocols, each taking 1 minute, on the treadmill.
• While walking at your normal walking speed, step so that your dominant leg is positioned over the force plate.
• Repeat all of this for the insoles at the other two angles.

Lower extremity biomechanics plays a significant role in the balance of joint loads and muscle activation patterns during walking. Lateral wedge insoles are an orthotic intervention designed to both correct foot-ankle alignment and alter load distribution in the frontal plane at the knee joint. However, findings regarding the effects of these insoles on lower extremity kinematics, kinetics, and muscle activation patterns in healthy individuals are limited.

The aim of this study is to investigate the acute effects of using lateral wedge insoles on knee adduction moment, lower extremity biomechanics, and muscle activation levels in healthy individuals. The study will utilize a three-dimensional motion analysis system, a force platform, and surface electromyography (EMG). Participants will undergo walking and running tests under three different conditions in a randomized order: a 0° neutral insole, a 5° inclined lateral wedge insole, and a 10° inclined lateral wedge insole.

The data obtained aim to elucidate changes in mechanical loading and muscle activation associated with lateral wedge insoles, thereby strengthening the biomechanical foundations of design principles in insole prescription. Additionally, the reference data obtained from healthy individuals may provide a scientific basis for personalized insole design and rehabilitation protocols applicable to conditions such as knee osteoarthritis in future stages.

Inclusion Criteria:

• Being able to walk and run 10 meters without assistance
• Not having sustained any injury to the lower extremities, pelvis, or trunk within the past 12 months
• Not having received any treatment for the lower extremities, pelvis, or trunk within the past 6 months
• Shoe size must be between EU 36 (22 cm) and EU 45 (28 cm) according to European Union (EU) standards
• Must have scored between 0 and +5 on the Foot Posture Index scale for both feet
• Have scored between 0 and 20 on the Revised Foot Function Index questionnaire
• Have a body mass index (BMI) between 18 and 25 kg/m²

Exclusion Criteria:

• Having cognitive impairment, vision or hearing problems, or a systemic disease that could affect overall health

• Having deformities, contractures, or any other abnormalities in the trunk or lower extremities that could affect participation

  • Having a diagnosed foot or ankle deformity (e.g., pes planus, pes cavus, hallux valgus, etc.)

• Having any neurological or muscular disorder

• Being an active professional athlete

• Failure to sign the informed consent form