Case Study: Measuring Gait Asymmetry with Pressure Sensors

 

 

When symmetry in foot function during gait is perturbed, undesired torque can be generated, and stress is transmitted along and within the tendons and muscles, ligaments and bones. Torque and stress are mechanical components that, over-time, place wear and tear on body tissues and can potentially cause symptoms of discomfort and pain. Asymmetry in gait can be measured using F-Scan®.     Symptoms associated with gait asymmetry include: Knee pain when running Stiff big toes when walking Calluses on medial side of big toe

 

 

Improving Asymmetry Using the Gait Curve (Force vs. Time Graph)

 

Gait Curve - Before

 

 

Note asymmetry in curve patterns. Right foot shows greater forces at toe-off (2) relative to left foot, and during heel strike (1) for both feet. Desired outcome is to reduce differences in peak forces during toe-off for right foot relative to right heel strike, and relative to heel strike and toe-off of left foot.

 

 

 

 

 

 

Gait Curve - After Change 1

¾ length test/temp orthotics with ¼ in. heel lift added under right heel.

 

 

 

 

Note reduction of peak forces at toe-off for right foot with respect to right heel strike, and relative to heelstrike and toe-off of left foot. Some reduction in asymmetry has been achieved.

 

 

 

 

 

 

 

 

Gait Curve - After Change 2

Cut-outs in orthotic under 1st metatarsal heads now made.

 

 

 

 

Note more reduction in peak forces during right toe-off relative to right heel strike, left heel strike and toe-off.

There is now much improved symmetry between left and right curve patterns.

 

 

 

 

 

 

 

Gait Curve - After Change 3

1/8 in. heel lift now added under both heels.

 

 

 

1/8 in. heel did not have effect on peak forces and patterns of curves. Lower limb mechanics can be such that 1/8 in. under both heels has little effect on symmetry of gait for this patient.

 

 

 

 

 

 

 

 

 

 

 

Typical Pressure Sensor Model Used to Measure Gait Asymmetry