Stride length-cadence relationship is disrupted in below-knee prosthesis users.

Area of Science:

• Biomechanics
• Prosthetics and Orthotics

Background:

• Gait analysis is crucial for understanding locomotion in individuals with lower-limb amputations.
• The relationship between stride length and cadence (STRIDELC) is a key indicator of gait stability and efficiency.
• Below-knee prosthesis users often exhibit altered gait patterns compared to able-bodied individuals.

Purpose of the Study:

• To evaluate the linearity of the stride length-cadence relationship (STRIDELC) in below-knee prosthesis users compared to controls.
• To assess the step length-cadence relationship (STEPLC) in prosthetic and intact limbs of users versus controls.
• To determine if the goodness of linear fit (R2) can differentiate prosthesis users from controls.

Main Methods:

• Participants included 14 below-knee prosthesis users and 20 controls.
• Participants walked at three self-selected speeds (slow, normal, fast).
• Linear regression analysis was used to assess the STRIDELC and STEPLC relationships, with R2 and slope as outcome measures.

Main Results:

• Prosthesis users walked significantly slower than controls due to lower cadence and shorter stride length.
• The goodness of linear fit (R2) for STRIDELC was significantly lower in prosthesis users (0.76±0.13) than in controls (0.91±0.03).
• R2 values for STEPLC were also significantly lower in prosthesis users' prosthetic (0.67±0.19) and intact (0.58±0.21) legs compared to controls (0.86±0.04).
• An R2 value of 0.84 for STRIDELC demonstrated high sensitivity (71%) and specificity (95%) in discriminating prosthesis users.

Conclusions:

• The coupling between stride/step length and cadence is disturbed in below-knee prosthesis users.
• The goodness of linear fit (R2) is a promising metric for assessing prosthetic design, optimizing fit, and predicting clinical outcomes in prosthesis users.