Determining Minimum Trial Numbers for Reliable Lameness Detection in Canine Kinematic Studies

Area of Science:

• Veterinary biomechanics
• Canine locomotion analysis
• Gait analysis in animals

Background:

• Orthopedic gait assessment in dogs is subjective and varies between observers.
• Biomechanical analysis offers objective lameness detection by quantifying limb asymmetry.
• The minimum number of trials for reliable lameness discrimination remains unclear.

Purpose of the Study:

• To determine the minimum number of stride cycles required for reliable detection of induced lameness in dogs.
• To establish a statistical framework for kinematic gait analysis in canine studies.
• To provide practical recommendations for trial collection in canine gait research.

Main Methods:

• Induced mild lameness in six healthy dogs using a cotton pad on a forelimb.
• Captured kinematic data (stride length, support time, elbow range of motion) using high-speed video.
• Computed symmetry indices and angles, derived asymptotic distributions, and performed statistical simulations to estimate required trials.

Main Results:

• The number of trials needed for reliable detection varied significantly with kinematic parameter and asymmetry magnitude.
• Detecting subtle asymmetries (≈4%) required up to 347 trials for stride length.
• For 6% asymmetry, 11-39 trials per limb provided 80-90% power.

Conclusions:

• Collecting only five trials is insufficient for detecting mild canine lameness.
• A minimum number of trials, guided by statistical analysis, is crucial for accurate gait assessment.
• The study provides a statistical framework and recommendations for optimizing canine kinematic gait studies.