PMC

Variables are expressed in dimensionless standardized units. Fencer A: Reflected tip distance increased with increased reflected blade distance (linear regression, both variables square root transformed for regression but not plotting, n = 67, p = 0.00016, r² = 0.20, slope_std = 0.45, plot). Not significantly related to reflected tip distance (forward step-wise linear regression) were angular blade velocity (p = 0.8), reflected blade velocity (p = 0.2), blade height (p = 0.9), reflected blade height (p = 0.05), and blade distance (p = 0.03). Fencer B. Reflected tip distance increased with increased reflected blade distance (linear regression, both variables square-root transformed for regression, n = 78, p<0.000001, r² = 0.29, slope = 0.62 based on non-transformed data). Not significantly related to blade velocity (p = 0.7), reflected blade velocity (p = 0.6), blade height (p = 0.3), reflected blade height (p = 0.2), or blade distance (p = 0.0005). Tip velocity was affected by both angular blade velocity and blade height (linear regression, n = 78, r² = 0.44). Tip velocity increased with increased angular blade velocity (multiple linear regression, n = 78, p<0.00001, slope_std = 0.59, partial plot). Tip velocity increased with decreased blade height (multiple linear regression, n = 78, p<0.00001, slope_std = -0.65, partial plot). Not significantly related to tip velocity (forward step-wise linear regression) were reflected angular velocity (p = 0.02), reflected blade height (p = 0.8), blade distance (p = 0.1), reflected blade distance (p = 0.6).

Variables are expressed in dimensionless standardized units. Fencer A: Reflected blade distance increased with increased reflected hand distance (linear regression, both variables square root transformed for regression, n = 67, p<0.000001, r² = 0.94, slope_std = 0.97). Not significantly related to reflected tip distance (forward step-wise linear regression) were finger velocity (p = 0.5), reflected finger velocity (p = 0.4), wrist velocity (p = 0.6), reflected wrist velocity 0.8), elbow velocity (p = 0.92, reflected elbow velocity (p = 0.8), shoulder velocity (p = 0.6), reflected shoulder velocity (p = 0.3), hand height, (p = 0.9) reflected hand height (p = 0.9), hand distance (p = 0.01). Fencer B: Blade velocity was affected by both wrist and shoulder velocity (linear regression, n = 78, r² = 0.23). Blade velocity increased with increased wrist velocity (linear regression, n = 78, p<0.0002, r² = 0.21, slope_std = 0.42, partial plot). Blade velocity increased with increased shoulder velocity (linear regression, n = 78, p<0.001, r² = 0.13, slope_std = 0.36, partial plot). Not significantly related to reflected blade velocity (forward step-wise linear regression) were finger velocity (p = 0.11), reflected finger velocity (p = 0.44), reflected wrist velocity (p = 0.99), elbow velocity (p = 0.6), reflected shoulder velocity (p = 0.9), hand height (p = 0.2), reflected hand height (p = 0.4), hand distance (p = 0.2), reflected hand distance (p = 0.32). Blade height increased with increased hand height (linear regression, n = 78, p<0.00001, r² = 0.97, standardized slope = 0.99, plot). Not significantly related to reflected tip distance (forward step-wise linear regression) were finger velocity (p = 0.9), reflected finger velocity (p = 0.3), wrist velocity (p = 0.15), reflected wrist velocity (p = 0.3), elbow velocity (p = 0.35), reflected elbow velocity (p = 0.1), reflected shoulder velocity (p = 0.6), reflected hand height (p = 0.6), hand distance (p = 0.18), reflected hand distance (p = 0.3). Reflected blade distance increased with increased reflected hand distance (linear regression, both variables square root transformed for regression, n = 78, p<0.000001, r² = 0.94, slope_std = 0.97 for non-transformed variables, partial plot). Not significantly related to reflected tip distance (forward step-wise linear regression) were finger velocity (p = 0.5), reflected finger velocity (p = 0.8), wrist velocity (p = 0.2), reflected wrist velocity 0.8), elbow velocity (p = 0.2), reflected elbow velocity (p = 0.6), shoulder velocity (p = 0.9), reflected shoulder velocity (p = 0.4), hand height (p = 0.3), reflected hand height (p = 0.1), hand distance (p = 0.003).

The transverse displacement of the saw blade under the action of the thrust force F_p, where: q₀ is the displacement resulting from the deflection of the saw blade corresponding to the displacement under the action of the F_p force applied at point O; q_s is the torsional displacement of the blade; h is the tooth height; b is the blade width; s is the blade thickness; y is the displacement of the pivotal point relative to the middle of blade O; α_b is the saw blade torsion angle; A_D and A_D’ is the cross-sections of the layers being cut.

Comparison of forces measured by the force plate and the blade from a representative drop landing. The blade force was calibrated from ten drop/jump landings onto the force plate. The blade force and force plate force typically agreed in overall shape, but disagreed in the presence of the initial impact peak, , (usually present in the force plate force but not in the blade force), and the height of the second peak , (usually higher in the force plate force).