Percent Of Total Force Research Articles

11 Use of pressure mat gait analysis in measuring pain following normal parturition in dairy cows

Abstract Research investigating the pain of normal parturition is lacking as there are few objective methods for measuring pain. The objective of this research was to describe the gait of cows following eutocia using pressure-mat gait analysis; and determine if meloxicam alters the gait of cows. Twenty Holstein cows within 26 h of unassisted calving were enrolled into the study. Treatment groups included: 1) post-partum cows administered meloxicam (MEL; n = 10); and 2) post-partum cows administered placebo (PLBO; n = 10). Meloxicam was administered by oral bolus at 1 mg/kg within 26 hours of calving. Placebo cows were given an oral bolus of dry whey powder within 26 hours of calving. A commercially available floor mat-based pressure/force measurement system was used to compare ambulation between treatment groups. Cows were walked across the mat before treatment administration, and 2, 4, 6, 8, 12, 24, 48 and 72 hrs post-treatment. The percent of total force, percent total contact pressure, and percent total impulse of the rear limbs was calculated. Outcome measures were statistically analyzed using repeated measures, with the cow serving as the experimental unit. Cows in the MEL group placed 48.9% (95% CI: 47.4 – 50.5%) of total force on the rear limbs compared to 46.3% (95% CI: 44.7 – 47.9%) in PLBO cows (P = 0.02). Total impulse on their rear limbs for the MEL cows was 50.5% (95% CI: 48.6 – 52.4%) compared to 46.7% (95% CI: 44.8 – 48.7%) for the PLBO cows (P = 0.01). No differences in contact pressure of the rear limbs was observed (P = 0.27). The PLBO cows had a longer gait 101.3 cm (95% CI: 95.9 – 106.6 cm) versus 90.8 cm (95% CI: 85.4 – 96.1 cm) (P = 0.03). These findings show meloxicam treated cows have altered weight distribution to the rear limbs as measured by pressure mat gait analysis, suggesting meloxicam may effectively treat post-partum pain.

Comparison of vertical force redistribution in the pads of dogs with elbow osteoarthritis and healthy dogs

Kinetic analyses are becoming increasingly important for biomechanical research in veterinary medicine and as a diagnostic tool for orthopaedic examinations in dogs. Such analysis enables accurate evaluation of the vertical force distribution (VFD) in canine paw pads. The aim of this study was to assess peak vertical force (PFz) as a percent of total force (%TF), vertical impulse (IFz, %TF) and time of occurrence of PFz (TPFz) as a percent of the stance phase (%SP) in the pads of all four limbs in 23 dogs with osteoarthritis in the elbow joint and 22 healthy dogs. Dogs walked over a pressure plate, and the pads were divided into four quadrants for VFD analysis. For statistical analysis, a general linear model was used to examine the difference in VFD between both groups, between fore- and hindlimbs, between body sides, and between medial/lateral and cranial/caudal quadrants.Lame dogs had lower PFz in the lame forelimb than in other limbs and transferred their weight to the caudal quadrants of the contralateral forelimb and the caudomedial quadrant of both hindlimbs. IFz was also lower in the affected forelimb and was compensated through higher loading of the caudal quadrants of the contralateral forelimb, the caudomedial quadrants of both hindlimbs and the caudolateral quadrant of the contralateral hindlimb. TPFz (%SP) occurred later in both forelimbs of the lame dogs than in those of healthy dogs. The analysis of force distribution over the paw quadrants can be used for further biomechanical studies of dogs with orthopaedic and neurological diseases.

Rapid Communication: Use of pressure mat gait analysis in measuring pain following normal parturition in dairy cows

Research investigating the pain of normal parturition is lacking as there are few objective methods for measuring pain. The objective of this research was to describe the gait of cows following eutocia using pressure mat gait analysis; and if meloxicam alters the gait of cows. Twenty Holstein cows within 26 h of unassisted calving were enrolled into the study. Treatment groups included: 1) postpartum cows administered meloxicam (MEL; n = 10); and 2) postpartum cows administered placebo (PLBO; n = 10). Meloxicam was administered by oral bolus at 1 mg/kg within 26 h of calving. Placebo cows were given an oral bolus of dry whey powder within 26 h of calving. A commercially available floor mat-based pressure/force measurement system was used to compare ambulation between treatment groups. Cows were walked across the mat before treatment administration, and 2, 4, 6, 8, 12, 24, 48, and 72 h posttreatment. The percent of total force, percent total contact pressure, and percent total impulse of the rear limbs were calculated. Outcome measures were statistically analyzed using repeated measures, with the cow serving as the experimental unit. Cows in the MEL group placed 48.9% (95% CI: 47.4% to 50.5%) of total force on the rear limbs compared to 46.3% (95% CI: 44.7% to 47.9%) in PLBO cows (P = 0.02). Total impulse on their rear limbs for the MEL cows was 50.5% (95% CI: 48.6% to 52.4%) compared to 46.7% (95% CI: 44.8% to 48.7%) for the PLBO cows (P = 0.01). No differences in contact pressure of the rear limbs were observed (P = 0.27). The PLBO cows had a longer gait 101.3 cm (95% CI: 95.9% to 106.6 cm) vs. 90.8 cm (95% CI: 85.4% to 96.1 cm) (P = 0.03). These findings show meloxicam-treated cows have altered weight distribution to the rear limbs as measured by pressure mat gait analysis, suggesting meloxicam may effectively treat postpartum pain.