The loading characteristics of landing in cats with different body weights

Nowadays, quadrupedal locomotion information is well established for dogs, horses, and pigs, and kinetic systems have been widely used for sensitive and reliable gait analysis. However, few studies have investigated cat locomotion and the data available are confusing and restricted, especially in relation to jumping. In addition, it has been suggested that several factors, including the influence of the body weight (BW), may be associated with the collection of the kinetic data measurements in dogs. This raises the question of whether the BW would influence the kinetic data measurements in cats. Therefore, this study was aimed at comparing the kinetic parameters of the landing during the jumping in cats with different BWs and to determine the associations between the BW and the kinetic parameters. Twelve client-owned cats were sub-divided into two groups based on the BW and were categorised as a thin group and a heavy group. Each cat was encouraged to jump from a table (1.0 m) onto a force plate several times. The trials were considered to be valid if the cat jumped normally onto the plate and then continued to walk forward. The kinetic parameters including the peak vertical force (PVF) and the vertical impulse (VI) were obtained for each limb. In addition, correlations between the PVF, VI, and BW and the symmetry index (SI) of the forelimbs and hindlimbs were also determined. Most of the kinetic parameters of the thin cats were significantly smaller than the heavy cats during the landing and these values increased as the BW increased, while the normalised PVF and VI of the forelimbs were significantly smaller in the heavy cats than in the thin cats. In addition, for both groups, the non-normalised or normalised PVF and VI were significantly larger in the forelimbs than the hindlimbs, and the SI of the PVF was significantly smaller at the forelimbs than in the hindlimbs. In conclusion, the results of this study showed substantial similarities and differences during the landing between thin and heavy cats. These findings should provide more reference data for the biomechanical motion analysis related to jumping in clinically intact cats.