The present invention relates to an indicating de¬ vice for indicating variations in the set-down force of the feet of race-horses, racing dogs or the like, or humans. With trotting horses in particular it is diffi¬ cult to make the horse run straight ahead, a prere- guisite of which is that the horse sets down its feet with the same force. Up to now, trainers have been obliged to study their horses on the training track to see if they tend to depart from a straight course or to run foul in some other manner. By cutting away part of the hoof or by attaching weights to the hoof, one then tried to mutually "balance" the horse's feet to make it run straight and without fault, but this procedure is complicated and time-consuming.

A variety of devices are known by which the pres¬ sure between the foot of a human or a quadruped and the base can be recorded. One such device is disclosed by US-A-2,290,387 in which pressure sensing means are applied for example to the sole of the foot or to muscles for measuring the weight load. A common fea¬ ture of this and a number of similar prior art devices is that they measure and record the pressure with which a foot or other part of the body is pressed against the ground or other base. If the movement is slow or rela¬ tively slow, it is possible to use the prior art de¬ vices for ascertaining if any unacceptable deviations occur in the load transfer during walking, if the foot is subjected to any abnormal strain, and also if the load is not uniformly distributed between the legs or the feet and the parts associated therewith. However, because of their basic construction, the prior art de¬ vices cannot be utilised for reliable recording of very fast movements, for example the leg and foot move-

ments of a trotting horse, primarily because of the inherent inertia to be found in sensing and recording devices operating on granulated carbon or the like, or actuated by the build-up of a fluid pressure, or in en- tirely mechanical contact means. For this reason, the prior art devices referred to above and proposed in other contexts for measuring the foot pressure against . the ground cannot be successfully used on trotting horses. It is the object of this invention to facilitate the conventional manual indication or control and to provide more reliable objective data about the racing qualities of a horse. This is achieved by means of a device which comprises a sensing unit adapted to be attached to each foot and to sense and record the g-force resulting from the impact of the _ foot against the ground or base, ^' and an indicating unit connected to said sensing units.

In this manner, one has the possibility of instan- taneously discovering any variations in the set-down force of the feet, and if the horse's gait is infring¬ ing the rules. Moreover, the device is capable of in¬ stantaneously indicating an unallowed change of gait, for example if the horse takes to gallop. This possi- bility can be used also for keeping a check on the par¬ ticipants of a walking competition to see if unallowed running occurs. In both cases, a change in the set-down force occurs, which is instantaneously indicated by the device, but which frequently escapes observation. The device can, of course, be used also during train¬ ing sessions to improve the performance of a runner or walker.

The invention will be described below in more de¬ tail, reference being had to the accompanying drawing which illustrates schematically an embodiment of the invention applied to a trotter and sulky.

The indicating device comprises sensor or trans¬ ducer units 1 attachable to the horse's legs. These units measure the g-forces which are generated when the horse sets down its feet on the ground, i.e. the retardation which occurs when the forwardly and down¬ wardly moving hoof strikes the ground, and are attached by suitable means to the legs directly above the hoofs, for example by means of elastic bandages. The sensor units generate electric signals proportional to the set-down force of the foot, and the signals are trans¬ mitted by suitable means 2 to the indicating unit 3. In the embodiment illustrated, the transmission means 2 are electric wires which are taped or other¬ wise affixed to the horse and drawn to the indicating unit 3 on the sulky. In other applications of the invention, for example dog racing, the transmission means may consist of a radio transmitter affixed to the dog and transmitting the signals to a receiver mounted on the indicating unit which is arranged in a different place.

The indicating unit 3 suitably comprises rows of light-emitting diodes arranged side by side on an indicating panel which comprises a multi-channel amplifier and other components required for amplifying and processing the transducer signals.

In the embodiment described above and illustrated in the drawing, the indicating device comprises four transducer units, one on each leg. However, it is also possible to use but two transducer units which are affixed to the legs of a human, the front legs or, alternatively, the hind legs of animals. In such a case, the indicating panel has, of course, but two indicating means.

The indicating device according to the invention quickly supplies accurate information about the running qualities of a human, a trotting horse or other animal so that any tendencies toward irregularities in the

running performance can be quickly corrected. Further¬ more, the invention can be used for rapidly detecting any incipient injury to a muscle or joint, which is manifested in that the injured leg is set down with less force than a healthy leg. Early detection thus makes it possible to prevent an injury from becoming aggravated.

Naturally, the invention is not limited to the embodiment described above and illustrated in the drawing, but may be modified within the scope of the appended claims.