Running shoes are aimed at supporting the sportsman's legs during the run, partly for the best and easiest contract with the ground, but also to stabilize the foot against distracting or even detrimental twist in overpronation (buckling invers) or supnation (buckling outwards of the running axis).

Another major impact is to be seen as to rolling the foot along its main axis.

Hitherto the paradigm was to firstly touch the soil by the heel and then roll along the center line unto the toe cap, wherefrom to perform the general push ahead.

Therefore the development of sport shoes emphasized a thick heel, since the heel would touch the ground first and therefore to dampen the impact to the knee and other anatomy.

However, for a more pleasant running style it is preferred first to touch the ground on the forefoot and to prevent an impact on the heel, which affects ankle joint, knee and hip joint, together with the spinal column, whereas best damping of impacts is performed through calves and thighs.

For to correct the latter it may be advisable to cut off the excess at the heel, - what would reduce the damping or even destroy running shoes.

As a matter of fact, runners have their personal style and must be able to choose among different sole constructions, so to achieve best performance.

Correctives like contoured inlays proved to be of not too much avail in this respect.

Shopkeepers's solution is to sell different types of shoes to each customer and let him decide about the best fitting for his needs and to let him dispose the rest - since shoes can rather not be given for test some time nor traded in - which would be essential for to decide after necessarily extensive testing.

This of course is displeasing for the customer, who is forced to decide about each buy after a few test steps inside the shop and may lead to a pile of unwanted sneakers in his basement.

PRIOR ART

There are some prior propositions for attachment of additional soles to sport shoes, as in:

DE 10 2006 061 482 A1 There, however, the sole is held by elastically encasing the basic sole together with the additional sole without exchangeability. DE 10 2010 053 316 A1 proposes additional protective cushions to be attached to sport shoes as a subshoe with elastic bands to be fastened above the shoes.

The problem might here be some kind of clumsiness as with all kinds of overshoes.

US 2016/0345661 A1 (applied for by Nike) proposes the fastening of a sole plate by locking it into recesses in a cavity in the basic sole "comprising one or more tabs extending from the perimeter towards the center of the cavity" - a method that is known from fixing cross-country ski or bicycle pedals to corresponding boots. Wether this would really be feasible with elastic sole plates will be seen.

Similar to it, PCT /US85/01131 , also registered as WO 86/ 04489, proposed in 1985 a fastening of soles or skiing equipment to one's foot , using a continuous groove within the outskirts of the original sole and an equivalent rigid key-type ridge to be locked within and some additional push-button type fasteners and a toe cap for fastening.

Moreover, CN 104114054A describes the locking of additional soles into the original sole by insertion of fixtures into recesses similarly to US 2016/0345661 A1. However it may be questionable wether this might work with sport shoes. As known from skiing, these cavities might be clogged after a few steps, and if it is not snow, but mud in it, it will be worse for locking or releasing it.

Other patens, as US 1.360.228, aim at connecting possible replacement soles to the shoe body by hooks, US 2.552.943 proposes an upper part of a ladie's shoe to be connected to an exchangeable base using a keyway in the latter and an insertable corded welting around the top, furthermore US 4.416.072, where a variable Heel may be fixed to a base using the same method.

However, these three latter and quite a few similar proposed solutions would obviously not work with flexible sport shoes or sneakers.

TASK OF THE INVENTION

It therefore is the task of the here disclosed invention, to alter the shoe sole in a reversible way, for to find out about the best fitting balance between tip and heel thickness.

However, is not an easy task to fit on parts to the sole that need to be easily exchangeable, but must be firmly attached for a longer run for to try out different gauges. SOLUTION

The inventive step therefore is to attach a slip-over cap for holding a corrective sole at the tip, which is further attached to the original sole with pins through itself and the original sole at an angle of approx. +40° off the longitudinal axis, while bending the shoe firmly along it.

CLOSER DESCRIPTION OF THE INVENTION ALONG TO THE DRAWING FIG. 1 :

A running shoe (1) is fitted with a soft covering cap (2), that contains an additional sole (4), that might be a little thinner than the original sole (3), so that the gauge on the forefoot (6) will equal that one at the heel (7)