Boots – shoes – and leggings – Boots and shoes – Occupational or athletic shoe
Reexamination Certificate
2001-11-16
2004-02-17
Stashick, Anthony D. (Department: 3728)
Boots, shoes, and leggings
Boots and shoes
Occupational or athletic shoe
C036S109000, C036S089000
Reexamination Certificate
active
06691434
ABSTRACT:
FIELD OF THE INVENTION
The present invention concerns a sports shoe or boot, notably for alpine skiing, ski touring, cross-country skiing, snowboarding, roller skating or ice skating, comprising a rigid frame arranged under the wearer's ankle and defining at least a housing in which is placed an inner boot receiving the wearer's foot and combining with this frame at least one link extension between the frame and one leg of the wearer, and at least one casing fitted to join the wearer's leg firmly to the link extension.
BACKGROUND OF THE INVENTION
The majority of sports shoes or boots such as shoes for in-line skates or skiing notably, comprise a rigid or hard shell stretching well above the ankle and gripping the latter so as to practically totally block its movements during sporting activities.
This type of shoe presents a certain number of disadvantages. Particularly due to their rigidity, the use of such shoes often causes injury such as notably:
diverse damage to knee and ankle ligaments;
painful tibia supports, posterior leg muscle affected;
bursitis on the foot, (Haglund's disease);
inflammation of the Achilles tendon;
painful condition of internal and external ankle bones;
shin splints;
displacement and damage to the semilunar cartilage;
compression of the metatarsus (Morton's syndrome);
stiffness of the lower member due to its compression;
atrophy of the foot muscles of the ankle and calf at the end of the season; and
cold feet, partial frostbite and associated circulatory complications.
Other sports shoes have been made with a hard shell which stops below the ankle and which is supposed to leave the ankle free. These shoes have the characteristic of blocking the foot in the shell by means of straps arranged on the instep.
The techniques employed in shoe and boot design have evolved to provide greater comfort, but this maintaining and locking action of the bottom of the leg still causes considerable injury and discomfort for wearers, often exposed to twisting of the bottom of the leg notably when falling. With hard shoes, the maximum resistance time of the twisting leg is considerably decreased by the rigidity of the shoes, which prevents complete movement of all the particular and muscular chain of the leg muscle segment. Violent twisting at the time of falling backwards is accentuated by the lack of posterior particular and muscular mobility of the leg, the effect of which is to transfer the twisting force abruptly onto the knees. The leg is blocked by the rigid neck of the shoe or boot. This type of fall widely described notably in the works of Professor Johnson in the United States shows up the dangers of ski boots that are too rigid, when falling and twisting backwards. On the other hand, it appears that blocking the feet and ankle articulations is responsible for the forced inactivity of leg muscles. These muscles are no longer correctly used to react in the case of a fall or unexpected change in direction and therefore do not correctly protect the knee and the ligaments. What is more, sensitivity of the foot is alleviated by this very same blocking of the foot and lower leg to which an external overall compression is added to obtain resistance and precision. The effect of this is to limit sensory activities. In the special case of skiing, this in part explains the difficulties of posture for many skiers.
Certain developments have been made to attempt to solve the problem of hard shell shoes or boots. One of these developments is illustrated in the U.S. Pat. No. 3,747,235. This document describes a ski boot comprising a rigid inner boot fixed to the ski and enveloping the foot, a lever fixed to the inner boot and extending practically up to the knee, a stirrup fixed to the lever and designed to prevent a sideways movement of the leg relative to the lever, and a strap which prevents longitudinal movement of the leg in relation to the lever. The rigid inner boot stops under the ankle and does not appear to block its movement. In actual fact, when the boot is held in a ski binding, the foot is blocked in the boot and the ankle articulation is blocked. The link between the leg and ankle is made by the lever that transmits the effort to the skis so as to allow the skier to direct the skis.
The aim of this boot is to avoid a certain number of problems associated with hard shell boots, in particular those due to compression of the foot in the shoe (bursitis, painful ankle bones, etc.). Unfortunately, this system does not allow using the muscular and particular locking of the whole leg. So, a certain number of problems persist and others appear.
The link between the leg and the ski is made just below the knee. This implies a risk of displacing and drawing of the knee. This “drawing” is very frequent with those suffering from laxity or damage in knee ligaments. This can also cause inflammation of knee ligaments as well as compression of the glands and Thorel's bundle. This link creates a compression and crushing of the posterior tibial artery, restricting irrigation of the lower leg. This strap is also directly against the fibula. It blocks the displacement of the latter which, during each leg movement, is normally displaced both in rotation and in translation.
The fact of blocking movements of the fibula causes pain and eliminates the natural particular and muscular blocking of the leg. Another problem associated with using a strap is the transmission of movement from the leg to the ski. If the strap is not very taut, this transmission is not perfect and the skis are difficult to direct. For transmission to be made in a reliable manner, it is essential that the leg cannot move at all in the strap. This implies that the strap must be very tight. It can result in pain of the same sort that appears with the use of hard shoes or boots.
Lastly, a major problem with this boot and its binding stems from the fact that the inner boot is firmly fixed in the binding. Although the ankle is not blocked by the boot itself, the rigid holding of the boot in the binding prevents natural movements of the foot, as is explained in detail below.
There are other documents describing sports shoes or boots designed to leave articulation of the ankle free. Among documents, the French patent applications published under No. FR-A-2 758 093 and FR-A-2 745 988 can be mentioned as well as the German publication No. DE 27 18 939.
The French patent application No. FR-A-2 758 093 describes an in-line roller skate formed by a conventional boot, a sole interdependent of the roller skates, a platform on which the boot rests, and a rigid extension linking the sole to the leg of the wearer. The rigid extension holds the leg through the use of a ring. This extension is mobile and can move forwards and backwards, but not sideways.
Given that the natural movement of the ankle implies also a sideways rotation during its forwards or backwards rotation, as the rotation axis of the ankle is not horizontal and perpendicular to the symmetrical line of the human body, the fact of stopping lateral rotation blocks rotation of the ankle at least partially. A chain displacement of leg articulations as a whole is therefore impossible, for one of the movements is blocked.
The German publication No. DE 27 18 939 describes a ski boot which can be used with a conventional inner boot. This boot comprises a shell in which the inner boot is immobilized by using air pads. The aim of this invention is to firmly maintain the foot in the shell, whilst avoiding restrictive zones. The fact of maintaining the foot stops natural movement of the leg.
Lastly, the French application No. FR-A-2 745 988 describes a sports shoe or boot comprising a rigid sole, a low drag-link which ends under the ankle and a guiding element which permits rotation of the tibia forwards, while at the same time preventing a sideways movement.
As is described in detail hereafter, all movement of the leg implies a coordinated movement of the ankle, knee and hip. The fact of preventing the movement of one of these articulations, even i
Davis & Bujold PLLC
Stashick Anthony D.
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