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X-Line: 15 years and a design that is still going strong

Movements of the human body are described in each of the three planes of motion, which gives us the concept of 3-D or three dimension. These planes allow movement up and down, side to side and forward and backwards. In biomechanics we give each of these movements a letter, y, for up and down, z for side to side, and x for backward and forward. Because most of the bodies movement is about going forward, the joints of our legs are shaped to give us most motion in this x plane of motion, also known as the sagittal plane.

The foot is no different with most motion allowing us to pass over the foot. To make this motion more efficient, the foot has evolved an arch, which drops to allow the ankle to bend over the foot so our body can pass forward. This drop in the arch stretches muscles and tendons that lie under the foot, while forward motion of the ankle stretches the powerful Achilles tendon. This stores energy (known as potential energy), which is released once the heel rises off the ground. This gives us an extremely efficient type of walking style, which although not one of the fastest forms of locomotion in the animal world, is one of the most efficient.

The X-Line insole is designed to enhance this natural cycle of motion in the sagittal plane. Many insoles are designed to block motion of the foot, as it was once thought that arch flattening was a bad thing (known as pronation). Many insoles are designed to hold the foot in subtalar neutral position, a special position, which was once thought to be the position the foot worked best in. We do not believe this concept, as pronation is a motion that allows the foot to store energy and release it. The X-Line insole has sagittal plane support, preventing over flattening of the arches of the foot, but not blocking the natural motion.

While highly successful in providing basic support as it is, the X-line is designed to be adjusted to the patient’s individual needs, with most of the essential sagittal plane support already built-in. Medial and lateral rear-foot and forefoot posts, as well as heel lifts can be quickly added to the X-Line, with a range of purpose-designed posts for the medial or lateral posting of the heel that can be ordered with the insole. For this reason, the X-line has a totally flat bottom surface for easy application of extra supports.

The X-line is available in two densities, the standard X-line  (shore 45) and the high-density version X-line 70 (shore 70), which offers the higher durability of a custom EVA device with all the tri-planar and tri-contoured support of the standard X-line. We recommend less posting adjustment is necessary with the X-line 70 compared to the standard device to maintain patient comfort.

With the X-line insole orthotic device you will be able to provide your patients with professional-looking, tailored orthoses at a highly competitive price.

Andy and Tim – still at the heart of the development team at .  Come and talk to us at the forthcoming COP conference in Harrogate.

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