Altra Impulse stability

ALTRA Running is an American brand that was born from a group of elite athletes who opted for different arguments to the traditional ones of the sports footwear industry. They realized that the design of most running shoes, rather than helping runners, was causing injuries. High heels increase the impact on the feet when landing and narrow toe boxes compress the toes, sacrificing their natural position.

They are committed to using technology in terms of cushioning but in an anatomical last design with a Footshape round toe and a radical bet on the drop, being ZERO in all their models, which requires an education in running technique for your enjoyment. This innovative combination of arguments favors the adoption of a low-impact running technique and allows the feet to move naturally and relaxed on all types of terrain.

I've been familiar with ALTRA 's running shoe construction for a couple of years now and I've tested some models with more cushioning, but I must admit that I was looking forward to testing this Impulse, a model with some stability.

Finally we can enjoy in Spain of a brand that defends different arguments, perhaps they are the ones that many running were looking for, distributed in Spain by Creixams Sporttotal.

Beautiful shoe with a very comfortable last, an asymmetrical instep adjustment, extra stability and with "zero drop ".

This Impulse is light with 255 gr, has a wide and minimalist upper, with hardly any thermosealing or reinforcements and the holes in the midsole that allow ventilation and facilitate the exit of water, something that can be valued in the middle of summer when you pour water over you or if you use them in competition. It has a correct cushioning thanks to the A-Bound / EVA and extra stability without losing flexibility combining Innerflex and StabiliPod technologies. This extra stability of the metatarsal area allows greater support of the 1st MTF joint, improving stability and impulsion, hence the name!

1-Midsole and Cushioning

Technology and performance

The midsole of the Impulse is 23 mm and has an overhang that provides greater support to the plantar arch in the internal and medial area and thus helps to stabilize the foot. The forefoot has 4 holes of various sizes that communicate with the internal part facilitating ventilation and water drainage.

The zero drop places the heel and forefoot at the same height from the ground, the defenders of this argument claim that it favors a low-impact running technique, naturally aligns the body posture and strengthens the calf muscles, weakened by running on high heels.

In this regard, it was Altra's founder, Golden Harper, who began molding soles to eliminate the excessive heel rise in traditional running shoes, which resulted in balancing the cushioning and cushioning of the heels with the cushioning and cushioning of the heels.

The result balanced the cushioning of body weight between the heel and forefoot, reducing the impact of the foot against the ground. It also calls for a different arrangement of the triceps suralis muscles (lower calf area) and the Achilles tendon and fascial complex, adapted to high-drop running.

The double-layer EVA midsole has a first layer of A-Bound, a softer rubber made from recycled materials that is located directly under the foot and its purpose is to try to reduce the first impact of the foot on the asphalt and, according to the advertising, to recover some of the compression energy. They literally say that "it is a layer of material that bounces between the asphalt and your feet" according to Altra the rubber used in the A-Bound compresses between two and three times less than those of the competition resisting more over time, something that is difficult to prove but certainly responds with a pleasant cushioning that is maintained over time. This Eva compound of the Impulse is harder than the one used in more cushioned models.

The NRS - Natural Ride System is a combination of rubber components of more discrete performance than the A Bound, and that form the 23 mm chassis of the midsole and in areas of the sole itself. The sole has a Stability pod rubber arch, harder and more resistant to abrasion in the metatarsal area and especially in the 1st MTF that provides stability and improves impulsion.

2 Last

The last of this Impulse is one of the most characteristic arguments, its FOOTSHAPE TOE BOX is based on a round toe but not excessive as in other models, with a design that perfectly allows the toes to move naturally, allowing the thumb to collaborate in the stability and propulsion something that is favored by the Stability Pod.

It has a 5 mm anatomical contour insole that is perforated and facilitates the exit of water to the ducts that communicate with the external holes of the midsole at the level of the forefoot.

Conventional Running shoes are characterized by sharp and slender toe boxes, which do not allow lateral movement of the toes, limiting their functionality. Altra's FootShape toe cap allows the toes to relax and expand naturally, with the thumb remaining straight. This improves stability and facilitates propulsion through the big toe improving running performance. This is an anatomical design of the shoe and applying the concept of ergonomics by facilitating the movement and natural stabilization of the foot at forefoot level.

I am convinced that an anatomical last with an ergonomic design is positive in all aspects and that most shoe brands should learn from Altra and apply it in all their models. In this Impulse the space for the toes is not excessive as in other models, in fact it is the last of this Impulse the most suitable for my foot type, I am delighted with them and I use them for all kinds of activities.

3 Upper

The most characteristic of this model is the clean upper without reinforcements and the asymmetrical and curved lacing adjustment system. The mesh is a wide exagonal Quick Dry breathable quick-drying mesh. It is a double layer with a fine hollow structure that facilitates breathability very well since it only has a thermo-sealed toe cap and a reinforcement on the outside.

The inside of the collar is relatively thin, but with enough padding to be comfortable. The tongue is relatively thin and wide, which allows the upper part of the instep to be well protected from the tension of the laces.

The adjustment system through eyelets arranged asymmetrically and in a curved arrangement as curved is the instep, achieves a fit proportional to the volume of the instep. The distance between the eyelets is narrower in the distal area and wider in the middle and then narrows again at the ankle collar. An ergonomic and anatomical design success.

4- Sole

The NRS - Natural Ride System is a combination of rubber components of more discreet performance than the A Bound, and that form the thick chassis of the midsole and in areas of the sole itself. The thick midsole block features a metatarsal parabola that tries to mirror the metatarsal location with its design. The outsole has reinforcements embedded in more resistant black rubber at the big toe and 2nd toe, protection of the metatarsal heads and InnerFlex grooves that promote flexibility in the longitudinal direction as if it were a guide of the footprint and transversely to facilitate flexibility in this direction.

The more abrasion resistant black rubber protection is also placed on the external part of the heel and external lateral part of the midfoot as well as on the phalanx of the big toe which facilitates propulsion and reduces wear.

Strengths :

The sole features a Stability pod rubber support, harder and abrasion resistant placed only in the metarsal area, especially stabilizes the 1st MTF which improves propulsion. Stabilizing the 1st MTF helps in propulsion and the increased support of the midsole at the plantar arch helps in the containment of the foot.

The adjustment system through eyelets arranged asymmetrically and in a curved arrangement, as curved is the instep, achieves a fit proportional to the volume of the instep. An ergonomic and anatomical design.

The zero drop favors the stimulation of the sural tendon muscle complex, making it possible with technique work to try to reduce the initial impact of the heel against the ground.

Opportunities for improvement:

Cushioning feels stiff compared to other Altra models.

Stabilizing the 1st MTF improves propulsion, but does not prevent the rearfoot and midfoot from pronating inward over time.

The 4 drainage holes are too many for water drainage and the increased ventilation of the sole is not noticeable. In addition, these transversal perforations in the midsole have a negative effect on stability, especially in the forefoot if you are a pronator.

A stability pod along the inner area of the sole would help to contain the foot. The more abrasion resistant black rubber protection is also placed on the external part of the heel and has a recess that facilitates heel entry, but it is an antithesis in a model in which the zero drop concept tries to avoid precisely that, heel entry.

The heel support is not rigid enough to hold the rearfoot in place for a stability model.

Absence of reflective elements

Conclusion and type of user

Trying these Impulse with their anatomical last, rounded toe cap, clean upper and peculiar asymmetrical fit system is recommended to all running enthusiasts. But that extra stability, especially in the big toe joint (1st MTF) which allows for improved propulsion, in my opinion is insufficient for those runners who need to control pronation. Therefore these Impulse are an ideal model for runners who require some forefoot stability but do not pronate excessively.

The upper is undoubtedly spectacular, but the libre mesh is unprotected and exposed to chafing, making it very vulnerable to wear. The water drainage holes are excessive in daily use and negatively affect the internal stability of the midsole. For all these reasons it is an ideal model for users looking for an ergonomic fit of the instep, an anatomical last and an extra simple stability and good water drainage. Perfect to compete in half marathons in summer and to use in triathlons, or in training sessions on very hot days when you are sure to pour water over yourself to cool down while running; with this impulse the water will drain out of the shoe easily, because it has plenty of holes...

Rating

• Comfort 9
• Lightweight 9
• Cushioning 7
• Flexibility 8
• Responsiveness 8
• Stability 9
• Grip 9