Recent training shoe test

Training shoe test summer 2017

Training shoes are one kind of sport shoes characterized by a requirement profile that is broad and difficult to define. They need to functionally support the athlete in different areas of training, which make great varying demands on the training shoes. In strength training especially stability and traction play an important role, whereas dynamic and reactive training contents require flexibility, marginal weight and great forefoot cushioning. Additionally, running in different intensities still belong to the basics of the general training concept and gets solicited accordingly by the leading brand manufactures. Therefore, a training shoe should feature high comfort and functionality while running. During high intensive training, especially indoors, a lot of heat and sweat is produced, hence climatic characteristics (temperature and moisture) of the foot should be considered, too. To adequately test the training shoe with the broad requirements, the training shoe test at hand consists of (a) a biomechanical part with 3D gait analysis and (b) a subjective part with subjective evaluation of experienced participants that completed a training circle.

Besides the training shoe of crivit PRO, we tested the two benchmark shoes with the current top distribution (Nike Metcon 2017m Reebok Nano 2017) used as comparison shoes. During the gait analysis the Nike Pegasus was additionally integrated in the test as a running shoe, to biomechanically test the crivit PRO training shoe with it. We tested male and female shoe models that are shown in the following figure and table.


Summary of shoe parameters

While the shoe’s outside length and the forefoot width showed no appreciable differences, the crivit PRO – TS had a slightly smaller forefoot width compared to the other tested shoe models. All three tested training shoes were somewhat heavier than an ordinary running shoe, which is explained by the higher demand of stable materials and that should not make any difficulties. At the female shoe models, the Reebok Nano was slightly heavier compared to the two other training shoes; concerning the male shoes, the crivit PRO – TS was heavier than the tested benchmark shoes.


Ground contact time

The ground contact time describes the retention period of the foot on the ground during one step. Common values while running vary between 200-300ms. Deviation of these standard values suggest an adjustment of the running technique, like a shift to forefoot-running for example.

In our investigation, the values of all testes shoes stayed within the general value range, no significant differences existed between the shoes (p=0.149). Additionally, there were no differences compared to the running shoe Nike Pegasus. Therefore, it can be concluded that non of the tested shoes provokes a great change of the running technique.

Foot plant

Angle at initial footplant

The angle of footplant works as an indicator of the running technique, because he indicates whether a runner fulfills a forefoot, midfoot or backfoot footplant. In general, round about 70% of all runners make a backfoot run. Hence shoes with only a marginal cushioning can lead to a shift from a backfoot to a forefoot running technique. Thereby runners compensate the missing cushioning of the shoe and enables mechanisms produce naturally by the body to cushion the impact load of the initial ground contact. Through these adaptions, other structures can be stressed in a great extend. Therefore, runners should be informed about these kind of shoes, that force runners to make such adaptions. On this account we analyzed the angle at initial footplant.

Even though the subjects showed a backfoot footplant in all shoe conditions with angle at initial footplant ranging between 22 and 25,5°. A significant difference of 2,5° was solely measured between the Nike Pegasus and the Nike Metcon, which can possibly be explained by a very stiff and backward positioned construction of the sole of the Nike Metcon. The crivit PRO- TS did not differ from the other tested shoes and was most likely geared to the values from the running shoe Nike Pegasus.

 

Maximum velocity of plantar flexion

The maximum velocity of plantar flexion unfolds during backfoot running through the foot’s hinge down directly after initial ground contact. By the use of running shoes, the lever around the rotation axis within the ankle joint increases, which leads to a higher angular velocity of the foot after the first heel-ground-contact, in which the foot shifts to an even footposition during the stance phase. If the angular velocity is too high, a greater load of the M. tibialis anterior, the muscle that is responsible for the plantar flexion of the foot. This can lead to muscle soreness, or in the worse case, to overuse symptoms in the front section of the shank. Therefore, the running shoe design generally tries to keep the lever as small as possible by incorporating for example a crash-pad at the back part of the heel. Thereby the distance between the initial contact point and the rotation axis of the ankle joint is reduced.

No significant differences of the velocity of plantar flexion could be found in all tested shoes (p=0.503). The crivit PRO-TS and the Nike Pegasus had the lowest velocities, whereas the other two benchmark shoes showed 3-6% higher values. However, these differences did not reach significance. An explanation might be the lever at the heel of the benchmark shoes that is unfavorably raised, so that the Nike Metcon with its backward overhanging sole-construction and the Reebok Nano with a very stiff sole reach higher values.

 

Cushioning

Loading rate

Cushioning is one of the most important characteristics of running shoes and it can be evaluated validly through the biomechanical parameter loading rate (s.a.). In this study the loading rate showed significant differences (p=0.000).  The training shoe with the greatest loading rate was the crivit PRO-TS, whereas the other two training shoes showed small loading rates. The running shoe Nike Pegasus reached valued that were between the benchmark training shoes and the crivit PRO-TS. The construction of the sole of the crivit PRO – TS is comparatively hard and the deflection through a small height of the sole very short, so that a ‘snap through’ of the heel can explain the higher values. However, the cushioning values range only 17% above those from a very good running shoe, hence the cushioning of this training shoe can still be rated adequately for training purposes.

Pronation

To evaluate the control of pronation, two parameters are used. On the one hand the maximum pronation (the inward roll of the foot in the lower ankle joint) and on the other hand the maximum velocity of pronation. Especially the maximum velocity of pronation appears consistently in the current literature in context with the origin of overuse injuries. In general, there exists a tendency that the smaller the pronation value, the better the stability characteristics of a shoe. The normal range (dependent on the method of measurement) is located fort he maximum pronation values of running around 10°.

In the present study no significant differences could be found within all tested shoe conditions neither for the maximum angle of pronation, nor for the maximum velocity of pronation. By trend, the crivit PRO –TS showed the greatest restriction of pronation. Although non of the tested shoes was displayed as a high stability shoe with high pronation control, all tested models showed small valued of pronation and therefore a good control of stability. This can be explained by a rather flat sole-construction, which minimizes the pronation-lever through a small distance between foot and ground and thereby the pronation movement is not unfavorably influenced.

Maximum velocity of pronation

Maximum pronation

 

Knee angle

Runners can make an increased use of the body’s own cushioning, if the running shoe has a small cushioning effect. In the context of backfoot running, the ankle joint plays a smaller role as the knee joint, which can be activated for the cushioning performance produced by the body. This would occur with a different angle of knee flexion in the landing and at maximum knee flexion.

In this study, the knee angle at initial ground contact or at maximum knee flexion showed no significant differences between the testes shoe models.

Knee angle at initial ground contact

 

Maximum knee flexion

 

Conclusion

Even though a training shoe is not constructed for running in particular, the three tested training shoes showed characteristics during running, which are comparable to those of a well-established running shoe. Therefore, from a biomechanical point of view there is no objection for the usage of training shoes in training sessions with a high part of running as well as for the warm-up with running units. However, it is not recommended to generally replace training shoes for running shoes, because especially the very small height difference between forefoot and backfoot (all three testes training shoes have less than 1cm height difference) produces a very high tension on the Achilles tendon. Particularly athletes that are used to high heels in their running shoes, the thereby produced stress can lead to overload injuries of the Achilles tendon due to high training volumes.

The tested training shoe crivit PRO – TS showed good biomechanical characteristics in the laboratory test without exception and it is comparable to the both benchmark models from Nike and Reebok. Whereas the positive valued for the control of pronation is marked as its strength, the cushioning characteristics lowers one’s sights.

No processing defects were observed in any of the tested shoe conditions in the present test.


Subjective testing

During the subjective testing, the participants completed with each of the three training shoes a training circle consisting of five exercises. Subsequent to the execution of the five stations, the subjects were asked to answer an online questionnaire with items to cushioning, traction, flexibility and shoe-climate, before the repeated the exercises with the next shoe model.

Cushioning

Training includes various exercises in which athletes land on their forefoot like jumps, sprints, drop-jump-landings. Therefore, a good cushioning of the forefoot is reasonable. However, the cushioning should not be too soft, because the power efficiency, stability and ground contact perception will be reduced through a too much cushioning. Values ranging in the middle of the scale are perceived as the ideal assessment.

All subjects rated the crivit PRO – TS (47/100) and the Nike Metcon (45/100) softer than the Reebok Nano (29,5/100). Even more explicit was the rating of the backfoot-cushioning: the Reebok Nano was assessed very hard with 25/100, while the crivit PRO – TS and the Nike Metcon were rated with each 45/100 medium hardness, neither too soft, nor too hard – therefore ideal.

Forefoot Cushioning

Backfoot Cushioning

Traction

Unlike simple running training, fitness training reveal movements that require a better traction / adhesion of the shoe. Especially decelerating-, cutting- and accession-movements need good traction. Moreover, athletes benefit at certain exercises, like the ones in our testing circle (burpees and mountainclimbers) from a shoe with high traction in the shoe’s center line to optimally push off the ground.

Participants fortunately rated the perceived traction of all tested shoe conditions with values between 67 and 77 of 100, which stands for good – very good traction characteristics. No significant difference could be found between the shoe models.

 

Flexibility

The requirement demand of training shoes includes a high degree of shoe-flexibility. Shoes associated with athletic strength sports follows the guidelines for weightlifter footwear that features a very high stiffness. Whereas fitness oriented footwear shows a high degree of flexibility. An allround training shoe therefore requires an average till high degree of flexibility.

In the present study, a bisection of the tested models happened again. The Reebok Nano showed a significant higher stiffness compared to the two other tested conditions. Nike Metcon and crivit PRO – TS showed medium flexibility, without significant differences among each other.

 

Comfort

Nike Metcon and crivit PRO – TS were rated with 3,8 und 3,6 of five stars, which stand for a good and slightly better fit for our participants compare to the Reebok Nano (3,0). However, the crivit PRO – TS showed small weaknesses in the fixation of the foot in the shoe through lacing compared to the two benchmark shoes. Those differences did not reach significance.

Concerning the shoe climate, all tested training shoes had a good climate, which was perceived as neither too damp, nor too warm.

Fitting

 

Shoe climate – dampness

Shoe climate – temperature

 

Overall impression

The participants rated the tested shoes with 2,8 till 3,9 of five stars, satisfying till good. The best overall rating had the Nike Metcon (3,9) followed by the crivit PRO – TS (3,2) and the Reebok Nano (2,7).

Considering the general present benefit due to the brand awareness of the benchmark shoes, the good rating of the overall impression of the crivit PRO – TS has to be evaluated very positively.


Conclusion and overall evaluation

In the present test the crivit PRO – TS could proofe itself as a training shoe. In the biomechanical testing, the crivit PRO – TS showed similar values like the benchmark shoes, with a small excellence in pronation control and slight disadvantages in the cushioning characteristics. However, the cushioning values still reached acceptable values and those were not negatively perceived by the subjects. In contrast, in the subjective assessment, the crivit PRO – TS was rated similar positive in the backfoot- as well as the forefoot cushioning compared to the Nike Metcon.

Altogether, the crivit PRO – TS satisfied participants and received positive values in the subjective testing. In combination with the good results of the biomechanical gait analysis, we can advise the crivit PRO – TS as a good allround training shoe that can also be used for short till medium running exercises.