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STUDY 1: Energy Use while Training With Jump Boots
Recently, an Australian study has proved
that Jump Boots spared articulations. It would be interesting to know energetic cost of
the Jump Boots compared to an aerobic activity such as jogging. The aim is to know with
what intensity it is better to practice it while raising the consumption of oxygen and the
energetic cost...Read More
STUDY 2: Joint Impact while Training With Jump Boots
Impact force experienced during running has been recognized as a source of injury. Much
less is known about these phenomena during Jump Boots, a revolution in shoe design,
which includes a spring attached to the sole of the shoe. The purpose of this study was to
investigate the impact characteristics for Jump Boots and to test the hypothesis that
there is lower impact shock during Jump Boots than in running...Read More
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Physiology Study
Recently, an Australian study has proved
that Jump Boots spared articulations. It would be interesting to know energetic cost of
the Jump Boots compared to an aerobic activity such as jogging. The aim is to know with
what intensity it is better to practice it while raising the consumption of oxygen and the
energetic cost.
In the beginning, this product was created to reduce the impact on the articulations of
the knees and ankles while jogging; it was then improved to be used in Fitness centres for
aerobic courses.
Aim
The experience consists in measuring the
difference of energetic cost that is created by using Jump Boots instead of usual shoes.
These Jump Boots have a rigid shell (the shoe) that is fixed on two semi-spherical
lamellas that act as a spring. A test in a laboratory is made in order to measure the
exchanges of gas and to calculate the real cost of the exercise at each speed.
Subjects
8 volunteers, male and females, participated
the experience. All of them weekly practice one or many sportive activities, and they have
already used the Jump Boots. The anthropometrical characteristics, means and standard
deviations are shown in the table xxx.
Protocol
The subjects accomplished a progressive
exercise that permitted to determine the consumption of oxygen. It is realised on a moving
walkway. The selection of the speed is possible thanks to a console of control. The speed
of the moving walkway has been checked with and without the subject. It corresponds to the
speed shown on the console. The exercise is made with a slope of OO/o
and consists in running at different speeds on a moving walkway
(8,10 and 12 kmlh).Each stage lasts 3 minutes, so that a state of equilibrium is reached.
There is no pause between the succession of the stages.
The first half of the group starts with the Jump Boots and the other half with usual
shoes. 45 minutes
later, the test is repeated by exchanging the different shoes.
The cardiac frequency is continuously measured by a Baumanns belt (BHL 6000) and
is processed by the program AncarElite 2.0 (Baumann).
Ventilation (VeBTps) is obtained by integrating the measure of the flow. Oxygen
consumption (Vo2 STPD) and carbonic gas
production are obtained thanks to Haldanes equation. The "breathing rate"
(QR) is also calculated. All factors are calculated within an mean of 30 seconds, while
taking into account the temperature and the pressure.
Results
The results of energetic costs, ventilation,
breathing rate, oxygen consumption and cardiac frequency are presented for each subject in
the table 2. We can notice that half of the subjects have reached or are above their
anaerobic limit while using the Jump Boots at 12 km/h. Mean values, standard deviation
and the statistic values that are presented above are exposed in the table 3. The mean
energetic cost obtained by the 8 subjects, at 8, 10 and 12 km/h with the Jump Boots is
respectively of 154, 165 and 206 Cal/mm/kg. With absolute or relative value (1kg), the
oxygen consumption is significantly higher (p<O,05) with the Jump Boots compared to
jogging. This difference is more important at lower speeds than at higher speeds. Indeed,
at 8 and 10 km/h, the difference varies between 20 and 13%, while at 12 km/h, this
variation is only of 7%. This diminution is also valid for the values of energetic expense
in kcal/min. Indeed, with the Jump Boots, we obtain values that are superior of 19% at 8
km/h and 7% at 12km/h. Figure 1 and 2 illustrate two mean values of table 3.
Discussion
The results that are obtained confirm the
previous hypothesis: the energetic expense is higher, at a same speed, in Jump Boots
than in jogging. Yet, it is interesting to notice that the more the speed increases, the
more the difference diminishes. This could spring from the fact that many subjects at a
speed of 12 km/h have reached or gone beyond their anaerobic limit (QR>1, showing the
anaerobic phase) and so the values of oxygen consumption (with or without Jump Boots)
come up to a common level. Furthermore, for these same subjects, no significant difference
concerning cardiac frequency is observed at 12 km/h, which would confirm the hypothesis
that these subjects are very close to their "limit". Yet, the more the speed
increases, the more the rate increases, the more the time of contact decreases, so the use
of elasticity of the Jump Boots is very much diminished or even non-existent. The
biomechanical factors should also be taken into account. At low speed, it is possible to
entirely exploit the elasticity of the blades of the Jump Boots.
The movement of the Jump Boots imitates
more and more the movement of jogging, which would diminish the energetic expense per
kilometre and consequently the oxygen consumption. Besides, with the increase of the
speed, the subject tends to bend forward, which prevent him to make the best use of the
Jump Boots. Indeed, the Jump Boots are built so that the maximum elasticity is
obtained when the subject presses vertically on the shoes. So it would be better to work
at low speed or at low rate.
It also worth noticing that with the subjects that often use the Jump Boots (subjects
2, 4 and 6), the difference of their oxygen consumption is 9o/o at 8 km/h and is
negligible at 12 km/h. So, part of the differences obtained in average results can be
explained by lower performances on behalf of the subject that are not used to it.
Conclusion
The Jump Boots are interesting for people
who wish to have a important energetic expense while sparing their articulations. We can
notice that at a same speed, the energetic expense with the Jump Boots is the same as by
jogging at a speed of 2 km/h inferior. The Jump Boots spare the articulations of the
knees and ankles by a diminution of the shocks. Finally, the use of the Jump Boots can
be therefore useful in sportive re-education of athletes. Note: a complementary study is
in progress.
We are very thankful to Doctor Gremions collaboration at the orthopaedic hospital
in Lausanne.
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Impact Study
Impact force experienced during running has been recognized as a source of injury. Much
less is known about these phenomena during Jump Boots, a revolution in shoe design,
which includes a spring attached to the sole of the shoe. The purpose of this study was to
investigate the impact characteristics for Jump Boots and to test the hypothesis that
there is lower impact shock during Jump Boots than in running. 11 athletes (6 males and 5
females subjects) participated in the study. Each completed two different trials
with low-mass accelerometers attached to the proximal tibia and to the lumbar spine (L5).
Each performed three trials of vertical jumping and a trial of running for 20 seconds
at a self-pace, wearing his or her normal training shoes and the Jump Boots.
Our results showed that the Kangoo Jump condition exhibited a significant reduction of the
acceleration force present during running. We observed an acceleration of 7g at the tibia
and 2.5g at the lumbar spine with the training shoes; with the Jump Boots, the
acceleration impact force was only 3.5g at the tibia and 1.9g at the lumbar spine.It is
concluded that Jump Boots running results in less impact shock to the body with each
foot contact and may be a useful exercise modality for the rehabilitation in case of
reducing impact shock during aerobic training.Impact, Shock Attenuation, Accelerometers,
Jump Boots
Introduction
Walking
and running are well known as exercises that can improve cardiovascular endurance,
strengthen muscles and reduce body fat. Under normal circumstances of running or jumping,
the elastic compliance of the internal structure of the foot such as the internal arch and
tendons reduce impact forces and provide only about 40 to 60% energy return.
One aspect of running which has been well-documented is the impact
shock transmitted through the body when the foot collides with the ground. This event
occurs about 6.000 times in a race of 10 km. The shock wave is transmitted across the
structures of the lower extremity and upward through the sine to the head. One positive
aspect of the shock is to stimulate the bone mass density of the lower extremities.
However repetitive landings and impacts have also been implicated in degenerative diseases
for the knees and the hips.
In case of injuries, it seems to be important to restore the full
ability to compete using different methods which diminish joint loading without
diminishing the capacity to improve the cardiovascular endurance.
Recently, there has been a fitness shoe system developed, which is fun
the Jump Boots shoe, that would appear to attenuate the impact of high acceleration
forces. The shoe is constructed in a similar fashion to that of an inline roller skate,
with the exception of wheels. Under the shoe is an elliptical arch stretching from the toe
to the heel of the shoe that is bisected with a removable band. At each step we observe a
depression of the arch that works like a spring and returns to its previous form.
The purpose of this study was to examine impact shock and the
attenuation characteristics during Jump Boots running. To that end we have measured
impact acceleration at the tibia and lumbar spine during Kangoo jumping and running and
compared these results with data collected from the same subjects while running with
normal training shoes.
Eleven healthy subjects (mean +1- SD age 31+!- 7 yr.; height 176
+1- 11 cm.; mass: 64.6 +1- 9 kg.), 6 males and 5 females volunteered
to take part in the study. They were sport teachers in fitness centers and none reported
any significant musculoskeletal disorder. All subjects were trained in Jump Boots. They
performed trials in each of 2 conditions: 2 jogging on a trail of 50 meters at self pace,
wearing his or her normal training shoes and the Jump Boots
The impact shock in each trial was quantified by measurement of the peak
acceleration (PA) that occurred just after foot landing in each stance phase at the
proximal tibia level and at the lumbar spine level by 3 piezoresistive accelerometers (IC
Sensors 3021) oriented in orthogonal directions.
The purpose of this study was to investigate the peak acceleration
force characteristics when jogging in a pair of Jump Boots compared to normal training
shoes. The results clearly show that the Jump Boots result in considerable less impact
forces being transferred to the lower limbs compared to the normal training shoes. In
particular, the impulse during first initial contact with the ground is reduced some 50%.
Furthermore, the length of the step measured by the time in the air is greater with
Kangoo shoes than with training shoes. This is a valuable contribution to attenuate the
frequencies of impacts of the lower limb with the ground for the same intensity of the
physical wok.
The frequency analysis of tibial and lumbar spine acceleration showed
that Jump Boots running condition demonstrated less impact acceleration, with lower
values than running with training shoes for peak and median frequency. The frequency range
is associated with the collision of the foot to the ground and this frequency band may be
implicated in musculoskeletal injuries. Some have suggested that removal of higher
frequencies may reduce the likelihood of degenerative joint diseases. Jump Boots may
therefore prove to be an aerobic exercise workout that is less harmful to the joints in
terms of repetitive impacts of the foot and ground.
The results of the frequency analysis for the running trials agree with
other studies. The running condition with training shoes displayed peaks between 6 and 10
g at the tibia level as found in previous studies. With Jump Boots, the peak
acceleration is 50% lower. The attenuation of the force impact is significant.
These preliminary results showed promise for the use of Jump Boots
for low impact exercise such as recreational jogging or fitness. The uninjured person may
be able to continue with a high volume ground based activity without the impact injury
risk inherent in the sport activity. Further there may be application of these shoes in
rehabilitating patients with lower limb injuries. The patients could perform activities
similar to normal jogging, maintaining cardiovascular endurance but in a lower impact
situation. Jogging with Jump Boots may be a valuable intermediate step in the
rehabilitation process.
Training for long distance races is another possible use for Jump Boots. Top level athletes have to train more than 10 hours in the week. To reduce the risk
of an overuse injury, many athletes perform aqua jogging, an other training method to
increase the aerobic capacity. Jump Boots shoes minimise the impacts with the ground and
offer a good opportunity to train outdoor without the risk of injuries like stress
fractures and tendinitis.
The time domain variables output for statistical analysis were PA tibia and PA lumbar spine. The main effect of
condition for these dependent variables was tested using a within-subject,
repeated-measures ANO VA.
Results
Typical examples of
tibial and spine accelerometer signals during the stance phase for both running with
Kangoo and training shoes are shown in figure 1 and 2.
During running we observed a lower significant peak impact for Kangoo shoes (P = 0.00 1). Mean PA tibia value for the Kangoo running
condition was 4 G, the mean spine value, 2.5 G whereas running with normal training
shoes showed higher values of force acceleration; 7.8 G PA tibial and 2.3 PA spine.
The length of the step measured by the time in air is greater with Kangoo shoes: 143 cm
with Jump Boots, 123 with training shoes.
Tables 1, 2 and 3 present a summary of all variables and the results of statistical
tests between conditions
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