Dr Mel Siff Blog

Barefoot training is currenlty popular, here is Dr Mel Siff’s take on the topic of should we train with shoes?

In view of all the comments on the use of shoes in sport, here are some
extracts from our “Supertraining” book (Siff & Verkhoshansky 1999 Ch that
are relevant to the discussion.

Later I have provided a collection of websites that will also shed some more
light on this issue.

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SHOES AND SAFETY

Shoe manufacturers would have athletes believe that the primary solution to
most athletic injuries is the wearing of expensive footwear. Ailments such as
shin splints, iliotibial band syndrome and peripatellar pain are attributed
variously to excessive shock loading of the limbs, pronation or supination.

Research, however, reveals that fewer injuries occur among those who wear
thin soled shoes and that current athletic footwear may even be injurious
(Robbins et al, 1988). The paradoxical observation of a much lower incidence
of running injuries reported in barefoot populations implies that modern
running shoes may produce injuries that normally would not occur without
their use (Robbins & Hanna, 1987). Furthermore, running shoes seem to be
associated with fewer injuries in fitness classes than so-called ‘aerobics
shoes’. Nigg (1986) reports that, on firm shock absorbing mats, the
difference in heel strike force is minimal between bare feet, thick-soled
shoes and thin-soled shoes. Nigg also points out that the use of any shoe
usually increases the tendency of the foot to pronate, particularly if the
impact forces are smaller.

Moreover, several studies have shown that there is no correlation between the
amount of shoe cushioning and impact absorption by footwear during locomotion
(Robbins et al, 1988; Clarke et al, 1982). Similarly, epidemiological
studies have failed to provide evidence that expensive modern athletic
footwear enhances protection from injury to the lower extremities (Caspersen
et al, 1984; Powell et al, 1986). Thus, it would appear that safety of the
lower extremity is not simply a consequence of suitable footwear, but of
learning how to move the body efficiently while wearing a specific type of
shoe.

SHOE DESIGN

Clearly, the science of athletic shoe design is far from being exact. For inst
ance, the current fo-cus is on foot pronation. Other possible causes of
injury such as toe, ankle, knee and hip movement in three dimensions are
largely neglected. Moreover, footwear design is based almost exclusively on
theoretical models which postulate that shock loading and the inability of
the human anatomy to adapt to this loading are the primary causes of running
injuries. This becomes evident from the claims of manufacturers that their
specific shoes correct excessive pronation, control the rearfoot, offer
superior arch support or absorb shock effectively. These shoes do not modify
the impact forces during locomotion, a fact which casts severe doubt on the
cushioning philosophy that forms the foundation of all current shoe design.

Studies by Robbins et al (1988) have shown that the sole of the bare foot
exhibits a powerful plantar surface protective response which diminishes
plantar loading on ground contact, thereby reducing the risk of damage from
overloading during locomotion. Their work also revealed that this response
was not apparent among subjects who always wear shoes, especially the highly
shock-absorbing shoes generally worn by runners. They concluded this
protective response prevents injury by decreasing system rigidity, thereby
diminishing the peak force during foot impact. The lack of the protective
response among shoe wearers apparently is due to diminished plantar sensory
feedback, possibly combined with mechanical interference with arch deflection
by shoe laces, heel counters and arch supports (Robbins et al, 1988). It
would seem that sufficient regular locomotor activity without footwear should
be done daily to maintain the sensitivity of the plantar protective reflex
and that less emphasis should be concentrated on designing passive
shock-absorbing or pronation-modifying shoes.

Little work has been done on relating lower limb injury to anthropometric
factors such as bodymass, height or limb length, or other factors including
level of qualification, movement intensity, muscle fibre distribution,
patterns of EMG activity, feedback processes or bone density. No research
has examined aerobics or ‘cross training’ shoes with this degree of
thoroughness, nor has it carried out entirely satisfactory three-dimensional
studies of all physical factors influencing the efficiency of whole body
movement from initiation to termination of a locomotor action, in particular
with respect to the optimal design of any shoe.

Irrespective of how well designed shoes are, they must be used correctly in
different move-ments. In doing so the user must be aware that shoes always
reduce the proprioceptive and tactile sensitivity to the surface on which
they are being used.

Another reflex is also worthy of attention. Forces exerted on the shoe are
delayed in being transmitted through its shock absorbing sole en route to the
foot. The reflex positive supporting reaction (see 3.5.3), which normally
operates highly effi-ciently in bare feet to produce strong reflex extension
of the legs and stabilisation of the body, is delayed in facilitating rapid
cybernetic control and correction of unsafe movements when shoes are worn.
In particular, the locus of application of pres-sure to the surface of the
sole of the foot determines the position to which the limb will extend
(Guyton, 1984), so that inappropriate geometry of the shoe can significantly
alter the pattern of recruitment of the muscles of the lower extremities.

In contrast, the use of bare feet on firm, very high density chip-foam mats
in the average fitness class preserves proprioceptive efficiency, lowers the
centre of gravity of the body and, unlike shoes, does not increase the lever
arm length from the point of heel contact to the ankle joint, thereby
reducing the moments of force about all joints of the lower limb.

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If anyone is interested in the biomechanics of shoe design and use, the
following book is very informative:

Nigg, B The Biomechanics of Running Shoes 1986

There are several useful websites on gait analysis and footwear that are also
relevant. Here is a small sample of ones that you might enjoy:

http://www.barefooters.org/medicine/med_sci_sports_exer-23.2.html (Barefoot
Running)
http://www.barefooters.org/medicine/ (Bare feet are healthier)
http://www.uni-essen.de/~qpd800/FWISB/sneakers.html (Footwear Biomechanics)
http://www.ortho.rush.edu/gait/cases1.htm (Gait Analysis – Educational site)
http://www.polyu.edu.hk:80/cga/ (Clinical Gait Analysis)

Dr Mel Siff

Selection of a sports shoe depends on the type of sport, the position or role
that one plays in that sport and individual needs.

One of the worst mistakes that one can make regarding selection of a gym
training shoe is to do so on the basis of information on running shoes or
from the world of general footwear.

For information on selecting a running shoe, consult the following website:

http://www.clark.net/pub/pribut/shoes.html

If you intend using a shoe for lifting heavier purposes, then it is important
to avoid any shoe that offers soft cushioning, alters natural ‘pronation’ or
’supination’ patterns, or constrains the foot or ankle from moving or
stabilising according to the needs of the different lifts.

It is also important to note, as many powerlifters do, that a shoe that is
suitable for squatting is not necessarily suitable for deadlifting. A
higher heel may be necessary for some lifters to enable them to squat
comfortably throughout the required range of movement, but during the
deadlifts, that sort of heel will tilt the body forwards and move the load
further from the body, thereby making the lift more difficult and dangerous.
This is why many powerlifters actually do lift in something that is as close
as possible to barefeet, namely a wrestling type shoe or slipper with a sole
that affords good grip.

In both Weightlifting and Powerlifting, the use of any shoe with a sole that
compresses in any direction or whose ‘uppers’ tilt in any direction, is
definitely inappropriate. For example, during the Olympic Jerk, if the heel
of the shoe compresses during the dip, some of the energy is lost that is
necessary for the subsequent overhead drive or the body will deviate from its
optimal driving position, resulting either in a more difficult or
unsuccessful lift.

In many sports, of course, the weight of the shoe can have a profound effect
on performance, because movement of a limb that is loaded requires far more
energy than one that is unloaded. This is why lightness of shoe is
especially important in running sports. In Powerlifting, this is not really
an important issue, but in Weightlifting, where the feet may move at speed, a
lighter shoe can make a difference to agility.

Finally, it should be remembered that one has to learn how to use every
different shoe. The effectiveness of shoe lies not only in its mechanical
properties or engineering design, but also the motor pattern that one
acquires in using that shoe. This is major reason why so many technically
‘ideal’ or ergonomically correct shoes or orthotic devices may not be of much
value to an athlete – all too often it is not stressed that safety and
efficiency of movement of the lower extremities depend heavily on motor
control processes, including the reflex management of factors such as the
damping ratio and mechanical stiffness of the joints.

In this regard, it has to be emphasised that the incidence of injuries to the
lower limbs tends to be higher among those who run and participate in
aerobics classes with shoes than those who do those activities barefooted.

The following references are provide useful information about foot mechanics
and injuries:

Nigg B, ed (1986) “The Biomechanics of Running Shoes”

Caspersen C, Powell K, Koplan P et al (1984) The incidence of injuries and
hazards in recreational and fitness runners Med Sci Sports Exerc 16: 113

Clarke T, Frederick E & Cooper L (1982) The effects of shoe cushioning upon
selected force and temporal patterns in running Med Sci Sports Exerc 14:
144

Robbins S & Hanna A (1987) Running related injury prevention through
barefoot adaptations Med Sci Sports Exerc 19: 148-156

Robbins S, Hanna A & Gouw G (1988) Overload protection: avoidance response
to heavy plantar surface loading Med Sci Sports Exerc 20(1) : 85-92

Powell K, Kohl H, Caspersen C & Blair S (1986) An epidemiological
perspective on the causes of running injuries Phys Sports Medicine 14:
100-114

Dr Mel C Siff