Biomechanical Analysis in Relation to Technique
Coaching in Boxing and the Martial Arts and Contact Sports
The
philosophy behind MACPAD is simple: it is all about providing safe, versatile
and above all, effective training for boxers, martial artists and athletes of
all ages and abilities. It has many advantages over conventional pads as
follows:
Safety
- The fixed hand
position decreases the risk of upper limb stress in coaches, particularly
of the wrist, elbow and shoulder.
- It mimics the
elasticity of a real opponent so making impact injury less likely for the
boxer.
Versatility
- MACPAD allows a
wider variety of punches and kicks due to its novel shape and movement
options facilitated.
- Coaches are able to
resist more powerful punches and kicks meaning that they are able to work
with a wider range of individuals.
- Ease of use allows
young athletes to work with each other reducing reliance on coach
availability for pad work.
Effectiveness
- MACPAD allows
faster more fluid combinations of moves to be used providing a less
stilted training regime.
- It mimics the
‘real’ opponent.
- It has the combined
efficacy of improving punching skills and enhancing aerobic and anaerobic
fitness levels and functional strength and power.
Of
the above, arguably safety is the most important quality of MACPAD as, without
it, neither the athlete nor the trainer could capitalise on its versatility and
effectiveness. In order to fully explain its safety, it is necessary to explore
the anatomy of the wrist, elbow and shoulder:
The Wrist
The wrist is formed where the distal aspect of the radius
and the fibrocartilage of the ulna join three of the four proximal carpal
bones. There are eight carpal bones in all, illustrated clearly
below. The carpal bones are gliding joints and are stabilized by
anterior, posterior, and connecting interosseous ligaments.
Carpal
Bones:
Proximal row: Pisiform; Triquetrum; Lunate; Navicular.
Distal row: Hamate; Capitate; Trapezoid; Trapezium.
Recent research
examining injuries resulting from resistance training activities have revealed
the surprising results that 60% of problems reported occur at the wrist and are
caused by forced hyperextension of the joint. Resulting conditions include
carpal tunnel syndrome, overgrowth of bones associated with the joint,
including the metacarpals, and nervous impingement, particularly at the radial
side. This has led to a radical change in the teaching points which should be
given to individuals participating in weight training in that the advice should
always be to maintain the wrist in a neutral position.
If consideration
is given to a boxing trainer holding conventional pads, the following dangers
are apparent:
·
If the pads are held
with ventrally facing palms, the wrists are continually extended at best and
forced into ballistic hyperextension by the impact of each punch thrown.
Advantages
of MACPAD
The
wrists are held in a neutral position; that is to say that the back of the hand
remained aligned with the forearm at all times.
The Elbow
The elbow is a
hinge joint lying where the humerus meets the radius and ulna. One of the 2
rounded surfaces of the humerus fits into a deep socket at the proximal end of
the ulna. The triceps muscle originates both at the scapula and the proximal
and of the humerus and attaches on the proximal end of the ulna. The primary
function of the triceps is to extend the arm at the elbow. When the elbow is
straight, the olecranon process, a projection at the end of the ulna, fits
against a hollow in the humerus and prevents the joint hyper-extending and
dislocating.
The other rounded
surface on the lower end of the humerus fits against a hollow in the upper end
of the radius. The biceps muscle originates at the scapula and proximal end of
the humerus and attaches at the proximal end of the radius. The biceps bring
about flexion at the elbow.
The unique
positioning and interaction of the bones belonging to the elbow joint allows
for a very small amount of rotation in addition to its more natural 2
dimensional hinge action. The rotational capability is easily exemplified by
considering hand to mouth eating motions.
Radius
Ulna
Humerus
The primary
stability of the elbow is provided by the ulnar collateral ligament on the
medial (inner) side of the joint. One of the most common injuries, however,
occurs on the lateral (outer) side of the joint – this is called Lateral
Epiconylitis (tennis elbow). The
symptoms of this condition are pain at the lateral epicondyle which is referred
to the surface of the forearm. The pain is exacerbated by resisted extension
the wrist or fingers.
Bearing the above
in mind, consider a typical position in which a boxing trainer would hold
conventional pads; he would have:
·
The elbow is forced
into a medial rotation beyond its full capacity.
·
The wrist is extended
or hyper-extended.
·
Punches to the ulna
side of the hand will force the elbow to medially rotate beyond its capacity.
This, coupled with the contra-indicatory wrist position, will over strain on
the lateral sector of the joint, resulting in lateral epicondylitis.
·
Punches to the radial
side of the hand will force lateral rotation which is an unnatural elbow
movement. This will have the effect of compacting cartilage and bone, resulting
in ultimate pain and disfigurement and stressing the medial ligaments. Bearing in
mind that the medial collateral ligaments are elbow stabilisers, risk of joint
dislocation will also be increased.
Superiority of MACPAD
·
The
elbow joint is maintained in slight but tolerable medial rotation.
·
Normal
elbow flexion is required in order that the hydraulics of the joint can aid in
dissipation of impact forces.
The Shoulder
The ‘shoulder’
complex is actually made up of 2 joints:
1)
The Shoulder Joint –
which comprises the humerus and radius and brings about such movements as
flexion, extension, rotation and adduction and abduction of the humerus.
2)
The Shoulder Girdle –
which comprises the humerus, scapula and clavicle and brings about such
movements as elevation, depression, rotation and adduction and abduction of the
scapulae.
The above rarely
work in isolation but there is usually one component which the most influential
in a movement with the other acting synergistically. For example, in a lateral
pull from above the head, the initial part of the exercise is effected by the
shoulder girdle (the muscles employed being trapezius 2 and secondly latissimus
dorsi), as the scapulae depress. The second part of the exercise, beyond the
point where the humerus is parallel to the floor is effected by the shoulder
joint (the muscles employed being latissimus dorsi and secondly trapezius 20),
as the humeri adduct.
The shoulder
joint has a huge range of motion due to the flexible ‘ball and socket’ nature
of the glenohumeral cavity where rounded head of the humerus meets the glenoid
cavity on the edge of the scapula. The flexibility and consequent range of
motion in this joint is biomechanically advantageous in movements which require
reach and speed but in disadvantageous from a stability point of view as it
leaves the entire shoulder complex open to risk of injury.
The joint cavity
is cushioned by articular cartilage which covers the head of the humerus and
the face of the glenoid cavity. Ligaments connect the bones of the shoulder
complex to one another and tendons join the bones to surrounding muscles which
include the pectoralis complex ventrally, latissimus dorsi, trapezius 1 and 2
dorsally and the deltoid complex ventrally, dorsally and medially. It is worthy
of note that 4 short, but vitally important, muscles originate on the scapula
and pass around the shoulder where their tendons fuse to form the rotator cuff.
The rotator cuff muscles help to stabilise the shoulder joint by holding the
humeral head in the glenoid cavity. When the muscles contract, they pull the
rotator cuff tendon bringing about upward, inward or outward rotation.
The uppermost tendon of the rotator cuff, the supraspinatus tendon, passes beneath
the bone on the top of the shoulder, called the acromion. The space between the under-surface of the acromion and
the top of the humeral head is quite narrow.
The rotator cuff tendon and the adherent bursa, or lubricating tissue, can therefore be pinched when the
arm is raised into a forward position. With repetitive impingement, the tendons
and bursa can become inflamed and
swollen resulting in one of the
most painful sports injury problems known as rotator cuff, or chronic,
impingement syndrome.
Impingement
syndrome can progress from the humerus which can occur if an impinged joint is
not rested and allowed to heal into rotator cuff disease. This is the
detachment of the supraspinatus tendon.
With reference
again to the boxing trainer holding pads:
·
The shoulder joint is
often flexed (arms forward)
·
Punching forces are
repeatedly transferred to the shoulder with it in a position known to be
contra-indicatory for rotator cuff impingement[1].
·
This would be the case
whether the pads were vertical to receive straight punches or horizontal to
receive jabs.
Both the pectoral
(chest) muscles and one member of the rotator cuff group have insertions on the
ventral aspect of the humerus. They are at their most vulnerable, in terms of
injury risk, when stretched: that is when the shoulder girdle is adducted (the
shoulder blades squeezed together.
Consider the
holding position for conventional boxing pads:
·
The humerus will be
partially, or fully abducted and horizontally flexed, the latter of which
maintains the pectorals in a stretched or semi-stretched position.
·
The shoulder joint will
be dorsally rotated to some extent in order to bring a pronated palm into a ventrally
facing position. This maintains the ventral rotator cuff in a stretched or
semi-stretched position.
·
Each time a punch is
thrown, both these muscle groups are forced into a situation of severe
ballistic stretch as the shoulder girdle is adducted under pressure and the
shoulder joint over rotates dorsally.
·
Severe pectoral and
rotator cuff tears could result as could impingement of the nerves originating
in the cervical spine. The latter would give the symptoms of whip-lash.
Superiority of MACPAD
·
Slight
contraction of the pectoral and ventral rotator cuff confers stability on the
shoulder complex and minimises the risk of injury associated with
over-stretching these muscles and/or cervically originating nervous
impingement.
·
Over-rotation
of the shoulder joint is prevented, so minimising the risk of rotator cuff
impingement and bursitis.
·
Normal
shoulder flexion and extension are maintained meaning that normal hydraulics of
the joint can still be used to dissipate impact forces.
.
Clavicle Scapula
N.B.
·
Although
the word ‘punch’ and ‘impact’ have been used for the most part herein to
describe forces on the pads or MACPAD, it should be noted that MACPAD is also
perfectly designed to withstand kick forces.
·
Not
only does MACPAD far greater confer biomechanical advantages to conventional
pads due to the holding position, it is also ideally designed in itself to
dissipate impact forces much better than conventional pads before the forces
even reach the trainer.