Pilates 'Jumpboard' Jumping
Defies
'Vertical' Jumping
By Aspasia Simeone
(A Speculative Analysis)
(A Speculative Analysis)
It would be difficult to describe Reformer jumpboard jumping to those that are unfamiliar with this activity, without a comparison first to a more common form, say various types of vertical high jumping. Even so, from the perspective of Pilates teachers or students that do participate, it would be informative to explore this subject matter further into the dynamics. Therefore for the unskilled or skilled knowing ‘what we do’ is just as important as ‘how we do it’. It is my intension to provide a comprehensive yet discernable description for all to grasp, with partiality toward the Pilates jumpboard method.
The most
significant difference in free style
vertical jumping and horizontal
Reformer jumpboard jumping are the effects of gravity and the impact on the
musculoskeletal system. In any free style vertical jumping activity
gravitational forces have a direct effect on the takeoff and landing of the
jumper with nothing amidst to absorb the final impact upon decent. While short in time and distance, this type
of motion can be considered free fall at its highest point. Basically all that is involved during
the deceleration up-phase motion and
the acceleration down-phase motion is a combined
effort of the gravitational forces and the power supplied by the jumper to
break ground contact. Although there are various other forms of vertical
jumping, (running is not included in this analogy. See Example: Vertical High
Jump, for other forms) they all have a common characteristic: jumping and
landing is performed vertically with respect to the ground. For the purposes of
this article I will be considering the ‘high vertical jump’, where the jumpers’
musculoskeletal system bears the full weight of ground contact. Not so
conventional when it comes to Reformer jumpboard jumping…
The one
peculiarity of Reformer jumpboard jumping is the obvious; with Pilates, jumping
is preformed from a (supine) face-up laying position …or a seated position…or a
kneeling position…or a lateral position…or for that matter, one may wonder if
it can be done while in a (prone) face-down laying position. If so, then that would imply any
anatomical orientation the Reformer can accommodate is suitable for jumpboard. Of
course! Jumping can be executed from a prone position, but who has ever
heard of lying face-down on the torso while jumping from the hands? Answer: Anyone
that knows Pilates knows this is not unusual because when the jumpboard was
introduced into the Pilates repertoire, it was meant to adapt all the planes of
movement into a single cardiovascular compilation of major muscle activation. (Perhaps
some pictures would be useful here; see Fig.1-Fig.6). In doing so, jumping feet
first or hands first is irrelevant since there is never contact with the ground
and the movement is relative to the jumpers’ body connection to the Reformer.
In all jumping cases the jumper loses contact with the jumpboard for a time
period proportional to the combined spring strength (restorative force) and the
external force applied by the jumper. A brief description of spring mechanics
will follow shortly to verify this theory.
Note that during
jumpboard intervals the carriage always moves in the direction of the spring
tension, whether away or toward the home base. With the force of gravity exerted
and pulling toward the ground, gravity is calculated into the combined mass of the
moveable carriage and the jumper but does
not affect the horizontal motion or the spring resistance. The positive
(horizontal) motion of the carriage relies solely on one’s own muscle strength
to overpower the spring restorative force and drive the carriage away from the
static home position. The forces of
gravity have no role in this direction, and as the carriage always moves
back and forth with the spring resistance, any variation in anatomical position
remains unaffected by gravity. This works during the return spring recoiling phase
as well, when the muscles activate to slow the return of the carriage home.
Although spring tension strengths are calculated by Hooke’s Law (F=-kX, F:force, -k:spring constant
always opposing direction of force F, X:displacement) for spring mechanics, the
numerical values in this description are inconsequential. Only the underlying
concept is applicable for this nonnumeric assessment. An addendum to this
article will further examine the selection of springs for various apparatus,
and the method of calculation.
“Is it
plyometric?”, one may ask and the answer being two fold; yes and no. As the definition of plyometric is based on explosive muscle
contractions in short intervals of time, the choice and/or combination of
Reformer tension springs could satisfy those conditions, when the muscle force
applied overcomes the stationary static holding force of the carriage. Keep in
mind the jumpboard platform acts as the ground and is stationary throughout the
interval, while the jumper and carriage move as a single unit. Both closed and
open kinetic chain exercises are applicable but not a necessary distinction in
this account. More importantly are the lessened affects that rebounding forces
have on the participant’s joints and the added benefits gained that constitute
this form of aerobic activity.
When the
motion is directly in-line to the force of gravity, Plyometric activity works
with gravity in the down-phase of the exercise using the eccentric contraction
to absorb and store the energy in the muscle for the explosive up-phase
concentric contraction. Although the concept is the same on the Reformer, the
motion of the carriage is 90 degrees to the ground and therefore gravitational
forces are not applied to horizontal motion, as mentioned earlier. Instead the
recoil phase of the spring works like the down-phase of the plyometric exercise,
absorbing the energy in the muscles and springs for the explosive jump-up-phase
cycle. A heavier combination of tension springs will require more power and
less time for sequential jump intervals hence will fall into plyometric
activity.
You don’t
have to be a physicist to understand the dynamics behind the method but some
background information will emphasize the great benefits Pilates jumping has
when compared to other vertical methods especially on the joints due to the ill
effects of compression forces. This is a fact of Newton’s laws of motion coupled
with spring mechanics and the conservation of energy (kinetic-motion,
potential-stored/static).
Example: Supine Jumpboard
1.
The carriage is stationary-static at
the home base. The jumper is in ready position in direct contact with the jumpboard
prepared for first interval:
·
The
energy stored in the jumpers ready muscles and the springs will be released in
the first jump. The body is supine, knees bent, pelvis neutral with full foot
contact in parallel.
·
In
a stationary pose, the effects of gravity in this position are proportional to the
combined weight of the carriage and the jumper. Gravity forces are not applied
in the direction of motion, which is horizontal.
·
Jumpboard Jump (plyometric activity
optional): From the
moment direct contact is broken with the jumpboard and the feet are no longer in
connection, the contraction of the muscles have exerted enough force to drive the
carriage and extend the springs a proportional distance away relative to the
home base. From this vantage point the initial restorative force of the springs
has been overcome. The spring force instantaneously pulls back on the carriage
in the opposite direction of the displacement once the external jumping force
is applied. The carriage motion is totally dependent on the jumper’s activity.
·
The
most significant aspect is the landing
phase or the return to home position. The timing derivative is directly dependent
on the restorative force of the springs and the jumper’s resistance against the
recoil. The landing forces are absorbed into the soft jumpboard platform, the recoiling
springs and the musculoskeletal system, as the eccentric contraction of the
muscles control the return speed once foot contact is made back on the
platform. This affects the timing and setup up for either the next sequential jump
interval or halt and jump interval.
·
GREAT BENIFITS:
a. The cardiovascular response can be either aerobic or anaerobic
depending on the jump frequency and the spring tension. This can be
predetermined by selection but also dependent on jumpers ability.
b. In this method as gravity has minimal force effects on
the musculoskeletal system, the compression forces on the joints are much less
substantial. The stress is absorbed into the other components connected to the
jumper; the recoil springs, the cushioned platform, the shoulder blocks etc.
c. High Spring Count: In this form of supine jumping, the back
body is supported. Since the timing cycle is dependent on the spring strength
and the force applied, the higher restorative force will shorten the jumping
cycle and allow the back body to remain connected to the moving carriage. Less voluntary
effort through the core is required to keep the lumbar and pelvis is a neutral
holding position. This method permits intense muscle response and stimulates
muscle gains and growth.
d. Low Spring Count Intensity: In this form of jumping, there is more air time as the carriage is propelled away for the base with less effort but more time for the limbs to be unsupported. When the legs are suspended in ungrounded space horizontal to gravity, the deep core must activate voluntarily to secure the lower region of the back body. The hip muscles spontaneously activate to keep the legs energized until jumpboard contact is made again.
e. Many variations are available as there is more air time to
utilize props and inventive jump routines both unilateral and bilateral. Usage
of the upper limbs moving opposite in the direction of the restorative force
will lessen the load upon landing. This is enhanced when using small hand
weights during jumping cycles.
Example: Vertical High Jump
1.
The jumper positions themselves in
close proximity to the ground in ready position for the first jump.
·
Vertical Jump (plyometric activity): It can be deduced that the effect
gravity has on the participant regarding compression forces is significant when
the motion is in the direct line of the opposing force. To break ground contact
and propel vertically in an upward direction, the force exerted by the muscles
must exceed the forces due to gravity. This would agree with vertical jumping
including but not limited to jumping rope, jogging in place, box jumps, high
vertical jumps, squat and jump, burpees, clapping pushups, lunge knee hops etc.
where returning to the lowest energy requires the greatest resistance to the
gravitational force in the vertical direction. Here the muscle and skeletal
systems must absorb the full impact of contact, when the feet (or hands in some cases) first return to
the ground.
·
The
forces of gravity coupled with the jumpers muscle power and mass will control
the timing and deceleration in a vertical upward jump. As the direction of
motion is subjective, the jump ‘negative is up’ and ‘positive is down’ and is defined
relative to the ground forces of gravity for deceleration and acceleration
respectively. The gravitational force on the jumper remain unaffected and are directly
in line with the motion.
·
Drawbacks:
a. Not much aside from the musculoskeletal systems to
absorb the impact forces when landing on a firm ground.
b. The feet, ankle and knee joints bare the initial impact
upon ground contact before rebounding if planned. The joints, tendons and
ligaments can be subjected to overuse over time.
VARIOUS JUMPBOARD POSITIONS