Transcript Understanding Controversial Exercises

Understanding High-Risk
Exercises
To Do, Or Not To Do
• "If it doesn't make scientific sense, and it defies
common sense, then it must be nonsense.” (Nick
Tumminnelo)
• You must determine the risk of any exercise by
considering the following:
– The individual you are working with
– What the exercise can, or cannot, do in terms of
accomplishing goals
• Flexibility
• Stabilization
• Endurance
• Strength
• Power
– Human Anatomy and Biomechanics
To Do, Or Not To Do
• Effective and safe exercise
design requires you to weigh all
the pros and cons of each
exercise-risk versus benefit-and
then to personalize each
exercise choice to the individual
client
Contraindicated Exercise
• Definition: high risk exercises that
may increase joint structure damage
or soft tissue injury, or might increase
the likelihood of a specific population
having a heart attack or stroke
–Example: Clients with high blood
pressure performing isometric
exercises
Black-and-White Answers Do Not Exist
• An exercise that is considered
contraindicated for the average,
deconditioned individual, might be
appropriate for an athlete with sportspecific needs
–Example: Plyometrics
• An exercise that is characterized as
safe for everyone probably isn’t
High-Risk Exercises
• High risk exercises are based on
joint mechanics, mechanisms of
injury, and injury predisposition
• Joint biomechanics research
indicates that certain movements
produce significant stresses and
those same motions are involved
in common injury mechanisms
High-Risk Exercises
•Always seek to
understand why the risk
of an exercise is high for
a given person or
population, and how it
can be lowered
High-Risk Upper Body Exercises
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Chest Press performed at extreme angles
DB Fly
Pec Deck Machine
Upright Row
Dip
Overhead Shoulder Press Behind The Neck
Lat Pull-Down Behind the Neck
Wide Grip Lat Pull-Down
Supine DB Pullover
Unsupported Bent Over DB Row
Lateral Raise
Preacher Curl, Machine Biceps Curl, BB Curl
How “Deep” Should a Chest Press or
Fly be Performed?
• Extreme angles at the glenohumeral joint under
load are not advisable
• This places the joint in a loaded, horizontally
abducted position, which puts
the glenohumeral
joint at risk
for injury
How “Deep” Should a Chest Press or
Fly be performed?
• In other words, hyperextension of the
shoulder behind the midline of the body
places excessive stresses on the
acromioclavicular joint during pressing
movements
• The ability of the pectoralis major muscle
to produce force decreases which leaves
the joint vulnerable to injury
• The joint is literally being held together by
weak shoulder muscles and ligaments
How “Deep” Should a Chest Press or
Sly be Performed?
• Any exercise that places the elbow behind
the midline of the body places the
shoulder at a mechanical disadvantage
that may contribute to rotator cuff injury or
anterior shoulder instability
• Regardless of body position-supine,
standing, or seated-the cue should be
that the elbow should not be greater
than 90 degrees
DB Fly
• When the DB fly is performed with a
neutral grip this places the glenohumeral
joint in a loaded, horizontally abducted
position, which puts the shoulder joint at
risk for injury
DB Fly
• To avoid potential injury, perform the exercise with a
pronated grip throughout the movement
• The hands should be seen, rather than disappearing
• Pectoralis major does not work efficiently from an
extremely stretched or horizontally abducted position
under a load
• When the shoulder is in this position the rotator cuff
muscles are placed at risk of injury
The Pec Deck
• This exercise is performed by sitting at the
machine with your back flat against the back pad,
placing your forearms on the padded levers and
positioning your upper arms parallel to the ground,
while pushing the levers slowly together
The Pec Deck
• It places the shoulder in extreme positions under load
(external rotation and 90 degrees of abduction) and
decreases a large percentage of pectoral involvement
• This exercise may cause glenohumeral instability and
stress
• Bringing the elbows together usually causes excessive
neck flexion which loads the cervical spine
Upright Row
• This exercise causes poor alignment of the
wrists, elbows, and shoulders
• Internal rotation of the shoulder is combined
with abduction which increases the risk for
shoulder impingement
• When the shoulder is extremely internally
rotated, bone or cartilage comes in contact with
bone
Upright Row
• Upright rows may accelerate rotator
cuff degeneration.
• You can risk developing chronic
tendonitis or bursitis
Dip
• The elbow is behind the midline of the body which
forces the shoulder into excessive extension under
load
• This can create wear and tear on the glenohumeral
joint when performed with chronic regularity
• The presence of muscular imbalances increases
chances of injury
Dip
• The concentric phase of the exercise
puts vertical stress directly on the
acromioclavicular joint which can
cause separation
Overhead Shoulder Press Behind The
Neck
• Extreme shoulder external rotation and
abduction under load stresses the
glenohumeral joint which can cause anterior
shoulder stability
• The neck is usually excessively flexed which
loads the cervical spine
The Lat Pull-Down Behind The Neck
• When the bar is pulled behind the head, the
neck must excessively flex (which loads the
cervical spine), and the shoulders are forced
into extreme external rotation
• This can contribute to rotator cuff injury or
anterior shoulder instability
Wide Grip Lat Pull-Down
• An excessively wide grip does not work
the “outer lats” but can increase shear
(horizontal force on the joint) forces
across the glenohumeral joint as well as
limiting ROM at the shoulder
Supine DB Pullover
• This exercise forces the shoulder to flex under
a load which causes anterior glenohumeral joint
instability
• This exercise can also stretch the connective
tissue that forms the linea alba. If the linea alba
tears, you have a hernia of the median rectus,
which produces a slight bulge in the center of
your abdominals that increases in size when
you strain
Unsupported Bent Over DB Row
• The risk of injury and cumulative stress to
the spine may be high, particularly if the
spine is flexed
• This posture is passively supported by
ligaments and fascia in the low back
Unsupported Bent Over DB Row
• The stabilizing muscles of the spine are
not in a good position to exert force in this
position because muscle activity of the
spinal extensors decreases
• The spine can only resist the force of the
weight being lifted through ligament and
fascial support
• There is a potential shearing force on the
disks positioned between the vertebrae of
the spine
Lateral Raise
• Lifting too much weight, keeping the
arms straight, and raising the arms
out away from the body in the plane of
the body may cause stress on the
rotator cuff muscles
Lateral Raise
• The proper way to execute a lateral raise is to keep
the elbows comfortably flexed (20-30 degrees) and
raise the arm to no higher than parallel to the floor.
• The arm should be in the scapular plane of motion
(approximately 30-45 degrees from being
perpendicular to the body) and the weight should be
relatively light
Preacher Curls/Machine Biceps Curls/BB Curls
• When you supinate the forearm to grab a bar or a
fixed grip handle, the forearm deviates laterally in
relation to the humerus, which accounts for the
anatomical carry angle
• Supinate your hands and note the lateral angle
• This is your individual carry angle.
Preacher Curls/Machine Biceps Curls/BB Curls
• If the anatomical carry angle is not
taken into consideration when curling
you may experience pain in the
forearm
Preacher Curls/Machine Biceps Curls/BB Curls
• Any time you train with your hands fixed to
a bar or a fixed machine you must follow
your anatomical carry angle
• If this adjustment doesn’t help, stay away
from bars or fixed machines
• Training with cables or dumbbells allow for
right/left handed independency; therefore,
obeying an individual’s carry angle by
enabling the forearm to adjust during an
exercise
High-Risk Lower Body Exercises
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Squats performed at extreme angles
Sumo (Plie) Squats
Smith Machine Squat
Hack Squat Machine
Leg Press Machine
Knee Extension Machine
Straight-Leg (Stiff-Leg) Deadlift
The Good Morning
Hip Adductor Machine and Hip Abductor Machine
• The Hurdler’s Stretch
Squat Depth
• The normal range of knee flexion is 0-135
degrees, but when you add a heavy load the
risk of injury increases
• Encourage clients to approach 60-90 degrees
of knee flexion when performing squats, lunges,
leg presses, and wall squats
• The compressive forces on the back of the
knee cap increases as the knee moves from 60
toward greater degrees of knee flexion
• High compression forces can cause wear and
tear on the articular cartilage
Squat Depth
• At 90 degrees the knee takes on three
times the compressive force as
measured in body weight
• The more weight being lifted, the more
compressive force present at the joint
• Beyond 90 degrees stretches the
posterior cruciate ligament within the
knee joint, which can destabilize the
joint
Sumo (Plie) Squats
• Most people feel this exercise in their glutes
• Prolonged use of this exercise may lead to increased
low back pain, knee pain, and ankle/foot pain
• The sumo squat requires that the individual laterally
rotate their hips, placing the gluteus maximus in a
shortened position
• The glutes in this position (shortened) are not able to
generate maximal force
Sumo (Plie) Squats
• As a result, this can lead to synergistic
dominance (when a helper muscle takes over
for a weakened prime mover)
• In this case, the piriformis and the biceps
femoris may become synergistically dominant
• When these muscles become dominant, they
alter the way the low back, hip, knee, and feet
move – predisposing you or your clients to low
back pain, sciatic nerve pain, lateral knee pain,
and plantar fasciitis (mid-foot pain from
increased pronation)
Smith Machine Squat
• Fixed plane of motion- it forces you to follow the
machine's straight line of motion rather than the
natural arc developed by the lumbo-pelvic hip
complex
• The machine forces you to move the bar on a
straight line while your body is planted in one spot.
This is not a natural movement pattern
Smith Machine Squat
• If you put your feet forward, to reduce knee flexion,
the lower back is put in a weak position, with
rounding of the lower back likely.
• In addition, there may be additional stress on the
knees as the feet want to slide forward but don't
because of the friction from the floor surface.
Hack Squat Machine
• Causes patella femoral shear
– Patella rubs against femur
• Forced plane of motion
• Alternative: squatting against the wall with a
stability ball
BB Front Squat Versus BB Back Squat and Leg
Press
• BB Front Squats decrease spinal load (torque,
compression, and flexion) and improve back posture
• BB Front Squats are safer than the BB Back
Squat and Leg Press
• Three major reasons people still do BB back squats
and leg press versus BB front squats:
– They always have (people really hate change)
– They can lift more weight (ego is always a big
problem)
– They perceive front squats as difficult due to poor
wrist flexibility
Leg Press
• The potential danger in this exercise is seen
when you bring the knees in close to the chest
on the eccentric phase. This rounds the lumbar
spine and increases the pressure on the spinal
discs. The high compressive forces can
cause the discs to herniate (rupture)
• Is this exercise really functional? Where in
real life do you have to push out with your feet
to move a heavy object and your back is
locked?
• If you cannot squat properly, have low back or
knee pain do not use the leg press
Knee Extension
• Unlike the squat, the load is placed at the ankle
that results in force being exerted across the hinge
joint
• This is like hanging an excessive weight on the top
of an open door
• Eventually, the force would cause the door hinges
(the knee) to creak and grind and not operate
smoothly
Knee Extension
• It may cause injury to the tibiofemoral
joint and anterior cruciate ligament
(ACL) of the knee
Straight-Leg Deadlift
• Improper form can cause injury
• Failure to keep the back in neutral during the
movement causes undue stress to the spine
forcing the internal fluids to compress towards
the back, and potentially causing a disk to
herniate
• This is especially true of the lumbar region of
the spine, which is designed to bear the bulk of
the compressive forces on the upper body
• In addition, the compression can squeeze the
spinal roots of the spinal cord, causing nerve
conditions like sciatica
Straight-Leg Deadlift
• The depth of this exercise is dependent on
hamstring flexibility and the ability of the back
musculature to stabilize the spine
• Alternative: Single-Leg Deadlift or Romanian
Deadlift
Would you teach
your clients how
to pick up an
object off the floor
like this?
The Good Morning Exercise
• Placing resistance behind your neck creates an
unacceptable shear, destabilizing force across
the spine
• The risk of injury to the spine is high!
Say Good Morning
To Your Orthopedic
Surgeon!
Hip Adductor and Abductor Machine
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Forced plane of motion
The hips must simultaneously rotate and rise
laterally or medially
These actions place great stress on the lumbar
spine, especially when heavy weights are used
The danger is even greater if the movement is done
quickly, with a jerk, or if there is excessive hip
rotation when the leg is out in front of the body
Hurdler’s Stretch
• The awkward knee position in the bent leg
creates stress on the medial collateral ligament
and may promote medial knee instability
– It may stretch the knee ligaments
– It may result in misalignment of the patella
• May injure the lumbar spine
High-Risk Trunk Exercises
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Sit-Up
Sit-Up Machine
Supine Leg Raise and Hanging Leg Raise
Scorpion Twist
90-90 Trunk Rotation (Windshield Wiper)
The Iron Cross (Hip Cross Over)
Seated Trunk Twist
Cobra
Superman
Sit-Up and Sit-Up Machine
• When the feet are fixed or the thigh is
stable the origin of the hip flexors are
pulled toward the insertion, causing
compression and sheer force on the
spinal disks, and resulting in a movement
where the trunk moves toward the femur
Supine Leg Raise and Hanging Leg Raise
• The majority of the movement is done with the
hip flexors
• Trunk hyperextension may injure the lumbar
spine
Physical therapist Shirley Sahrmann, in
her book "Diagnosis and Treatment of
Movement Impairment Syndromes",
states:
"The overall range of lumbar rotation is
...approx 13 degrees. The thoracic spine,
not the lumbar spine should be the site of
greatest amount of rotation of the trunk…
when an individual practices rotational
exercises, he or she should be instructed
to "think about the motion occurring in the
area of the chest" (Sahrmann, pg. 61)
The Scorpion Twist
• It requires the individual to simultaneously
extend and rotate the spine.
• This type of motion can cause injury to the
spine
90-90 Trunk Rotation (Windshield Wiper)
• "Rotation of the lumbar spine is more
dangerous than beneficial and rotation of the
pelvis and lower extremities to one side while
the trunk remains stable or is rotated to the
other side is particularly dangerous."
(Sahrmann, pg. 72)
The Iron Cross (Hip Cross Over) and
Seated Trunk Twist
• These movements require excessive trunk rotation
with lateral trunk flexion
• Combining lateral trunk flexion with trunk rotation
under load may lead to back injury
• "The combination of lateral bending and rotation
constitutes one of the most dangerous maneuvers for
the lumbar spine." (Dr. Mel Siff, Sport Scientist)
Cobra
• Lying prone on the floor and hyperextending the
neck and trunk may cause injury to the spine
Superman
• Sport scientist Dr. Mel Siff, in his book Fact and
Fallacies of Fitness, explains why the superman is a
high-risk exercise:
"Since the lower extremities are heavier than the
upper extremities, this can impose a torque or twisting
action around the lumbar spine. In fact, it's not
uncommon for this exercise to cause acute back
pain and spasm." (Siff, p.36)
Siff then goes on to say that "Current research has
shown that the superman exercise and several of
its variations have little or no benefit on back
strength and posture." (Siff, p.36)
• This exercise results in about 1300 lbs of compression
to a hyperextended spine, loads the spinal joints and
ligaments
• Alternative: Quadruped opposite arm-leg raise