Highly Vulnerable to Injury
The area that comprises the lower back is responsible for more dehabilitating injuries than any
area of the body. In fact, injuries sustained to the region of the lower back ruins more weight-training
careers than the rest of the body combined. Lower back pain and injury are not only prevalent in
weight-resistance training but in everyday “civilian” activity as well. How many times have we heard
about someone bending over to tie a shoelace and then not being able to straighten up? Or how
about the weekend-at-the-cottage syndrome where an unsuspecting victim has reached for a tow line
on the row boat or stretched down to gather some firewood and was left bent-over in agony. Acute
(or chronic) aching-back symptoms plague almost everyone at one time or another in their lives.

Why is it that the lower back is so highly vulnerable to injury?

Poor Mechanical Advantage
The foremost cause of lower back ailment is due to the extremely poor mechanical advantage of
the vertebral column. Whenever a person bends forward during the performance of an activity, from
lifting a bag of groceries to executing the initiation of the concentric contraction phase of the deadlift
exercise, great force is exerted upon a specific area of the vertebral column. The forces that are applied
are: the resistance that is being moved; the weight of the upper torso; and the force of gravity
(9.8 m•s-2). If the combined forces were to be endured by the entire structure of the vertebral column
the risks would be significantly reduced. However, as the forces are focused upon just two or three
vertebrates, the stress upon a small portion of the vertebral column is all too often of sufficient magnitude
to cause injury to the vertebrates, the discs, or the facet joints located on the vertebral column.

Muscles of the Lower Back Weak
Not helping the cause is the fact that the muscles of the region are often underdeveloped and as
a result are too weak to provide sufficient support to the area. Without proper assistance from the
surrounding muscle groups, the bony structure of the vertebral column is forced to endure the
stresses of the forces placed upon the region of the lower back.

Abdominal Muscles Weak
Additional problems arise from the fact that they rarely are the individual’s abdominal muscles
developed to the point where they could provide support for the duress placed upon the lower back.
Poorly-developed abdominals force the vertebral column to endure the forces placed upon the region
of the lower back. Conversely, strong abdominal muscles can provide ample support for the
muscles of the lower back and work in harmony to protect the vulnerable vertebral column from
stress-related injury.

Hamstring Muscles Not Flexible
Another major contributing factor to lower back injury is the lack of fully-stretched and welldeveloped
hamstring muscles. Most people have not done anything to provide for development of
their hamstrings as a result whenever they attempt to bend down to lift something they exert great
force upon the lower back. As the muscles of the lower back are not usually worked in everyday activities
they too are weak. The hamstring muscles insert into the pelvic region. If the hamstrings are
inflexible, they are not able to stretch out and “cushion” the effects of the load. The exerted forces
pull the pelvis downward creating a stretching of the lower back muscles which can cause injuries to
the muscular structure of the region.

When weight-resistance trainees attempt to work their lower backs through bending movements,
the exertion upon the lower back is severely magnified. If the hamstrings have not been worked and
are neither strong nor flexible, and if the abdominal muscles have not been developed, the forces that
are directed into lower back easily overpower the relatively weak muscles of the region. Without support
from the lower back muscles the vertebral column is forced to endure the force of the load.

Poorly-Applied Movement Methodology
The one area of consideration that the athletes have control over is the quality of their movement
methodology; yet, many weight-resistance trainees approach their back training with reckless
abandon. Poor exercise execution represents the single-most preventable cause of lower back ailment.
Poor exercise execution is fostered mainly by the fact that few athletes understand the basis of
vulnerability the lower back is exposed to. If the trainees were fully aware of the dangers involved in
poorly-applied technique in lower back training it is presumed that they would pay more attention to
detail when executing the various lower back exercises. The keys to success in providing for safe and
efficient training of the lower back are:
- Establish and maintain proper posture throughout the lift in order to reduce the stress exerted
upon the lower back;
- Utilize strong neural-impulsing into the muscles of the lower back to protect the vertebral column.

Location and Function
There are two basic sets or groups of spinal muscle that comprise the region of the lower back.
There is a deeply-set group known as the transversospinal muscles and a superficial group known as
the erector spinae muscles. Both muscle groups are covered by a thick sheath of muscle tissue known
as the thoracolumbar fascia which inserts along the origins of the latissimus dorsi. It should be noted
that fascia does not have the flexibility of muscle and as a result is highly-vulnerable to injury during
stress-related actions of poorly-performed exercise execution.

Erector Spinae Muscle Group
The superficial erector spinae muscle group is comprised of three separate (but intertwined)
muscles: iliocostalis (thoracis, and lumborum); longissimus dorsi; and spinalis dorsi. Together these
muscles cover the vast region between the neck to the sacrum which is located on the posterior portion,
and on both sides of the spine. The erector spinae muscles comprise the large ridges that can be
seen running down the length of the mid-line of a well-developed back.

Iliocostalis — Thoracis (A1), Lumborum (A2), Cervicis (A3)
The most laterally located of the erector spinae muscle group the iliocostalis (thoracis and lumborum)
muscle originates on the crest of the ilium and inserts into the nos. These two related muscles
act strongly to rotate the vertebral column.

Longissimus — Dorsi (B1), Cervicis (B2), Capitis (B3)
The longest of the erector spinae muscles, the longissimus dorsi runs almost the full length of
the area of the back. It originates from the most lateral projections of the vertebrae (transverse
processes), and insert in transverse processes which are located superiorly to their location. The longissimus
dorsi is involved in rotation of the spine.

Spinalis (C)
The spinalis muscle is the most medially located muscle of the erector spinae group and, unlike
the semi-spinalis muscle which originated at the mid-way point of the back, travels the entire length
of the mid-line of the back. It originates from the spinous process of the lumbar and thoracic (lower)
regions and insert in the thoracic and cervical vertebrae. The spinalis is involved in rotation of the
spine.

Transversospinal Muscle Group
The deep spinal muscle group derives its name from the location of the fibers which run from
the transverse process to the spinous process of the vertebrae. The transversospinal group is comprised
of the interspinalis (semi-spinalis), intertransversarii, rotatores, and multifidus muscles which
are generally structured in pairs.

Interspinalis (Semispinalis)
The interspinalis or semi-spinalis (as it is sometimes better known)—as its name would imply—
takes its place of origin at about the mid-portion of the vertebral column from the lower thoracic
vertebrae and will generally insert on the fifth to seventh vertebrae which are slightly superior (above)
its location. The interspinalis muscle is involved in the action of extension of both the cervical and.
thoracic vertebrae. This muscle is also involved in the action of rotation of the vertebrae.

Intertransversarii
Takes its place of origin along the vertebral column and attaches to the adjacent vertebrae. This
muscle is involved in extending the vertebral column.

Rotatores
The rotatores muscles originate on the transverse process of one
vertebra and insert into the spinous process of the next superior vertebrae.
This origin and insertion structure of the rotatores muscles
(as their name would imply) provide for a rotating action of the trunk
and are also involved in extension of the vertebral column.

Multifidus (D)
The multifidus muscle has the most fibers and is the thickest and
thus strongest of the transversospinal muscle group. This muscle is
situated in the hollows on either side of the vertebrae. The fibers of
this muscle take their origin from an inferior (lower) vertebra and
insert on superior (usually more than two) vertebrae. The multifidus
muscle aids in the action of rotation of the vertebral column and it
serves to stabilize the vertebral column during lifting actions.

The 45° ankle leg press machine ankle-joint extension exercise provides opportunity to accelerate
the anterior calves with a heavy load application – the trainee is encouraged to provide proper technique
on this movement as injuries can occur if breakdown in form are experienced.

Movement Analysis
This exercise can be performed on either the inverted leg press or 45° angle leg press machine.
The lower lumbar region of the back is particularly vulnerable when the exercise is performed on the
inverted leg press machine due to the exaggerated position of the body. If the movement is performed
on the 45° angle leg press machine the back can become hyperextended due to the movement
application angle. The tendency is to work with too much weight which encourages a buckling
of the knees which results in an arcing-of-the-back response which exposes the lumbar region to
high injury-risk.

Risk of Developing Shin-Splits
While the trainee may escape without incurring a dehabilitating back injury, the odds that he/she
would avoid shin splits (muscle being tom away from the bone) are extremely slim. The force vector
directly attacks the highly-vulnerable tibialis anterior and forces the major muscle of the anterior region
of the lower leg to pull away from its insertion on the tibia. Remember, the tibialis anterior runs
the entire length of the anterior portion of the lower leg. The shin splits will run the entire length of
the anterior portion of the lower leg resulting in painful shin-split syndrome that could prevent the
trainee from engaging in all running and or jumping events for a very long time. At the very least the
participant would be performing under extreme pain.

Summary of Correct Exercise
Execution
- Assume the correct preparatory
posture for the exercise by sitting
on the provided seat with the back
firmly against the back rest.
- Place the front of the feet (not just
the toes) on the lower portion of
the foot platform.
- You will want to make certain that
the legs are in the fully-extended
position.
- Initiate the concentric contraction
phase of the exercise by lifting the
foot platform off its rests through
the utilization of ankle joint extension.
- Complete the concentric contraction
phase by extending the anklejoint
to the fully extended position.
Pause for two counts while making
certain to maintain the locked knee
position of the legs.
- Begin the eccentric contraction
phase of the exercise by lowering
the platform down slowly through
the utilization of the action of dorsi
flexion of ankle joint. Once again,
you will want to remember the desired locked out position of the knee joint.
- Complete the eccentric contraction phase by lowering the weight slowly to the fully contracted
(dorsi flexion) position of the ankles.

Keys to the Lift
- Utilize light resistance.
- Apply slow speed of contraction movement application.
- You will want to perform full ROM contractions.
- Resist the natural tendency to bend the knees during the movement application. Remember, the
actions required are ankle joint extension and flexion as opposed to knee joint and hip joint extension
and flexion.

Whenever reference is made to the calf muscles the general thinking appears to center upon the
above-mentioned gastrocnemius and soleus muscles of the posterior portion of the calves. The con
siderations given to the anterior portion of the lower leg
range from minimal to non-existent. Most weightresistance
trainees assume the anterior musculature of
the calves is really the posterior muscles being visible
from the anterior view.

No one can argue the highly-visible musculature of
the fully developed gastrocnemius and, to a lesser degree,
the soleus muscles; however, there is much more to the
considerations for anterior lower leg development than
merely being able to see the posterior muscles form the
anterior vantage point.

Location and Function
The muscles that comprise the anterior portion of
the lower leg are the tibialis anterior, extensor hallucis
longus, and extensor digitorum longus.

Tibialis Anterior (A)
Location
Originates on the tibia bone just below the knee and
runs the entire length of the lower leg inserting on the
cuneiform on the back of the foot as well as the medial
portion of the foot on the metatarsal bone just behind
the big toe.

Function
This highly-visible muscle is involved in dorsi flexion
and inversion actions of the ankle joint.

Extensor Digitorum Longus (B)
Location
It originates on the lateral condyle of the tibia near
the knee and from the upper region of the anterior surface
of the fibula. This prominent muscle also runs the
entire length of the anterior lower leg and inserts on the
phalanges of the middle and distal bones of the second
to fifth toes.

Function
Actions of dorsi flexion and eversion of the ankle as well as extension of the toes involve the extensor
digitorum longus.
In addition, the beginning weight-training student would be well-advised to consider the muscles
of the lateral portion of the lower leg in designing his/her calf routine. The muscles of the lateral
portion of the calves offer accentuation and definition of the muscular structure of the calves. Two
major muscles of the lateral region of the lower leg are the peroneus longus and peroneus brevis.

Extensor Hallucis Longus (C)
Location
Lies between the tibialis anterior and the extensor digitorum longus muscles and originates on
the anterior middle portion of the fibula and inserts on the distal phalanx of the big toe.

Function
The extensor hallucis longus is involved in dorsi flexion of the ankle and extension of the big
toe.

Peroneus Longus (D)
Location
Originates on the head and upper portion of the shaft of the fibula and inserts under the sole of
the foot on the base of the first metatarsal.

Function
This muscle is involved in plantar flexion and eversion of the ankle.

Peroneus Brevis (E)
Location
Originates on the distal shaft of the fibula and inserts on the base of the malleolus and on the
base of the fifth metatarsal.

Function
Plantar flexion and eversion of the ankle involve this muscle.

Muscle Activation
The muscles of the anterior portion of the calf do not posses the same force-generating capability
as the muscles of the posterior calf and as such, great care must be taken to avoid straining the
more delicate anterior calf region.

Heavy weight should be avoided with
anterior calf training and slow speed of
contraction movement application should
be used in order to provide for safe efficient
training of the delicate anterior lower
leg muscles.

Hamstrings

Often Overlooked
The posterior muscles of the thigh are
often overlooked by many weight-training
enthusiasts. Even those trainees who devote
additional time to their leg training so
as to include isolation work on their quadriceps,
frequently neglect to include hamstring
movements into their leg exercise
portfolio. It seems that many weightresistance
trainees apply the “out-of-sightout-
of-mind” adage to their leg training. It
is much more encouraging to work on the
quadriceps where the deep cuts and crevices
can be readily admired. The hamstrings
are not as visible, and thus they require
more diligence on the part of the trainee to
provide proper development. From a tangible
perspective, the “hams” are not called
upon as prominently as the quads in performing
various athletic movements.

However, neglecting the hamstrings
reduces the trainee’s ability to fully develop
their legs. No trainee would ever think of
building only their biceps and not devoting
any attention to their triceps why is it then
that it can be assumed that proper and thorough
leg development can be accomplished
by placing emphasis on only the
anterior thigh and leaving the posterior
thigh untouched?

The benefits of providing for balanced
development of the legs can be realized
from an injury reduction perspective as
well. How many times have you heard of an athlete pulling their hamstrings? In fact I would be willing
to bet that the first mention you heard of the hamstring muscles (outside of the gym), was in reference
to an injury. Sprinters for example, who have built up their quadriceps through their running,
undergo the risk of pulling their weaker hamstrings due to the imbalance of strength.

While running encourages the development of the quadriceps it should be noted that the hamstrings
work in synergy with the quads. If the frontal thigh muscles are developed well beyond the
level of the posterior thigh muscles the posterior muscles become highly- vulnerable to injury risk.
From all perspectives, it makes sense to offer equal devotion to both the anterior and posterior regions
of the thigh.

Location and Function
The posterior region of the thigh is comprised of three main muscles all of which cover both the
knee and the hip joints. Since the hamstrings cross two joints they provide a function at each of
those joints. They serve as extensor of the thigh at the hip joint and flexors of the lower leg at the
knee joint.

Semitendinosus (A)
Location
Originates from the ischial tuberosity of the posterior hip and inserts on the medial surface of
the superior portion of the tibia at the knee.

Function
In addition to providing for hip joint extension and knee joint flexion, the semitendonosous is
also involved in medial rotation of the tibia.

Semimembranosus (B)
Location
Originates on the ischial tuberosity of the posterior hip and inserts on the posterior portion of
the medial condyle of the tibia at the knee joint.

Function
The Semimembranosus is also involved in medial rotation of the tibia.

Biceps Femoris (C)
Location
The biceps femoris of the posterior thigh is similarly constructed to the biceps femoris of the anterior
upper arm in that the muscle has two distinct (long and short), heads. The long head originates
on the ischial tuberosity where it shares a common tendon with the semitendonosous which crosses
at the hip joint. The short head originates from the lateral edge of the linea aspera alongside the femur
bone of the upper leg and the supracondyle region located on the proximal (inside) area of the
femur. Both the long and short heads of the biceps femoris combine via a single tendon and insert
on the head of the fibula of the lower leg.

Function
Both the long and short heads are involved in the action of leg flexion at the knee joint and are
also involved in the lateral rotation of the leg during knee flexion. It should be noted that because the
short head of the biceps femoris does not cross the hip joint it serves no function in hip joint activity.

Muscle Activation
Unlike the quadriceps muscles, the hamstring muscle group is not readily called upon during
many events involving physical activity. While the “quads” are called into action during such activities
as the ascending and descending of stairs or in the relatively simple task of walking, the hamstrings
relatively speaking lay mostly dormant with the result being that the muscles of the posterior thigh
are not nearly as developed as the quadriceps. As a consequence of their reduced activity, whenever
the hamstrings are called upon during movements requiring their high activation, they become correspondingly
highly susceptible to injury. It is important to realize the level of caution that must be
applied to hamstring training in order to stimulate growth and development while at the same time
reducing the risk of injury to this highly-vulnerable muscle group. As a manner of general approach,
the trainee would be well advised to work with light resistance and to utilize slow speed-of- contraction
movement applications featuring full range-of-motion contractions. In this report we will be
analyzing three hamstring movements. Two movements will feature knee joint flexion (lying and
standing leg curls) and one will highlight a stretching action of the posterior thigh (deadlift).

Quadriceps

Location and Function
The showy muscles that provide the cuts
and definition of the frontal region of the thigh
are called the quadriceps femoris. As their name
suggests, the quadriceps are comprised of four
muscles that cover the anterior and lateral portions
of the femur bone of the thigh. The
“quads” consist of the rectus femoris and the
three “vasti” muscles: vastus lateralis, vastus
medialis, and vastus intermedius. The four
muscles of the frontal thigh join together to
form the quadriceps tendon which allows them
to share a share a common insertion on the
tibial tuberosity of the patellar ligament of the
knee. All are considered extensor muscles and
are involved in the action of knee joint extension.

Rectus Femoris (A)
Location
Originates on the iliac crest of the hip and
inserts on the tibial tuberosity of the patella
ligament of the knee.

Function
It is involved in leg extension at the knee
and is also involved in leg flexion at the hip
joint.

Vastus Lateralis (B)
Location
A large sweeping muscle that covers the
entire lateral portion of the anterior thigh and
extends into the anterior and posterior aspect
of the region of the thigh.

Function
It is involved in the action of leg extension at the knee joint.

Vastus Medialis (C)
Location
Originates on the medial lip of the linea aspera and rests on the inside portion of the anterior
thigh.

Function
It is involved in extension of the leg at the knee joint.

Vastus Intermedius
Location
Originates on the anterior and lateral surfaces of the femur and on the lower trochanter on the
head of the femur. It also takes its origin from the lateral region of the linea aspera along the lateral
ridge of the femur.