BRYAN FASS, ATC, LAT, EMT-P, CSCS
TISSUE FATIGUE AND HIGH-VOLUME EXERCISE
FOR FIRST RESPONDERS
It is common for first responders to spend an excessive amount
of time sitting, often with faulty postures. Take ambulance seats
as an example; the front seats force the responders into an
altered resting position manifested by weakness in the erector
spinae, multifidus, and rotators. The ligaments of the back
become progressively weak from these sitting postures, which
can destabilize spinal mechanics leading to pain and injury (1).
This does not even account for the severely altered mechanics
of attending to a patient in the ambulance sitting on the bench
seat or sitting on poorly designed furniture in the station. Fatigue
from faulty repetitive postures can possibly lead to higher training
induced injury and higher rates of occupational injury. This is
why it is important for tactical facilitators to take into account
the effects of tissue fatigue from these altered postures when
implementing high-volume exercise into a training program for
first responders.
If tactical facilitators follow the teachings of Dr. Vladimir Janda
as it pertains to upper crossed and lower crossed syndromes,
they can step back and realize that most, if not all, responders
(especially emergency medical technicians and law enforcement
officers) can be victims of severe postural distortions (3). Seated
posture, standing postures, and just about all movements inbetween for first responders may alter muscle length and length
tension relationships over a long period. In turn, this may alter the
optimal position of force generation for a muscle typically in the
altered posture.
As Janda explains, “upper crossed syndrome is characterized by
facilitation of the upper trapezius, levator, sternocleidomastoid,
and pectoralis muscles, as well as inhibition of the deep cervical
flexors, lower trapezius, and serratus anterior,” (3). These
alterations in posture can manifest as headaches, subacromial
bone spurs, and rotator cuff disorders.
For example, take any responder through some mobilization drills
using a foam roller or massage ball and it will quickly become
apparent that the pectoralis minor, subscapularis, teres minor,
levator scapula, and middle trapezius will likely be incredibly sharp
and painful. Years of upper crossed pattern have created a sense
that rounded shoulders and forward head posture are normal.
Lower crossed syndrome, on the other hand, is “characterized by
facilitation of the thoracolumbar extensors, rectus femoris, and
iliopsoas, as well as inhibition of the abdominals (particularly
transversus abdominis) and the gluteal muscles,” (3). The anterior
pelvic tilt associated with prolonged sitting and lower crossed
syndrome creates a profound inhibition of the gluteal muscles.
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This inhibition of the glutes, coupled with thoracic kyphosis
from the combination of upper and lower crossed syndrome
and the gear associated with the job, creates profoundly altered
lifting mechanics, especially when tasked with lifting below the
knees, which is very common in emergency medical services and
firefighting. This pattern can be seen as hinging at the base of
the spine between the lowest of the lumbar spine’s five vertebrae
and the sacrum (L5-S1 often called the lumbosacral joint) at the
initiation and/or the completion of any deep lifts. If watching
video of this hinge, it would be clear that there is a complete lack
of hip drive due to gluteal inhibition, and therefore, the spine ends
up taking the entire load.
With poor posture and altered length tension relationships, a
clearer picture of the tissue fatigue that responders encounter on
a daily basis comes into focus. Now throwing poor ergonomics
into the picture adds another layer. Dr. David Frost discussed the
importance of tissue load over time and tissue load above the
“margin of safety” in his presentation at the 2014 NSCA TSAC
Conference. Essentially, this can be manifested in two ways (2):
A responder may “get away” with repetitive faulty movements
(spine board lift) for years but over time the tissue begins to
deteriorate and weaken. Degenerative changes occur that are
often not felt by the responder or are simply ignored. Surrounding
tissue may become tight as a protective response and local trigger
points may form as appreciated by foam rolling. As the faulty
movement continues and the tissue continues to weaken, the
load will exceed the margin of safety for that tissue and injury
will occur.
Since the glutes are inhibited when a responder lifts, pulls,
transfers, or exercises in a spinal posture that is not neutral with
an associated hip hinge to achieve trunk flexion, the anterior
shear forces cannot be counteracted and the spine takes all the
associated load through a shear mechanism (2,4). This load will
exceed the margin of safety and eventually exceed the failure
tolerance of the tissue. This can also be exacerbated through head
down lifting with truck flexion occurring through the spine and not
the hips.
Most emergency medical technicians or law enforcement officers
are sedentary and tied to their ambulance/car for around 12
hr per day. Tactical facilitators must account for the profound
levels of tissue fatigue and distortion that accompany this job
requirement. As tactical facilitators design training programs for
their first responders, they must take these fatigue patterns into
consideration so exercises can be both safe and effective.
NSCA’S TSAC REPORT | ISSUE 34