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The study of and science behind
myofascial trigger points (TrPs) has grown exponentially in recent
years, but the importance of understanding TrPs in physical therapy
treatment may still be underappreciated. TrPs are one of the leading
causes of musculoskeletally driven pain, especially chronic pain,
with an incidence rate of TrP as high as 85% (Fischer et al., 2018).
This statistic is especially important seeing that chronic pain
impacts quality of life, emotional response, socioeconomic status
and gross domestic product in the global economy (Iaroshevskyi,
Morozova, Logvinenko & Lypnyska, 2019).
TrPs are often of insidious origin and can be a major factor in many
limitations treated in physical therapy, such a pain and functional
limitations (Fischer et al., 2018). They are known as taut bands
found in muscle tissue that are palpable and are considered latent
or active (Fischer et al., 2018). Active TrPs cause pain
spontaneously or continuously, while latent TrPs cause pain when
compressed and do not consistently present with symptoms (Fischer et
al., 2018). Common symptoms include referral pain, paresthesia,
mobility limitations, deficits in proprioception and coordination,
and autonomic nervous system irregularities such as nausea and
dizziness (Fischer et al., 2018). This tissue dysfunction originates
for multiple reasons, including trauma, chronic overload or chronic
overstretching of a muscle (Fischer et al., 2018). Regardless of
mechanism, it is theorized that TrPs are due to extended release of
calcium from the sarcolemma from a malfunction of the motor endplate
(Fischer et al., 2018). The body attempts to increase calcium
reuptake through increase ATP use, but the body cannot keep up and
an energy crisis ensues within the muscle (Fischer et al., 2018).
Some common treatments of these taut bands are biomechanical
correction, dry needling, therapeutic exercise and manual therapy,
with the most improvement shown when all treatments are used in
conjunction (Iaroshevskyi et al., 2019). Eliminating the presence of
TrPs result in increased motor function due to ability for the motor
units involved to be recruited during muscle activation (Roach,
Sorenson, Headley & San Juan, 2013).
The gluteus medius (glute med) is a commonly worked muscle that is
especially prone to the development of TrPs.This muscle acts as a
dynamic stabilizer of the hip, working to keep the pelvis level
during single limb stance of gait in closed chain and acts to abduct
the leg in open chain. Weakness or inability to recruit motor units
in this muscle can have multiple negative effects, such as genu
valgum or trendelenburg gait where an individual sways from side to
side. Not only is this muscle’s strength critical to daily
ambulation, but TrPs in this muscle can be a source of symptoms in a
variety of other conditions.
Patellofemoral pain syndrome (PFPS) is a common diagnosis that
physical therapists treat, and accounts for anywhere to 21-40% of
knee issue seen in sports medicine centers. This condition has been
associated with weak hip musculature, which includes the glute med,
in terms of decreased force production and stabilization. When this
muscle is weak, the eccentric control of hip adduction during single
limb stance causes increased frontal plane motion of the pelvis that
leads to increased knee valgum moments and resulting PFPS.
Individuals with this condition are proven to high a higher
prevalence of TrPs in bilateral glute meds (87%) when compared to
controls (13%) and have less hip abductor strength. However, TrP
pressure release therapy alone does not increase hip abduction
strength in this condition. Thus, PT treatment to alleviate this
condition must be multimodal, and should address TrPs to improve
overall motor function of the glute med to reduce stress placed on
the patellofemoral joint (Roach et al., 2013).
Another condition in which many clinicians might not associate with
TrPs is nonspecific low back pain (LBP). The definition of LBP is
pain between the costal margins and gluteal folds that includes
limitation of movement due to pain but can also be associated with
referred pain. This condition is a common health problem that
reduces quality of life through a decrease in sleep quality, an
increase in disability ratings, and an increase in pain. Relating to
LBP, studies have shown that the glute med has an increased number
of active TrPs in those with LBP than controls. Additionally, the
higher the number of TrPs present, the higher the pain intensity
experienced by the individual with LBP. These TrPs may cause an
unfortunate positive feedback system by increasing sensory and motor
symptoms in individuals with LBP and further contribute to
sensitizing mechanisms that cause the condition itself. Thus,
analyzing glute med TrPs may be a helpful tool to battling a
stubborn and chronic condition (Iglesias-Gonazalez, Munoz-Garcia,
Rodriques-de-Souza, Alburquerque-Sendin, Fenandez-de-las-Penas,
2013).
Often associated and concurrent with LBP is the presence of pain in
the leg. In a study that compared TrPs in those with LBP only, leg
pain only and LBP with leg pain, TrPs in all cases were the highest
in the glute med. This same study proved that manual therapy with
soft tissue release and a TrP block are useful in reducing symptoms
in individuals with these conditions. Thus, incorporating glute med
TrP release in a variety of low back and leg pain is clinically
relevant to help manage patient pain and symptoms (Kameda & Tanimae,
2019).
Moving forward, chronic pelvic pain (CPP) has been associated with
an increase in TrPs in the glute med, but is much less common in the
general population with a prevalence between 5.7-26.6%. CPP is
described as noncyclic pain last a minimum of six months within the
pelvis, anterior abdominal wall, region inferior to the umbilicus,
lower back or gluteal region that is not caused by sexual
intercourse or menstruation. Pain in CPP can be continuous or
intermittent and can reduce quality of life. While there are many
causes for this condition, the musculoskeletal system is often not
considered a factor by clinicians. However, TrPs present in this
condition can cause hyperalgesia and contribute to the altered pain
sensation, reinforcing central sensitization and CPP. It has been
shown through research that those with CPP have significantly more
active TrPs in the glute med and surrounding areas, and it is likely
that central sensitization, depression and anxiety play a role in
their development. These TrPs have been shown to reproduce symptoms
of CPP, showing that TrP evaluation and treatment in the glute med
and surrounding musculature should be a part of clinical practice in
treating a patient with this condition (Fuentes-Marques, Carmen
Valenza, Cabrera-Martos, Rios-Sanchez & Ocon-Hernandez, 2019).
While it is not logical to state that TrPs located within the glute
med cause all of the conditions aforementioned, it is important to
note that the role of TrPs in this important muscle are a factor
that should be considered in patients who possess these diagnoses. A
trained professional is reliable at finding and diagnosing TrPs,
even within a muscle as deep as the glute med (Rozenfelf, Finestone,
Moran, Damri & Kalichman, 2017). Additionally, there are a variety
of interventions that physical therapists can use to treat TrPs in
myofascial tissue to help alleviate pain and other symptoms
associated with many diagnoses. All in all, while TrP science has
gained popularity, they may have a more critical role in patient
pain and symptom intensity than many physical therapists realize.
Last revised: 12/17/19
by Mallory Washington, SPT
References
Fischer, M. J., Horvath, G., Krismer, M., Gnaiger, E., Goebel,
G., & Pesta, D. H. (2018). Evaluation of mitochondrial function in
chronic myofascial trigger points - A prospective cohort pilot study
using high-resolution respirometry. BMC Musculoskeletal Disorders,
19(1), 388. doi:10.1186/s12891-018-2307-0
Fuentes-Marquez, P., Carmen Valenza, M., Cabrera-Martos, I.,
Rios-Sanchez, A. & Ocon-Hernandez, O. (2019). Trigger points,
pressure pain hyperalgesia, and mechanosensitivity of neural tissue
in women with chronic pelvic pain. Pain Medicine, 20(1), 5-13.
https://doi.org/10.1093/pm/pnx206
Iaroshevkyi, O. A., Morozova, O. G., Logvinenko, A. V. & Lypynska,
Y. V. (2019). Non-pharmacological treatment of chronic neck-shoulder
myofascial pain in patients with forward head posture. Wiadomosci
Lekarskie, 72(1), 84-88. Retrieved from
http://medlist.org/pdf/wl/2019_01_16.pdf
Iglesias-Gonzalez, J. J., Munoz-Garcia, M. T., Rodrigues-de-Souza,
D. P., Alburquerque-Sendin, F. & Fernandez-de-las-Penas, C. (2013).
Myofascial trigger points, pain, disability, and sleep quality in
patients with chronic nonspecific low back pain. Pain Medicine,
14(12), 1964-1970. https://doi.org/10.1111/pme.12224
Kameda, M., & Tanimae, H. (2019). Effectiveness of active soft
tissue release and trigger point block for the diagnosis and
treatment of low back and leg pain of predominantly gluteus medius
origin: A report of 115 cases. Journal of Physical Therapy Science,
31(2), 141–148. doi:10.1589/jpts.31.141
Roach, S., Sorenson, E., Headley, B. & San Juan, J G. (2013)
Prevalence of myofascial trigger points in the hip in patellofemoral
pain. Archives of Physical Medicine and Rehabilitation, 94(3),
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https://doi.org/10.1016/j.apmr.2012.10.022https://doi.org/10.1016/j.apmr.2012.10.022
Rozenfeld, E., Finestone, A. S., Moran, U., Damri, E. & Kalichman,
L. (2017). Test-retest reliability of myofascial trigger point
detection in hip and thigh areas. Journal of Bodywork and Movement
Therapies, 21(4), 914-919.
https://doi.org/10.1016/j.jbmt.2017.03.023
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