The topic of endangerment sites leans heavily on our profession’s oral traditions about safety. What I learned about endangerments comes from what my teachers learned, which came from their teachers’ teachers, ad infinitum. As such, we don’t have a deep evidence base on which to build this important information.
It isn’t possible to conduct clinical trials to validate or disprove endangerment sites, but we can look to the medical literature for case reports that link massage therapy to client injuries. This represents only a tiny portion of all instances of course, but it may help us prioritize our understanding of potentially vulnerable areas. An overview on the published research about client endangerments can be found in my Pathology Perspectives column in this issue on page 30.
In addition to published research, I drew input from the Entry Level Analysis Project (ELAP) and the Massage Therapy Body of Knowledge. Then I harassed and harangued several core curriculum educators and continuing education providers to look over the final list for their input. My thanks go out to all my colleagues who were so patient and generous.
What is an Endangerment Site?
Generally speaking, we avoid causing injury to endangerment sites by using broad, flat, and often light pressure in these areas—as opposed to more intrusive work that may injure or irritate delicate tissues. Identifying an area as an endangerment or cautionary site doesn’t mean it can’t be touched; it just has to be touched and incorporated into the massage with special care. We can classify cautionary sites by tissue type or by location.
Bony Prominences
Nerves
Blood Vessels
Organs
Lymph Nodes
Lymph nodes include the cervical, axillary, and inguinal nodes, among others, and may be palpable when they are enlarged—which indicates the risk of infection and immune system activation. If lymph nodes are healthy, then they are typically not palpable with massage.
Location
Head and Face
Structures of Note
Eyes
Obviously, eyes are a local caution for massage, and special care must be taken with clients who wear contact lenses, who may prefer not to lie prone. Some practitioners keep a bottle of distilled water and a clean lens case available in case clients might want to remove their contacts.
Trigeminal Nerve Branches
Three pairs of foramina allow the mental (from the chin), infraorbital (from the cheek), and supraorbital (from the forehead) branches of the trigeminal nerve to exit from the skull to provide sensation for the face. Heavy pressure on these spots can elicit unnecessary pain, and may even bruise the nerves as they emerge (Image 1).
Retromandibular Fossa
If you put your index finger behind your earlobe, and press gently anteriorly, you will find the retromandibular fossa where the facial nerve exits. This area is close to the mastoid process where the sternocleidomastoid attaches, so it is not unusual for massage therapists to work in this neighborhood. But if our pressure strays, we are close enough to the facial nerve to cause a problem.
The styloid processes of the temporal bone are located medial to the mastoid process. It is extremely unlikely that a massage therapist would encounter these very sharp, fang-like bony prominences, but sometimes they grow extra-long or the ligaments that attach to them become injured, so it’s useful to have the styloid processes of the temporal bone on our radar (Image 2).
Occipital Ridge
The left and right greater occipital nerves (the occipital ridge) emerge from the deep fascia of the posterior neck, about an inch lateral to the spinous process of C2. Transient pressure at this site is unlikely to damage the nerves, but headache symptoms can occur if pressure is sustained (Image 6).
Location
Anterior Neck
The anterior triangle of the neck is defined by the medial edge of the sternocleidomastoid muscle and the midline of the neck. Valuable work can be done in the anterior triangle of the neck to assist with muscles involved in swallowing, speech, and breathing. However, many structures are vulnerable to damage here, and advanced education is necessary to work safely in this area. Medical literature shows many cases where inappropriate massage has caused damage to anterior neck structures, with potentially catastrophic consequences for clients (Image 3).
Structures of Note
Common Carotid Artery
This huge artery runs just deep to and alongside the medial sternocleidomastoid muscle, carrying blood upward to the brain. Downward (superior-to-inferior) pressure on or near the carotid artery may cause shearing of the arterial walls and a risk of blood clots and stroke.
About level with the thyroid cartilage, the carotid artery splits into internal and external branches. This point of division, called the carotid sinus, is equipped with nerves that track blood pressure to ensure that adequate blood flow to the brain is always maintained. Manual pressure applied at the carotid sinus can interfere with this function, leading to dizziness and faintness.
Atherosclerotic plaque is common in the carotid artery, which makes this area a special caution for any client with a history of, or risk for, cardiovascular disease.
Jugular Vein
The jugular vein also runs alongside the sternocleidomastoid muscle. Compression to this vessel is less likely to have a negative outcome, but it still should not be manipulated. The external branch of the jugular vein is also accessible as it crosses over the sternocleidomastoid.
Hyoid Bone
The delicate U-shaped hyoid bone is attached to the thyroid cartilage, just inferior to the mandible, and it moves with swallowing and vocalization. The hyoid bone anchors muscles of the tongue and neck that are associated with speech and swallowing.
Thyroid Cartilage
The thyroid cartilage or “Adam’s apple” is a moveable piece of connective tissue that forms the anterior wall of the larynx. It bobs up and down as we modulate our voice and swallow. This cartilage is strong but compression here can elicit pain and a choking sensation.
Trachea
This tube is part of the respiratory system that carries air to the lungs. It is tough and resilient, composed of cartilaginous rings that keep the airway open. Pressure here causes an unpleasant choking sensation.
Thyroid Gland
The thyroid gland (which has nothing to do with the thyroid cartilage) is a butterfly-shaped organ that wraps around the trachea. It is an endocrine gland, secreting hormones that help control metabolism and calcium levels in the blood and bones. The tiny parathyroid glands are embedded within the thyroid. This whole structure is mostly made of delicate epithelial tissue, with little connective tissue protection.
The thyroid gland may become enlarged for various reasons; this is called goiter, and may be clearly visible in some people. The thyroid gland may also develop single or multiple cysts or nodules.
Very early studies in animals and humans suggest that manipulation of the thyroid may stimulate hormone release. This is flatly outside our scope of practice—massage therapists should not be trying to alter hormone secretion through manipulation of the thyroid gland.
Cervical Lymph Nodes
About 300 lymph nodes are located in the neck, in the posterior triangle, the anterior triangle, and under the mandible. Under normal circumstances lymph nodes do not require special adaptations in bodywork, but when they are hardened, enlarged, or painful for any reason they should be at least locally avoided.
Esophagus
The esophagus runs from the pharynx to the stomach. It is on the posterior side of the larynx and trachea, so it is seldom vulnerable to damage from massage—unless the practitioner is working deeply in the anterior triangle of the neck.
Location
Lateral Neck
The posterior triangle of the neck, defined by the lateral sternocleidomastoid, medial trapezius, and middle one third of the clavicle, is not actually on the posterior aspect of the body. Rather, this label refers to the area between the lateral sternocleidomastoid, the medial trapezius, and the middle third of the clavicle (Image 4).
Structures of Note
External Jugular Vein
The external jugular vein crosses over the sternocleidomastoid. This is also shown clearly in Image 2. This is important, because lots of massage techniques involve some specific handling of this muscle—and remember the internal jugular vein and carotid artery are close by as well.
Transverse Processes of the Cervical Vertebrae
A lot of helpful massage can be done in the posterior triangle of the neck, especially as we seek to access the scalene muscles that are often involved in neck and upper back pain. However, we need to be aware that the transverse processes of the vertebrae can feel sharp and pointy. It is not helpful to impale the scalenes on these bony prominences.
Roots of Brachial Plexus
The roots of the brachial plexus emerge from the intervertebral foramina between C5 and T1, and these nerve roots are substantial—the size of shoelaces, in some people. Any pressure here that elicits tingling, numbness, shooting pain, or other neurological signs needs to be changed immediately.
Spinal Accessory Nerve
The spinal accessory nerve supplies motor control to the sternocleidomastoid and the trapezius. It is vulnerable in the posterior triangle of the neck, where damage can lead to long-term weakness in the nearby muscles.
Location
Chest
Structures of Note
Brachial Plexus, Cephalic Vein, Subclavian Vein
Just below the clavicle, where the lateral part of the pectoralis major and the anterior portion of the deltoid meet, there’s a groove where the brachial plexus nerves and the blood vessels of the upper arm pass through. The pectoralis minor muscle, which is often involved in neck and upper back pain, can be accessed in this area, but these nearby structures are mostly unprotected. It is important to be careful to work in this area with a broad, flat surface rather than with sharp, pointy fingertips (Image 4).
Breast Tissue
Breast tissue can be tender and uncomfortable when manipulated carelessly. Both male and female clients may need care to work around this delicate tissue.
If you have special education in breast massage, and if your local legislation allows it (and if your client gives consent), then this modality can be a helpful intervention, especially in situations involving fluid congestion and lymphatic flow.
Location
Abdomen & Upper Extremity
The abdomen is often an under-addressed area in typical relaxation massage, and that’s a pity. It is important to incorporate this part of the body into massage, for many reasons. That said, several structures can be accessed here, and they are vulnerable to damage, especially if they are inflamed, enlarged, or not functioning normally (Image 5).
Structures of Note
Xiphoid Process
The xiphoid process can be broken if sharp, downward pressure is exerted on it. This can cause damage to the liver, which is right underneath.
Floating Ribs
Massage is unlikely to damage floating ribs, but tracing or outlining the rib cage can cause ticklishness or even pain if a therapist does not know exactly where the floating ribs are and how to avoid pinning soft tissue against them.
Liver and Gallbladder
A massage therapist would have to be working much too deep and hard than is usually called for to bruise a healthy liver. However, clients with enlarged livers due to hepatitis, jaundice, cirrhosis, or other problems (such as an inflamed gallbladder) may be particularly sensitive in this area.
Spleen
The spleen is tucked up way under the left ribs. For most people, the spleen is not a significant endangerment, but if it is enlarged for any reason (for instance as a person is recovering from mononucleosis) the whole area can be uncomfortable.
Small Intestines and Colon
While massage therapy is generally helpful for constipation, if a person has any kind of impaction or structural damage to the intestines, then intrusive work here risks damaging these structures. Whether effleurage in a counterclockwise direction over the abdomen can actually cause reverse peristalsis is highly debatable, but clockwise effleurage appears to be soothing for most clients.
Ovaries and Uterus
The ovaries and uterus of a person who is not pregnant and who has no history of inflammation or scarring in the pelvis are normally located so low and central that they are inaccessible to massage therapists. But pregnancy, ovarian cysts, endometriosis, pelvic surgery, infection, or other situations can cause disruption in the pelvic cavity, making the uterus and ovaries susceptible to being pinned or bruised with intrusive abdominal work.
Abdominal Aorta
This major artery of the abdomen is not typically visible or palpable. However, if the therapist observes a prominent throb (the abdomen can be seen obviously and substantially pulsating), then it is best not to do compressive work, and to recommend that the client consult their primary care physician about their cardiovascular health. If no visible pulse is present, but it is palpable with pressure, then withdraw and replace to avoid compressing the aorta.
Vena Cava
The vein that drains the lower half of the body is carried deep in the abdomen and is not typically palpable. However, the weight of a late-term fetus can compress it, leading to muscle cramping or faintness. This is one reason it is important for well-advanced pregnant clients not to lie supine.
Location
Posterior Trunk
Structures of Note
Kidneys
The kidneys are vulnerable to damage because they are only partially protected by the rib cage. The right kidney sits a bit lower than the left. Traditionally we learn that the kidneys might be bruised with tapotement in this area. Such tapotement would have to be very aggressive indeed, because several layers of muscle and fascia lie between the kidneys and the skin, but the musculature in the low back is highly reactive, and sudden or intrusive pressure here may stimulate a reflexive contraction (Image 6).
Spinous Processes
Spinous processes are listed as endangerments because massage therapists can cause pain by pressing paraspinal muscles in toward the spinous processes, rather than out and away from them. Pressure toward the spine can be appropriate, as long as soft tissues are not being impaled or ground into hard ones.
Location
Upper Extremity
Structures of Note
Axilla
The axilla is defined by the pectoralis major on the front, and the latissimus dorsi on the back. It houses the brachial plexus, lymph nodes, and blood vessels (Image 4).
Radial Nerve
The radial nerve wraps around the posterior humerus on its way from the axilla to the posterior side of the forearm. It is vulnerable to irritation when massage therapists work specifically on the triceps muscle. (Image 6).
Cephalic and Basilic Veins
Veins run in pathways that are unique from one person to the next, so it is impossible to state categorically where they might be vulnerable. One thing that is consistent, however, is that they run at least part way up the medial side of the upper arm. Conveniently, this is already an area to avoid because some of the brachial plexus nerves are also vulnerable here. The cephalic vein can also be trapped where it runs along the edges of the anterior deltoid and pectoralis major (Image 4).
Brachial Plexus Nerves
The musculocutaneous, median, and ulnar nerves run down the humerus, mostly on the medial aspect. The radial nerve detours to the posterior side. (Images 4 and 6).
Antecubital Fossa
The antecubital fossa (bordered by the epicondylar line of the humerus, brachioradialis, and pronator teres) or “elbow pit” houses the blood vessels that connect the upper to lower arm, along with the median nerve and a portion of the radial nerve (Image 5).
Cubital Tunnel
The ulnar nerve is vulnerable in the cubital tunnel, which is a groove between the olecranon and the medial epicondyle of the humerus. The familiar sensation of irritation here is what we call the “funny bone” (Image 7).
Carpal Tunnel
The carpal tunnel is not generally considered an endangerment site. But, if the median nerve is irritated, then pressure here could elicit symptoms in the hand (Image 5).
Location
Lower Extremity
Structures of Note
Femoral Triangle
The femoral triangle, bordered by the inguinal ligament, medial sartorius, and adductor longus, is a particularly rich area for vulnerable structures. The femoral artery and vein are both accessible here, as are the inguinal lymph nodes and the femoral nerve. Deep, specific work on the adductors must be conducted with special care to avoid damaging these structures (Image 5).
Sciatic Notch
The sciatic notch is located deep to the deep lateral rotators. To access it manually would require pressing in deeply and intimately in the medial buttocks—typically not an area where most massage therapists work. The sciatic nerve, about as thick as a thumb where it emerges from the lumbosacral plexus, runs through the sciatic notch, into the deep lateral rotators (sometimes bifurcating the piriformis), and down the back of the leg, where it splits into the common peroneal nerve and the tibial nerve.
The sciatic nerve is difficult to pin or damage because the musculature surrounding it is so thick, but if the nerve is irritated for any reason it can become inflamed along its entire length, and careless massage may exacerbate the situation (Image 6).
Popliteal Fossa
The popliteal fossa (defined by hamstrings superiorly and the gastrocnemius and plantaris inferiorly) or “knee pit” holds several structures, including the small saphenous vein where it joins to the popliteal vein, the popliteal artery, and the lower extensions of the sciatic nerve: the tibial and common fibular nerves (Image 8).
Great Saphenous Vein
The great saphenous vein runs up the medial side of the calf where there is little to protect it from being pinned to the tibia. On the upper leg, the vein runs over the quadriceps along the edge of the sartorius. This area is bulky enough that pinning the great saphenous to the femur is not generally possible.
The great saphenous vein is the most likely location for varicosities to develop. If the skin is healthy, then light, broad, flat pressure here moving distally to proximally can be appropriate. Anything more challenging than that may not be a good idea (Image 9).
Tarsal Tunnel
The tarsal tunnel is on the medial side of the ankle, between the medial malleolus of the tibia and the calcaneus. It is not considered by most people to be an endangerment site. But, because the posterior tibial nerve can become entrapped here, in a condition called tarsal tunnel syndrome, it’s a good anatomical feature to keep in mind. The tibial artery and vein also run through the tarsal tunnel (Image 9).
Small Saphenous Vein
The small saphenous vein begins at the lateral ankle, and then wraps to the posterior side of the lower leg. It comes up between the heads of the gastrocnemius, and then dives into the popliteal fossa, where it joins the popliteal vein. The small saphenous vein is also prone to varicosities, and it’s something we need to keep in mind when working deeply in this area to access the soleus or deep foot flexors (Image 8).
Common Fibular Nerve
The common fibular nerve is vulnerable for a short distance just inferior to the head of the fibula. Specific pressure or friction on the fibularis longus can sometimes irritate this nerve, which will send shock-like electrical sensations down into the foot (Image 10).
In Conclusion
In conclusion, I want to reiterate two important points:
• Any place on the body can become an endangerment site if the massage therapist is uneducated, careless, or inattentive.
• An endangerment site is not a “no-go” area; it is an area where extra education and expertise are required to work safely if we’re doing anything more than gentle effleurage.
Remember, the target client for this discussion is someone who is fundamentally healthy and also not pregnant. Illness, recent surgery, injuries, and pregnancy obviously add to our list of cautions and concerns about potential endangerment sites. But, for most people, massage therapy is widely accepted as a remarkably safe intervention, especially compared to other ways people manage pain (e.g., with medications or surgery). We can each do our part to take the danger out of endangerment sites by knowing these areas well, getting advanced education to work here safely, and modifying our massage accordingly. If we do that, our insurance providers will thank us. And much more importantly, our clients will thank us.
Contributors and Reviewers
• Carole Osborne, BCMT, Body Therapy Education