Diagnosed with thoracic outlet syndrome (TOS)

A woman working at a company near Yokohama Station visited my clinic, reporting numbness throughout her right arm that began two weeks ago. It was her first visit to Spine Chiropractic in Bashamichi, but I had previously treated her at a different chiropractic clinic where I used to work. At that time, her symptoms were related to the lumbar region. Based on her past experience, she felt that chiropractic care would be more effective for her condition than visiting a hospital. As a result, she searched for Spine Chiropractic and decided to consult.
During the two weeks before her visit, she had been taking medication prescribed at a hospital—Loxoprofen (an anti-inflammatory analgesic) and Methycobal (a medication for peripheral nerve disorders). While these medications helped alleviate her symptoms temporarily, she relied on them when the numbness became severe. However, as the effects wore off, the symptoms would intensify in frequency and severity. Seeking a more fundamental solution, she chose to visit my clinic, recalling the positive results from my previous treatment.

[Initial Symptoms]

Interview:

The patient reported numbness in her arm, which she started noticing gradually and has since increased in frequency, eventually spreading throughout the entire arm. Initially, she thought it might be due to fatigue from work and tried massaging her arm, but the symptoms worsened after a few days, causing her concern. She then took leftover medication that had been previously prescribed to her. Around the time the numbness became frequent, she also noticed that her right hand felt colder compared to her left hand. While the medication temporarily eased the numbness, the symptoms would return, creating a cycle of taking the medication, feeling symptoms, and taking the medication again. Seeing no signs of improvement, she searched for my name online, which led to her visit to the clinic.

Visual Inspection:

No abnormalities observed.

Static Palpation:

Increased muscle tension was observed in the right cervical region, upper trapezius, and sternocleidomastoid(SCM) muscles. Tension was also noted in the right upper arm and forearm compared to the left.

Motion Palpation:

The numbness in her right arm slightly intensified during left rotation of the neck. Stretching her arm in a direction that stretches the chest muscles caused the numbness to worsen.

Orthopedic Tests:

  • Morley’s Test: Positive (+), indicating possible entrapment of the anterior scalene muscle.
  • Adson’s Test: Positive (+), similar findings as Morley’s Test.
  • Costoclavicular Maneuver: Negative (-), ruling out nerve compression between the first rib and clavicle.
  • Wright’s Test: Positive (+), suggesting nerve entrapment caused by the pectoral muscles.

Muscle Strength Examination:

Not perform

[Initial Treatment Plan]

Based on the history and examination findings, the patient’s symptoms were assessed to be consistent with thoracic outlet syndrome (TOS). In chiropractic care, it is crucial to determine the location of nerve compression affecting the nerves that supply the arm. To normalize nerve flow (nerve transmission), treatment was focused on relieving tension in the primary muscles likely causing nerve entrapment. In this patient’s case, these were the scalene muscles (deep neck muscles) and the pectoralis minor (chest muscles). Additionally, as myofascial referred pain could also be contributing, myofascial release was performed.
Cervical adjustments were applied to the C4–C6 vertebrae, which were identified as the cause of restricted range of motion during neck rotation (difficulty turning left).
Although some numbness remained after the treatment, the overall sensation of numbness had improved, and the patient reported easier neck rotation to the left. The initial session was concluded, and the patient was scheduled for a follow-up visit in five days.

[Prognosis]

Second Session:

The patient mentioned that the symptoms eased slightly for about two days after the first treatment but then returned to the same level as before. Considering this, the second session used the same approach as the first but added extra focus on the shoulder joint. I noticed a forward shoulder posture (rounded shoulders), which suggested possible nerve compression due to tension in the chest muscles. The treatment was adjusted to address this. A follow-up was scheduled for a week later.

Third Session:

The effects of the second treatment seemed to last longer than the first. When the patient came back a week later, she reported that her symptoms had reduced to less than half their original intensity, rating them at 4 out of 10. The same treatment as the second session was performed, and the interval between visits was extended to 10 days. She also mentioned that the cold sensation in her hand had improved significantly.

Fourth Session:

While there was a slight increase in symptoms with the longer interval between treatments, both the intensity and the range of numbness were much better than when she first came in. The cold sensation in her hand was completely gone. I continued the same treatment, expanding it to include the entire arm (upper arm and forearm) since the symptoms were steadily improving. The interval between sessions was stretched to two weeks for further observation.

Fifth Session:

Two weeks later, the patient said her symptoms were almost gone. She shared with a smile, “If I really think about it, I might notice it slightly, but otherwise, I don’t even remember it when I’m busy.” This confirmed her recovery.

With her symptoms resolved, the chiropractic treatment sessions came to an end. At her request, she moved to a maintenance care plan, coming in once a month to prevent recurrence and manage work-related fatigue.

[Practitioner’s Opinion]

Thoracic Outlet Syndrome (TOS), characterized by numbness in the arm, is primarily caused by nerve compression at one of three key anatomical regions:

Scalene Muscle Syndrome:
The brachial plexus, which branches out from the cervical spine to supply the arms, passes beneath the scalene muscles located at the front of the neck. Tension in these muscles can compress the nerves, leading to numbness in the arm, a hallmark symptom of this condition.

Costoclavicular Syndrome:
After exiting the neck, the brachial plexus passes directly beneath the clavicle. Compression in this area can occur if the clavicle is displaced downward due to factors like trauma or a history of clavicle fractures, though this is relatively uncommon.

Pectoralis Minor Syndrome:
Over-tension in the pectoralis minor muscles in the chest can compress the nerves before they reach the arm. This is often seen in individuals with rounded shoulders, commonly caused by prolonged desk work. This condition, also known as Hyperabduction Syndrome, is aggravated by movements involving arm elevation, such as holding onto a train strap, cleaning windows.

I concluded that her symptoms were due to Thoracic Outlet Syndrome (TOS), caused by a combination of Scalene Muscle Syndrome and Pectoralis Minor Syndrome.

The nerve compression was due to tension in these muscle groups along the nerve pathways from the cervical spine to the arm. While temporary relief can be achieved by releasing muscle tension, lasting improvement requires addressing the skeletal alignment where the muscles attach.

Additionally, the root cause appeared to lie in habitual imbalances in daily activities. Since the symptoms were isolated to the right side, we advised the patient to review her daily habits and body mechanics to correct these tendencies.

My chiropractic treatment takes into account not only musculoskeletal adjustments but also environmental and lifestyle factors. This holistic approach, along with the patient’s active efforts to improve her habits, likely contributed to her recovery.

I am pleased to welcome this patient back to my clinic, as her workplace near Yokohama Station made Bashamichi a convenient location, and she remembered her positive experience with my care in the past.

At Spine Chiropractic, I address a wide range of musculoskeletal conditions directly impacting daily life, not merely as a form of relaxation therapy. Conveniently located within a one-minute walk from Bashamichi Station, an eight-minute walk from Nihon-Odori Station, a seven-minute walk from JR Kannai Station, and a 12-minute walk from JR Sakuragicho Station, my clinic is well-suited for residents and workers in the Yokohama area.

If you are experiencing similar symptoms, please feel free to visit Spine Chiropractic. I am committed to providing care with sincerity and professionalism.