↓↓English Below↓↓
皆さんこんにちは！！
東京都千代田区、麹町駅と半蔵門駅の間、新宿通り沿いのビル２階・３階にある整形外科クリニック One Clinic 麹町 院長の栗本です。
急に熱くなりましたが皆様いかがお過ごしでしょうか？今日は久しぶりに肩関節の痛み、特に肩関節周囲炎について書いてみたいと思います。
「肩が痛くて腕が上がらない。」
「服を着るのがつらい。」
「夜になると肩がズキズキして眠れない。」
40～60歳くらいの方から、このようなご相談をいただくことは多くあります。
多くの方が「四十肩・五十肩ですね」と言われた経験があるかもしれません。しかし実は、「四十肩・五十肩」という言葉は正式な病名ではなく、医学的には肩関節周囲炎、あるいは癒着性関節包炎（Adhesive Capsulitis）と呼ばれる疾患です。
今回は近年の研究をもとに、肩関節周囲炎の原因、鑑別疾患、そして治療、特にリハビリテーションの重要性について解説します。
肩関節周囲炎とは？
肩関節周囲炎は、肩関節を包む関節包に炎症が起こり、その後に線維化や拘縮が進行することで、痛みと可動域制限を生じる疾患です。
以前は「自然に治る病気」と考えられていましたが、近年では必ずしもそうではないことが分かってきました。
適切な治療を受けなかった患者さんの一部では、数年経っても可動域制限や痛みが残ることが報告されています。
原因は？
原因は完全には分かっていませんが、最近では、
- 関節包の炎症
- 炎症に続く線維化
- コラーゲン沈着
- 関節包の肥厚
が病態の中心と考えられています。
その他、糖尿病 甲状腺疾患 長期間肩を動かさなかった状態 外傷や手術後
などでは発症リスクが高くなることが知られています。糖尿病患者さんでは症状が重く、治療に時間を要する傾向があります。
「五十肩」だけではない
肩が痛いからといって、すべてが肩関節周囲炎ではありません。
代表的な鑑別診断は
腱板断裂や石灰沈着性腱板炎・上腕二頭筋長頭腱炎・滑液包炎
変形性肩関節症 頚椎症や頚椎椎間板ヘルニア などです。
例えば腱板断裂では「腕を上げられない」ことが主症状になりますが、肩関節周囲炎では「他人が動かしても肩が動かない（他動可動域も制限される）」ことが特徴です。
診断
診断は問診と診察が基本です。
肩関節周囲炎では、
- 自動運動・他動運動ともに制限される
- 外旋制限
- 特に夜間の痛み
- 徐々に進行する可動域制限
が特徴です。
レントゲンや超音波検査で骨の状態や腱板断裂の有無を評価します。
MRIは全例に必要ではありませんが、診断が難しい場合や手術を検討する場合には有用です。
治療方針
肩関節周囲炎は一般的に
① Freezing（炎症期・急性期）
② Frozen（拘縮期）
③ Thawing（回復期）
の3段階で進行すると考えられています。
この病期を考えずに同じリハビリを続けても、十分な効果は期待できません。
基本は保存療法
現在のガイドラインでも、まずは保存療法が推奨されています。
薬物療法
NSAIDsやアセトアミノフェンは痛みの軽減に役立ちます。
痛みが強い時期には、運動療法を行いやすくするためにも鎮痛が重要になります。
ステロイド注射
近年のガイドラインでも、関節内ステロイド注射は短期的な疼痛改善と可動域改善に有効とされています。
特に炎症期では痛みを軽減し、その後のリハビリを円滑に進める目的で行われます。
一方で効果は永続的ではなく、注射だけで治癒するわけではありません。
リハビリテーション
最新のレビューでも、運動療法は肩関節周囲炎治療の中心であることが繰り返し示されています。
ただし、「痛いほど伸ばす」のは現在では推奨されません。
炎症期では無理なストレッチは炎症を悪化させる可能性があります。
まずは疼痛をコントロールしながら、振り子運動や軽い可動域運動を行います。
拘縮期になると徐々に関節包へのストレッチや関節モビライゼーションを取り入れます。
回復期では肩甲骨や腱板、体幹を含めた筋力強化へ移行します。
近年の研究では、
- 運動療法
- 徒手療法（関節モビライゼーション）
- ホームエクササイズ
を組み合わせることで、疼痛や可動域、機能改善が最も期待できることが示されています。
また、自宅で毎日行うホームエクササイズは非常に重要です。
リハビリの中で自宅でできるトレーニングもお話しさせていただきます
私たちは肩関節周囲炎を「肩だけの病気」とは考えていません。
肩甲骨の動き、胸椎の柔軟性、姿勢、体幹機能などを評価すると、肩に過剰な負担が集中している原因が見えてくることは少なくありません。
そのため当院では、レントゲンや超音波検査で診断したうえで、理学療法士によるリハビリテーションを重視しています。
必要に応じて薬物療法や関節内注射等を組み合わせながら、患者さん一人ひとりの病期に合わせた治療を行っています。
私たちが目指しているのは、痛みを一時的に軽減するだけではなく、「肩を以前のように使える状態まで回復させること」です。
まとめ
肩関節周囲炎は単なる「年齢のせい」ではありません。
正確な診断を行い、腱板断裂などの疾患を除外したうえで、病期に応じた治療を選択することが重要です。
最新のエビデンスでは、薬物療法や注射は痛みを軽減するために有効ですが、長期的な機能改善にはリハビリテーションが欠かせません。
適切な運動療法とホームエクササイズを継続することが、肩の動きを取り戻し、再発を防ぐ最も重要なポイントです。
肩の痛みや動かしにくさが続く場合は、「年齢のせい」と我慢せず、ぜひ一度ご相談ください!(^^)!
暑さが続きます。
くれぐれもご自愛くださいませ!(^^)!
Hello everyone!!
I’m Dr. Kurimoto, Director of One Clinic Kojimachi, an orthopedic clinic located on the 2nd and 3rd floors of a building along Shinjuku Street, between Kojimachi Station and Hanzomon Station in Chiyoda City, Tokyo.
The weather has suddenly become very hot. I hope you’re all staying healthy and keeping cool.
Today, I’d like to talk about shoulder pain—particularly frozen shoulder, also known as adhesive capsulitis.
Many patients tell us:
- “My shoulder hurts so much that I can’t lift my arm.”
- “Getting dressed has become difficult.”
- “The pain becomes worse at night, and I can’t sleep.”
These complaints are especially common among people in their 40s to 60s.
Many of you may have been told that you have “frozen shoulder.” However, this is a common term rather than an official medical diagnosis. The condition is medically known as adhesive capsulitis, or in Japanese clinical practice, shoulder periarthritis.
In this article, I will explain the causes of frozen shoulder, the conditions that should be differentiated from it, current treatment options, and—most importantly—the vital role of rehabilitation, based on recent scientific evidence.
What Is Frozen Shoulder?
Frozen shoulder is a condition in which the joint capsule surrounding the shoulder becomes inflamed, followed by fibrosis and tightening of the capsule. This process causes pain and progressive restriction of shoulder motion.
For many years, frozen shoulder was considered a condition that would eventually resolve on its own. However, recent studies suggest that this is not always the case.
Some patients who do not receive appropriate treatment continue to experience pain and limited shoulder motion for several years.
What Causes Frozen Shoulder?
Although the exact cause remains unclear, current research suggests that the disease process involves:
- Inflammation of the joint capsule
- Progressive fibrosis following inflammation
- Collagen deposition
- Thickening and tightening of the joint capsule
Certain medical conditions are known to increase the risk of developing frozen shoulder, including:
- Diabetes mellitus
- Thyroid disorders
- Prolonged shoulder immobilization
- Previous trauma or shoulder surgery
Patients with diabetes, in particular, often experience more severe symptoms and may require a longer recovery period.
Not Every Painful Shoulder Is Frozen Shoulder
It is important not to assume that every painful shoulder is frozen shoulder.
Several other conditions can produce similar symptoms, including:
- Rotator cuff tears
- Calcific tendinitis
- Biceps long head tendinitis
- Shoulder bursitis
- Glenohumeral osteoarthritis
- Cervical spondylosis or cervical disc herniation
For example, patients with a rotator cuff tear may be unable to actively lift their arm, whereas patients with frozen shoulder typically have limitations in both active and passive range of motion—meaning that even when someone else tries to move the shoulder, movement remains restricted.
Making the correct diagnosis is essential because the treatment differs significantly among these conditions.
Diagnosis
Diagnosis begins with a careful medical history and physical examination.
Typical findings in frozen shoulder include:
- Restriction of both active and passive shoulder motion
- Marked limitation of external rotation
- Night pain
- Gradually worsening stiffness
X-rays and ultrasound examinations are useful for evaluating the bones and determining whether a rotator cuff tear is present.
MRI is not necessary for every patient but can be valuable when the diagnosis is uncertain or when surgical treatment is being considered.
Treatment Depends on the Stage of the Disease
Frozen shoulder generally progresses through three stages:
- Freezing Stage – Painful inflammatory phase
- Frozen Stage – Stiffness predominates
- Thawing Stage – Gradual recovery of motion
Because each stage has different characteristics, the rehabilitation approach should be adjusted accordingly. Using the same treatment throughout the entire course of the disease is unlikely to produce the best results.
Conservative Treatment Is the First Choice
Current clinical guidelines recommend conservative treatment as the first-line approach.
Medication
Non-steroidal anti-inflammatory drugs (NSAIDs) and acetaminophen can help relieve pain.
Adequate pain control is important because it enables patients to participate more effectively in rehabilitation exercises.
Corticosteroid Injection
Recent guidelines also support intra-articular corticosteroid injections for short-term pain relief and improvement in shoulder mobility.
These injections are particularly helpful during the inflammatory (freezing) stage, allowing rehabilitation to begin more comfortably.
However, steroid injections are not a permanent solution and should be viewed as part of a comprehensive treatment plan rather than a cure.
Rehabilitation: The Key to Recovery
Recent systematic reviews consistently identify exercise therapy as the cornerstone of treatment for frozen shoulder.
However, current evidence no longer supports the idea that “the more painful the stretch, the better.”
During the inflammatory stage, aggressive stretching may actually worsen inflammation and increase pain.
Instead, treatment should begin with adequate pain control, gentle pendulum exercises, and light range-of-motion exercises.
As stiffness becomes the primary problem, stretching of the joint capsule and joint mobilization techniques can gradually be introduced.
During the recovery phase, rehabilitation should progress to strengthening exercises involving the rotator cuff, scapular stabilizers, and core muscles.
Recent studies have shown that combining:
- Therapeutic exercise
- Manual therapy (joint mobilization)
- Home exercise programs
provides the greatest improvements in pain, range of motion, and shoulder function.
Equally important is performing home exercises every day.
At One Clinic Kojimachi, our physical therapists teach patients exercises that can be safely performed at home so rehabilitation continues even between clinic visits.
Our Approach at One Clinic Kojimachi
At One Clinic Kojimachi, we do not believe frozen shoulder is simply a problem affecting the shoulder itself.
By carefully evaluating scapular movement, thoracic spine mobility, posture, and core stability, we can often identify movement patterns that place excessive stress on the shoulder.
For this reason, we emphasize rehabilitation provided by experienced physical therapists after establishing an accurate diagnosis using X-rays and ultrasound examinations.
When appropriate, rehabilitation is combined with medications and intra-articular injections, allowing us to tailor treatment according to each patient’s stage of recovery.
Our goal is not merely to reduce pain temporarily, but to help our patients regain the ability to use their shoulder naturally and confidently once again.
Conclusion
Frozen shoulder is not simply “part of getting older.”
An accurate diagnosis is essential to distinguish it from conditions such as rotator cuff tears, and treatment should always be tailored to the stage of the disease.
Current evidence indicates that medications and injections are effective for reducing pain, but long-term recovery depends on rehabilitation.
Consistent exercise therapy combined with daily home exercises remains the most effective way to restore shoulder function, improve mobility, and reduce the risk of recurrence.
If you continue to experience shoulder pain or stiffness, don’t assume it’s just a normal part of aging. Early evaluation and appropriate treatment can make a significant difference in your recovery.
Thank you for reading.
The hot weather is expected to continue, so please take good care of yourself and stay hydrated. We wish you good health throughout the summer.
