Where Do We Start? Navigating Uncertainty in Sessions

One of the biggest challenges in clinical practice is figuring out how much is too much when it comes to evaluation and treatment. If we’re too aggressive, we risk flaring patients up, breaking their trust, or even causing harm. If we’re too passive, we might miss key data or underdose our care. This is especially tough in early sessions, where we’re still learning what our patient can tolerate. That’s where the SINSS model comes in, a framework to systematically assess where someone’s at and how vigorous our examination and treatment should be.

Let’s walk through each part of SINSS and see how you can use it in real time.

Severity

Severity refers to how intense and disruptive the patient’s symptoms are. Consider:

• Pain Scale:

  • Minimal: 0–3/10

  • Moderate: 4–7/10

  • Maximal: 8–10/10

• Impact on ADLs: Minimal severity = no impact; Maximal = significant interference, even with basic self-care

• Medication use & night pain: Frequent narcotics or disrupted sleep often signal high severity

Key Point: Severity helps determine how vigorous your exam/intervention can be. More severe = gentler start.

Irritability

Irritability tells us how reactive the condition is, how easily symptoms are aggravated, how long they take to ease, and what kind of activities set them off or calm them down. The ratio of aggravating to easing factors is your clinical compass here.

• Minimal irritability: It takes a lot of movement or load to provoke symptoms, and symptoms ease quickly with rest or position changes (≥2:1 ratio of aggravating to easing).

• Moderate irritability: Moderate activity provokes symptoms, and easing requires a roughly equal period of rest or relief strategies (1:1 ratio).

• Maximal irritability: Minimal activity brings on intense symptoms that take significant time or intervention to settle (≤1:2 ratio or worse).

Key Point: Think about what aggravates the patient and how long it takes to recover. High irritability = go slow. Use both the activity type and recovery time to guide how vigorous you get.

Nature

Nature refers to (1) the type of pain, (2) the specific condition, (3) patient characteristics, and (4) red/yellow flag indicators.

• Type of pain: Mechanical, inflammatory, neurogenic, central sensitization, or autonomic. Recognizing the pain type gives insight into underlying physiology.

• Specific condition: Consider if this is a local MSK issue (e.g. rotator cuff tear, FAI) or something systemic (e.g. autoimmune, cardiovascular, or visceral referral).

• Patient characteristics: Coping strategies, cultural beliefs, personality, and psychosocial stressors all influence how patients interpret and report pain.

• Red flags: Listed below are just a few examples.

  • Unrelenting night pain not eased by position

  • Unexplained weight loss

  • Saddle anesthesia or bowel/bladder changes

• Yellow flags: Listed below are just a few examples.

  • Catastrophizing or fear-avoidance behavior

  • High pain vigilance or passive coping

  • Litigation or compensation issues

Key Point: Nature isn’t just what’s wrong, it’s who the patient is, how they respond to pain, and whether anything in their story requires extra caution, further screening, or referral.

Stage

Stage = how long the issue’s been around and where it is in the healing process.

• Acute: <3 weeks

• Subacute: 3–6 weeks

• Chronic: >6 weeks

• Acute on Chronic: New flare-up on top of a chronic issue

• Subacute on Chronic: Moderate recurrence of a chronic issue

Key Point: A patient with chronic low back pain who comes in crying and rating the pain a 12/10 is in an acute flare. Don’t treat them like a chronic case, respect the current episode.

Stability

Stability refers to how the condition is trending:

• Improving – symptoms easing, function returning

• Worsening – increased pain/frequency, declining function

• Not changing – plateaued symptoms

• Waxing and waning – symptoms fluctuate based on external factors

Key Point: If someone’s not improving in 2–3 visits, reassess. Look again for red/yellow flags or non-MSK sources. Be humble and don’t be afraid to refer out.

Case Example: Applying SINSS in Real Time

Patient History:

A 42-year-old male presents to your clinic with a history of chronic right shoulder pain that has flared significantly over the past weekend. He reports the pain began after lifting a heavy box overhead while helping a friend move. Since then, the pain has been sharp, constant, and rated as 9/10. He states it’s been interfering with sleep, requiring frequent changes in position and occasional use of hydrocodone, which he had left over from a previous surgery. He hasn’t worked out in three days, and even dressing or reaching for a cup causes discomfort. He appears guarded, anxious, and frustrated during the subjective interview.

Objective Examination:

• Active shoulder flexion limited to 90° with pain

• Pain reproduced with resisted ER and empty can test

• Palpation of the anterior shoulder elicits sharp tenderness

• Sleep log reveals 3–4 awakenings per night

• Negative red flag screen

• Mild scapular dyskinesis observed during overhead reach

• Patient reports some relief with passive pendulum exercises

My SINSS Breakdown:

• Severity: Maximal – Pain 9/10, disrupted sleep, ADLs impaired, narcotic use

• Irritability: Moderate to high – Minimal to moderate activity aggravates symptoms; easing requires prolonged rest or medication

• Nature: Likely mechanical shoulder pathology (suspect rotator cuff or impingement), with no systemic red flags. Psychosocial overlay includes frustration, guarded demeanor, and minimal coping strategies

• Stage: Acute on chronic – Longstanding issue with a recent intense flare-up

• Stability: Worsening – Rapid decline in function, increased intensity and frequency of symptoms compared to baseline

How This Will Guide my Clinical Decision Making:

Gonna keep my exam conservative. Skip repeated resistive testing or aggressive mobility work. Begin with symptom control (e.g., pendulums, pain education, light ROM) and set short-term goals focused on calming the flare. I will plan to reassess irritability and stability closely over the next 1–2 visits.

Parting Thoughts

The SINSS model doesn’t give you every answer, but it gives you a framework to start asking better questions. It helps you make real-time decisions that protect your patient, tailor your exam, and build trust from Day 1.

Use it. It’ll help you think faster, treat smarter, and stop accidentally blowing people up when they’re just trying to get better.

References:

1. Petersen EJ, Thurmond SM, Jensen GM. Severity, Irritability, Nature, Stage, and Stability (SINSS): A clinical perspective. J Man Manip Ther. 2021;29(5):297-309. doi:10.1080/10669817.2021.1919284Disclaimer:

Disclaimer:

I am a current Doctor of Physical Therapy (DPT) student sharing information based on my formal education and independent studies. The content presented in this newsletter is intended for informational and educational purposes only and should not be considered professional medical advice. While I strive to provide accurate and up-to-date information, my knowledge is based on my current academic and clinical rotations and ongoing learning, not extensive clinical practice.