Clinical Reasoning, Patient History & Diagnostic Classifications – Comprehensive Study Notes

Clinical Reasoning Process

• Starts with the PATIENT INTERVIEW → proceeds through data analysis, differential diagnosis, SINSS characterization, triage & management decisions.
• “Funnel” strategy: begin broadly, then narrow • ensures nothing is missed • places the chief complaint in full context.
• Purposes
  • Decide PT appropriateness vs. referral (TRIAGE).
  • Generate diagnostic hypotheses (pre-test probability).
  • Select regions to screen vs. examine in detail.
  • Establish baselines for future outcome comparison.
  • Determine examination vigor based on Severity & Irritability (SINSS).

Why the History Is Critical

• 80–90 % of the information required for Dx often surfaces during the subjective exam.
• Guides every subsequent choice: tests, manual techniques, dosage, education, prognosis.
• Collects both biomedical & psychosocial factors → influences flag identification (red, yellow, blue, black).

PARTS of the PATIENT INTERVIEW (mnemonic: WHO → WHERE → WHY → WHAT → WHEN/IF → HOW)

• WHO – person & impact
  • Age, sex, culture, occupation, lifestyle, language, referring provider.
  • Self-report outcome measure & screening questionnaire obtained here.
• WHERE – symptom description & link
  • Chief complaint in pt’s own words.
  • Exact location(s) on body diagram; multiple areas → explore relationships.
• WHY – chronological history
  • Sequential account of current episode: onset (insidious vs MOI), progression, prior care, prior episodes.
• WHAT – behavior of each symptom
  • Aggravating factors (load, motion, reps, time).
  • Easing factors (rest, positions, movement, meds).
  • 24-hour pattern (AM stiffness, night pain, diurnal changes).
• WHEN/IF – precautions & contraindications
  • Systems review, red-flag questioning, medication effects, imaging/lab results.
• HOW – patient expectations & success criteria
  • “How will you know you are better?” • establishes patient-defined goals.

Data-Collection TOOLS

1. Medical History Screening Questionnaire

• Detects systemic disease mimicking NMS conditions.
• Inquires about recent health changes, family history, cardiopulmonary, endocrine, pregnancy, depression, communication barriers.

2. Region-Specific Self-Report Outcome Measures

• Disability Indices (higher = worse): ODI, SPADI.
• Functional Indices (higher = better): LEFI, UEFI, FFI, CSI.
• Track change pre/post intervention; identify poor-prognosis sub-groups (e.g., pain-related fear).

3. Generic Measure – Patient-Specific Functional Scale (PSFS)

• Pt chooses 3–5 difficult activities → rates each 0\,(unable)\text{ – }10\,(pre-injury).
• Total score formula: PSFS_{total}=\dfrac{\sum activity\;scores}{#\;activities}
• MDC: 2 points (average) or 3 points (single activity).

4. Pain-Related-Fear Questionnaires (Yellow-Flag Screen)

• Capture kinesiophobia, catastrophic beliefs (e.g., "I’ll re-tear my ACL" or "activity will damage my spine").

5. Flag System

• Red Flag – serious pathology (fx, cancer, infection, constant non-varying pain).
• Yellow Flag – adverse prognosis / fear-avoidance.
• Blue Flag – beliefs about work & health (unsupportive environment).
• Black Flag – constraints from systems, policy, or insurer.

6. Chief Complaint

• Open prompt → “In your own words, tell me about your problem.”
• May NOT equal underlying pathology → keep open mind.

7. Demographic & Social Profile

• Occupation & work demands (light/medium/heavy, current duty status, impact of Sx).
• Recreation/exercise frequency, volume, effect of Sx.
• Other: language, culture, compensation issues, living environment.

Pain Science & Symptom DESCRIPTION

• IASP definition: pain = “unpleasant SENSORY & EMOTIONAL experience associated with actual or potential tissue damage.”
• Neuromatrix Theory: thoughts + stress + immune influences → altered output (movement changes & chronic pain).

Three Broad Pain Types

1. Nociceptive – acute tissue injury; mechanical, chemical, thermal.
2. Peripheral Neuropathic – nerve root/peripheral nerve lesion → burning, electric, dermatomal.
3. Central Sensitization – hypersensitive CNS, disproportionate pain.

Qualitative Descriptors

• Deep diffuse ache (local or referred); hot/burning/electric (radicular); numbness/tingling (pins & needles).
• Always ASK specifically about paresthesia if unreported.

Temporal Patterns

• Constant (varies) vs. intermittent vs. constant NON-VARYING (= red flag for sinister pathology).

Intensity Scales

• VAS & Numeric Pain Scale (NPS) highly correlated (r ≈ 0.67–0.96).
• MCID for low-back pain ≈ 2 points.

Referred Pain Types

• Somatic Referred – joint/muscle/tendon source; deep, poorly localized.
• Radicular – nerve root inflammation/compression; sharp, lancinating along dermatome.
• Visceral Referred – organ origin; often anterior chest or abdomen, may mimic back pain (kidney, pancreas, aortic aneurysm).

CURRENT & PAST EPISODE Details

• Current: onset (traumatic vs. insidious), timing, progression, self-treatment.
• Previous: frequency, recovery time, prior Rx effectiveness, residual deficits.

Symptom BEHAVIOR

• Aggravating factors (Severity & Irritability)
  • Document load/duration to provoke, nature & magnitude of increase, time to ease.
• Easing factors
  • If NOTHING eases → consider inflammatory/systemic origin.
  • Rest easing → typical for mechanical NMS issues; document position & latency.
• 24-Hour Pattern
  • AM stiffness? Night pain? Diurnal swelling? Sleep disturbance threshold?

REVIEW of SYSTEMS

• Needed when no formal questionnaire; targets nutrition, weight change, fever, malaise, dizziness, light-headedness, vision, ENT, etc.
• Evaluate medication side-effects (statins → myalgia, corticosteroids → osteoporosis).
• Imaging & lab data: note modality, date, results, precautions.

PATIENT EXPECTATIONS (HOW)

• Establish patient-specific goals → integral for shared decision-making.

SINSS FRAMEWORK (Data Analysis)

• Severity (0–10, impact): 0–3 mild, 4–6 mod, 7–10 severe.
• Irritability: ease of aggravation × time to settle ↓
  • Mild → High continuum.
• Nature: guides triage & hypothesis list (NMS vs non-NMS; pathology type; flags).
• Stage: acute (≤ 14 days), sub-acute (2 wk–3 mo), chronic (> 3 mo) PLUS pain mechanism (nociceptive, neuropathic, central).
• Stability: better / worse / unchanged.
• Utilisation
  • Determines examination vigor & re-testing frequency.

TRIAGE DECISIONS

• Appropriate for PT?
  1. Pure NMS → treat.
  2. Non-NMS/systemic → refer.
  3. Mixed → treat + refer.

DIAGNOSTIC CLASSIFICATION SYSTEMS

1. Pain-Mechanism Classification

• Nociceptive | Peripheral Neuropathic | Central Sensitization (see above).

2. Impairment-Based Diagnosis

• Links specific impairment to functional deficit (what the pt CAN’T do & WHY).
• Main contributing factors
  • Pain
  • Decreased motor control / weakness
  • Limited ROM (joint & soft tissue)
  • Joint hypomobility: confirmed by PROM/PAM; treated w/ mobilization + exercise.
  • Soft-tissue hypomobility
    • Contracture (adaptive shortening)
    • Adhesion (abnormal collagen adherence)
    • Trigger point (hyper-irritable nodule → local or referred pain).

3. Clinical Practice Guidelines (CPG)

• Summarize high-quality evidence; grade recommendations for exam, Dx, prognosis, intervention.
• Pros: comprehensive; evidence-graded; guides decisions.
• Cons: high inclusion threshold; limited to studied populations; doesn’t automatically integrate clinician expertise or patient values.

4. Treatment-Based Classification (TBC) – Lumbar & Cervical Spine

• Manipulation Subgroup – recent onset, hypomobility, LBP only, low FABQ. NOT for: distal Sx, high frequency, peripheralization.
• Stabilization Subgroup – younger age, +prone instability, aberrant movements, high SLR ROM, segmental hypermobility.
• Specific Exercise Subgroup – directional preference, centralization with repeated motion, peripheralization opposite to centralization.

5. Structural / Pathology-Based (Medical) Model

• Identifies tissue pathology; sometimes weak correlation with Sx severity & treatment guidance.

Ligament Sprains

• Grade 1: pain, mild swelling, painful but firm PAM, full WB possible.
• Grade 2: partial tear, moderate swelling, mild laxity w/ pain, functional losses.
• Grade 3: complete rupture, marked laxity/no end-feel, high instability; surgery often.

Muscle Strains

• Grade 1 (mild): minor swelling, local tenderness, minimal performance loss; resisted strong-painful; passive stretch pain.
• Grade 2 (moderate): partial tear, ecchymosis, moderate strength loss; resisted weak-painful.
• Grade 3 (severe): complete tear, severe pain → often loss of function, surgery.

Dislocation vs Subluxation

• Dislocation = complete loss of joint congruency.
• Subluxation = partial/incomplete.

Tendinopathy

• Hx of overload; pain w/ PROM stretch & active/resisted contraction; local tenderness.
• EBM exercise progression: isometric (analgesic) → slow heavy isotonic incl. ECCENTRIC.

Fractures

• Healing phases
  • Inflammation \text{Day 1–6} – coagulation/hematoma.
  • Reconstruction \text{Day 7–9} – soft → hard callus.
  • Remodeling \text{Day 10–30+} – cortical reorganization.
• Avulsion, compression, stress. Pediatric SALTR: Straight, Above, Lower, Through, Rammed.

Cartilage Injuries

• OA (DJD) – primary (idiopathic) / secondary (post-trauma). Sx: pain, stiffness, crepitus, ↓flexibility.
• RA – systemic autoimmune, bilateral small joints; > 60 min AM stiffness, fever, fatigue, deformity.
• Chondromalacia / OCD – focal “pothole” defects.

Nerve Injuries

• LMN (peripheral): neuropathy, radiculopathy → ↓ DTR (hyporeflexia).
• UMN (spinal cord): myelopathy → ↑ DTR (hyperreflexia).
• Severity spectrum
  1. Neuropraxia – transient conduction block; pain, weakness; full recovery in minutes–days.
  2. Axonotmesis – axon/myelin disrupted; CT intact; Wallerian degeneration; atrophy; prolonged recovery.
  3. Neurotmesis – complete severance incl. CT; anesthesia, atrophy; poor spontaneous recovery.
• Compartment Syndrome – nerve/vascular compression → irreversible damage after 4\text{–}8 h; causes: fx, crush, restrictive cast, burns, snake bite.

Practical Implications & Connections

• Most decision algorithms (SINSS, TBC, impairment-based) derive from the subjective data → underscores interview mastery.
• Understanding pain mechanisms helps educate pts & choose appropriate dosing (e.g., avoid over-loading sensitized CNS).
• Flag identification integrates ethics & health-system context: addressing yellow & blue flags often necessary for long-term success.
• Utilising CPGs plus individual impairments & patient values realises evidence-based practice’s three pillars (research, clinician expertise, patient preference).

Numerical & Formula Highlights

• MCID_{NPS\,(LBP)} = 2 points.
• PSFS{MDC(avg)} = 2, PSFS{MDC(single)} = 3.
• SINSS severity cut-offs: 0!–!3 mild, 4!–!6 mod, 7!–!10 severe.
• Fracture healing timeline embedded above.

Ethical & Practical Take-Aways

• Early detection of red flags via history can be life-saving → ethical duty to refer.
• Blue & black flags remind clinicians to advocate for workplace adaptation & navigate insurance constraints.
• Pain-related fear (yellow flag) requires empathy, graded exposure, & education to prevent chronicity.
• Evidence synthesis (CPGs) must be personalized; one size never fits all.