Back Pain OSCE - Mechanical Lower Back Pain | Free OSCE Practice

Case Overview

Age/Sex: 59-year-old male
Occupation: Office manager (sedentary, predominantly desk-based)
Setting: Primary care / urgent clinic
Chief complaint: "Back pain"

Patient Script

Who I Am

I'm 59, I work at a desk all day as an office manager and I drive to work most days.

What Brings Me In

My lower back has been hurting for about a week and it's not getting better on its own.

My Story

I started noticing a dull ache in my lower back about 7 days ago after a long week of sitting to finish a project. It's mainly in the lower back on both sides, worse when I bend forward or when I get up from sitting, and it improves a bit with rest and lying down. The pain is constant during the day but I get brief sharp twinges if I twist suddenly. I had a similar but milder episode about 6 months ago that went away after a few days with over-the-counter pills and keeping active. I have no loss of control of my bladder or bowels, no fever, and I haven't lost weight. I did slip on some wet pavement about 3 months ago but I didn't feel much pain then and I didn't have to see anyone. I smoke about 15 cigarettes a day and I lead a fairly sedentary life.

My Medical Background

Past medical history: well-controlled high blood pressure (diagnosed 5 years ago)
Medications: lisinopril 10 mg once daily; takes ibuprofen occasionally for aches
Allergies: none known
Social: smokes ~15 cigarettes/day, drinks 2–3 beers on weekends, lives with wife, works full time at a desk
Family: father had prostate cancer in his 70s; mother alive with osteoarthritis

What I Think & Worry About

I think it might be just a pulled muscle from sitting too long.
I'm worried it could be something more serious like a slipped disc or something that will stop me working.
I expect to get something to ease the pain and maybe some exercises or advice to stop it happening again.

If You Ask Me About Other Symptoms...

Pain radiation: "No, it doesn't really shoot down my legs — sometimes I feel a little twinge into my left thigh if I bend the wrong way."
Numbness/tingling: "No pins and needles in my feet or legs, just the twinge now and then."
Bowel/bladder: "No problems — I'm emptying normally and haven't had accidents."
Fever/weight loss/night pain: "No fevers and I've not lost any weight. It doesn't wake me up every night but it's harder to get comfortable."
Recent infections: "No cough, no recent infections."
Other joints: "My left knee aches sometimes from playing football years ago but that's not worse now." (red herring)
Activity: "I sit a lot — I also drive my kids around and haven't been exercising much lately." (relevant)

Clinical Summary

Examination

General: comfortable at rest, afebrile, not pale
Vitals: BP 138/86 mmHg, HR 82 bpm, RR 14/min, Temp 36.8°C
BMI: 29 kg/m2 (overweight)
Gait: normal, no antalgic gait
Inspection: no spinal deformity or visible swelling
Palpation: tenderness over the lumbar paraspinal muscles, maximal at L3–L5 region
Range of motion: flexion limited to ~40° with pain, extension mildly uncomfortable, lateral flexion reduced on the left
Neurological: lower limb motor strength 5/5 bilaterally (L2–S1 muscles), sensation intact to light touch, reflexes: knee and ankle reflexes 2+ bilaterally
Straight leg raise: negative bilaterally (no radicular pain up to 70°)
Special tests: no focal nerve root signs, no saddle anesthesia

Investigations

CBC: WBC 6.8 x10^9/L (normal) — no leukocytosis
ESR: 9 mm/hr (normal) — argues against inflammatory/infectious process
CRP: <5 mg/L (normal)
Plain lumbar spine X-ray: mild multilevel degenerative changes, reduced L4–L5 disc height consistent with osteoarthritic change (no fracture or destructive lesion)
Urinalysis: normal (no infection)
MRI lumbar spine: not performed initially (not indicated given lack of red flags)

Diagnosis

Primary: Mechanical lower back pain (lumbar paraspinal muscle/degenerative mechanical origin)
- Evidence: insidious onset related to prolonged sitting, pain localized to lumbar region, worse with movement and bending, improved with rest, normal neurological exam, negative straight leg raise, normal inflammatory markers, plain X-ray showing degenerative change consistent with mechanical disease.
Differentials:
- Lumbar radiculopathy (e.g., L5/S1 disc herniation): less likely given absence of persistent radiating leg pain, negative SLR, and intact neuro exam
- Spinal compression fracture: unlikely (no significant trauma, no focal point of vertebral tenderness, normal X-ray aside from degenerative change)
- Metastatic spinal disease: unlikely but considered due to age and smoking; low probability given normal systemic symptoms, normal inflammatory markers, and no alarming findings on X-ray
- Inflammatory spondyloarthritis (e.g., ankylosing spondylitis): unlikely due to age of onset and pain pattern (mechanical rather than inflammatory)

Management

Patient education: explain likely mechanical cause and good prognosis; reassure regarding absence of red flags
Analgesia: start regular paracetamol and consider short course of NSAID (e.g., ibuprofen 400 mg TID with food) if no contraindication; avoid prolonged high-dose NSAID without review
Activity advice: remain active, avoid prolonged bed rest, encourage regular short walks and gradual return to normal activities; advise on proper sitting ergonomics and frequent breaks from sitting
Physical therapy: refer to physiotherapy for supervised exercise program focused on core strengthening, flexibility, and education
Adjuncts: consider heat packs and simple stretching; short trial of muscle relaxant if significant spasm
Lifestyle: advise weight reduction and smoking cessation counseling to improve recovery and reduce recurrence
Safety net / follow-up: arrange review in 4–6 weeks; advise urgent return for red flags — new progressive neurological deficits, saddle anesthesia, loss of bladder/bowel control, fever, unexplained weight loss
Imaging/referral: reserve MRI or specialist referral if symptoms persist beyond 6 weeks despite treatment or if red flags develop sooner

Key Learning Points

Most acute low back pain is mechanical and improves with conservative management: stay active, analgesia, and physiotherapy.
Red flags (fever, unexplained weight loss, progressive neurological deficit, bowel/bladder dysfunction) necessitate urgent imaging and specialist assessment.
A focused neurological exam (motor, sensation, reflexes, straight leg raise) helps differentiate mechanical back pain from radiculopathy or more serious pathology.