Back pain and leg symptoms — examine the legs

Candidates: do not open until you have consulted.

Persona and manner

• Priya Nair, 41, team leader in a parcel warehouse; lives with your partner Sam and your daughter, 9.
• Practical, a little embarrassed to be “making a fuss about a bad back”; frightened underneath, because this is spreading and you do not know why. You sit forward, shifting your weight, and stand up slowly.

Opening line — say this verbatim

• “It started as a bad back from lifting, but now it’s going down both legs and I’m scared something’s really wrong.”

How to show the signs

• Walk in slowly and stiffly, leaning slightly to the left; sit forward on the chair and get up with a hand on the arm.
• When asked to walk on your heels: let the right foot drag slightly — the toes do not come up as well as on the left. Toe-walking is normal.
• When the doctor tests pulling your right foot and big toe upwards against resistance: give way a little — “it’s weaker, that one.” Everything else — pushing down, hips, knees, the left leg — is full strength.
• When the right leg is lifted straight with the knee locked: at about 40 degrees, grimace and say the pain shoots down the back of the leg to the foot; if the doctor then bends your foot up, say it is worse. On the left, the same at about 60 degrees but milder.
• When sensation is tested with cotton wool or the pin: on the outside of the right calf and the top of the right foot, say “that’s duller than the other side.” Everywhere else is normal.
• You cannot show reflexes; the findings at the end of this script are read out. If asked how it feels between your legs or around your back passage, give the wiping answer — only if asked.

Volunteer freely if given the space

• Ten days ago you lifted a heavy tote onto a trolley and felt your back “go”. Low back pain since, worse sitting and bending.
• Four days ago the pain started shooting down the back of the right leg to the foot, with pins and needles on the outside of the calf and the top of the foot. Since yesterday the left leg aches down the back too — not as bad, but new.

Only if asked

• Passing urine — if asked directly whether there is any difficulty passing urine, starting the flow, or knowing when your bladder is full: “This morning it took ages to get going, and I wasn’t sure I’d finished. That’s never happened before.” If asked only “any problems with your waterworks?” say “I don’t think so — a bit slow this morning” and no more. No leaking; you have not needed a pad. No burning; no blood.
• Bowels: opened yesterday, normal; no leaking; no loss of control. If asked whether you can feel it when you need to go: “I think so.”
• Sensation between the legs and around the back passage — only if asked: “It felt odd when I wiped this morning — sort of numb on the right side. I thought it was the painkillers.”
• Sex: not asked about unless the doctor asks — “we haven’t, with my back.” If asked specifically about feeling or numbness in the genitals: “I haven’t noticed.”
• Weakness: the right foot feels “floppy” on the stairs today; you tripped on the top step this morning.
• No fever, no sweats, no weight loss; no previous back problems; no cancer in you or the family; no steroids, no injected drugs, no recent infections. No history of osteoporosis; no falls apart from the trip on the stairs this morning; the lift was the only injury. You are not pregnant; periods normal.
• Painkillers: ibuprofen 400 mg three times a day and paracetamol — taking the edge off, no more. Nothing else. No allergies.
• Driving: you drove here — slowly, in pain.

Impact on daily life — home and work (only if asked)

• You have been off work for a week and your manager has been texting about the Christmas peak rota; you are the one who usually covers.
• You cannot sit through a meal; you sleep in snatches on the floor; Sam has been doing the school run and everything else.
• Your daughter has started asking whether you are going to be “in a wheelchair”.

Ideas, concerns and expectations

• Idea: a slipped disc — a workmate at the warehouse had one.
• Concerns: that the spreading to both legs means something serious — you have been searching online and read the word “paralysis”; losing the job.
• Expectation: stronger painkillers, a sick note and “a scan”.

Cues to deliver, timed

• Minute 1–2: “Is it because I kept working on it? I should have come sooner.”
• While your right foot is being tested: “It feels floppy — I tripped on the stairs this morning.”
• If nothing has been said about the hospital by minute 7: “So is it just painkillers and physio, then?”

If the doctor summarises and asks whether you want to add anything

• If the wiping has not come up: “I should say — when I wiped this morning it felt sort of numb, on the right side. Is that anything?”
• If it has: “And it took ages to get the wee started this morning — is that connected?”

How to respond to the doctor

• If the doctor explains that the disc is probably pressing on the nerve to the right leg, that the new left-leg pain, the numbness when wiping and the slow wee are warning signs that the nerves to the bladder and bowel may be getting squeezed, and that you need to go to hospital now for an emergency scan: frightened — “Today? Right now?” — then, if told plainly that treating it early is what protects the bladder and the legs, you agree. “Sam can bring me.”
• If the doctor says “it’s sciatica” and offers stronger painkillers, physio, a routine scan or an urgent clinic appointment, or says to come back if it gets worse: relieved — “So it’s nothing serious?” You accept and start to get up.
• If the doctor asks to examine your back passage or says they need to put a finger inside: alarmed — “Do you have to? Can’t they do that at the hospital?” (The doctor should not examine there; if they insist, decline.)
• If told you must not drive yourself: “Sam can bring me — he’s outside.”
• If told not to eat or drink anything until the hospital has seen you: “Not even a cup of tea?” — then, if the reason (a possible operation) is given, “All right.”
• If the doctor gives a plain explanation of what cauda equina means in words you could tell Sam: you repeat it back.
• If the doctor uses words like “radiculopathy” or “neurogenic”: “Is that the paralysis thing?”
• If the examination is rough or your leg is lifted past the pain: “Stop — please.”

Do not

• Volunteer the slow wee, the numbness when wiping or the trip on the stairs unless asked, or invited to add anything (apart from the timed cues).
• Use the words “cauda equina”.
• Show weakness anywhere other than lifting the right foot and big toe; show no weakness on the left.

Findings to give the candidate — only if asked for

This is an examination station: give each finding as the candidate performs that step, or asks for it. The role player shows the weakness and the straight-leg-raise pain; sensation, reflexes and the saddle answer are read out when tested or asked. Do not offer findings for steps the candidate has not performed, and do not volunteer the saddle answer unless the question is asked. (Where a separate examiner is present, the examiner reads them.)

Domain marks — with the key facts that earn a 4 at this station

Domain score (educational construct):

This 1–4 domain score and its descriptors are an Acumen educational construct: the GMC publishes the three marking domains and the four-mark maximum, but not the descriptors its examiners use, and it does not publish station mark sheets. See Legal & Regulatory.

Marks are 1 to 4 in each domain; the generic descriptor for each mark is on the mark scheme page, and the structure of the eight minutes is on the 8-minute station page. The full standard for this case is in section 3 and the GMC feedback statements, with examples from this case, are in section 4. The examination findings that the role player gives — only if the candidate asks for them — are at the end of section 1.

The top row is the full picture of what a competent FY2 could do at this station, including the working diagnosis with its justified differentials, the safety-net and the follow-up; lower rows describe how performance falls away. It is a debriefing aid, not a checklist to recite: nobody says every line in eight minutes, and a 4 is a judgement that the essentials — the italic key facts on the mark sheet — were done well, in plain language and at the patient’s pace. Acumen training standard — the GMC does not publish station mark sheets.

A feedback statement marks where underperformance was identified in the consultation. With PLAB 2 results the GMC may attach any combination of the ten statements to a station — none, one or several. The right-hand column shows what each one looks like at this station. Record the statements that applied in the practice log.

Points of fact the examiner should have to hand

1. Cauda equina syndrome is rare (about 1 to 3 per 100,000) but a spinal emergency: acute or rapidly progressive compression of the lumbosacral nerve roots, usually by a large disc prolapse, which if untreated causes permanent loss of bladder, bowel and sexual function and lower-limb paralysis. No single symptom or sign is diagnostic, and an MRI on its own cannot make the diagnosis; the emergency triggers are recent (14 days or fewer) or worsening difficulty initiating micturition or impaired sensation of urinary flow, altered perianal, perineal or genital sensation (reported or tested), severe or progressive neurological deficit of both legs, loss of the sensation of rectal fullness, and new sexual dysfunction; sudden bilateral sciatica, or unilateral sciatica that has become bilateral, is a warning sign (GIRFT / NHS England National Suspected Cauda Equina Syndrome Pathway, February 2023, updated to March 2026; NICE CKS Low back pain, revised August 2026). Ms Nair has new hesitancy and altered sensation when wiping, so the emergency route applies.
2. Emergency referral (GIRFT pathway): a patient with ongoing cauda equina symptoms or signs that started within the last two weeks is referred to the nearest hospital with an emergency MRI facility — “patient should attend hospital now”; a telephone assessment can trigger the referral if face-to-face review would delay it. Urgent referral (seen within two weeks, musculoskeletal triage): sudden-onset bilateral sciatica, or unilateral sciatica that has become bilateral, without cauda equina symptoms or signs — with a warning card and the MACP safety-net video.
3. What the referral must record (GIRFT pathway): the time and date of assessment; power and sensation in the lower limbs; which cauda equina symptoms and signs are present, with duration, frequency and progression; who was referred to and when; any advice received if the case was not accepted. “A digital rectal examination is not necessary, but subjective perianal sensation should be recorded.” The patient takes a copy of the clinical summary to hospital. In the examination, saddle sensation is asked about — and the role player is never examined rectally.
4. Imaging (GIRFT pathway, with the Royal College of Radiologists): emergency MRI for suspected cauda equina syndrome at the presenting hospital, in and out of hours, as soon as possible and certainly within four hours of the request; the report is reviewed promptly and the spinal service is contacted if compression is shown; the patient is kept nil by mouth when an emergency scan is requested, in case emergency surgery is needed — so the GP tells her not to eat or drink on the way (the pathway gives this instruction to the hospital team requesting the scan; the practice advice is a precaution). A bladder scan is an adjunct, never a discriminator: a post-void residual over 200 ml makes the diagnosis about 20 times more likely, but 60% of patients who needed emergency decompression had a residual under 200 ml.
5. NICE NG59 (Low back pain and sciatica in over 16s, 2016, last updated 29 July 2026, when recommendations 1.2.13 and 1.2.14 were withdrawn):think about alternative diagnoses and exclude specific causes — cancer, infection, trauma, inflammatory disease — particularly with new or changed symptoms (rec 1.1.1); do not routinely image in a non-specialist setting (1.1.4); advise self-management and staying active; for sciatica, be aware of the harms and limited evidence of benefit of NSAIDs and, if prescribing, use the lowest effective dose for the shortest time with gastroprotection where needed (1.2.20–1.2.21); do not offer gabapentinoids, other antiepileptics, oral corticosteroids or benzodiazepines for sciatica (1.2.16), and do not offer opioids for chronic sciatica (1.2.17); do not offer paracetamol alone for low back pain (1.2.26).
6. Red flags for other serious causes of back pain (NICE CKS Low back pain, August 2026): spinal fracture — sudden severe central pain relieved by lying down, trauma or osteoporosis, a step, point tenderness; cancer — age 50 or over, gradual progressive or night pain, thoracic pain, weight loss, past cancer; infection — fever, recent infection, diabetes, injected drug use, immunosuppression. She has none of these.
7. Localising the root: L4 — knee extension and ankle dorsiflexion, knee jerk, sensation over the medial shin; L5 — big-toe extension, dorsiflexion and eversion, no reflex, sensation over the lateral calf and dorsum of the foot into the big toe; S1 — plantarflexion and eversion, ankle jerk, sensation over the lateral foot and sole; S2–S4 — saddle sensation and the anal reflex, which is why those questions are asked. Weakness is graded on the MRC scale (0–5). A straight leg raise that reproduces pain below the knee between about 30 and 70 degrees, worse with dorsiflexion of the foot, indicates nerve-root tension; pain in the other leg when the unaffected leg is raised (crossed straight leg raise) is more specific for a prolapse.
8. Driving and work: she must not drive herself to hospital with weakness of the right foot and severe pain. Fit notes cover time off and amended duties; the Christmas peak is not a reason to delay.
9. Patient safety-netting materials: the Musculoskeletal Association of Chartered Physiotherapists cauda equina warning card and video, available in 35 languages, list the symptoms in plain words (numbness between the inner thighs or genitals, altered feeling when wiping, difficulty starting or stopping the flow, leaking or needing pads, not knowing when the bladder is full or empty, loss of bowel control, loss of genital sensation) and are linked from the GIRFT pathway.

Where candidates lose marks at this station

• Testing power and reflexes without ever asking about wiping, the wee and the bowels.
• “Any problems with your waterworks?” — and accepting “I don’t think so”.
• Asking to examine the back passage on the role player.
• “It’s sciatica” — stronger painkillers, physio and a sick note.
• An urgent clinic letter, or a routine MRI, instead of a telephone call and “go now”.
• Letting her drive herself to hospital.

Guidelines for this station

• GIRFT / NHS England — National Suspected Cauda Equina Syndrome Pathway (February 2023, updated March 2026)
• NICE NG59 — Low back pain and sciatica in over 16s: assessment and management
• NICE CKS — Low back pain: assessment and red flags
• NICE CKS — Sciatica (revised August 2026): emergency and urgent referral for suspected cauda equina syndrome
• GIRFT — Pathway supports clinicians to diagnose and treat cauda equina syndrome without delay
• NHS — Sciatica (patient information)

Record your three domain marks, your station total, the GMC feedback statements that applied (where underperformance was identified), and what you will keep and change. The form is already labelled with this case and its web address; a copy of your entry is emailed to you, so your practice log builds up in your inbox and can be downloaded.

Record my marks and reflection for P2-25