Pivot

Safety — what Pivot does and does not do

Last updated: 9 September 2026

Draft

Draft — not yet reviewed by a clinician or a lawyer. The symptom lists and the advice below are generated from the app's own src/engine/redFlags.ts, so this page and the app cannot say different things. Whether they say the right thing is a question for the physiotherapy review — see LAUNCH.md blocker 1c, which asks specifically whether anything here is routed too gently.

This page exists because a rehabilitation app that is vague about its own limits is dangerous. It is the plain-English version of the position, and it is linked from inside the app.

If something is wrong right now

Do not use this page to work out what is happening. Contact someone.

Contact 111 now, or 999 if you have chest pain or breathlessness. Tell them you have had recent knee surgery. Do not wait for a physio appointment and do not do today's session.

For any of these:

  • Calf pain, or a calf that feels hot, hard or swollen — Pain, tightness or tenderness in the calf of either leg, or a calf that is warm, red or noticeably bigger than the other.
  • Breathlessness or chest pain — Sudden shortness of breath, chest pain, or coughing up blood — especially alongside any calf symptoms.

These can be signs of a blood clot — a recognised risk after knee surgery, and treated urgently. A clot in the leg needs assessment today; one that has reached the lungs, which is what chest pain and breathlessness can mean, is an emergency.

Contact your physiotherapist or surgeon today. If you cannot reach either of them, call 111. Do not do today's session.

For any of these:

  • A temperature, or feeling unwell and shivery — A temperature above 38°C, chills, or feeling flu-like.
  • Fluid, pus or increasing redness from a wound — Any discharge from the incisions, redness spreading outwards from them, or a wound that has opened.
  • The knee locking or getting stuck — The knee catching, jamming, or refusing to straighten or bend past a point.
  • The knee giving way — The knee buckling or shifting under you, whether or not you fell.
  • Swelling that has come on suddenly — A knee that has become visibly more swollen over hours rather than gradually, or swelling after a specific incident.
  • Numbness, pins and needles, or a cold foot — Loss of feeling in the foot or lower leg, or a foot that is cold or pale.

Contact your physiotherapist or surgeon before your next session. Skip today's session.

For:

  • Sharp pain, or pain much worse than it has been — A sharp, catching or stabbing pain, or a clear step up in pain that painkillers are not touching.

What Pivot does when you report one of those

It shows you which number to call. That is all.

It does not:

  • assess the symptom — it will not tell you what it is, how likely it is to be serious, or whether you can wait;
  • rank or triage — where you report several things it shows the most urgent advice of the ones you selected, which is a rule about the list and not a judgement about your knee;
  • tell anybody — no clinician, no next of kin, nobody. Pivot is not a monitoring service and there is no one at the other end;
  • decide it is resolved — it records that you reported it and stops reminding you to exercise for the rest of that day. That is the extent of it.

Pivot cannot call an ambulance and does not know where you are.

Why it works this way

Deciding whether a symptom matters is clinical reasoning. An app doing it from a few taps would be guessing, and guessing at exactly the moments that matter most: a calf that is a bit sore at 11pm three weeks after surgery is either nothing or the start of something serious, and that is not determinable from a phone.

So the app is deliberately unhelpful in one specific way — it will not reassure you. It has no way to know whether you are fine, and an app that told you so anyway would be worse than one that stays quiet.

The programme, and its limits

  • The exercises, doses and thresholds are a conventional programme drawn from published consensus, not a prescription for you.
  • Pivot never progresses you on time. Every phase change needs the measurements met and your physiotherapist's clearance. There is no override and no way to ask for one.
  • Meeting the measurements early does not mean your knee is ready. Healing takes as long as it takes, and your surgeon knows things about your operation that the app does not.
  • If your clinician has given you something different, follow them. You can hide anything the app offers that they have not asked for, and it will not come back.
  • Where Pivot holds something back that your surgeon has cleared — after a meniscal repair, say — that is the app being cautious, not your surgeon being wrong.

What we ask you to record, and how it can mislead you

The phase gates are built on numbers you measure at home, which is why every measurement screen carries instructions. A gate built on a number taken wrongly is worse than no gate: it will tell you that you are ready when you are not.

If you are unsure whether you are measuring something correctly, ask your physiotherapist to watch you do it once. It takes a minute and it makes every reading afterwards worth something.

Who this is for

Adults recovering from ACL reconstruction. Pivot is not a paediatric protocol, not a protocol for other knee surgery, and not general training. If you are under 18, follow the programme your own clinician gives you.

Getting in touch

support@broadai.co.uk — for anything about the app.

Not for anything about your knee. We are not clinicians and will not answer clinical questions, because answering them is precisely what this page says the app does not do.