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Rucking with a bad back or bad knees

Can you ruck with a bad back or bad knees? What weight does to your joints, when to skip it, and how to start carefully.

The honest answer is: it depends on what is wrong, and a website cannot decide that for you. This page is general beginner information, not treatment. It explains what load does to backs and knees, which signs mean stop, and how to start if you get the go-ahead.

This is not treatment

There is a difference between general advice for healthy beginners and advice for a specific injury. This page is the first. If you have a known disc injury, a knee injury, a recent operation, arthritis, pregnancy, osteoporosis or pain you cannot explain, the decision belongs with your doctor or physiotherapist, who knows your diagnosis and can examine you.

That is not a formality we add to be safe. Rucking loads exactly the joints the problem lives in, and whether loading helps or harms depends entirely on what is wrong. Two people with "a bad back" can need opposite things.

What load actually does to your back

A backpack does not simply make you heavier - it changes how you walk. In a 2025 EMG and biomechanics analysis using a load of 12% of body weight, erector spinae activity dropped by roughly 33-35%, and mobility at L5-S1 was sharply restricted: around 35% less lateral bending and 67-69% less rotation. The body handles the load by stiffening up around the lower back.

That is worth understanding, because it explains why placement matters. Weight held high and close to your back behaves mostly like extra body weight. Weight that hangs low, bounces or pulls backwards forces you to lean forward - and forward flexion is the position that increases pressure on the lower back most.

The literature is not unanimous on placement, though. A 2022 review found mixed results: at 15% of body weight it could not measure a clear difference between high, medium and low placement. So treat "high and close" as a sensible default, not a proven rule.

What load does to your knees

Knees feel it most on the way down. Walking downhill, the thigh muscles work as brakes - eccentrically - and that is the kind of work that produces the most muscle fatigue and next-day soreness.

A 2024 systematic review examined what walking with a backpack does to the knee muscles ability to produce force. It concluded that the negative effects on neuromuscular function are dose-dependent and arise mainly through that eccentric work during the walk. The heavier and the longer, the more.

In practice: flat ground and short walks are a gentler place to start than a hilly route, and if anything should be dialled back first, it is the descents.

When to end the walk

This is training judgement, not medical advice: end the walk and go home if the joint itself hurts while you walk, if the pain changes from steady to sharp, if you start limping or altering your gait to avoid pain, or if the knee gives way.

Joint pain is not the same as tired muscles. Tired muscles are diffuse, symmetrical and better within a couple of days. Joint pain is local, often sharp, and typically worse with the specific movement that loads the joint. Telling them apart is the whole point.

When to seek medical help

Here we defer to a public health authority rather than inventing our own criteria. These are the NHS thresholds for back pain, and they apply whether the pain came from a weighted walk or from something else entirely.

Call emergency services or go to A&E for: pain, tingling, weakness or numbness in BOTH legs; loss of feeling around the genitals or anus; changes in bladder or bowels, such as difficulty peeing or peeing or pooing yourself; chest pain; or pain that started after a serious accident.

Get urgent same-day help for: feeling hot, cold, shivery or generally unwell alongside the pain, or severe pain that starts suddenly or is getting worse quickly.

See a GP for: pain that does not improve after treating it at home for a few weeks, pain stopping your day-to-day activities, pain that is worse at night or does not improve with rest, unexplained weight loss, a lump or swelling in your back or a change in its shape, or pain that is worse when sneezing, coughing or going to the toilet.

That list is the NHS wording relayed, not our interpretation. If in doubt, phone your doctor rather than treating a training page as the authority.

If you get the go-ahead

Start lighter than you think. Three to five kilos is a sensible place to begin when joints are sore, even though it feels like nothing. Feeling like nothing is the point.

Be aware that "5-10% of body weight" is a practical rule of thumb from beginner literature, not a scientifically established safety threshold. Research typically works with far heavier loads - the 2022 review recommends generally not exceeding 40% of body weight for healthy adults, and under 10% for children, whose spines are still developing. There is no number documented as safe for a sore knee.

Start short: twenty minutes on flat ground, and pay attention to how the next day and the day after feel before you even think about distance.

Build one thing at a time, in this order: time first, then terrain, then weight. Increase several at once and you will not know what hurt.

Repeat the same route a few times. It is far easier to notice a change on a walk you know than to compare two different ones.

Where RuckClub fits

RuckClub helps with the boring part: keeping walks similar enough that you can tell whether things are going the right way. RuckScore combines distance, weight, time and terrain into one number, so two walks can actually be compared.

RuckScore is a training signal, not a medical measurement. It knows nothing about your knee, and it cannot tell you whether a walk was wise. It can show you that Thursday was harder than Tuesday.

Group walks state pace and distance up front, so you can pick a walk you know you can finish rather than finding out halfway.

  • Ask a professional first
  • Weight high and close
  • Stop on joint pain
  • Time before terrain before weight

Sources

Last checked: 31 July 2026. Every claim on this page is either cited from the sources above or flagged as a practical rule of thumb. The thresholds for seeking medical help are relayed from the NHS. This page has not been reviewed by a health professional, and it does not replace an examination by a doctor or physiotherapist.