Core work beat ankle drills for knee arthritis pain

Knee osteoarthritis is one of the most common musculoskeletal conditions, driven in part by aberrant joint loading and marked by pain and reduced function. Rehabilitation thinking has shifted from treating the knee in isolation towards addressing the whole kinetic chain — the linked segments above and below the joint that influence how it is loaded. That raises a practical question: if you are going to add something to standard knee exercises, should it target the trunk above or the foot and ankle below? Direct head-to-head comparisons of proximal and distal add-ons have been scarce, which is the gap this trial addressed.

One hundred participants aged 40 or over with Kellgren-Lawrence grade II-III knee osteoarthritis were randomly assigned to core stability exercise (n=50) or foot-ankle strengthening (n=50). Both groups performed conventional knee exercises three times weekly for 8 weeks, supplemented by their group-specific training. The primary outcome was resting pain on a visual analogue scale. Secondary outcomes included the KOOS knee-function subscales, functional tests (40-m fast-paced walk, 30-second chair stand and 11-step stair climb) and distal structural measures such as Achilles tendon thickness and the navicular/foot ratio, assessed at baseline and 8 weeks with analyses adjusted for baseline values.

The core stability group improved significantly more than the foot-ankle group across all outcomes. Between-group differences exceeded validated minimal clinically important differences for resting pain and every KOOS subscale, met those thresholds for the walk and chair-stand tests, and surpassed minimal detectable change for the stair-climb test and the distal structural measures, with large effect sizes favouring core training. Notably, even the foot- and ankle-level structural parameters shifted more in the core group. The authors stress, however, that these distal structural findings are exploratory and likely reflect localised soft-tissue fluid shifts rather than permanent anatomical remodelling.

This trial adds a rare direct comparison to a literature that has mostly tested proximal or distal interventions against usual care rather than against each other. Its result supports the kinetic-chain view that trunk control can meaningfully influence knee outcomes, and it suggests that, at least over 8 weeks, working above the knee outperformed working below it. Open questions remain: whether the advantage persists beyond the short term, whether it holds in more or less severe disease, and whether the distal structural changes can be validated with advanced imaging, as the authors themselves call for.

For anyone managing knee osteoarthritis with exercise, this is a reason to think that the trunk deserves attention alongside the knee itself, rather than assuming all the useful work happens at the affected joint. It also illustrates a broader principle: how a joint is loaded depends on the segments around it, so rehabilitation can be about more than the painful site. That said, this is a single 8-week trial in one population, and both groups still did conventional knee exercises as their base — the comparison was between add-ons, not replacements. Anyone with knee OA considering a change to their programme would sensibly discuss it with the professional overseeing their care.