Comparison of KAFO and AFO for extension thrust pattern after stroke: a randomized N-of-1 trial.
Hideyuki Ogawa, Satoshi Shirogane, Hirokazu Haruna
PMID 42544349WHAT IT FOUND
In one stroke patient with knee hyperextension, a knee-ankle-foot orthosis improved walking speed and step count more than an ankle-foot orthosis, but the knee angle itself did not differ between the two.
Results apply to this one patient only.
Key findings
01KAFO produced better hip flexion, ankle dorsiflexion, 10-m walking time, and step count than AFO, while the knee flexion angle showed no significant difference (p = 0.08).
02Effect sizes were large for hip flexion (d = 3.69) and ankle dorsiflexion (d = 2.77), suggesting meaningful biomechanical changes at those joints.
03The authors state these results are specific to this one patient and caution against widespread applicability.
STILL TO COME
How it was doneWhat they foundWhat it means for PTs
Read the rest of this summary
You get three full summaries a month, free, and we do not ask for a card. Search, the TL;DRs and your library stay unlimited either way.
What it does not show
Single patient; results cannot be generalised to other stroke survivors. The two conditions were not delivered under identical conditions: KAFO sessions used hands-on assistance from behind while AFO sessions used a cane, making it impossible to attribute differences to the orthosis alone. Both orthoses were rental devices that did not fit the patient's feet perfectly. The patient was in the spontaneous recovery phase after stroke, so natural improvement may have contributed to the observed changes. Ankle joint angles were measured with a 2D video-based system (OpenPose), which the authors acknowledge may be inaccurate due to out-of-plane foot rotation. Only immediate effects were measured; no long-term follow-up was performed. The patient received ongoing physical therapy (balance, ADL, gait training) throughout the entire study, including washout periods, so the comparison was not against a true no-treatment control.
Declared interests
The authors declare no conflicts of interest.
The easy way to misread this
Do not read the significant differences in hip angle, ankle angle, walking time, and step count as proof that a KAFO is superior to an AFO for knee hyperextension. The knee angle itself, which is the target of the extension thrust pattern, did not reach significance (p = 0.08), and the two conditions were delivered with different levels of physical assistance (hands-on vs. cane), so the comparison is confounded.