The association of equinus and primary genu recurvatum gait in cerebral palsy.
In bilateral spastic CP, early-onset genu recurvatum is tied to tighter equinus—check ankle dorsiflexion first.
01Research in Context
What this study did
The team looked at kids with bilateral spastic cerebral palsy who walk on their toes.
They counted how many also snap their knees backward while walking.
Motion-capture cameras measured ankle and knee angles during normal gait.
What they found
Eight out of every 100 kids had the knee-snap pattern called genu recurvatum.
The worse the ankle tightness, the more the knee bent backward.
Kids whose knee snapped right after the heel hit the floor had the tightest ankles.
How this fits with other research
Eussen et al. (2016) later showed ankle surgery helps most when the knee snaps early.
Capio et al. (2013) proved calf-muscle lengthening cuts knee hyper-extension by ten degrees.
Together the three papers build a timeline: tight ankle → early knee snap → surgery works best.
Why it matters
If a child with CP walks on toes and snaps knees, check ankle dorsiflexion first.
Early ankle tightness predicts bigger gains from calf surgery.
Note when the knee snaps during stance; early snap means ankle work is urgent.
Want CEUs on This Topic?
The ABA Clubhouse has 60+ free CEUs — live every Wednesday. Ethics, supervision & clinical topics.
Join Free →Watch the child’s knee during the first second after heel strike—if it snaps backward, flag ankle tightness for the PT or ortho team.
02At a glance
03Original abstract
Primary genu recurvatum (GR) is less investigated and data presenting the prevalence among patients with bilateral spastic cerebral palsy (BSCP) is lacking in the literature. Equinus is mentioned as one of the main underlying factors in GR, but its influence on the severity and onset type of GR is mainly unanswered, yet. Hence, the purpose of this retrospective study was to assess the prevalence of GR in a large sample size in children with BSCP and to investigate sagittal plane kinematics to evaluate the influence of equinus on different GR types using data of three-dimensional gait analysis. GR was defined as a knee hyperextension of more than one standard deviation of an age matched control group during stance phase in either one or both of the limbs. Primary GR was defined as a GR without having previous surgery regarding the lower extremity, no selective dorsal rhizotomy and/or interventions like botulinum toxin injection, shock wave therapy or serial casting during the last 6 months in the patient history. In a retrospective study 463 patients with BSCP (GMFCS Level I-III) received three-dimensional gait analysis and were scanned for the presence of primary GR. Finally, 37 patients (23 males, 14 females) matched the determined inclusion criteria and were therefore included for further analysis in this study. Out of those patients seven walked with orthoses or a walker and were excluded from further statistical comparison: Kinematics of the lower limbs were compared between patients having severe (knee hyperextension>15°) and moderate (knee hyperextension 5-15°) GR and between patients showing an early (first half of stance phase) and a late (second half of stance phase) GR. Primary GR was present in 37 patients/52 limbs (prevalence 8.0/5.6%). Severe GR was associated with a decreased ankle dorsiflexion compared with moderate GR. Early GR showed an increased knee hyperextension compared to late GR. In conclusion GR is less frequent compared with crouch or stiff gait. Our findings support the importance of equinus as a major underlying factor in primary GR. In this context the influence of equinus seems to be more important in early GR.
Research in developmental disabilities, 2014 · doi:10.1016/j.ridd.2014.03.032