The relationship between lower limb proprioception and balance performance in children with cerebral palsy: a multisystem and multi-joint approach.

BACKGROUND

Balance problems are a frequent focus of rehabilitation approaches in children with cerebral palsy (CP). Although proprioceptive impairments, affecting 46-90% of children with CP, are commonly observed, their role in postural control remains insufficiently understood.

AIM: Given the multisystemic nature of postural control, this study aimed to investigate the association between lower-limb proprioception (hip, knee, ankle) and distinct postural control systems in children with CP compared to typically development (TD).

DESIGN

Cross-sectional case-control study.

SETTING

Different outpatient settings and the community.

POPULATION: Children aged 5-12 years with TD (N.=30, 8.6±2.2y; boys: 15) and spastic CP (N.=32, 8.4±2.1y; boys: 16; GMFCS-I/II/III: 24/7/1; uni-/bilateral: 17/15).

METHODS

Postural control was assessed using the age-specific Kids-Balance Evaluation Systems Test - extended version (Kids-BESTest-2). Hip, knee, and ankle proprioception were assessed using passive-ipsilateral Joint-Position-Reproduction (JPR). Joint Reproduction Error (JRE,°) was calculated from 3D kinematics for the joints of the dominant (JREd) and nondominant (JREnd) leg. Associations between Kids-BESTest-2 (total and domain scores, %), JRE<inf>total</inf> (all joints) and summed joint JRE<inf>ankle</inf>, JRE<inf>knee</inf> and JRE<inf>hip</inf> (JREd+JREnd) were analyzed using general linear models with correction for multiple testing.

RESULTS

JRE<inf>total</inf> was not significantly associated with Kids-BESTest-2 scores in either group (P>0.01). In CP, higher JRE<inf>hip</inf> (reflecting poorer proprioception) was significantly associated with lower total (η<inf>p</inf>2=0.24, P<0.001) and 3 out of 5 domain scores (η<inf>p</inf>2=0.14-0.22, P<0.004), reflecting poorer balance performance. Similarly, JRE<inf>knee</inf> predicted scores for 'Transitions and Anticipatory Postural Adjustments' (η<inf>p</inf>2=0.13, P=0.008). Across both groups, poorer hip (JRE<inf>hip</inf>) and ankle (JRE<inf>ankle</inf>) proprioception were significantly associated with poorer performance for 'Transitions and Anticipatory Postural Adjustments' (η<inf>p</inf>2=0.16, P=0.003) and 'Reactive postural responses' (η<inf>p</inf>2=0.12, P=0.005), respectively.

CONCLUSIONS

Postural control deficits in children with CP affect multiple systems, and each system is associated with joint-specific proprioceptive impairments (particularly at the hip), rather than overall proprioceptive accuracy. These findings suggest task-dependent and pathology-dependent associations, the latter likely reflecting limitations in compensatory proprioceptive reweighting across lower-limb joints.

CLINICAL REHABILITATION IMPACT: These findings underscore the need for a system- and joint-specific approach to better understand postural control deficits in children with CP and tailor interventions that enhance proprioceptive input during task-specific balance training.