Spinal injury recovery varies widely—study reveals why some walkers face hidden joint damage
A new analysis of how incomplete spinal cord injury patients walk reveals that even those who appear to recover well may be overloading their hips in ways that could cause long-term joint problems. The findings could reshape rehabilitation protocols and identify which patients need targeted intervention to prevent future disability and healthcare costs.
Originaltitel: Characterizing the effects of muscle weakness on margins of stability and joint mechanics during gait in persons with incomplete paraplegia due to spinal cord injury.
Incompleta ryggmärgsskador skapar skiftande gångförmåga beroende på vilka muskler som är svaga — kunskap som gör det möjligt att skräddarsy rehabilitering och förebygga framtida komplikationer. KTH MoveAbility och Karolinska Institutet analyserade 21 patienter med inkompleta ryggmärgsskador och delade in dem i fyra grupper utifrån svaghetsmönster. Gruppen med mild fotsularsvaghet gick nästan normalt men utvecklade ökade belastningar i höftleden — en långsiktig hälsorisk. Patienter med måttlig svaghet kompenserade genom långsammare gång utan återstående avvikelser. De två svårast drabbade grupperna med kombinerad fot- och höftsvaghet visade försämrad balans i sidled, bredare steg och omfördelad mekanisk belastning från anklar till höfter respektive knän. Resultaten visar att gånganpassningar beror på exakt svaghetsprofil, inte bara skadans allvarlighetsgrad. Denna differentiering möjliggör målgruppsanpassad träning och reducerar risken för sekundära ledskador — relevant för kliniker som planerar rehabiliteringsprogram och medicintekindustrins utveckling av stödprodukter.
Individuals with incomplete spinal cord injury (iSCI) exhibit diverse walking capabilities due to partial sensory and/or motor impairment below the injury level. This study examined how neuromuscular weakness patterns influence compensatory gait strategies, dynamic balance (margins of stability, MoS), and joint-level mechanics across iSCI subgroups compared to non-disabled controls. We analyzed gait data from 21 iSCI participants previously classified into four subgroups through dynamic time warping and hierarchical clustering. Temporospatial parameters, anterior-posterior (AP) and mediolateral (ML) MoS, and joint kinetics were analyzed using linear mixed-effects models with walking speed as a covariate to isolate group differences beyond speed. The most functional individuals, with mild plantarflexor weakness, walked comparably to controls but exhibited elevated peak hip flexion moments, suggesting a possible long-term hip joint health concern. The individuals with moderate plantarflexor weakness adopted slower walking speed as their primary compensation, with no residual differences from controls once speed was accounted for. The two most impaired groups of individuals, with combined plantarflexor and hip muscle weakness, additionally compromised frontal-plane balance - adopting wider step widths and higher ML MoS - and showed a redistribution of mechanical demand during stance, with the hips contributing a larger proportion of total positive joint work than the ankles. The individuals with most impairment further showed elevated AP MoS persisting beyond speed reduction, lower peak plantarflexion moment, and a shift of mechanical work toward the knee. These findings indicate that gait adaptations in iSCI depend on the muscle weakness profile rather than severity alone, supporting tailored rehabilitation strategies.