Table 1. Causal model.
| Clinical Feature | Measure | Causes |
|---|---|---|
| Injury | ||
| Age | Age | |
| Motor Control | MC, Latent | Injury |
| Selective Motor Control | SCALE | Motor Control, Age |
| Dynamic Motor Control | DMC | Motor Control, Age |
| Strengtha | Strength | Injury, Motor Control, Age |
| Spasticity | Spasticity | Injury, Age |
| Contracture | Latent | |
| Ankle Dorsiflexion Contractureb | AnkleDF | Strength, Spasticity, Dynamic & Selective voluntary motor control, Age |
| Knee Extension Contractureb | KneeExt | Strength, Spasticity, Dynamic & Selective voluntary motor control, Age |
| Hamstrings Contractureb | Popliteal | Strength, Spasticity, Dynamic & Selective voluntary motor control, Age |
| Hip Extension Contractureb | HipExt | Strength, Spasticity, Dynamic & Selective voluntary motor control, Age |
| Torsion | Latent | |
| Tibial Torsionc | TibRot | Strength, Spasticity, Dynamic & Selective voluntary motor control, Age |
| Femoral Anteversionc | FemRot | Strength, Spasticity, Dynamic & Selective voluntary motor control, Age |
| Gait Pattern | GDI | Strength, Spasticity, Dynamic & Selective voluntary motor control, Age, Ankle ROM, Knee ROM, Popliteal ROM, Hip ROM, Tibial Torsion, Femoral Anteversion |
| Gross Motor Function | GMFM-66 | Strength, Spasticity, Dynamic & Selective voluntary motor control, Age, Ankle ROM, Knee ROM, Popliteal ROM, Hip ROM, Gait Pattern |
Features included in the causal model illustrated in Fig 1. Measures here match the Fig 1 variable names. The hypothesized direct causes of each feature are listed.
a. Because we measure strength in an age-adjusted manner, we do not include an explicit causal link in our graphical model used for testing plausibility and determining adjustment sets.
b. Ankle, Knee, Hamstrings, and Hip contractures are influenced by an unmeasured latent variable Contracture so that Contracture → Ankle Dorsiflexion Contracture, Contracture → Knee Extension Contracture, Contracture → Hamstrings Contracture, Contracture → Hip Extension Contracture.
c. Tibial Torsion and Femoral Anteversion are influenced by an unmeasured latent variable Torsion so that T → Tibial Torsion, T → Femoral Anteversion.