A prospective longitudinal design was employed to describe early (first 6 weeks post-injury) motor function recovery in 16 individuals with severe traumatic brain injury (TBI). Reliable, standardized testing and scoring protocols were used by a physical therapist to evaluate subjects on several different aspects of motor function, including primitive reflexes, equilibrium/protective reactions, and a wide range of motor skills. The findings revealed that subjects demonstrated significant changes (chi 2, p < or = 0.05) between 1 and 6 weeks for the following variables: equilibrium reactions in sitting, rolling prone to side-lying, sitting (supported and unsupported), kneeling, standing (assisted and independently), walking (assisted and independently), stair climbing with the use of the handrail and walking 25 m on even ground. A significant change in ability to sit supported between 1 and 3 weeks post-injury was also observed. In addition, recovery was found to be a heterogeneous process, in that different patterns of recovery were evident for the 26 variables and among individual subjects. The clinical implications for physical therapists involved in the rehabilitation of adults with a severe TBI are discussed.