  Ankle proprioceptive deficits are common after stroke and occur independently
of ankle motor impairments. Despite this independence, some studies have found
that ankle proprioceptive deficits predict gait function, consistent with the
concept that somatosensory input plays a key role in gait control. Other
studies, however, have not found a relationship, possibly because of
variability in proprioception assessments. Robotic assessments of
proprioception offer improved consistency and sensitivity. Here we
relationships between ankle proprioception, ankle motor impairment, and gait
function after stroke using robotic assessments of ankle proprioception. We
quantified ankle proprioception using two different robotic tests (Joint
Position Reproduction and Crisscross) in 39 persons in the chronic phase of
stroke. We analyzed the extent to which these robotic proprioception measures
predicted gait speed, measured over a long distance (6-minute walk test) and a
short distance (10-meter walk test). We also studied the relationship between
robotic proprioception measures and lower extremity motor impairment,
quantified with measures of ankle strength, active range of motion, and the
lower extremity Fugl-Meyer exam. Impairment in ankle proprioception was present
in 87% of the participants. Ankle proprioceptive acuity measured with JPR was
weakly correlated with 6MWT gait speed (\r{ho} = -0.34, p = 0.039) but not
10mWT (\r{ho} = -0.29, p = 0.08). Ankle proprioceptive acuity was not
correlated with lower extremity motor impairment (p > 0.2). These results
confirm the presence of a weak relationship between ankle proprioception and
gait after stroke that is independent of motor impairment.
