Can active proprioceptive training improve proprioception in freezing of gait?

Abstract

Freezing of gait (FOG) is arguably the most debilitating symptom in Parkinson's disease (PD). Impairments specifically in proprioception have been argued to underlie FOG behaviour, therefore, proprioceptive training could be beneficial for FOG. Currently, only one study has demonstrated the potential for proprioception to be improved with training but not in patients with FOG. In the current study, individuals with PD and FOG (n=13) completed proprioceptive training involving a target-matching task utilizing active and self-defined movements with the upper and lower limbs. Training sessions were one hour long, occurring twice weekly for a period of four weeks. Proprioceptive accuracy was assessed pre- and post-intervention using a passive upper limb joint-angle matching task at three positions (10, 30, and 60 degrees away from the starting position). Absolute, constant, and variable error were calculated for the limb most affected by disease. No improvements in constant or absolute error were found, however, a significant improvement was found in variable error at the 60 degree position. A subsequent analysis was conducted to compare participants divided into LOW and HIGH proprioceptive error groups (using a median split), and found significant time x group interactions in constant error at the 30 and 60 degree positions, and in variable error at the 60 degree condition. These findings suggest that improvements in joint-position matching are possible with proprioceptive training in FOG. It appears that the greatest benefit is in larger angles. This may be a viable treatment option for FOG behaviour, although further investigation quantifying FOG is required.