Parkinson’s disease is a primarily idiopathic progressive neurodegenerative disease, which involves a loss of dopaminergic neurons in the basal ganglia.
This decrease in dopamine leads to many signs and symptoms such as tremors, bradykinesia, rigidity, gait and postural control deficits. 1
Gait deficits include reduced cadence, shorter stride and step length, and a decreased time in swing phase. 2,3
PD is the second most common neurodegenerative disease, affecting more than one million people in the US with incidence increasing with age. 4,5
Falls are common for people with PD with 70% experiencing a fall each year and half of these individuals experiencing multiple falls. 5,3
Direct consequences of falls consist of fractures, head trauma, contusions and other injuries, and even death.
Falling may also induce fear of new falls, which can in turn reduce mobility and lead to osteoporosis, a loss of independence, social isolation, and depression.
Finally, falls increase the risk of admission of patients with PD to hospitals and nursing homes. 5
Many falls occur while patients are either moving backward or after a posterior perturbation. 5
Due to decreased visual cues, individuals must rely more on proprioception while ambulating backward.
In individuals with PD, inappropriate processing of proprioceptive input in the basal ganglia may contribute to postural instability. 2,5
Extensive research regarding forward gait has been conducted 2,4,6 ; however, the research investigating backwards gait in patients with PD is limited.