Factors influencing obstacle crossing performance in patients with Parkinson's disease.
BACKGROUND
Tripping over obstacles is the major cause of falls in community-dwelling patients with Parkinson's disease (PD). Understanding the factors associated with the obstacle crossing behavior may help to develop possible training programs for crossing performance. This study aimed to identify the relationships and important factors determining obstacle crossing performance in patients with PD.


METHODS
Forty-two idiopathic patients with PD (Hoehn and Yahr stages I to III) participated in this study. Obstacle crossing performance was recorded by the Liberty system, a three-dimensional motion capture device. Maximal isometric strength of the lower extremity was measured by a handheld dynamometer. Dynamic balance and sensory integration ability were assessed using the Balance Master system. Movement velocity (MV), maximal excursion (ME), and directional control (DC) were obtained during the limits of stability test to quantify dynamic balance. The sum of sensory organization test (SOT) scores was used to quantify sensory organization ability.


RESULTS
Both crossing stride length and stride velocity correlated significantly with lower extremity muscle strength, dynamic balance control (forward and sideward), and sum of SOT scores. From the regression model, forward DC and ankle dorsiflexor strength were identified as two major determinants for crossing performance (R(2) = .37 to.41 for the crossing stride length, R(2) = .43 to.44 for the crossing stride velocity).


CONCLUSIONS
Lower extremity muscle strength, dynamic balance control and sensory integration ability significantly influence obstacle crossing performance. We suggest an emphasis on muscle strengthening exercises (especially ankle dorsiflexors), balance training (especially forward DC), and sensory integration training to improve obstacle crossing performance in patients with PD.
Department of Physical Therapy and Assistive Technology, National Yang-Ming University, Taipei, Taiwan ; Department of Rehabilitation, Jen-Teh Junior College of Medicine, Nursing and Management, Miaoli, Taiwan.
Ying-Yi
YY
Liao
Department of Physical Therapy and Assistive Technology, National Yang-Ming University, Taipei, Taiwan.
Yea-Ru
YR
Yang
Department of Neuromuscular Disorders, Chang Guan Memorial Hospital, Linkou, Taiwan.
Yih-Ru
YR
Wu
Department of Physical Therapy and Assistive Technology, National Yang-Ming University, Taipei, Taiwan.
Ray-Yau
RY
Wang
D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007866:Leg / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009068:Movement / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology; D010300:Parkinson Disease / Q000503:physiopathology*; D012044:Regression Analysis; D012677:Sensation; D011795:Surveys and Questionnaires; D013624:Taiwan