Background: Studies about the effects of walking training with additional body load in Parkinson's disease (PD) are lacking. There is evidence that the increase of body load during treadmill walking improves reflex activity and leg extensor muscle activity, which are impaired in subjects with PD.

Purpose: The purpose of this study was to assess the effects of treadmill walking training with additional body load on the ground reaction forces, spatiotemporal, and kinematic variables of the gait of subjects with moderate PD.

Design: This study was an A1-B-A2 single-case. Setting: The evaluation and the training were conducted in a movement analysis laboratory, and at the rehabilitation unit of the University, respectively.

Participants: Nine patients with PD (Hoehn and Yahr 2 through 3) and gait disturbances.

Interventions: Phases A1 and A2 included 6 weeks of gait training on a treadmill with 10% increase of normal body mass. Phase B included 6 weeks of conventional physical therapy.

Measurements: Measures included the ground reaction forces, spatiotemporal, and kinematic variables during overground walking, at baseline and after each phase.

Inclusion Criteria:

• Idiopathic PD (previously diagnosed by one specialist physician,)
• Hoehn and Yahr (H-Y) stages 2 through 3,
• Absence of dementia (Mini-Mental Status Examination - MMSE, defined according to educational level) and,
• Capacity to ambulate independently for at least 10 meters.

Exclusion Criteria:

• Change medication (dopaminergic) during the study period,
• Use treadmill for at least six months prior to the study, and
• Other neurologic problems or musculoskeletal, cardiovascular and respiratory disease or uncorrected visual deficit that could represent risk and interfere in the performance of the training.