Parkinson Disease is a degenerative process that affects millions each year, and has devastating effects on patients and their families. The mobility symptoms that manifest as the disease progresses can result in social isolation as patients may be embarrassed or fear falling in public. One of the common risks resulting from the PD is falls. Falling in PD is primarily related to musculoskeletal issues such as muscular rigidity, postural instability & stooped posture. These kinds of manifestations should be amenable to treatment with OMT. There are studies showing the positive impact that OMT has on gait in PD, and a study showing improvement in balance in non-PD subjects. This investigation is designed to address these components via the following specific aims:

1. Identify the effects of a Neck-down OMT (OMT-ND) protocol on gait kinematics and postural control in Parkinson disease The investigators hypothesize that the application of an OMT protocol will improve gait kinematics and increase subjects' ability to respond to a postural challenge. The theoretical mechanism for this is due to the improved joint flexibility, improved proprioception and decreased muscle co-activation.
2. Determine the efficacy of Whole-body OMT (OMT-WB) protocol including cranial manipulation on gait kinematics and postural control in Parkinson disease The investigators hypothesize that the addition of a cranial manipulation protocol will further improve gait kinematics and increase subjects' ability to respond to a postural challenge. The theoretical mechanism for this is due to the improved arterial blood flow to the brain, which results from improving the cranial bone motion, maximizing venous drainage, and reducing any restrictions around the vestibular system.

Disordered health does not simply progress in one direction from disease process, to disability, to handicap; rather, the process is a complex interaction between health conditions, body structure and function, environmental and personal factors, and limitations in activity and participation. Biologic,behavioral, environmental, and socioeconomic risk factors can all contribute to this progression. In the case of Parkinson disease (PD), this progression includes the degradation of balance and stability resulting in falls. Parkinson disease (PD) is the second most common neurodegenerative disease worldwide. It results from a lack of dopamine production within the substantia nigra, and is characterized by slowness of movement (bradykinesia), muscle rigidity (akinesia), postural instability, and resting tremor. As a result, PD patients have a characteristic short shuffling gait, with a loss of associated arm motion. Gait initiation is difficult and sudden freezing may impair components of movement such as turning. Postural instability and gait difficulty increase over the course of the disease, and expose PD patients to a nine times greater risk of falls. Falls can cause physical injuries such as fractures and/or head injuries leading to functional incapacity, increased risk of nursing home admission and higher mortality rate. Musculoskeletal manifestations of PD may be as impactful as the nervous system manifestations. For example, muscle rigidity associated with dopaminergic loss can lead to somatic dysfunction, which can impact posture and gait. Osteopathic medicine, with its philosophical understanding of the central role of the musculoskeletal system, is in an ideal model for this direction of research. Recent evidence has demonstrated OMT's efficacy in improving postural control in healthy older subjects. Wells et al., were the first to examine the effects of an OMT protocol in a cohort of persons with PD. While this study demonstrated a positive effect on gait kinematics, it investigation failed to examine static components of postural control, which are the most common cause of falls in PD.

The investigators have carefully designed this study to identify the effects that an OMT protocol has on gait kinematics and postural control in subjects with PD. This design compares the effectiveness of two OMT protocols: the Neck-Down (OMT-ND) protocol focuses on addressing biomechanical dysfunctions from the neck down; and the Whole-Body (OMT-WB) protocol, includes the ND techniques and adds specific Osteopathic Cranial Manipulative Medicine (OCMM) techniques to address dysfunctions in the head.

The investigators hypothesize that the application of an OMT protocol will improve gait kinematics and increase subjects' ability to respond to a postural challenge due to improved joint flexibility, improved proprioception and decreased muscle coactivation. The investigators hypothesize that the addition of a cranial manipulation protocol will further improve gait kinematics and increase subjects' ability to respond to a postural challenge. The theoretical mechanism for this is due to the improved arterial blood flow to the brain, which results from improving the cranial bone motion, maximizing venous drainage, and reducing any restrictions around the vestibular system.

The investigators also include a sham group to strengthen the internal validity of the OMT- ND and OMT-WB protocols. Research on OMT's specific effects is sometimes difficult to differentiate from placebo effects. Distinct placebo components include assessment and observation, therapeutic ritual, and a supportive patient-practitioner relationship. The sham treatment will control for these components with minimal impact on the biomechanical dysfunctions in our subjects.

The investigators plan to investigate the effect of these OMT protocols via the following specific aims:

1. Identify the effects of a Neck-down OMT protocol (OMT-ND) on gait kinematics and postural control in Parkinson disease;
2. Determine the efficacy of a Whole-body OMT protocol (OMT-WB) including cranial manipulation on gait kinematics and postural control in Parkinson disease.

The investigators' long-term goal is create a reproducible protocol that improves gait and postural control, and helps to reduce falls and improve quality of life in persons with PD. If the results validate the previous studies and prove the hypotheses, this study will advance osteopathic medicine by demonstrating OMT as a useful adjunct treatment in patients with PD. The investigators' expectation is that by improving gait and postural control, OMT can help PD patients reduce falls, which may allow them to be more active and lead a better quality of life.

Inclusion Criteria:

• For PD participants: Neurologist-diagnosed idiopathic PD, H&Y stages 1.0-3.0
• Ability to stand independently for 1 minute and ambulate 100 yards independently
• Healthy (not under ongoing medical care for health problems that could impact performance on study tasks)
• for controls: age-matched healthy adults

Exclusion Criteria:

• Idiopathic PD in Hoehn & Yahr stages >3.0
• Previous surgical management of PD (pallidotomy, deep brain stimulation
• Central or peripheral nervous system disorders other than PD including, but not limited to multiple sclerosis, cerebral palsy, Alzheimer's diseases, or chronic fatigue syndrome
• Cognitive impairment as defined by the Mini-Mental Status Examination (<26 for subjects with PD and <24 for control subjects)
• Unable to stand independently for 1 minute and to walk independently for 100 yards
• Body weight >400lbs