Hippotherapy and Parkinson's Disease

Parkinson's disease (PD) is associated with motor symptoms such as bradykinesia, rigidity and postural instability 1 which interfere with the patient's independence, and ability to carry out activities of daily life 2. In addition, losses in functional may result in a decreased health-related quality of life (HRQL) 3. Thus, as PD progresses HRQL gets worse 4.

Exercise programs are suggested to improve functional capacity and HRQL in people with PD 3. However, in the later stages of PD, mobility problems restrict the potential to participate in exercise programs, resulting in even greater loss in functional capacity and HRQL. Furthermore, a decline in the efficacy of pharmacological treatment and complications due to motor fluctuations and medication side effects make the role of complementary treatments such as hippotherapy critical to individuals with PD at late stages. Hippotherapy is a therapeutic intervention commonly used in populations with mobility deficits, since they do not require effort or walking from patients who can no exercise in standing position. When is on the horse, the patient exercises as he/she is walking unassisted 5. Neurological conditions are improved by horse's movement stimulations. The set formed by the patient and his horse performs rhythmic and three-dimensional oscillations which trigger very important neuromuscular responses from the rider's postural reflex mechanisms 6. The horse's movements are sensed by the participant on the saddle, and when the horse is slowly walking it has been argued to be similar to the pelvic movement produced by human gait, thereby strengthening the trunk muscles and improving balance 7. The senses are integrated during the act of riding performing sensory stimulation 8. Furthermore, hippotherapy has been demonstrated to be an effective method to improve functional capacity by increasing gait velocity in people with brain disorders 9, functional mobility in elderly 10 and functional strength in people after stroke 11 and in people with spinal cord injury 5. In addition, hippotherapy has been shown to improve HRQL in children and in adults 6.

Considering the potential benefits of hippotherapy to anticipatory postural adjustments and sensory stimulation 9, 11, it could be hypothesized that hippotherapy may increase functional capacity and improve HRQL in individuals with PD. This hypothesis has not been tested yet. Therefore, the purpose of this study was to assess the effects of a hippotherapy program on functional capacity and on HRQL in people with PD.

(4) Methods

Subjects People with confirmed diagnosis of PD by medical report were invited through advertisements on radio, on television, public announcements and posters around the hospitals to participate in the Physical Activities Program for Persons with Neurodegenerative Diseases. Among 81 registered volunteers, 18 participants, six women and twelve men, unable to perform usual physical activity because they were in the late stages according to Hoehn and Yahr scale (H \& Y≥ 3), or because they need to use a wheelchair for severe mobility problems were enrolled in the hippotherapy program which formed the sample (n=18). Exclusion criteria were uncontrolled hypertension, unstable cardiovascular disease and had practiced riding or hippotherapy six months before the intervention period. Among the 18 volunteers from the sample, three women and six men were randomized for the intervention group called hippotherapy group (HT) (n=9), which performed ten weeks of hippotherapy sessions (2 familiarization + 8 hippotherapy weeks) twice a week with each session lasting thirty minutes. Nine other participants who were waiting to be allocated to the hippotherapy program in the following semester attended lectures on PD, twice a week for ten weeks, with each session lasting thirty minutes. Demographics and characteristics of the sample can be seen in Table 1. This study was approved by the Research Ethics Committee of the University of Brasilia on 10/10/2013 by the number CAAE 17329213.7.0000.0030. All participants were informed about the procedures and agreed to participate in the study signing the informed consent term.

Instruments Quality of life was measured using the Parkinson's Disease Quality of Life Questionnaire (PDQL) Brazilian version 4.

Functional mobility was evaluated by the Timed Up and Go Test (TUG) according Podsiadlo and Richardson 12.

Strength endurance was measured using the Thirty-second Chair Stand Test (30CST) according Gill and McBurney 13.

Gait velocity was evaluated using the Ten Meter Walk Test (TMW) according Bohannon, Andrews and Thomas 14.

All functional tests had three trials with a 2 minutes interval between each trial, and the average of the two last measurements was used for analysis.

Hippotherapy Procedures Familiarization sessions were initially 15 minutes and gradually evolved to 30 minutes in order to allow all participants to adapt to the horse's rhythmic movements and to the act of mounting the horse. The sessions were performed at the First Regiment of Cavalry Guard of the Brazilian Army. All practitioners used helmet, shirt, pants and closed shoes. The team was composed by an auxiliary guide, a physical education teacher and two auxiliaries. In order to mount and dismount, all participants used a specific ramp for hippotherapy classes. All horses used saddle and riding equipment, the stirrups were individually adjusted.

The sessions began with a 5 minutes warm up that involved stretching and body awareness exercises. Then, the training was conducted for 20 minutes with arms and torso exercises, changes of direction called serpentine movements; up and down hip movements with feet on stirrups, and forced expiration. In the final 5 minutes, exercises for relaxation were conducted with the horse which involved moving the hand on the horse's neck, laying forward on the head and stroking the horse. The horses walking speed was between 5.8 and 6.4 Km/h.

In order to assess the effect of the hippotherapy the difference between post and pre-tests scores for each dependent measure was calculated (delta (∆)).

To assess whether data had normal distribution the Shapiro-Wilk test was used, which did not indicate a normal distribution for functional capacity variables. Thus, the Mann-Whitney U test for independent samples was used in order to compare the changes in functional capacity between groups. The Shapiro-Wilk test demonstrated a normal distribution for PDQL variables data, and then parametric statistics was performed with a one-way analysis of variance (ANOVA). Statistical analysis was performed using the program Statistica 7.0 (StatSoft Inc., Tulsa, Oklahoma, USA), adopting a significance level of p≤0.05.