A SYSTEMATIC REVIEW OF THE EFFECTS OF PSYCHOTHERAPY ...

of hippotherapy, with the goal of developing a standardized curriculum; this led to the
development of the American Hippotherapy Association (AHA) in 1992 and, in 1993, AHA was
approved as the first subsection of NARHA. Shortly thereafter, AHA established therapist
registration and standards of practice and, in 1999, subsequent to the establishment of the
American Hippotherapy Certification Board, the premier Hippotherapy Clinical Specialist
examination was administered (AHA). In 2004, AHA seceded from NARHA and was installed as
an independent governing body for the accreditation of therapists endeavoring to employ this
treatment approach.
For many years the body of research on the efficacy and effectiveness of hippotherapy
consisted of anecdotal reports and case studies, albeit valuable precursors and adjuncts to
quantitative methods of assessment. Measurement was complicated by the lack of sensitive
instruments to assess physiological improvements (Sterba, 2007). Until recently, most of the
supporting evidence for the beneficial physical effects of activities involving horses consisted of
single-subject designs which lacked comparison groups, studies which lacked standardized
measures, and results that were frequently reported in non-peer-reviewed publications (Silkwood-
Sherer & Warmbier, 2007; Snider et al., 2007). However, more rigorous research evidence has
begun to accumulate, as illustrated by two systematic reviews (Snider er al.; Sterba, 2007) which
demonstrated clinically significant beneficial effects of hippotherapy for children with cerebral
palsy, and concluded that hippotherapy is a promising intervention.
In a breakthrough study recently completed by a team of researchers at Washington
University (Shurtleff, Engsberg & Standeven, in press), researchers showed large effect sizes for
dynamic trunk/head stability and functional reach in children with spastic diplegia cerebral palsy,
which continued at twelve weeks follow-up. These results are encouraging given that in its
Clinical Policy Bulletin (2008), policy-writers for the insurance giant Aetna recommended that
hippotherapy sessions not be reimbursed pending further research. Typically, hippotherapy
sessions are reimbursable by third-party payers such as Harvard Pilgrim Health Care when they
are part of a supervised physical or occupational therapy program provided by a contracted
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