The thrust technique [also called the high-velocity, low-amplitude (HVLA) technique, or mobilization with impulse] is one of the oldest and most widely used forms of manual medicine. Although there are different types of thrust techniques, including the low-velocity, high-amplitude technique, this chapter focuses on HVLA techniques. HVLA had been the main technique taught in colleges of osteopathic medicine until recent years, where curricula now contain a variety of direct and indirect techniques as well. Several physiotherapists and other practitioners such as Maitland, McKenzie, and Mennell heavily influenced many of the HVLA techniques used and taught by early osteopathic physicians.

Many theories exist regarding the prevalence of the technique in osteopathic colleges. A. T. Still was known to use thrust sparingly in favor of myofascial release and indirect techniques (1). The faculty and students who assisted in teaching may have been largely responsible for the popularity of thrust techniques over other techniques known at the time. Teachers were able to very accurately describe the joint restriction and provide techniques for correcting the dysfunction. These techniques were much more easily learned and practiced than the myofascial and indirect techniques preferred by Still, which required much more skill in assessing the motion patterns in the tissues in order to precisely treat the dysfunction (1).

Thrust is a direct technique, meaning that the joint exhibiting somatic dysfunction is moved through its restrictive barrier of physiologic motion by an extrinsically applied thrusting force. This extrinsic force allows the joint to return to its appropriate physiologic motion, which Mennell refers to as “joint play” (2). He defines joint play as the movement allowed within a synovial joint, which is independent and cannot be introduced by voluntary muscle contraction (2). The movement is small (less than 1/8 inch) with the range dependent on the contour of the joint surfaces. He also postulates that this motion is necessary for normal, pain-free movement of the synovial articulation and, if restricted or absent, voluntary movement will, in turn, become restricted and frequently painful (2,3). In this sense, the goal of treatment is to use a small thrust—not to force the joint “back into place,” but to restore motion loss at the dysfunctional segment by gapping the joint. Joint gapping can be accomplished with or at right angles to the plane of the joint, or with distraction of the joint (3). Key points to remember regarding joint play are that it is a small, precise movement that is elicited passively, it is independent of voluntary muscle action, and it is found in all synovial joints. Effective treatment results in an immediate increase in range of motion, a decrease in muscle hypertonicity, and often a decrease in pain associated with the dysfunctional area.