TRADITIONAL MIRROR THERAPY (TMT) IN THE PHYSICAL THERAPY MANAGEMENT OF MOVEMENT AND POSTURAL CONTROL PROBLEMS
Authors: Martin J. Watson
Abstract: Mirrors have a long history as an ‘essential’ piece of rehabilitation equipment, and can be found in many physical therapy treatment areas. Traditionally one of their main uses is to provide patients with a reflected body image of themselves, usually as (a component of) a therapeutic strategy aimed at retraining movement control and posture. For example, when as a result of central nervous system (CNS) damage such as stroke, people have impaired postural control, then therapists might provide them with a reflected mirror image of themselves to deliver augmented visual feedback during treatment sessions where motor training is occurring. There has recently been much interest in the therapeutic use of mirrors placed perpendicular to the patient’s coronal plane; i.e mirrors able to reflect an image of one limb onto the limb of the opposite body side. Recent works by researchers such as Ramachandran [1-4], and Sutbeyaz and Yavuzer [5, 6], have indicated that this may be a useful therapeutic strategy in instances where CNS pathology has resulted in unilateral instances of paresis, neglect or phantom pain. So for example, a mirror might be used to reflect the left (sound) arm onto the right (paralysed) arm following a stroke, as part of a therapeutic strategy aiming to rehabilitate movement on the affected side. One proposed mechanism is that reflection creates an illusion of normal movement/sensation on the affected side of the body, thus facilitating voluntary production of movement and/or normal sensory processing on that side. Whilst this newer work, now often referred to as ‘mirror therapy’, is advancing, the original more traditional and (possibly) simpler therapeutic use of mirrors described at the start appears to be being somewhat overlooked and neglected. In this more traditional context (hereafter referred to as ‘Traditional Mirror Therapy’ or TMT), a full length body mirror is typically placed in front of the person (i.e. parallel to their coronal plane), thus providing them with a full frontal image of their body and its movements. In this way the person is provided with augmented (visual) feedback of their postural alignment and/or bodily movement. This might typically be carried out in conjunction with corrective instructions from the therapist. One of the puzzles regarding TMT is the apparent absence of any evidence base or instructional advice for what is in effect a fairly simple and straightforward training strategy with a seemingly long history. The notion of therapist/educator-provided augmented feedback during (motor) learning is a well established one; in a recent narrative review for example, van Vliet and Wulf identified a reasonably substantial (albeit nascent) evidence base for this general strategy for motor skills training following stroke . They identified verbal, visual, video and kinematic feedback strategies as the main ones which have been used and evaluated by therapists working with this very common patient group. Interestingly however, this overview did not identify any literature relating to TMT. Similarly, if one accesses key physical therapy instructional texts, there is usually a very limited amount of information on TMT. For example, in a fairly seminal UK text, Howe and Oldham  state that “Full length mirrors are frequently used in physiotherapy departments to make patients more aware of their static posture either in sitting or standing and dynamic posture during movement. Mirrors are also employed in gait retraining...” (p.237). However no further details are provided.