Patient Presentation | Low Tone Pronation

To help organize the brace selection process, Cascade has defined several patient groupings, based on the foot, ankle and knee presentations most often seen in our patient population. Within each of these groups, we have described how various levels of involvement present. We then matched each of these presentations to an appropriate brace design. Directly associating a brace design / bracing strategy with a defined patient presentation has worked well, both in theory and in practice.

The focus of each of the defined clinical groups is the biomechanical presentation—the posture, position or gait—that can be identified independent of the diagnosis behind the presentation. This grouping system is used with the understanding that, while not perfect, it is a reasonable and clinician-friendly way of presenting the brace selection process. In this newsletter edition we will briefly discuss the clinical grouping: Low Tone Pronation. (Visit our website in January for a more detailed discussion of all clinical groupings).

A physical therapist or physician will diagnose Low Tone when low muscle tone appears to be affecting develop-mental motor skills. If the low muscle tone presents with pronation, the practitioner will refer the patient to an orthotist. Some of the common patient conditions that present as “Low Tone” and then result in pronation are Down syndrome, developmental delay, spina bifida, spinal cord injury and cerebral vascular accident (CVA). With an infant, low muscle tone usually presents with decreased head and trunk control and therefore delayed rolling, sitting, crawling and walking. In addition to presenting as developmental delay, low muscle tone can also affect muscular skeletal tissues.

At Cascade the Low Tone Pronation category is defined when the foot and ankle muscles are unable to support the forces of body weight against gravity. The results can be collapse of the arches of the feet, eversion of the hindfoot and abduction of the forefoot. The foot of the younger low tone patient is usually flexible and can be fully corrected to a normal alignment with manipulation. In older patients, the foot may become more fixed over time, and as a result more difficult to correct.

There are many exercises that can strengthen affected muscles, but depending on the severity of the low muscle tone, a person may never gain the ability to support gravitational force on his or her feet and ankles. In these cases, orthoses are necessary to provide support for upright and weight bearing skills and/or to prevent additional musculoskeletal damage.

Cascade Dafo has developed a range of orthoses to help patients with varying degrees of pronation resulting from low muscle tone. Our HotDog^TM and PattiBob^TM off-the-shelf shoe inserts are recommended for patients with mild pronation, with little or no hindfoot involvement. The PollyWog^TM shoe insert wraps partially around the foot to help control the heel eversion and forefoot abduction of more moderate pronation.

Several models in our DAFO® line of custom braces address more severe low tone pronation issues. The DAFO 4 provides full wrap-around control of the hindfoot and forefoot, while leaving the ankle free. For the most severe cases where low tone begins to affect ankle stability, the DAFO 3.5 controls the foot pronation while adding medial/ lateral stability to the ankle and knee.

Low Tone Pronation serves as a broad grouping for clinical purposes, but we recognize there is a wide range of issues within the category. Although we have found this clinical grouping approach to be quite helpful, we recognize that not all patients fit neatly into any group, no matter how broad the description. And many patients will actually fit into more than one clinical group.

Cascade will be publishing a section on brace selection as a part of our website improvement. This will include details on the clinical groupings we find most useful. It is anticipated that this system will be helpful to even the experienced clinician, and those in allied professions will find the information interesting and useful. For greater detail on Low Tone Pronation and information on all clinical groupings, check out our website at www.dafo.com in early 2006.