BY RICHARD A. MOSS, SPORTS REHABILITATOR

INTRODUCTION

Within the field of sports medicine, there has been a recent rapid growth in the use of ultrasonography as a frontline diagnostic tool for musculoskeletal injuries. Ultrasound scanning was first developed in 1958 by Professor Ian Donald (1) and so it is not a new technology within the medical world. Its use to date has mostly been confined to scanning of unborn fetuses. More recently, the technology has been utilised by more widespread medical applications, including diagnosis of musculoskeletal lesions. This application of has been met with caution and reservation, treating it very much as a “dark art” rather than the evolutionary progression that it represents. The technique allows therapists to “see” within a patient’s body without the need for invasive procedures such as arthroscopy. The technique is a safe, quick and increasingly readily accessible alternative to other modalities such as X-ray and computed tomography (CT). A number of authors have used ultrasound scanning to measure patella position (2,3) and have shown this method to be both reliable and valid. The technique therefore lends itself to the diagnosis of knee-related problems in both clinical and field settings. Although this technology has been shown to be increasingly reliable and available, it is currently still out of reach of many therapists working in the lower reaches of the sporting world. This article aims to show that

although ultrasonography is the diagnostic tool of choice in a field setting, similar measurements can be made using simple taping measurements. This allows significant improvements to be made to injury-prevention protocols for patellofemoral pain.

WHY MEASUREMENT IS NEEDED

It is thought that establishing and

MEASUREMENT OF PATELLA DISPLACEMENT

Although first developed in 1958, ultrasound scanning has become a popular diagnostic technique in sports medicine only relatively recently. Ultrasound provides an ideal tool to measure patella position; however, this article appreciates that ultrasound scanning is not widely available to everyone and therefore describes a reliable practical alternative using tape.

maintaining the position of the patella is imperative when investigating the aetiology of patellofemoral pain and planning its subsequent treatment. The traditional clinical measurement techniques described by McConnell (4) were initially thought to be unreliable. These techniques have gained support more recently (5). The McConnell technique is useful in quantifying patella position but, when compared with the potential use of ultrasonography, it does not reliably allow for the real-time measurement of patella position during the dynamic components of knee movement. Being able to establish a “normal” patella position allows the development of important injury rehabilitation tools, including injury- prevention screening of patellofemoral problems. In order to minimise some of the risk factors and effects of patellofemoral pain syndrome, maintaining the position of the patella within its “normal” position in the trochlear groove of the tibia is important. This minimises the

ALLOWS THE DEVELOPMENT OF IMPORTANT INJURY REHABILITATION TOOLS

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BEING ABLE TO ESTABLISH A “NORMAL” PATELLA POSITION

physical trauma and the biomechanical abnormalities that can cause the condition to manifest itself. This technique is therefore ideally split into two elements, first by establishing each patient’s individual “normal” patella position and then by using that position as an intervention, such as taping, to maintain the position during sporting actions. If a patient presents with patellofemoral pain but previous data for their “normal” patella position are unavailable before the onset of pain, the “normal” position that has been established clinically can then be used – although this is not the ideal scenario.

MEASUREMENT TECHNIQUE The method used to measure the lateral patella displacement using tape is that first described by McConnell (6). The patient should be positioned lying supine. The therapist should palpate the significant anatomical landmarks around the knee, consisting of the medial and lateral epicondyles of the femur and the centre and borders of the patella of the leg. The knee is placed in a position of 20° or flexion, with the quadriceps muscle group relaxed, in order to engage the patella within the trochlear groove. This position can easily be maintained using some form of support under the patient’s knee, such as a first- aid bag or the therapist’s knee. This is important, as Shih and colleagues

sportEX dynamics 2009;22(Oct):18-20