Achilles Tendinopathy Toolkit: Section B - Outcome Measures

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Introduction

An outcome measure is a tool used to assess a patient’s current status. Outcome measures may provide a score, an interpretation of results and at times a risk categorization of the patient. Prior to providing any intervention, an outcome measure provides baseline data. The initial results may help determine the course of treatment intervention. Once treatment has commenced, the same tool may be used in serial assessments to determine whether the patient has demonstrated change. With the move towards Evidence Based Practice (EBP) in health care, outcome measures provide credible and reliable justification for treatment on an individual patient level.

Patient-Reported Outcome Measures (PROMs)

PROMs are an important tool in today's physiotherapy practise. They provide feedback on a patient's health condition that comes directly from the patient and does not take into account any interpretation of the patient's response by a health professional. PROMs can take the form of questionnaires (in paper or electronic form) that include instructions and can be completed independently by the patient.

There are four commonly used PROMs for achilles tendinopathy - the Victorian Institute of Sports-Achilles (VISA-A) [ref 1] and the VISA-A (Sedentary) [ref 5], both of these are population specific and have been designed for achilles tendinopathy, and the Numeric Pain Reporting Scale (NPRS 0-10) and the Lower Extremity Functional Scale (LEFS) both of which are generic outcome measures that have not been specifically designed for achilles tendinopathy.

Victorian Institute of Sports-Achilles (VISA-A) Scale

This is the only questionnaire validated specifically for mid-portion Achilles tendinopathy. Recommended as the primary outcome measure in clinic and research setting for mid-portion Achilles tendinopathy[ref 3]

• 8-item scale. Max score= 100
• 3 domains: pain, function, activity.
• Clinically, scores >90 suggest full recovery.[ref 2]
• Minimal Clinically Important Difference (MCID) = 15.4
• No Minimal Detectable Change (MDC) to report for mid-portion Achilles tendinopathy.[ref 3]

VISA-A (Sedentary)

The original VISA-A questionnaire was designed for sports men/women and does not suit inactive individuals with Achilles tendon problems. As such it is difficult for doctors and Physiotherapists to measure change in symptoms and function in this group of patients, they often score badly on the questions despite a high level of functional improvement. This means that the results make it difficult to determine the effectiveness of treatment.

It has been estimated that up to 33% if mid-portion Achilles tendinopathy cases occur in non-active individuals.[ref 6] In response to this the VISA-A (Sedentary) [ref 5] was developed for the sedentary population - [ref 5] Available here.

There is no MCID or MDC currently available to report specific to this population.[ref 5]

Numeric Pain Rating Scale

This is a generic outcome measure and not designed specifically for Achilles Tendinopathy. The Numeric Pain Rating Scale (NPRS) is a segmented numeric version of the Visual Analogue Scale (VAS) and is used to measure pain intensity only in adults. Although it is not validated for achilles tendionpathy, the psychometric properties of the NPRS are consistent across a variety of other musculoskeletal conditions [ref 7] and for people who experience chronic pain.

When used on patients with mid-portion achilles tendinopathy, it is considered a useful tool to measure the immediate response to functional testing or post treatment response.

Lower Extremity Functional Scale (LEFS)

The LEFS is another generic outcome measure that has been developed to measure lower limb extremity function. Expert opinion supports the LEFS as an outcome measure for mid-portion Achilles tendinopathy, but the LEFS has not been specifically validated in this population. [ref 8]

The objective of the Lower Extremity Functional Scale (LEFS) is to measure "patients' initial function, ongoing progress, and outcome" for a wide range of lower-extremity conditions.[ref 9]. The LEFS is a self-report questionnaire where patients answer the question "Today, do you or would you have any difficulty at all with:" in regards to twenty different everyday activities.

• 20 item scale. Max score = 80
• Minimal Clinically Important Difference (MCID) = 9 - Minimal Detectable Change (MDC) =6[ref 9]

Performance-Based Outcome Measures: (Clinician-Reported)

Performance-Based clinical reported outcome measures require the patient to perform a task or set of movements that are supervised by a health care professional. Scores for performance-based measures can be either an objective measurement (e.g., time to complete a task) or a qualitative assessment that is assigned a score (e.g., normal or abnormal mechanics for a given task).

Heel-Rise Test

Measures a combination of load tolerance and calf muscle endurance. It aims to challenge the stretch-shorten cycle (SSC) of plantarflexors required for functional activity of the Achilles tendon. [ref 12] The test is considered reliable[ref 9] and requires no additional equipment for clinical use. It is suggested as the main impairment measure for Achilles tendinopathy [ref 11].

• A unilateral test performed in standing, using the single leg stance

• For symptomatic individuals, comparison is made between leg scores and to track improvement over time.
• Pain levels can be assessed during testing using the NPRS for immediate feedback

You can watch the following video to see how this test is performed.

1. Heel-Rise test (10-14) It is suggested as the main impairment measure for Achilles tendinopathy. It measures a combination of load tolerance and calf muscle endurance. Click here to see a video of how to correctly perform the Heel-Rise test.

2. Single Leg Hop Test Assesses energy storage-release function of tendon, and the stretch-storage cycle (SSC) required for cyclic weight bearing activities such as running. Available here

• Click to go back to the Main Achilles Tendinopathy Toolkit page
• Click to go back to Section A - Clinical Evaluation
• Click to continue to Section C - Summary of Evidence and Recommendations for Interventions
• Click to continue to Section D - Exercise Programs
• Click to continue to Section E - Low Level Laser Therapy Dosage Calculation
• Click to continue to Section F - Medical and Surgical Interventions