Streamlining the Achilles Tendinopathy Assessment

Keturah Orji places fourth in the women’s triple jump at 14.13m during the 49th Pre Classic at Hayward Field. Mandatory Credit: Kirby Lee-USA TODAY Sports

When someone presents with Achilles tendinopathy, they exhibit mechanical pain that is localized to the Achilles, improves with warm-up exercises, and typically impairs their function in some way⁽¹⁾. One of the important tasks of a sports medicine practitioner is asking the right questions⁽²⁾. The subjective assessment can determine the tendinopathy severity to offer specific advice, enable planning, and manage expectations, as the severity will directly impact the management plan’s extensiveness⁽²⁾. However, which questions are the best to delineate someone with mild versus severe tendon-related disability is unclear⁽³⁾. Clinicians need to make these decisions in the absence of empirical evidence. Therefore, an international collaboration of researchers sought to answer this important clinical question.

They borrowed the methodological approach to discover the questions that best delineate mild versus severe symptoms from other research fields. Specifically, the approach to determine the ‘best’ questions a clinician should ask is identical to the approach used in education to determine those questions on a test or examination that best delineates the low versus high achievers. For example, there are often questions in a test where some responses are so easy that everyone will get it correct. These types of questions do nothing to delineate the high and low-achieving students. However, those hard questions, where few people will score full marks, are far better at separating the high and low achievers. Therefore, the researchers took this approach to determine the best questions to assess the severity of tendon-related disability in Achilles tendinopathy. They swapped out the types of questions, from ones that measure knowledge to those that measure tendon-related disability.

Methods

The researchers conducted a cross-sectional study and extracted data from the larger Tendinopathy Severity Assessment – Achilles (TENDINS-A) database⁽⁴⁾. They collected all the data between January and May 2023. 

The researchers organized a group of expert clinicians and academics specializing in tendinopathy to identify people with Achilles tendinopathy (either insertional or mid-portion). Then, they asked them to complete a short online survey. The diagnosis of tendinopathy for this study was localized Achilles tendon pain (as identified on a pain map) and Achilles tendon-related pain or symptoms⁽⁵⁾.

The researchers explored questions from the TENDINS-A (13 questions), Foot and Ankle Outcome Score (FAOS, 42 questions), and Victorian Institute of Sport Assessment- Achilles (VISA-A, eight questions) (see table 1)^(6,7). Clinicians commonly use these tools to quantify the severity of Achilles tendon-related disability. However, the TENDINS-A is the only outcome measure for Achilles tendinopathy that has acceptable content validity, structural validity, and reliability^(4,8). 

Table 1: Outcome measure information

Analysis

The primary analysis for this study involved calculating the ‘discrimination index,’ which is a score of how different high versus low achievers are for the specific question⁽¹¹⁾. Reflecting on the background, an easy question that most people can answer correctly would have a lower ‘discrimination index,’ reflecting poor capacity to discriminate mild versus severe Achilles tendon-related disability. A question that is answered very differently between people with mild and severe tendinopathy would have a higher ‘discrimination index,’ reflecting a good capacity to discriminate severity. Then, the researchers ranked all questions from the best to the worst, and for their top 10 questions, they combined any questions that essentially asked the same thing (e.g., pain with single leg hopping and how many single leg hops can be done without pain).

Results

The study results created the top 10 questions to ask someone with Achilles tendinopathy to determine their overall disability level.

1. Numerical rating scale of pain with single leg hopping.
2. Numerical rating scale of pain with double leg jumping.
3. How many single-leg hops can be completed without pain? 
4. Time taken for pain to subside following aggravating activities (minutes).
5. Numerical rating scale of pain with single leg calf raises.
6. Numerical rating scale of pain with double leg calf raises.
7. Time taken for stiffness/symptoms to subside following waking (minutes).
8. Time taken for stiffness/symptoms to subside following prolonged sitting (minutes).
9. The degree of reduction in physical activity from pre-injury levels.
10. Difficulty in completing running in the past week.

When they combined similar questions and grouped them under the separate domains they represented, the researchers categorized the best questions to ask people with Achilles tendinopathy as follows:

•    Pain with loading the Achilles tendon:

1. Numerical rating scale of pain with single leg hopping.
2. Numerical rating scale of pain with double leg jumping.
3. Numerical rating scale of pain with single leg calf raises.
4. Numerical rating scale of pain with double leg calf raises.
5. The degree of reduction in physical activity from pre-injury levels.

•    Time for pain to settle after aggravating activity:

1. Time taken for pain to subside following aggravating activities (minutes).

•    Time taken for tendon stiffness to subside after prolonged sitting or sleeping:

1. Time taken for stiffness/symptoms to subside following waking (minutes).
2. Time taken for stiffness/symptoms to subside following prolonged sitting (minutes).

Conclusion

When combining clinically comparable questions, eight questions are highly effective in differentiating those people with mild versus severe Achilles tendon-related disability. There are three key domains: i) pain with loading the Achilles tendon, ii) the time taken for pain to settle following aggravating activity, and iii) the time for the tendon symptoms to subside after prolonged sitting or sleeping.

Mechanical loading is the best way to differentiate the severity of Achilles tendon-related disability. This is unlikely to be surprising to clinicians as tendinopathy is closely linked to mechanical loading, but it provides them with the confidence to use these assessments to determine someone’s overall functional capacity and avoid tests such as palpation, which does not represent pain during function(5). Importantly, these questions will assist clinicians when providing patients advice, increase confidence in knowing where to start, the impact on a patient’s physical activity (goals), and provide an opportunity to teach patients when to listen to their tendons.

Clinicians can use these questions for a meaningful clinical assessment and diagnosis. The other advantage of these questions is that they are simple to complete and can be monitored over time in people with Achilles tendinopathy. Asking these questions throughout treatment can help quickly identify a flare-up of symptoms without having to complete an entire patient-reported outcome measure such as the TENDONS-A or VISA-A, which can be  burdensome⁽¹²⁾. Therefore, introducing these simple questions as a part of clinical monitoring is an efficient and accurate method to monitor for symptom exacerbation and mitigate the risk of missed training or matches.

Key Takeaways

Key questions that clinicians can ask to determine the severity of tendinopathy. These questions fall under three main domains:

1. Pain with loading the Achilles tendon.
2. Time for pain to settle following aggravating activity.
3. Time taken for the tendon symptoms to subside after prolonged sitting or sleeping.

References

1. British Journal of Sports Medicine. 2020;54(5):260-2
2. The Journal Of Manual & Manipulative Therapy. 2021;29(5):297-309
3. British Journal of Sports Medicine. 2019;54(8):444-51
4. British Journal of Sports Medicine. 2024;Accepted: In Press
5. Journal of Orthopaedic & Sports Physical Therapy.0(ja):1-28
6. Foot & Ankle International. 2001;22(10):788-94
7. British Journal of Sports Medicine. 2001;35(5):335-41
8. Journal of Orthopaedic & Sports Physical Therapy. 2023;0(11):1-16
9. Arthritis Care Research (Hoboken). 2014;66(3):395-403
10. British Journal of Sports Medicine. 2001;35(5):335-41
11. Journal of Clinical Epidemiology. 2010;63(7):737-45
12. BMJ Open Sport Exerc Med. 2022;ePub ahead of print