𝐀𝐜𝐡𝐢𝐥𝐥𝐞𝐬 𝐭𝐞𝐧𝐝𝐢𝐧𝐨𝐩𝐚𝐭𝐡𝐲: 𝐚𝐫𝐞 𝐲𝐨𝐮 𝐜𝐨𝐦𝐩𝐚𝐫𝐢𝐧𝐠 𝐰𝐞𝐚𝐤 𝐯𝐬 𝐰𝐞𝐚𝐤?
We often compare left versus right when dealing with a one-sided injury, but what if the other side is never strong to begin with? Enter the importance of normative values.
🤓Seth O'Neill in his 2018 study on the function of those with Achilles tendinopathy concluded:
“𝘞𝘪𝘵𝘩 𝘴𝘺𝘮𝘱𝘵𝘰𝘮𝘢𝘵𝘪𝘤 & 𝘢𝘴𝘺𝘮𝘱𝘵𝘰𝘮𝘢𝘵𝘪𝘤 𝘭𝘪𝘮𝘣𝘴 𝘣𝘦𝘪𝘯𝘨 𝘸𝘦𝘢𝘬𝘦𝘳 𝘪𝘯 𝘵𝘩𝘰𝘴𝘦 𝘸𝘪𝘵𝘩 𝘈𝘛, 𝘳𝘦𝘴𝘦𝘢𝘳𝘤𝘩𝘦𝘳𝘴 & 𝘤𝘭𝘪𝘯𝘪𝘤𝘪𝘢𝘯𝘴 𝘤𝘢𝘯𝘯𝘰𝘵 𝘶𝘴𝘦 𝘵𝘩𝘦 𝘯𝘰𝘯-𝘴𝘺𝘮𝘱𝘵𝘰𝘮𝘢𝘵𝘪𝘤 𝘭𝘪𝘮𝘣 𝘢𝘴 𝘢 𝘤𝘰𝘮𝘱𝘢𝘳𝘢𝘵𝘰𝘳 𝘸𝘩𝘦𝘯 𝘢𝘴𝘴𝘦𝘴𝘴𝘪𝘯𝘨 𝘴𝘵𝘳𝘦𝘯𝘨𝘵𝘩 & 𝘦𝘯𝘥𝘶𝘳𝘢𝘯𝘤𝘦, 𝘪𝘯𝘴𝘵𝘦𝘢𝘥 𝘯𝘰𝘳𝘮𝘢𝘵𝘪𝘷𝘦 𝘷𝘢𝘭𝘶𝘦𝘴 𝘯𝘦𝘦𝘥 𝘵𝘰 𝘣𝘦 𝘤𝘰𝘯𝘴𝘪𝘥𝘦𝘳𝘦𝘥.”
This was reinforced to us recently when we saw a patient present with a 6month history of left-sided Achilles tendinopathy. One may expect the involved side to be weaker, but there is little difference here between the left & right.
🔎BUT using normative values we know that the ideal strength range for runners on a seated calf isometric is 1.5-2 x bodyweight. At a bodyweight of 96kg, we would expect this individual to be able to produce 144-192kg of peak force, which is well above the 97-93 they are currently able to produce on our state of the art AxIT system.
🔑These results seen in this patient are in agreeance with Seth O'Neill's observations: those suffering Achilles' tendinopathy often possess loss of strength & function in BOTH sides!
🔑So the key takeaway here is comparing side to side isn't always reliable, and therein lies the importance of normative values.
🙋🏼♂️If you are suffering from Achille's tendinopathy, don't hesitate to contact us!
O'Neill, S., et al. (2018). "Acute sensory and motor response to 45-s heavy isometric holds for the plantar flexors in patients with Achilles tendinopathy." Knee Surg Sports Traumatol Arthrosc.