Tendinopathy affects millions of people in athletic and occupational settings as well as the general population.[7]Maffulli N, Kader D. Tendinopathy of tendo achillis. J Bone Joint Surg Br. 2002 Jan;84(1):1-8.
http://www.ncbi.nlm.nih.gov/pubmed/11837811?tool=bestpractice.com
[8]Paavola M, Kannus P, Järvinen TA, et al. Achilles tendinopathy. J Bone Joint Surg Am. 2002 Nov;84-A(11):2062-76.
http://www.ncbi.nlm.nih.gov/pubmed/12429771?tool=bestpractice.com
[9]Maffulli N, Wong J, Almekinders LC. Types and epidemiology of tendinopathy. Clin Sports Med. 2003 Oct;22(4):675-92.
http://www.ncbi.nlm.nih.gov/pubmed/14560540?tool=bestpractice.com
Because tendinopathy affects such a diverse population and can occur at different sites, the true incidence is unknown.
It is estimated that half of all sports injuries are secondary to over-use. Of these injuries, the muscle-tendon unit is the most commonly affected.[10]Herring S, Nilson K. Introduction to overuse injuries. Clin Sports Med. 1987 Apr;6(2):225-39.
http://www.ncbi.nlm.nih.gov/pubmed/3319201?tool=bestpractice.com
Approximately 10% of runners develop Achilles' tendinopathy, which tends to affect men aged >30 years.[11]Lopes AD, Hespanhol Júnior LC, Yeung SS, et al. What are the main running-related musculoskeletal injuries? A Systematic Review. Sports Med. 2012 Oct 1;42(10):891-905.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4269925
http://www.ncbi.nlm.nih.gov/pubmed/22827721?tool=bestpractice.com
Patellar tendinopathy usually affects young adults in their teens to 30s, but can also occur in older individuals.[12]Hyman J, Rodeo SA, Wickiewicz T. Patellofemoral tendinopathy. In: DeLee JC, Drez D, Miller MD, eds. DeLee & Drez's orthopaedic sports medicine: principles and practice. Philadelphia, PA: Saunders; 2003:1840-56. There is a 1% to 3% annual incidence of lateral epicondylitis, which affects men and women equally. It is more common in people aged >40 years.[13]Johnson GW, Cadwallader K, Scheffel SB, et al. Treatment of lateral epicondylitis. Am Fam Physician. 2007 Sep 15;76(6):843-8.
http://www.ncbi.nlm.nih.gov/pubmed/17910298?tool=bestpractice.com
A registry-based study in Denmark found that patients with tendinopathies were significantly older than all registered patients (46.0 years vs. 38.8 years, respectively).[14]Riel H, Lindstrøm CF, Rathleff MS, et al. Prevalence and incidence rate of lower-extremity tendinopathies in a Danish general practice: a registry-based study. BMC Musculoskelet Disord. 2019 May 22;20(1):239.
https://bmcmusculoskeletdisord.biomedcentral.com/articles/10.1186/s12891-019-2629-6
http://www.ncbi.nlm.nih.gov/pubmed/31113484?tool=bestpractice.com
The Achilles' tendinopathy incidence rate was 1.7 per 1000 patients, with a prevalence of 5.2 per 1000 patients.[14]Riel H, Lindstrøm CF, Rathleff MS, et al. Prevalence and incidence rate of lower-extremity tendinopathies in a Danish general practice: a registry-based study. BMC Musculoskelet Disord. 2019 May 22;20(1):239.
https://bmcmusculoskeletdisord.biomedcentral.com/articles/10.1186/s12891-019-2629-6
http://www.ncbi.nlm.nih.gov/pubmed/31113484?tool=bestpractice.com
The authors concluded that, in a general practice with 5000 patients, primary care clinicians may anticipate seeing in excess of 80 patients with a lower-extremity tendinopathy each year.[14]Riel H, Lindstrøm CF, Rathleff MS, et al. Prevalence and incidence rate of lower-extremity tendinopathies in a Danish general practice: a registry-based study. BMC Musculoskelet Disord. 2019 May 22;20(1):239.
https://bmcmusculoskeletdisord.biomedcentral.com/articles/10.1186/s12891-019-2629-6
http://www.ncbi.nlm.nih.gov/pubmed/31113484?tool=bestpractice.com
A cross-sectional study performed in a general practice population in the Netherlands reported lower-extremity tendinopathy incidence and prevalence rates of 10.5 and 11.8 per 1000 person years, respectively.[15]Albers IS, Zwerver J, Diercks RL, et al. Incidence and prevalence of lower extremity tendinopathy in a Dutch general practice population: a cross sectional study. BMC Musculoskelet Disord. 2016 Jan 13;17:16.
https://bmcmusculoskeletdisord.biomedcentral.com/articles/10.1186/s12891-016-0885-2
http://www.ncbi.nlm.nih.gov/pubmed/26759254?tool=bestpractice.com