Risk Factors for the Development of Plantar Heel Pain Syndrome - A Literature Review

Original Editor - Merinda Rodseth based on a course by Bernice Saban

Top Contributors - Merinda Rodseth, Kim Jackson, Jess Bell and Tarina van der Stockt  

Introduction[edit | edit source]

Many factors have been proposed as risk factors for the development of plantar heel pain syndrome (PHPS). These include limited ankle dorsiflexion, obesity, pes planus (excessive foot pronation), occupations requiring prolonged periods of standing, pes cavus (high foot arch), increased plantar fascia thickness, leg length discrepancy, heel pad thickness, muscle imbalance, limited range of motion of the first metatarsophalangeal joint (MTPJ), calcaneal spur, heel neuroma, inferior calcaneal exostosis, entrapment neuropathies, foot posture, abductor hallucis morphology, excessive running, sedentary lifestyle, age, gender, running variables such as surface, speed, frequency and distance per week, improper shoe fit and wear, sports activity, etc.[1][2][3][4][5][6][7][8][9][10][11]

There are numerous research studies about PHPS, but not all studies are of equal quality. It is, therefore, important to keep the criteria of  good-quality studies in mind when reading the literature:

  • An adequate sample size of more than 30 participants
  • Randomisation of participants and the presence of a matched control group

For ease of understanding, the literature review of the risk factors for PHPS will be divided into three different categories:[2][6][12]

  • Intrinsic factors specific to the foot  
  • Intrinsic factors related to the anatomy or biomechanics of the individual
  • Extrinsic factors related to external influences acting on the foot


The following intrinsic and extrinsic factors will be discussed in more detail (Figure 1):[12]

Risk factors PHPS.pptx.jpg

Figure 1. Risk factors proposed to be associated with PHPS (intrinsic foot level factors - dark blue, other intrinsic factors - light blue, extrinsic factors - green) [12]

Intrinsic Foot-Level Factors[edit | edit source]

A variety of factors intrinsic to the foot are considered as potential risk factors for the development of PHPS and will be further explored. These include:

Calcaneal Spur[edit | edit source]

Calcaneal spur (enthesophyte) refers to “an abnormal bone outgrowth at the inferior part of the calcaneus” often from the attachment site of the plantar fascia ligament.[13]

A calcaneal spur is considered to be a common cause of heel pain. However, it is difficult to define what should be considered a pathological spur. Moreover, there is controversy over whether or not calcaneal spurs actually contribute to the symptoms of plantar heel pain (PHP).[13][14] Many researchers disagree about the site and aetiology of calcaneal spurs and whether they are a cause of PHP, as many patients also present with painless plantar heel spurs.[14] 

While studying the relationship between plantar heel spurs and plantar fasciitis, Ahmad et al[14] classified plantar heel spurs based on their morphology into 4 shapes: 0 or absent, 1 or horizontal, 2 or vertical and 3 or hooked, with type 1 (horizontal) being the most prevalent (60.6%).  Zhou et al[15] classified calcaneal spurs into 2 types based on their anatomical location as found in patients with plantar fasciitis as Type A (superior to the plantar fascia) and Type B (from the plantar fascia insertion and within the plantar fascia).

Calcaneal spurs are often regarded as incidental products of the same risk factors causing PHP and coexisting with PHP.[2][16] Moroney et al,[16] however, found that patients with calcaneal spurs are more than twice as likely to have foot pain than individuals without spurs and the prevalence of heel spurs increased with:

  • Advancing age
  • Female gender
  • Obesity
  • Diabetes mellitus
  • Osteoarthritis

The connection between calcaneal spurs and PHPS is still not clear, but studies are showing that:

  • Calcaneal spurs might not be merely incidental
  • The presence of plantar calcaneal spurs does matter


Large Heel spur.png

Figure 2. Large calcaneal spur [13][13]

Heel Pad[edit | edit source]

The subcutaneous layer of adipose tissue underneath the calcaneus on the heel is known as the heel fat pad. It is designed to provide cushioning and shock absorption to the underlying calcaneus during weight-bearing.[17][18] Changes to the mechanical properties of the heel fat pad have been proposed to be associated with the development of PHP.[18] Local trauma, advancing age and overuse may cause changes in the structure of the heel pad, including a reduction in thickness. This diminishes its compressibility and shock-absorbing capacity and leads to diffuse heel pain.[12][18] Many studies have analysed the relationship between heel pad thickness and PHP with varying results (Figure 3).

Heel pad thickness in PHP.jpg

Figure 3. Heel pad thickness in heel pain [12]

No conclusive evidence, therefore, exists that the heel fat pad can contribute to heel pain.

Plantar Fascia Thickness[edit | edit source]

Plantar fasciitis has long been considered a significant cause of PHP.[4]  Histopathological changes in the plantar fascia taken from surgical biopsy confirm a range of degenerative processes resulting in collagen breakdown, fibrocyte cell population changes (including death), matrix degradation and vascular ingrowth, and these appear to represent a similar process observed in the tendinopathy continuum.[12] Imaging studies have indicated an association between PHP and thickening of the plantar fascia.[2] Wall et al[19] suggested that a plantar fascia thickness of more than 4.0mm would be consistent with plantar fasciitis as a general rule. This has subsequently been accepted as the general guide for plantar fascia thickening. Numerous studies found that patients with heel pain presented with thickened plantar fascia of more than 4 mm compared to asymptomatic individuals (Figure 4).

Plantar fascia thickness studies.jpg

Figure 4. Evidence on plantar fascia thickness [12]

A link between increased plantar fascia thickness and PHPS has, therefore, been established.[2][12]

Intrinsic Factors Related to the Anatomy or Biomechanics of the Individual[edit | edit source]

Alternative intrinsic factors not inherent to the foot, but related to the anatomy and biomechanics of the individual can also be potential risk factors for the development of PHPS.[6][8][12] These intrinsic factors will be further discussed below.

Posture and Alignment of the Ankle and Foot[edit | edit source]

Posture and alignment of the foot have long been considered significant in the development of PHP.[6] Many factors concerning the posture and alignment of the foot and ankle have been implicated in PHPS and include:[6]

  • Longitudinal arch height - both a low-arched foot (pes planus) and a high-arched foot (pes cavus)
  • Calcaneal angle / alignment
  • Limited range of motion (ROM) of the 1st metatarsophalangeal joint (MTPJ)
  • Toe flexor strength deficits

A summary of the findings from numerous studies on the posture and alignment of the foot and ankle can be found in Figure 5.[20][21][22][23][24][25][26][27]

Postural factors for-PHPS.jpg

Figure 5. Postural factors associated with PHPS [12]

There is, therefore, insufficient evidence to support the view that clinical and biomechanical findings of the foot and ankle function affect PHPS.

Posture and Alignment of the Knee[edit | edit source]

Posture and alignment of the knee have also been proposed as possible risk factors for the development of PHPS and studies produced varied results (Figure 6).[22][24][28]

Posture and alignment of the knee in PHPS.jpg

Figure 6. Posture and alignment of the knee [12]

There is, therefore, currently no evidence of a link between posture or alignment of the knee and PHPS.

Limitation of Ankle Joint Dorsiflexion[edit | edit source]

Limited dorsiflexion range of the ankle is often proposed as a risk factor for PHP.[6] A lack of dorsiflexion during the stance phase of the gait cycle is postulated to lead to a compensatory increase in mid-foot dorsiflexion, lowering the arch of the foot and increasing tensile load on the plantar fascia.[6] A continuous connection between the plantar fascia and Achilles tendon has been described in anatomical studies. It is proposed that in individuals where this link exists, the increased tensile load in the gastrocnemius-soleus complex following inflexibility could be directly transmitted to the plantar fascia.[6] Many studies have investigated the relationship between limited ankle joint dorsiflexion and PHPS with conflicting results (Figure 7). [1][5][20][23][29][30][31][32][33][34]

Ankle DF limitation and PHPS.jpg

Figure 7. Ankle Dorsiflexion limitation [12]

As can be seen from these studies, there is no agreed evidence that limited ankle dorsiflexion range is associated with the development of PHPS.

Dynamic Foot and Ankle Motion[edit | edit source]
Figure 8. Vertical Ground reaction forces during walking

When individuals walk or run, the plantar aspects of the feet are subjected to considerable forces during the ground contact phase of each step. The heel is often the first part of the foot to strike the ground and large forces are generated by the impact.[35] The heel strike phase of the gait cycle, therefore, represents heavy loading for the heel pad tissues.[12] Heel strike is seen as a short spike of force (typically 10-20 ms), superimposed on the upslope of the ground reaction force (GRF), immediately following initial foot contact.[12] The graph in Figure 8 represents the vertical ground reaction force produced by an individual walking:

  • the initial peak during the stance phase represents the initial force produced during heel contact whereas
  • the later force peak is produced by the more distal parts of the foot.


The functioning of the foot changes during the dynamic actions of gait and running, resulting in increased pressure on the plantar aspect of the foot, as well as changes in the plantar pressure distribution.[27] It has, therefore, been proposed that individuals with plantar fasciitis would present with altered ground reaction forces and patterns of plantar pressure distribution   (Ribeiro 2011). Ribeiro et al[27] found no changes in plantar pressure distribution patterns in recreational runners with plantar fasciitis when compared to control runners. Pain also did not interfere with the dynamic patterns of the plantar pressure distributions.[27] Chang et al [36] found that when compared to healthy controls, individuals with plantar fasciitis exhibited significantly:

  • Greater total rear foot eversion
  • Greater forefoot plantar flexion at initial contact
  • Greater total sagittal plane forefoot motion
  • Greater maximum dorsiflexion of the 1st MTPJ
  • Decreased vertical GRF during propulsion


Controversially, Bovonsunthonchai et al[37] reported that adaptations in intra-foot motion showed a reduction in some angles, but no significant differences in GRF between individuals with plantar fasciitis and healthy individuals when walking at a similar gait speed.

There is, therefore, no conclusive evidence that a change in walking dynamics exists in individuals with PHPS.

Ankle Plantar Flexion Endurance[edit | edit source]

Reduced calf muscle (plantar flexion) endurance has also been postulated as a risk factor for PHPS.[6][20][32] Two studies have, however, reported no relationship between plantar flexion endurance and PHP as can be seen in Figure 9.[20][32]

Plantar flexion endurance in PHPS.jpg

Figure 9. Plantar flexion endurance [12]

Reduced plantar flexion endurance is, therefore, not likely to be associated with PHPS.

Body Mass Index[edit | edit source]

Body mass index (BMI) is an expression of weight compared to height and is classified as:[4]

  • Underweight: < 18.5 kg/m2
  • Ideal weight: 18.5 -24.9 kg/m2
  • Overweight: 24.9 - 29.9 kg/m2  
  • Obese: >30 kg/m2

BMI has been associated with alterations in foot posture and is proposed as a risk factor for PHPS.[2][6][32] Many studies investigating PHPS found that individuals with PHP had a higher BMI and were middle-aged  (Figure 10).[1][16][29] [32][38][39][40][41]

Body mass index and PHPS.jpgFigure 10. Body Mass Index compared to age [12]

The relationship between BMI and PHPS has been extensively studied and a consistently strong clinical association between increased BMI and PHPS has been reported.[2][4][42][43]

Extrinsic Factors Related to External Influences Acting on the Foot[edit | edit source]

Environmental and circumstantial influences acting on an individual are collectively known as extrinsic factors and include: [20]

  • Prolonged standing
  • Inappropriate shoe fit
  • Previous injury
  • Running surface, speed, frequency and weekly distance


Evidence is limited for most of these factors and the role they play in the development of PHPS is not well understood.[20]

Activities Related to Sports[edit | edit source]

It has long been debated whether participation in sports leads to PHPS or if it is protective against PHPS. Many individuals with PHPS note that they do not participate in sports which are reported to put them at risk for PHPS.[41][44] The lack of participation in regular exercise has been associated with an increased prevalence of plantar fasciitis whereas physical activity 3 times/week for more than 20 minutes has been associated with a decrease in prevalence. This suggests that participation in sports is protective against PHPS.[42]

Yet, even though PHPS is more common in sedentary individuals, those who participate in sport do also experience PHP, raising the question of whether it could also lead to PHPS.

In a study by Di Caprio et al,[45] 31% of 166 runners reported one or more episodes of plantar fasciitis preventing them from running for more than 2 weeks. The incidence of plantar fasciitis was statistically related to (Figure 11):[45]

  • Years of activity
  • Days of practice per week (>6 days/week)
  • Number of kilometres per week (>60 km/week)
  • Athlete’s height

Running and PHP.jpg

Figure 11. Factors affecting the occurrence of plantar fasciitis in runners [12][45]

For these athletes, no statistically significant relationships were found between age, weight and BMI.[45]

Even though a strong association exists between increased BMI and PHPS in the non-athletic population[43], there appear to be 2 distinct populations affected by PHP - sedentary individuals with a higher BMI and athletes with the correct BMI and high activity level (Figure 12).[42]

PHPS BMI and sports.jpgFigure 12. Relationship between PHPS, BMI and sport [12]

As far as the evidence is concerned, participation in sports appears to protect against PHPS, but prolonged, intense activity can also become the cause of PHPS.

Activities Related to Standing Time[edit | edit source]

Prolonged standing is often proposed as a risk factor for the development of PHPS. Standing time is, however, not easy to assess and different methods have been used between studies to assess its impact - most studies have reported no significant relationship between standing time and PHPS (Figure 13).[20][24][25][30][32]

Activity level - standing time and PHPS.jpg

Figure 13. Evidence for the relationship between standing time and PHPS [12]

Mental Health[edit | edit source]

An association between psychological disorders and musculoskeletal pain has been firmly established by numerous studies.[46][47][48] Psychological factors, such as anxiety, depression and stress, have been identified as strong risk factors for pain and disability.[46][48] In the foot and ankle, an association was also found between anxiety, depression and chronic foot and ankle pain.[46][48] Cotchett et al[47] also reported symptoms of depression, anxiety and stress to be independently associated with PHP. This association was also found in the foot and ankle (Figure 14).[46][47][48]

Mental health and PHPS.jpg

Figure 14. Studies on the association between mental health and PHPS [12]

A link does, therefore, exist between mental health and PHPS, even though it might not be the main cause of PHPS.

Conclusion[edit | edit source]

PHPS is a complex, multifactorial condition that affects various tissues.[2] A number of intrinsic and extrinsic factors are proposed to be associated with the development of PHPS, many with inconsistent results. Of all the risk factors assessed, only plantar fascia thickness, increased BMI and to some extent, mental health, have been consistently associated with PHPS.

References[edit | edit source]

  1. 1.0 1.1 1.2 Rome K, Howe T, Haslock I. Risk factors associated with the development of plantar heel pain in athletes. The foot. 2001 Sep 1;11(3):119-25.
  2. 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 Menz HB, Thomas MJ, Marshall M, Rathod-Mistry T, Hall A, Chesterton LS, Peat GM, Roddy E. Coexistence of plantar calcaneal spurs and plantar fascial thickening in individuals with plantar heel pain. Rheumatology. 2019 Feb 1;58(2):237-45.
  3. Trojian T, Tucker AK. Plantar fasciitis. American family physician. 2019 Jun 15;99(12):744-50.
  4. 4.0 4.1 4.2 4.3 Valizadeh MA, Afshar A, Hassani E, Tabrizi A, Rezalo S, Dourandish N. Relationship between anthropometric findings and results of corticosteroid injections treatment in chronic plantar heel pain. Anesthesiology and pain medicine. 2018 Feb;8(1).
  5. 5.0 5.1 Landorf KB, Kaminski MR, Munteanu SE, Zammit GV, Menz HB. Clinical measures of foot posture and ankle joint dorsiflexion do not differ in adults with and without plantar heel pain. Scientific Reports. 2021 Mar 19;11(1):1-8.
  6. 6.0 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 6.9 Sullivan J, Pappas E, Burns J. Role of mechanical factors in the clinical presentation of plantar heel pain: implications for management. The Foot. 2020 Mar 1;42:101636.
  7. Allam AE, Chang KV. Plantar Heel Pain. StatPearls [Internet]. 2021 Feb 5.
  8. 8.0 8.1 Hogan KK, Prince JA, Hoch MC. The evaluation of the foot core system in individuals with plantar heel pain. Physical Therapy in Sport. 2020 Mar 1;42:75-81.
  9. Irving, D B, J L Cook, and H B Menz. 2006. Factors Associated with Chronic Plantar Heel Pain: A Systematic Review. Journal of Science and Medicine in Sport / Sports Medicine Australia 9 (1–2): 11–22; discussion 23-4.
  10. Crawford F, Thomson CE. Interventions for treating plantar heel pain. Cochrane Database of Systematic Reviews. 2003(3).
  11. McPoil TG, Martin RL, Cornwall MW, Wukich DK, Irrgang JJ, Godges JJ. Heel pain—plantar fasciitis. journal of orthopaedic & sports physical therapy. 2008 Apr;38(4):A1-8.
  12. 12.00 12.01 12.02 12.03 12.04 12.05 12.06 12.07 12.08 12.09 12.10 12.11 12.12 12.13 12.14 12.15 12.16 12.17 12.18 12.19 Bernice Saban. Literature Review of Risk Factors in Plantar Heel Pain. Plus Course. 2021
  13. 13.0 13.1 13.2 13.3 Alatassi R, Alajlan A, Almalki T. Bizarre calcaneal spur: A case report. International journal of surgery case reports. 2018 Jan 1;49:37-9.
  14. 14.0 14.1 14.2 Ahmad J, Karim A, Daniel JN. Relationship and classification of plantar heel spurs in patients with plantar fasciitis. Foot & ankle international. 2016 Sep;37(9):994-1000.
  15. Zhou B, Zhou Y, Tao X, Yuan C, Tang K. Classification of calcaneal spurs and their relationship with plantar fasciitis. The Journal of Foot and Ankle Surgery. 2015 Jul 1;54(4):594-600.
  16. 16.0 16.1 16.2 Moroney PJ, O’Neill BJ, Khan-Bhambro K, O’Flanagan SJ, Keogh P, Kenny PJ. The conundrum of calcaneal spurs: do they matter?. Foot & ankle specialist. 2014 Apr;7(2):95-101.
  17. Khatiwada P, Chataut D, Subedi K. Sonographic Evaluation of Plantar Fasciitis and its Relation to Body Mass Index and Heel Pad Thickness. Nepalese Journal of Radiology. 2019;9(2):32-9.
  18. 18.0 18.1 18.2 López López D, Becerro de Bengoa Vallejo R, Losa Iglesias ME, Soriano Medrano A, Palomo López P, Morales Ponce Á, Rodríguez Sanz D, Calvo Lobo C. Relationship between decreased subcalcaneal fat pad thickness and plantar heel pain. A case control study. Pain Physician. 2019. 22:109-116
  19. Wall JR, Harkness MA, Crawford A. Ultrasound diagnosis of plantar fasciitis. Foot & ankle. 1993 Oct;14(8):465-70.
  20. 20.0 20.1 20.2 20.3 20.4 20.5 20.6 Irving DB, Cook JL, Young MA, Menz HB. Obesity and pronated foot type may increase the risk of chronic plantar heel pain: a matched case-control study. BMC musculoskeletal disorders. 2007 Dec;8(1):1-8.
  21. Allen RH, Gross MT. Toe flexors strength and passive extension range of motion of the first metatarsophalangeal joint in individuals with plantar fasciitis. Journal of Orthopaedic & Sports Physical Therapy. 2003 Aug;33(8):468-78.
  22. 22.0 22.1 Labovitz JM, Yu J, Kim C. The role of hamstring tightness in plantar fasciitis. Foot & ankle specialist. 2011 Jun;4(3):141-4.
  23. 23.0 23.1 Wenzel EM, Wrobel JS. Prevalence of equinus in patients diagnosed with plantar fasciitis. Foot Ankle Online J. 2009;2(3):1.
  24. 24.0 24.1 24.2 Taunton JE, Ryan MB, Clement DB, McKenzie DC, Lloyd-Smith DR, Zumbo BD. A retrospective case-control analysis of 2002 running injuries. British journal of sports medicine. 2002 Apr 1;36(2):95-101.
  25. 25.0 25.1 Werner RA, Gell N, Hartigan A, Wiggerman N, Keyserling WM. Risk factors for plantar fasciitis among assembly plant workers. PM&R. 2010 Feb 1;2(2):110-6.
  26. Fessel G, Jacob HA, Wyss CH, Mittlmeier T, Müller-Gerbl M, Büttner A. Changes in the length of the plantar aponeurosis during the stance phase of gait–an in vivo dynamic fluoroscopic study. Annals of Anatomy-Anatomischer Anzeiger. 2014 Dec 1;196(6):471-8.
  27. 27.0 27.1 27.2 27.3 Ribeiro AP, Trombini-Souza F, Tessutti VD, Lima FR, João SM, Sacco IC. The effects of plantar fasciitis and pain on plantar pressure distribution of recreational runners. Clinical Biomechanics. 2011 Feb 1;26(2):194-9.
  28. Mahmood S, Huffman LK, Harris JG. Limb-length discrepancy as a cause of plantar fasciitis. Journal of the American Podiatric Medical Association. 2010 Nov;100(6):452-5.
  29. 29.0 29.1 Porter D, Barrill E, Oneacre K, May BD. The effects of duration and frequency of Achilles tendon stretching on dorsiflexion and outcome in painful heel syndrome: a randomized, blinded, control study. Foot & ankle international. 2002 Jul;23(7):619-24. 
  30. 30.0 30.1 Riddle DL, Pulisic M, Pidcoe P, Johnson RE. Risk factors for plantar fasciitis: a matched case-control study. JBJS. 2003 May 1;85(5):872-7.
  31. Bolívar YA, Munuera PV, Padillo JP. Relationship between tightness of the posterior muscles of the lower limb and plantar fasciitis. Foot & ankle international. 2013 Jan;34(1):42-8.
  32. 32.0 32.1 32.2 32.3 32.4 32.5 Sullivan J, Burns J, Adams R, Pappas E, Crosbie J. Musculoskeletal and activity-related factors associated with plantar heel pain. Foot & ankle international. 2015 Jan;36(1):37-45.
  33. Lee SH, Suh DH, Kim HJ, Jang WY, Park YH, Sung HJ, Choi GW. Association of Ankle Dorsiflexion With Plantar Fasciitis. The Journal of Foot and Ankle Surgery. 2021 Mar 6.
  34. Kibler WB, Goldberg C, Chandler TJ. Functional biomechanical deficits in running athletes with plantar fasciitis. The American Journal of Sports Medicine. 1991 Jan;19(1):66-71.
  35. Bennett MB, Ker RF. The mechanical properties of the human subcalcaneal fat pad in compression. Journal of anatomy. 1990 Aug;171:131.
  36. Chang R, Rodrigues PA, Van Emmerik RE, Hamill J. Multi-segment foot kinematics and ground reaction forces during gait of individuals with plantar fasciitis. Journal of biomechanics. 2014 Aug 22;47(11):2571-7. 
  37. Bovonsunthonchai S, Thong-On S, Vachalathiti R, Intiravoranont W, Suwannarat S, Smith R. Alteration of the multi-segment foot motion during gait in individuals with plantar fasciitis: a matched case-control study. Acta of bioengineering and biomechanics. 2019;21(4).
  38. Rompe JD, Meurer A, Nafe B, Hofmann A, Gerdesmeyer L. 2005. Repetitive low‐energy shock wave application without local anesthesia is more efficient than repetitive low‐energy shock wave application with local anesthesia in the treatment of chronic plantar fasciitis. Journal of orthopaedic research, 23(4), pp.931-941. 
  39. Baldassin V, Gomes CR, Beraldo PS. Effectiveness of prefabricated and customized foot orthoses made from low-cost foam for noncomplicated plantar fasciitis: a randomized controlled trial. Archives of physical medicine and rehabilitation. 2009 Apr 1;90(4):701-6.
  40. Landorf KB, Keenan AM, Herbert RD. Effectiveness of foot orthoses to treat plantar fasciitis: a randomized trial. Archives of internal medicine. 2006 Jun 26;166(12):1305-10.
  41. 41.0 41.1 Saban B, Deutscher D, Ziv T. Deep massage to posterior calf muscles in combination with neural mobilization exercises as a treatment for heel pain: a pilot randomized clinical trial. Manual therapy. 2014 Apr 1;19(2):102-8.
  42. 42.0 42.1 42.2 Van Leeuwen KD, Rogers J, Winzenberg T, van Middelkoop M. Higher body mass index is associated with plantar fasciopathy/‘plantar fasciitis’: systematic review and meta-analysis of various clinical and imaging risk factors. British journal of sports medicine. 2016 Aug 1;50(16):972-81.
  43. 43.0 43.1 Butterworth PA, Landorf KB, Smith SE, Menz HB. The association between body mass index and musculoskeletal foot disorders: a systematic review. Obesity reviews. 2012 Jul;13(7):630-42.
  44. Rano JA, Fallat LM, Savoy-Moore RT. Correlation of heel pain with body mass index and other characteristics of heel pain. The Journal of foot and ankle surgery. 2001 Nov 1;40(6):351-6.
  45. 45.0 45.1 45.2 45.3 Di Caprio F, Buda R, Mosca M, Calabrò A, Giannini S. Foot and lower limb diseases in runners: assessment of risk factors. Journal of sports science & medicine. 2010 Dec;9(4):587.
  46. 46.0 46.1 46.2 46.3 Shivarathre DG, Howard N, Krishna S, Cowan C, Platt SR. Psychological factors and personality traits associated with patients in chronic foot and ankle pain. Foot & ankle international. 2014 Nov;35(11):1103-7.
  47. 47.0 47.1 47.2 Cotchett M, Munteanu SE, Landorf KB. Depression, anxiety, and stress in people with and without plantar heel pain. Foot & ankle international. 2016 Aug;37(8):816-21.
  48. 48.0 48.1 48.2 48.3 Drake C, Mallows A, Littlewood C. Psychosocial variables and presence, severity and prognosis of plantar heel pain: A systematic review of cross‐sectional and prognostic associations. Musculoskeletal Care. 2018 Sep;16(3):329-38.