Revision as of 15:09, 28 November 2014

The design and selection of running shoes does not match the available science. The commonly held beliefs follow this logic: Runners get injured due to impact and excessive Pronation, running shoes reduce impact and pronation, and therefore running shoes reduce injury. Unfortunately, every part of this rationale seems to be flawed.

• Injuries due to impact. There is surprisingly little evidence that impact forces cause injuries, and there is even some evidence that lower impact forces are associated with higher injury rates. It's been suggested that excessive impact can result in injury, while more moderate impact can produce important adaptations that are necessary for improved performance.
• Injuries due to over pronation. The science around Pronation and injury rates is quite mixed. Part of the problem is science does not generally look at pronation directly, but uses arch height with the assumption that low arches pronate more. There is some evidence that high or low arches have slightly higher injury rates, or that different arch heights have different patterns of injury.
• Running shoes reduce impact. There is good evidence that increased cushioning does not reduce impact forces. Runners who normally run in shoes will have higher impact when initially running barefoot, but after adaptation the impact forces are actually lower without shoes.
• Running shoes reduce pronation. Motion control shoes (the highest level of anti-pronation) only reduce pronation by about 1.5% when compared with a simple cushioned shoe. It seems unlikely that this is enough to produce any real-world effect.
• Running shoes reduce injury. There is no evidence that running shoes reduce injury rates. Assigning shoes based on arch height does not change injury rate, nor is there any indication that more cushioned shoes have a lower injury rates. There is some evidence that motion control shoes cause greater leg pain and more training days lost, and this applies to all arch types.
• Raised heel. Another common feature of running shoes is a raised heel, which is intended to reduce the strain on the Achilles tendon. However there is little evidence that the raised heel actually reduces the strain on the Achilles tendon, and no evidence that the raised heel actually reduces Achilles tendon injuries.
• Barefoot running. The reduced impact seen with barefoot running led many people (myself included) to believe that this would in turn result in lower injury rates. However, there is no evidence that barefoot runners have a lower injury rates. More importantly, there is a growing body of evidence to suggest that the transition to barefoot running is associated with a high injury risk.

1 The Myth of Running Shoe Types

There is good evidence to support the widely held belief that injury rates among runners are quite high, with estimates of injury rates varying between 20% and 80% of runners^[1]. It is widely assumed that impact forces and excessive pronation cause running injuries, and that running shoes are designed to alleviate these problems^{[2][3][4][5][6][7]}. This leads to the common recommendation that different types of shoes should be recommended based on a runners arch height. In fact, REI^[8], Zappos^[9], Runners' World^[10], and Road Runner Sports^[11] all include this advice.

This image probably originated with the "The Running Shoe Book"^[12].

2 Impact & Injury

The relationship between impact and injury is less clear than one might suppose. It has been suggested that while excessive impact can result in injury, lower levels of impact are the stimulus for improved strength and performance^[13][14] (See Supercompensation.) There is evidence that the impact seen in running does not result in injury:

• Impact forces are not related to injury rates in epidemiologic studies^[14].
• The impact forces at the heel are not related to the forces at common injury sites such as the ankle, Achilles, or knee.^[15].
• A study of 131 runners showed that injury rates were highest in those with the lowest impact levels^[16].

However, there is also some evidence of a relationship between higher impact and injury:

• A study that compared 20 runners who had never been injured with 20 runners that had prior injuries found that peak impact rates were higher in those that had been previously been injured^[17].
• A study of five female runners who had previously had a stress fracture showed higher peak impact forces than subjects without stress fractures^[18].
• A meta-analysis of 13 studies found that while there was no correlation between rates of stress fracture and impact, there was a relationship for the rate of loading^[19].

3 Pronation, Arch Height & Injury

The evidence for the correlation between pronation and injury is rather mixed. This is compounded by the use of arch height as a proxy for pronation.

• An analysis of 29 studies showed that high or low arched feet had slightly higher risk of injury than normally arched feet^[20].
• There is also evidence for the opposite conclusion, where high or low arched feet have a lower risk of injury^[21].
• One study found that while injury rates are the same for different arch heights, the location of the injuries varies with arch height^[22].
• Another study found that while injury rates are similar for different arch heights, those with low arches had more expensive injuries^[23]. (This was a study in the military, where such expenditure is more easily tracked.)
• A year-long study of 927 novice runners showed no correlation between arch height and injury rates^[24].
• A study of 1597 runners found that those with the lowest arches were 2.7x more likely to have knee (patellofemoral) pain than those with the highest arches^[25]. (Note that this study used navicular drop as an indicator of pronation, but other factors contribute significantly to navicular drop^[26].)
• A retrospective study found that arch height was not different between runners who had previously been injured and those that had never been injured^[17].

A graph of peak vertical impact force and the frequency of running-related injuries^[16].

4 Running Shoes & Impact

There is good evidence that increased cushioning does not reduce impact^{[27][28][29][30]}. However, runners who normally run in shoes have greater impact forces when running barefoot, but this is reversed with barefoot experience^[27][31][32].

5 Running Shoes & Pronation Control

The evidence indicates that even Motion Control shoes can only reduce pronation by around 1.5%, which is unlikely to be enough to make any real-world difference.

• A meta-analysis of 5 studies showed that motion control shoes can reduce pronation when compared with barefoot or simple cushioned shoes, but only by about 2%^[33].
• A study compared a Motion Control shoe (MC) with a Cushioned shoe (CT) with 20 high arched (HA) and 20 low arched (LA) runners^[34]. The motion control shoe was the New Balance 1122 and the cushioned shoe was the New Balance 1022. The change in pronation (in degrees) is shown below.

• A study of 10 male runners compared "normal" running shoes with and without a 10 degree orthotic wedge showed the orthotic reduced pronation by 6.7 degrees^[35].
• A study of 25 inexperienced, over-pronating female runners looked at differences in pronation in motion control and cushioned shoes, before and after a 1.5 Km (~1 mile) run^[36]. These runners only averaged 2.1 Km (1.3 miles) per week and had pronation of more than 6 degrees. The Motion Control shoes reduced pronation by 3.3 degrees before the run, but after just this short run the Motion Control shoes made no difference. The motion control shoes were Adidas Supernova Control and the cushioned shoes were Adidas Supernova Cushion. The results are shown below:

• A study of 10 experienced rear foot runners were tested with shoes of varying heel flare^[37]. This heel flare is how much wider the heel is at the bottom than the top, and the flared heels reduced pronation from 12.6 to 11.1 degrees (1.5 degree decrease) when compared with any heel without any flare. In practice, it's rare for a shoe to be this narrow at its base, and other studies have not shown this effect^[38][39].
  
• The heel counter is intended to link the heel of the foot to the shoe, but a study found that a rigid heel counter did not prevent slippage within the shoe any better than a flexible heel counter^[40]. Also, the pronation of the foot can be twice as large as the pronation when measured on the shoe^[39].

6 Running Shoes and Achilles Strain

A common feature in running shoes is for the heel to be thicker than the forefoot, something that is commonly called "drop". In the 1980's a drop of 12-15mm was recommended to prevent Achilles tendon and calf injuries^[41], but there is little evidence to support this:

• No studies have shown raised heels reduce Achilles (or other) injuries^[1].
• Shoes with the different levels of a drop do not change the range of motion of the ankle during running^[42].
• A study of five runners, each running in five different shoes with heel heights of 2.1-3.3cm (5.0 to 9.5 degrees) did not support the idea that heel height changes stress on the Achilles' tendon^[42].
• A study looked at 30 runners that were either assigned a minimal drop shoe (4mm) or were trained to adopt a midfoot strike (MFS) pattern^[43]. The minimal drop shoe reduced heel impact, but the MFS training had no effect.
• A study looked at 12 Rear Foot Strike runners using 16 combinations of midsole thickness and drop^[44]. The lower drop shoes had a more midfoot strike pattern, but the thickness had no impact. (Ground contact time was greater with lower drop shoes.)
• A drop of 15mm or 7.5mm did not produce a significant reduction in Achilles tendon stress^[45].

7 Injury Rates & Shoes

Several studies have found there is no evidence to support the idea that running shoes can reduce injury rates^[46][1][47].

• A study of 247 runners over 5 months showed no difference in injury rates between firm and softly cushioned shoes^[48].
• Three studies compared evaluated the idea that shoe type should be determined by arch height^[49]. Runners were put into two groups, with one group assigned shoes based on the shape of the arch, and the other group just assigned a stability shoe regardless of their arch. These studies found no difference in injury rates. The studies were done by the US Army (2168 men, 951 women), Air Force (1955 men, 718 women), and Marine Corps (840 men, 571 women).
• A study of 81 women training for a half marathon were randomly assigned cushioned, stability and motion control shoes^[50]. The cushioned shoe was a Nike Pegasus, the stability was Nike Structure Triax, and the motion control was Nike Nucleus. The runners were then analyzed based on their arch height.
  • The study found that the motion control shoe was associated with the highest levels of pain while running for all foot types, though the difference was only significant for the neutral and pronated foot types.
  • All the highly pronated runners wearing the motion control shoe missed a training day due to pain, the highest proportion of any of the subgroups.
  • The neutral runners had higher levels of pain in the neutral shoe than the stability shoe. The pronating runners had higher levels of pain in the stability shoe than the neutral shoe. This is the opposite of most recommendations for shoe and foot type.
  • Note that while the overall sample size was reasonable (81), each individual subgroup was quite small (5 to 18 runners) and variation within subgroup of results was large. The subgroups also varied significantly in weight, BMI, age, and years of running experience.

8 Minimalist & Barefoot Running

Most research looks at factors that might be related to injury risk, rather than injury rates directly. I found no studies that evaluated barefoot or minimalist running and injury rates. So while barefoot and minimalist running tends to have lower impact, it's unclear if this will have any bearing on injury rates. Of greater concern is some compelling evidence that the transition to barefoot or minimalist footwear is correlated with higher injury rates, especially stress fractures in the foot.

• A review of 23 studies found moderate evidence for higher Cadence and lower impact, but noted a lack of high quality evidence^[51]. Examples include:
  • Barefoot running can produce reduce impact forces compared with cushioned shoes^[31]
  • Shoes increase Ground Contact Time compared with barefoot^[52].
  • Compared with barefoot, running shoes reduced the ability to estimate surface angle, with a greater estimation error with thicker shoes^[53][54].
• There are some instances of Metatarsal Stress fractures in runners who had changed to minimalist shoes, with no other changes in their training habits^[55].
• A study of 99 runners were randomly assigned a traditional cushioned shoe (Nike Pegasus), partial-minimalist shoes (Nike Free 3.0 V.2) or minimalist shoes (Vibram 5-Finger Bikila)^[56]. The runners had a minimum of 5 years' experience and had no injuries in the previous 6 months. The runners took part in a 12 week training program in which they gradually adopted their assigned footwear. They increased their time in the assigned footware from 10 min (19%) in week 1 to 115 min (58%) in week 12. Runners in the two minimalist shoes had a greater rate of injury compared with runners in the traditional shoes. Runners with the partly minimal shoes (Nike Free) had the highest overall injury rate. Runners in the minimalist shoes (5 Fingers) had the greatest shin and calf pain.
• A study looked at bone marrow edema in 36 experienced runners transitioning to Vibram FiveFingers (VFF) shoes^[57]. The runners were randomly assigned VFF or their normal running shoes, with the VFF runners gradually transitioning based on the recommendations of Vibram at that time. Only 1 of the 17 runners in the control group showed signs of a bone marrow edema, compared with 9 of the 19 VFF runners.
• In 2014, Vibram settled a lawsuit that they made false and unsubstantiated claims that their FiveFingers shoes could reduce injury rates.

9 References

<references> ^{[46] [41] [42] [52] [45] [53] [54] [48] [24] [24] [47] [2] [15] [3] [4] [26] [25] [14] [16] [5] [6] [7] [1] [49] [22] [23] [17] [21] [20] [33] [50] [55] [31] [51] [56] [57] [42] [27] [31] [32] [28] [29] [30] [8] [9] [10] [11] [12] [13] [18] [19] [43] [44] [34] [35] [36] [37] [38] [39] [40]}

1. ↑ ^{1.0 1.1 1.2 1.3} RN. van Gent, D. Siem, M. van Middelkoop, AG. van Os, SM. Bierma-Zeinstra, BW. Koes, Incidence and determinants of lower extremity running injuries in long distance runners: a systematic review., Br J Sports Med, volume 41, issue 8, pages 469-80; discussion 480, Aug 2007, doi 10.1136/bjsm.2006.033548, PMID 17473005
2. ↑ ^{2.0 2.1} BM. Nigg, The role of impact forces and foot pronation: a new paradigm., Clin J Sport Med, volume 11, issue 1, pages 2-9, Jan 2001, PMID 11176139
3. ↑ ^{3.0 3.1} Beat Hintermann, Benno M. Nigg, Pronation in Runners, Sports Medicine, volume 26, issue 3, 1998, pages 169–176, ISSN 0112-1642, doi 10.2165/00007256-199826030-00003
4. ↑ ^{4.0 4.1} DC. McKenzie, DB. Clement, JE. Taunton, Running shoes, orthotics, and injuries., Sports Med, volume 2, issue 5, pages 334-47, PMID 3850616
5. ↑ ^{5.0 5.1} CA. Johnston, JE. Taunton, DR. Lloyd-Smith, DC. McKenzie, Preventing running injuries. Practical approach for family doctors., Can Fam Physician, volume 49, pages 1101-9, Sep 2003, PMID 14526862
6. ↑ ^{6.0 6.1} Barbara Heil, Running Shoe Design and Selection Related to Lower Limb Biomechanics, Physiotherapy, volume 78, issue 6, 1992, pages 406–412, ISSN 00319406, doi 10.1016/S0031-9406(10)61525-8
7. ↑ ^{7.0 7.1} MH. Yamashita, Evaluation and selection of shoe wear and orthoses for the runner., Phys Med Rehabil Clin N Am, volume 16, issue 3, pages 801-29, Aug 2005, doi 10.1016/j.pmr.2005.02.006, PMID 16005404
8. ↑ ^{8.0 8.1} Running Shoes: How to Choose, http://www.rei.com/learn/expert-advice/running-shoes.html, Accessed on 26 November 2014
9. ↑ ^{9.0 9.1} http://www.zappos.com/running-shoe-fit-guide, http://www.zappos.com/running-shoe-fit-guide, Accessed on 26 November 2014
10. ↑ ^{10.0 10.1} Take This Simple Test To Learn If You Have High or Low Arches, http://www.runnersworld.com/running-shoes/take-wet-test-learn-your-foot-type, Accessed on 26 November 2014
11. ↑ ^{11.0 11.1} http://www.roadrunnersports.com/rrs/content/choosing-running-shoes/, http://www.roadrunnersports.com/rrs/content/choosing-running-shoes/, Accessed on 26 November 2014
12. ↑ ^{12.0 12.1} Peter R. Cavanagh, The running shoe book, date 1980, publisher Anderson World, location Mountain View, CA, isbn 0890371822
13. ↑ ^{13.0 13.1} A. Hreljac, Impact and overuse injuries in runners., Med Sci Sports Exerc, volume 36, issue 5, pages 845-9, May 2004, PMID 15126720
14. ↑ ^{14.0 14.1 14.2} Nigg, Benno M. "Impact forces in running." Current Opinion in Orthopaedics 8.6 (1997): 43-47.
15. ↑ ^{15.0 15.1} SH. Scott, DA. Winter, Internal forces of chronic running injury sites., Med Sci Sports Exerc, volume 22, issue 3, pages 357-69, Jun 1990, PMID 2381304
16. ↑ ^{16.0 16.1 16.2} Alexander Bahlsen, The Etiology of Running Injuries: A Longitudinal, Prospective Study, 1988
17. ↑ ^{17.0 17.1 17.2} A. Hreljac, RN. Marshall, PA. Hume, Evaluation of lower extremity overuse injury potential in runners., Med Sci Sports Exerc, volume 32, issue 9, pages 1635-41, Sep 2000, PMID 10994917
18. ↑ ^{18.0 18.1} Susan K. Grimston, Benno M. Nigg, Veronica Fisher, Stanley V. Ajemian, External loads throughout a 45 minute run in stress fracture and non-stress fracture runners, Journal of Biomechanics, volume 27, issue 6, 1994, pages 668, ISSN 00219290, doi 10.1016/0021-9290(94)90983-0
19. ↑ ^{19.0 19.1} AA. Zadpoor, AA. Nikooyan, The relationship between lower-extremity stress fractures and the ground reaction force: a systematic review., Clin Biomech (Bristol, Avon), volume 26, issue 1, pages 23-8, Jan 2011, doi 10.1016/j.clinbiomech.2010.08.005, PMID 20846765
20. ↑ ^{20.0 20.1} JW. Tong, PW. Kong, Association between foot type and lower extremity injuries: systematic literature review with meta-analysis., J Orthop Sports Phys Ther, volume 43, issue 10, pages 700-14, Oct 2013, doi 10.2519/jospt.2013.4225, PMID 23756327
21. ↑ ^{21.0 21.1} DN. Cowan, BH. Jones, JR. Robinson, Foot morphologic characteristics and risk of exercise-related injury., Arch Fam Med, volume 2, issue 7, pages 773-7, Jul 1993, PMID 7906597
22. ↑ ^{22.0 22.1} DS. Williams, IS. McClay, J. Hamill, Arch structure and injury patterns in runners., Clin Biomech (Bristol, Avon), volume 16, issue 4, pages 341-7, May 2001, PMID 11358622
23. ↑ ^{23.0 23.1} Teyhen, LTC Deydre S., et al. "Impact of Foot Type on Cost of Lower Extremity Injury."
24. ↑ ^{24.0 24.1 24.2} R. O. Nielsen, I. Buist, E. T. Parner, E. A. Nohr, H. Sorensen, M. Lind, S. Rasmussen, Foot pronation is not associated with increased injury risk in novice runners wearing a neutral shoe: a 1-year prospective cohort study, British Journal of Sports Medicine, volume 48, issue 6, 2013, pages 440–447, ISSN 0306-3674, doi 10.1136/bjsports-2013-092202
25. ↑ ^{25.0 25.1} MC. Boling, DA. Padua, SW. Marshall, K. Guskiewicz, S. Pyne, A. Beutler, A prospective investigation of biomechanical risk factors for patellofemoral pain syndrome: the Joint Undertaking to Monitor and Prevent ACL Injury (JUMP-ACL) cohort., Am J Sports Med, volume 37, issue 11, pages 2108-16, Nov 2009, doi 10.1177/0363546509337934, PMID 19797162
26. ↑ ^{26.0 26.1} MJ. Mueller, JV. Host, BJ. Norton, Navicular drop as a composite measure of excessive pronation., J Am Podiatr Med Assoc, volume 83, issue 4, pages 198-202, Apr 1993, doi 10.7547/87507315-83-4-198, PMID 8473991
27. ↑ ^{27.0 27.1 27.2} SE. Robbins, GJ. Gouw, Athletic footwear and chronic overloading. A brief review., Sports Med, volume 9, issue 2, pages 76-85, Feb 1990, PMID 2180026
28. ↑ ^{28.0 28.1} I.C. Wright, R.R. Neptune, A.J. van den Bogert, B.M. Nigg, Passive regulation of impact forces in heel-toe running, Clinical Biomechanics, volume 13, issue 7, 1998, pages 521–531, ISSN 02680033, doi 10.1016/S0268-0033(98)00025-4
29. ↑ ^{29.0 29.1} T. Clarke, E. Frederick, L. Cooper, Effects of Shoe Cushioning Upon Ground Reaction Forces in Running, International Journal of Sports Medicine, volume 04, issue 04, 2008, pages 247–251, ISSN 0172-4622, doi 10.1055/s-2008-1026043
30. ↑ ^{30.0 30.1} B.M. Nigg, H.A. Bahlsen, S.M. Luethi, S. Stokes, The influence of running velocity and midsole hardness on external impact forces in heel-toe running, Journal of Biomechanics, volume 20, issue 10, 1987, pages 951–959, ISSN 00219290, doi 10.1016/0021-9290(87)90324-1
31. ↑ ^{31.0 31.1 31.2 31.3} C. Divert, G. Mornieux, H. Baur, F. Mayer, A. Belli, Mechanical comparison of barefoot and shod running., Int J Sports Med, volume 26, issue 7, pages 593-8, Sep 2005, doi 10.1055/s-2004-821327, PMID 16195994
32. ↑ ^{32.0 32.1} SE. Robbins, AM. Hanna, Running-related injury prevention through barefoot adaptations., Med Sci Sports Exerc, volume 19, issue 2, pages 148-56, Apr 1987, PMID 2883551
33. ↑ ^{33.0 33.1} RT. Cheung, MY. Wong, GY. Ng, Effects of motion control footwear on running: a systematic review., J Sports Sci, volume 29, issue 12, pages 1311-9, Sep 2011, doi 10.1080/02640414.2011.591420, PMID 21751855
34. ↑ ^{34.0 34.1} RJ. Butler, IS. Davis, J. Hamill, Interaction of arch type and footwear on running mechanics., Am J Sports Med, volume 34, issue 12, pages 1998-2005, Dec 2006, doi 10.1177/0363546506290401, PMID 16902231
35. ↑ ^{35.0 35.1} SD Perry, MA Lafortune, Influences of inversion/eversion of the foot upon impact loading during locomotion, Clinical Biomechanics, volume 10, issue 5, 1995, pages 253–257, ISSN 02680033, doi 10.1016/0268-0033(95)00006-7
36. ↑ ^{36.0 36.1} R. T. Cheung, G. Y. Ng, Influence of Different Footwear on Force of Landing During Running, Physical Therapy, volume 88, issue 5, 2008, pages 620–628, ISSN 0031-9023, doi 10.2522/ptj.20060323
37. ↑ ^{37.0 37.1} TE. Clarke, EC. Frederick, CL. Hamill, The effects of shoe design parameters on rearfoot control in running., Med Sci Sports Exerc, volume 15, issue 5, pages 376-81, 1983, PMID 6645865
38. ↑ ^{38.0 38.1} BM. Nigg, M. Morlock, The influence of lateral heel flare of running shoes on pronation and impact forces., Med Sci Sports Exerc, volume 19, issue 3, pages 294-302, Jun 1987, PMID 3600244
39. ↑ ^{39.0 39.1 39.2} A. Stacoff, C. Reinschmidt, BM. Nigg, AJ. Van Den Bogert, A. Lundberg, J. Denoth, E. Stüssi, Effects of shoe sole construction on skeletal motion during running., Med Sci Sports Exerc, volume 33, issue 2, pages 311-9, Feb 2001, PMID 11224823
40. ↑ ^{40.0 40.1} Van Gheluwe, Bart, Rudi Tielemans, and Philip Roosen. "The influence of heel counter rigidity on rearfoot motion during running." Sort 100 (1995): 250.
41. ↑ ^{41.0 41.1} DB. Clement, JE. Taunton, A guide to the prevention of running injuries., Can Fam Physician, volume 26, pages 543-8, Apr 1980, PMID 21293616
42. ↑ ^{42.0 42.1 42.2 42.3} C. Reinschmidt, BM. Nigg, Influence of heel height on ankle joint moments in running., Med Sci Sports Exerc, volume 27, issue 3, pages 410-6, Mar 1995, PMID 7752869
43. ↑ ^{43.0 43.1} M. Giandolini, N. Horvais, Y. Farges, P. Samozino, JB. Morin, Impact reduction through long-term intervention in recreational runners: midfoot strike pattern versus low-drop/low-heel height footwear., Eur J Appl Physiol, volume 113, issue 8, pages 2077-90, Aug 2013, doi 10.1007/s00421-013-2634-7, PMID 23584279
44. ↑ ^{44.0 44.1} N. Horvais, P. Samozino, Effect of midsole geometry on foot-strike pattern and running kinematics, Footwear Science, volume 5, issue 2, 2013, pages 81–89, ISSN 1942-4280, doi 10.1080/19424280.2013.767863
45. ↑ ^{45.0 45.1} Dixon, Sharon J., and David G. Kerwin. "The influence of heel lift manipulation on Achilles tendon loading in running." Journal of Applied Biomechanics 14 (1998): 374-389.
46. ↑ ^{46.0 46.1} C E Richards, P J Magin, R Callister, Is your prescription of distance running shoes evidence-based?, British Journal of Sports Medicine, volume 43, issue 3, 2009, pages 159–162, ISSN 0306-3674, doi 10.1136/bjsm.2008.046680
47. ↑ ^{47.0 47.1} W. van Mechelen, Running injuries. A review of the epidemiological literature., Sports Med, volume 14, issue 5, pages 320-35, Nov 1992, PMID 1439399
48. ↑ ^{48.0 48.1} D. Theisen, L. Malisoux, J. Genin, N. Delattre, R. Seil, A. Urhausen, Influence of midsole hardness of standard cushioned shoes on running-related injury risk, British Journal of Sports Medicine, volume 48, issue 5, 2013, pages 371–376, ISSN 0306-3674, doi 10.1136/bjsports-2013-092613
49. ↑ ^{49.0 49.1} Joseph J. Knapik, Daniel W. Trone, Juste Tchandja, Bruce H. Jones, Injury-Reduction Effectiveness of Prescribing Running Shoes on the Basis of Foot Arch Height: Summary of Military Investigations, Journal of Orthopaedic & Sports Physical Therapy, volume 44, issue 10, 2014, pages 805–812, ISSN 0190-6011, doi 10.2519/jospt.2014.5342
50. ↑ ^{50.0 50.1} M. B. Ryan, G. A. Valiant, K. McDonald, J. E. Taunton, The effect of three different levels of footwear stability on pain outcomes in women runners: a randomised control trial, British Journal of Sports Medicine, volume 45, issue 9, 2010, pages 715–721, ISSN 0306-3674, doi 10.1136/bjsm.2009.069849
51. ↑ ^{51.0 51.1} K. P. Perkins, W. J. Hanney, C. E. Rothschild, The Risks and Benefits of Running Barefoot or in Minimalist Shoes: A Systematic Review, Sports Health: A Multidisciplinary Approach, volume 6, issue 6, 2014, pages 475–480, ISSN 1941-7381, doi 10.1177/1941738114546846
52. ↑ ^{52.0 52.1} B. Braunstein, A. Arampatzis, P. Eysel, GP. Brüggemann, Footwear affects the gearing at the ankle and knee joints during running., J Biomech, volume 43, issue 11, pages 2120-5, Aug 2010, doi 10.1016/j.jbiomech.2010.04.001, PMID 20462583
53. ↑ ^{53.0 53.1} K. Sekizawa, MA. Sandrey, CD. Ingersoll, ML. Cordova, Effects of shoe sole thickness on joint position sense., Gait Posture, volume 13, issue 3, pages 221-8, May 2001, PMID 11323228
54. ↑ ^{54.0 54.1} S. Robbins, E. Waked, J. McClaran, Proprioception and stability: foot position awareness as a function of age and footwear., Age Ageing, volume 24, issue 1, pages 67-72, Jan 1995, PMID 7762465
55. ↑ ^{55.0 55.1} Jeffrey Giuliani, Brendan Masini, Curtis Alitz, Brett D. Owens, Barefoot-simulating Footwear Associated With Metatarsal Stress Injury in 2 Runners, Orthopedics, 2011, ISSN 0147-7447, doi 10.3928/01477447-20110526-25
56. ↑ ^{56.0 56.1} M. Ryan, M. Elashi, R. Newsham-West, J. Taunton, Examining injury risk and pain perception in runners using minimalist footwear, British Journal of Sports Medicine, volume 48, issue 16, 2013, pages 1257–1262, ISSN 0306-3674, doi 10.1136/bjsports-2012-092061
57. ↑ ^{57.0 57.1} Sarah T. Ridge, A. Wayne Johnson, Ulrike H. Mitchell, Iain Hunter, Eric Robinson, Brent S. E. Rich, Stephen Douglas Brown, Foot Bone Marrow Edema after a 10-wk Transition to Minimalist Running Shoes, Medicine & Science in Sports & Exercise, volume 45, issue 7, 2013, pages 1363–1368, ISSN 0195-9131, doi 10.1249/MSS.0b013e3182874769