Effect of Footwear on Dancers a Systematic Review

Original Article

Effect of Footwear on Dancers A Systematic Review

Alycia Fong Yan, B.App.Sc., Claire Hiller, Ph.D., Richard Smith, Ph.D., and Benedicte Vanwanseele, Ph.D.

Abstract accomplishment. Therefore, the foot- percussive characteristics of flamenco Dancers need their feet to be healthy and wear that dancers use is very impor- and tap dancing, for example, can have pain-free; therefore, the footwear they use tant. Dance shoes range in design and an effect on the health of the dancer.3-5 is of great importance. Footwear has the construction depending on the dance The shock absorbing qualities of the potential to enhance or restrict move- style and purpose.1 The stiffness and shoes used in these styles should be ment and impact the dancer’s body in thickness of the sole, materials used in examined for their role in amplifying various ways. To evaluate the effects of construction, and overall design con- or reducing these forces. Both flamenco footwear on dancers, in particular the tribute to the flexibility and function- and some jazz routines require heeled effects on foot motion and injury dur- ality of the shoe. Research examining shoes, and the resultant forward move- ing dance movements, we undertook a systematic review of the literature. The the effects of footwear on the general ment of the center of mass can change population has found that stiffness body alignment and have implications major databases were searched for articles 2 6-8 on theatrical dance styles and dance affects the mechanics of walking ; it for posture and lower back pain. Bal- footwear. Sixteen articles were selected can restrict the amount of forefoot let dancers spend a large proportion of for inclusion in this study, ten on ballet plantar flexion required during the their training and performance with and the remainder covering a variety of propulsive toe-off phase of gait and their feet in maximal plantar flexion of other genres. The contribution of dance cause excessive rear foot motion inside the ankle and foot. The ability of the shoes to the quality of dance movement the shoe. Similarly, footwear has the ballet shoe to protect the pointed foot, is a relatively unexplored subject; little potential to enhance or restrict dance including the shoe’s effect on impact experimental research has been done. movement and impact the dancer’s forces during jumps and pointe work, Prospective scientific evidence is needed body in various ways. needs to be understood. to support or disprove traditional beliefs regarding the effects of footwear on dance The dance style being practiced and As the requirements of dance styles performance and dancers’ health. its technical requirements dictate what cannot be modified too greatly, foot- types of movement are of particular wear should be designed to minimize ancers are on their feet most importance, and the footwear used may impact forces and injury risk to danc- of the time, and healthy, require special capabilities beyond those ers and to assist them in achieving pain-free feet are imperative associated with the genre’s aesthetics. maximal performance. Therefore, forD dancers regardless of age or level of Vibration and impact forces from the the aim of this systematic review was to evaluate the current state of ex- Alycia Fong Yan, B.App.Sc., Exercise, Health and Performance Research Group, perimental evidence for the effects of Faculty of Health Science, University of Sydney, Lidcombe, Australia. Claire dance footwear on dancers, in particu- Hiller, Ph.D., is a Post-doctoral Fellow with the Faculty of Health Science, lar the effect on foot motion and risk University of Sydney, Lidcombe, Australia. Richard Smith, Ph.D., is a Professor of injury during dance movements. of Biomechanics, Exercise, Health and Performance, Faculty of Health Science, University of Sidney, Lidcombe, Australia. Benedicte Vanwanseele, Ph.D., is at the Methods University of Sidney, Australia, and Health Innovations and Technology, Fontys Search Strategy University of Applied Sciences, Eindhoven, The Netherlands. Database searches were carried out Correspondence: Alycia Fong Yan, B.App.Sci., Exercise, Health and Performance, through May 2009 using MedLine, Faculty of Health Science, University of Sydney, PO Box 170, Lidcombe NSW SPORTDiscus, CINAHL, PubMed, 1825, Australia; [email protected]. PEDro, Scopus and Embase. Key-

86 Journal of Dance Medicine & Science • Volume 15, Number 2, 2011 87

aim, objectives, or hypothesis clearly stated; a clear description of the subjects, with inclusion or exclusion criteria stated; main outcomes of the study adequately described; main findings of the study well defined; variability figures given; methodology validated and reliable, or at least an attempt to validate the methodology with reference to previous work or a pilot study; actual probability (p) values given, unless p < 0.001; correct statistical tests chosen, and a power analysis performed. Criteria were based on those described by Downs and Black.9 Data Analysis Cohort descriptors, study design, outcome measures, results and conclu- sions were extracted from the articles by two investigators and compared to ensure there were no errors or dis- agreements. Articles were categorized by dance style for analysis. Results Ultimately, a total of just 16 articles (out of 242 searched) were found to be acceptable for review. The number of articles examining the different dance styles were: 12 ballet; 2 flamenco; 1 Figure1 Literature search methodology. Irish; and 1 modern or contemporary. Six of the studies were retrospective, words used in the search were: dance, contemporary, flamenco, or Irish), and using questionnaires to obtain infor- dancer, dancers, dancing, dances, examined the role of footwear or shoes. mation on footwear use and injury ballet, shoe, shoes, and footwear. All Articles were excluded from selection histories of dancers.10-15 The relation- searches were limited to full articles in if they indicated disease, pre-existing ship between dance footwear and the English language. or congenital deformity, or examined injury was directly addressed in four Articles were eliminated using set subjects aged 50 years or older. These articles.12-14,16 Most of these acknowl- inclusion and exclusion criteria based population characteristics describe a edged that pointe shoes lead to painful on title, then abstract, then full text minority of people who participate feet13,14,17,18 and nail trauma.14,16 Only (see Fig. 1). The reference lists of the in theatrical dance styles. Aerobic one study investigated the effect of included articles were then searched dancing and dancing for fitness were different types of footwear on ankle to ensure that relevant literature was excluded because their movement style injury rate, and found that there was not missed. The Journal of Dance and technique are not closely related to a decreased risk with the use of jazz Medicine and Science, Dance Medicine theatrical dance. All abstracts, clinical sneakers in Irish dancers.12 Eleven and Science Bibliography (4th edition), commentaries, reviews or letters were articles concluded that footwear might and The Dancer as Athlete: The 1984 excluded. Two investigators indepen- be a contributing factor in lower limb, Olympic Congress Proceedings were dently reviewed all articles identified foot, or ankle injuries.10-12,14,15,17-22 hand searched for any relevant ar- by the search criteria, and any disagree- None examined the effects of dance ticles. Any articles that could not be ments were resolved by consensus or footwear on foot motion. retrieved were eliminated from review. by a third party. Quality Assessment Inclusion and Exclusion Criteria Quality Assessment The overall quality of the papers was Articles were included if they were Two investigators performed a simple quite poor. All of the studies but one14 experimental, referred to theatrical quality assessment of the included clearly described their aim and objec- dance styles (ballet, jazz, tap, modern, studies using the following criteria: tives or hypotheses, but only 10 stud- 88 Volume 15, Number 2, 2011 • Journal of Dance Medicine & Science ies were able to sufficiently describe in proportion to the cross-sectional design fixed the shank against the sole their participants by stating the inclu- areas of the muscles.21 The forces at of the foot during rise to the pointe sion or exclusion criteria.7,11-13,15,20-24 the extremes of ankle joint range of position, and the memory foam lining Methodology of the studies was motion were found to be comparable accommodated the individual dancer’s reasonably described, but only four to the bone–on–bone forces occurring toe lengths and alignment in the toe reported on the validity or reliability during running25—i.e., up to 13 times box. of the measurement tools used.7,13,21,25 body weight.27 Only two studies examined the The main findings were adequately A study of the mechanical proper- effects of the pointe shoe on joint identified in most studies, but only ties of pointe shoes demonstrated that stability and injury.13,16 Bentley- half reported standard deviation, axial strength was greater than vertical Phillips and associates found that a standard error, or confidence inter- strength across all shoes tested. Over- group of ballerinas (n = 150) did not vals,7,11,13,15,17,20,23,24,26 or provided exact all, there was variability between the present with any cases of koilonychia, p values in their results.7,12,13,15,19,20,26 brands tested for stiffness, strength, a unique form of toenail deformation No power analysis was performed in and durability. One type of pointe where the toenail becomes concave any of the quantitative studies. shoe stood out among the five mod- due to trauma.16 However, the balle- els tested; the shoe manufactured by rinas did have a number of other types Ballet Shoes Gaynor Minden withstood ten times of foot and nail trauma. The invesiga- Pointe Shoe the number of cycles of loading be- tors suggested that padding inside Not surprisingly, the pointe shoe fore it reached fatigue.11 No “reliable the pointe shoe provided adequate was the most extensively researched predictive relationship” was found be- protection against the development footwear type. The research covered tween the dimensions of the shoe and of koilonychia.16 foot biomechanics, shoe mechanics, its mechanical properties. The design Nunes and coworkers found that and resultant pain and injury of the of this study had some flaws—e.g., painful sites were more numerous in foot and ankle. the authors used an “arbitrarily” cho- their subjects who danced on pointe Biomechanics of the foot and ankle sen threshold, with no background, than in those who did not (n = 19 and were examined in six studies, using context, or comparison given to define n = 12, respectively), but dancing on plantar pressures, toe alignment, or the point of failure. The method used pointe did not increase the likelihood kinetic analysis.14,17,18,21,24,25 It was for testing the stiffness of the shoe in of ankle or knee instability.13 found that the greatest plantar pres- simulated demi-pointe position was sures occurred during the transition to less than desirable; a vertical load ap- Soft Technique Shoe full pointe,17 and the distal hallux bore plied to the dorsal aspect of the toe Only one article looked at the soft the greatest pressures while settled on box while the shoe is placed flat does ballet technique shoe, examining pointe,17,18,24 regardless of length of the not accurately represent the demi- plantar pressures and pressure dis- first three toes.18 Albers and colleagues pointe position.11 tribution when landing from ballet found that walking in pointe shoes The pointe shoe was found to play jumps. Miller and colleagues22 set out produced greater plantar pressures a large role in the support and stabil- to redistribute the plantar pressures than walking barefoot, while relevé ity of the foot while the dancer is on across the foot toward the medial and on pointe produced even greater pres- pointe, assisting the ligaments in the lateral arches by using inserts of vary- sures by comparison. No significant midfoot. This was demonstrated by ing materials to develop 11 modified difference was found between elevé progressive sectioning of first and trial shoes. The standard technique on pointe and relevé on pointe.20 second ray ligaments while loading a shoe appeared to shift the pressure Alignment of the toes, in particular cadaver foot on pointe inside a pointe distribution toward the hallux, second incidence of hallux valgus, was exam- shoe.26 An increase in angle at the sec- metatarsal head, and lateral arch when ined in a study of female dancers using ond metatarsocuneiform joint was the compared to barefoot landings. All moulds inside the pointe shoe toe only significant result after complete modified shoes were able to distribute box.14 All subjects showed “dynamic sectioning, and once the shoe was the pressures more evenly across the positional hallux valgus” while on removed, the foot collapsed. foot when compared to the standard pointe but had varying degrees of hal- Colucci and Klein10 researched soft technique shoe. lux valgus when standing flat on the ballet dancers’ needs in a pointe shoe floor. Two studies examined the forces by observing the anatomical and me- Other Dance Shoe Types acting at the foot and ankle joints on chanical interaction between shoe and Flamenco, Irish, and modern or con- pointe using inverse dynamics and foot during a rise to full pointe posi- temporary dance were the other dance electromyographic data.21,25 Plantar tion in a prototype shoe design. All styles investigated in the included flexor muscles crossing the metatarso- dancers (n = 10) tested and liked the articles. Different footwear types are phalangeal joint were found to work prototype pointe shoe design, which specific to each style. 2.5 to 3 times harder than the plantar included a boot shoe concept and Studies of flamenco dancing all flexor muscles crossing the ankle joint, memory foam lining. The boot shoe mention the effects of high heels on Journal of Dance Medicine & Science • Volume 15, Number 2, 2011 89 the incidence of injury, especially low- movements between barefoot and shoes in particular, must fit the foot er back pain and foot problems.7,8,19 shod conditions. Restriction of foot well; otherwise the foot motion is The effect of wearing high heels in motion could possibly lead to incor- inhibited52 and the dancer is at risk of flamenco dancing on plantar pres- rect technique and muscle imbalances injury.3,6,36,39,40,42,50,53-55 Ill-fitted shoes sures and posture was examined in and thus contribute to injury. In ad- can cause corns,42,50,54 blisters,42,50,54 two studies. Changes in pelvic tilt dition, altered muscle activity in the bunions,36 neuromas, or digital ab- and spinal curves when standing on lower limb before and after the impact scesses42,54; however, the aesthetics of a two-inch platform were found to of heel strike has been found when ballet can compel dancers to select a be highly individual.7 No difference wearing running shoes as opposed pointe shoe that is too small, short, or between walking and dancing in high to running barefoot.30,32 Applying narrow.36,42,46,53,54 Perhaps as a result of heels was observed for either pressure the findings of this research to dance ill-fitting ballet shoes, dancers tend values or distribution of pressure at footwear could have implications for to tie the ribbons tightly around the the heel or forefoot.19 dance shoe design and identification ankle, attempting to secure the shoe One article examined the various of the causes of lower limb injuries. and increase the support. It has been footwear worn in Irish dancing and This review supports common suggested that although ballet shoe established that dancers who wore opinion in the current literature that ribbons can indeed provide added jazz sneakers significantly reduced dance footwear is inadequate for support and stability for the ankle,52 the rate of ankle injury.12 There was protecting the foot and could be a tight ballet shoe ribbons may cause no significant relationship between risk factor for injury to the foot and or aggravate Achilles tendinosis or a ankle injury rates and the use of shock ankle.1,3,6,10,11,14,22,25,36-51 Poorly fitted compressed dorsalis pedis artery.39,40,56 absorbing innersoles, traditional hard shoes, the lack of adequate shock Future attempts to redesign dance shoes, traditional pomps, or shock absorbing materials in footwear, footwear should aim to minimize the absorbing pomps. and high-heeled shoes have all been risk of injury and assist dancers in A retrospective questionnaire ex- identified as being causes of injury.3 selecting a shoe that complies with amined the various types of footwear However, there were no experimental the traditional ballet demand for a used by professional modern dancers trials that examined the shock absorb- slight, narrow foot while ensuring during technique classes. Weiss and ing qualities of dance shoes and no the comfort and health of dancers’ associates15 hypothesized that the soft prospective studies investigating the feet. Prospective scientific evidence is ballet technique shoe did not have effects of different shoe types on dance needed to support or disprove these sufficient shock absorbing qualities injury. ideas and beliefs. and that this deficiency might lead Injuries, pain, and bone deformi- Irish and flamenco dancers wear a to injury due to the highly repetitive ties from pointe shoes could be due variety of shoes that traditionally, like forces in dance. The only footwear to the archaic and “primitive” shoe ballet shoes, do not provide adequate used that provided ”cushioning” was design.10 The imposed misalignment shock absorption,3,8,12,19 although the jazz sneaker, a cross between run- of the toes within the pointe shoe toe some Irish dancers wear shoes with ning shoes and traditional soft, thin- box is almost surely a contributing shock absorbing innersoles.12 The jazz soled jazz shoes. factor to foot injuries such as bunion sneaker was mentioned as the only deformity14,17,18 and bruised, painful, dance shoe that provided adequate Discussion or infected toenails.14 This could be shock absorption,8,15 despite the lack This systematic review was intended to further exacerbated by the incorrect of scientific evidence to support this evaluate the effects of dance footwear technique of everting the foot while notion. Irish and flamenco dancers on dancers, in particular its effect on pointe.18 However, one report have worn the jazz sneaker as a train- on foot motion and the potential suggested that the pointe shoe and ing shoe.8,12 Unfortunately, jazz sneak- for injury during dance movements. the padding inside the shoe provided ers are not allowed in competition, so Although there were a wide variety of adequate protection for the toenails.16 the possibility of modifying the design investigations, no studies examined Despite widespread belief in the po- of traditional Irish shoes to decrease the effects of dance footwear on foot tentially injurious effects of pointe the risk of ankle injury needs to be motion, and few directly assessed the shoes on dancers, only five papers explored further. issue of injury. This was surprising, called for major redesign in dance The thickness of the sole is an especially as findings from barefoot28,29 footwear,10,14,21,37,51 and only one of important aspect of footwear design. and running shoe research30-35 have these seriously attempted this.10 Ballet dancers spend a considerable demonstrated changes in foot mo- An aspect of the shoe-foot in- proportion of their dance life in thin- tion and muscle activity as a result terface that was not covered in this soled, soft technique shoes, so it was of different types of footwear. The review is the influence of incorrect surprising to see that only one article construction of dance shoes should fitting of dance shoes on pain and examined these shoes.22 It appears that be examined for their stiffness to injury. Clinically, it is a common currently there is a trade-off between see if there is any restriction in foot belief that dance footwear, pointe the “feel of the floor” provided by the 90 Volume 15, Number 2, 2011 • Journal of Dance Medicine & Science soft technique shoe and the need for The design differences between ballet stated that the jazz sneaker signifi- cushioning and shock absorption of pointe shoes and Irish shoes should be cantly reduced the incidence of ankle the foot.1,15 As ballet jump landings examined further. injuries, yet no values of significance are associated with ground reaction Another component of dance were provided, which undercut the forces of 424 to 13 times body weight,37 footwear design is the high heel. quality of the study.12 By reporting and there is no significant difference Even though flamenco, tap, and jazz the inclusion and exclusion criteria in vertical force between landings dancers all wear high heels, only their of subjects, ensuring that valid and in pointe shoes and soft technique effects on flamenco dancers have reliable methods are developed and shoes,23 it seems apparent that the been explored. One study concluded recorded, performing statistical tests dissipation and absorption of these that the plantar pressures were not when appropriate, reporting p values forces is an important matter. statistically different between walk- and performing a power analysis, a Although jazz dancing is quite ing and flamenco dancing in high higher standard of dance shoe research popular, there is a distinct lack of sci- heels. However, the specific style of can be achieved. Future improvements entific research focused specifically on steps that were studied could possibly in the quality of experimental design this dance style. A similarity between have an effect on the results found in could lead to standardized testing and the soft technique shoe in ballet and a particular study. The filigree steps ratings for dance shoes and advance the traditional jazz shoe is that they that were examined in the study un- dance research in line with other both have thin soles and do not ap- der consideration here were described fields. pear to offer much protection from as being “a light-footed school of The contribution of dance footwear ground reaction forces. Application dance.”19 Perhaps testing a “heavier” to the alteration of foot motion is a of research findings from other styles style of flamenco dance steps would relatively uncharted area of research. of dance to jazz dancing should be produce different results. Taking an Prospective scientific evidence is undertaken to ascertain whether the individual approach appears to be the needed to support or disprove the effects of jazz footwear are similar. recommended method for minimiz- traditional beliefs regarding the effects Research examining the distribu- ing the injury risk of dancing in high of dance footwear on injury. Further tion of ground reaction forces and re- heels, particularly when correcting research in the areas of jazz and tap sultant pressure across the foot should technique and posture to reduce the dancing is needed, and application produce data showing the amount incidence of lower back pain.7 The of current running shoe research to of force that is absorbed by the shoe study of injury as a result of dancing all dance genres will be beneficial in itself and be compared across both in high heels should be expanded to improving dance performance and dance and non-dance shoe types. The include jazz and tap. the health of dancers. Research in magnitude of the forces and pressures In ballet, pointe work requires end- dance footwear so far has taken a first acting on the feet during dance needs less repetitions of rising onto pointe. step, illustrating that the correlation to be compared to data from running Considering the cross-sectional areas between dance footwear and injury shoes or barefoot activity to provide an of the muscle groups involved in that needs to be further explored in order understanding of the relative severity movement, the relative demand on the to quantify the causative or protective of these forces. A comparison between intrinsic plantar flexors is far greater relationships. 37 the materials used in construction of than on the extrinsics, thus placing References running and ballet shoes highlighted the lower limbs at increased risk of the inadequate shock absorbing na- injury. Similarly, excessive repetition 1. Cheskin M. Dancing feet. World ture of ballet shoes and the need for of escobias in flamenco could be the Sports Activewear. 2000;6(1):30-5. 2. Atwells RL, Smith RM. Shoe control research and development to be done primary cause of overuse injuries in of foot motion during walking and in this area.48,49 that genre, rather than the footwear 3 running. XVIII International Sym- Every dance style makes different used. It appears that the repetitive posium of Biomechanics in Sports. specific demands on the footwear used nature of loading that occurs during The Chinese University of Hong in its practice. This was apparent from dance practice and performance, in Kong Department of Sports Science the various reports included in this combination with the unique forces and Physical Education: The Chinese review. Although Irish dancing uses a and pressures placed on the foot by University of Hong Kong, 2000. position similar to ballet dancing on dance footwear, are contributing fac- 3. Bejjani FJ. Occupational biome- pointe, the shoes differ greatly in their tors in overuse injuries.25,39,47 This hy- chanics of athletes and dancers: a design. A case study of an Irish dancer pothesis could certainly be applicable comparative approach. Clin Podiatr who was wearing away her interpha- to all forms of dance. Med Surg. 1987 Jul;4(3):671-711. 4. Mayers L, Bronner S, Agraharasa- langeal joints due to performing the makulam S, Ojofeitimi S. Lower pointe position in the Irish dancing Conclusion 41 extremity kinetics in tap dance. J hard shoe implicates the lack of It is clear from the quality of these Dance Med Sci. 2010;14(1):3-10. support for the midfoot and forefoot studies that this area of research is still 5. Mayers L, Judelson D, Bronner S. offered by the Irish dancing footwear. very young. For example, one study The prevalence of injury among Journal of Dance Medicine & Science • Volume 15, Number 2, 2011 91

tap dancers. J Dance Med Sci. ley H. Pressures on the foot in ture. 1999;9(2):95-100. 2003;7(4):121-5. pointe shoes. Foot Ankle. 1985 Mar- 29. Wolf S, Simon J, Patikas D, et al. 6. Micheli LJ. Back injuries in Apr;5(5):216-21. Foot motion in children shoes – a dancers. Clin Sports Med. 1983 19. Bejjani FJ, Halpern N, Pio A, et comparison of barefoot walking Nov;2(3):473-84. al. Musculoskeletal demands on with shod walking in conventional 7. Wilmerding V, Gurney B, Torres V. flamenco dancers: a clinical and and flexible shoes. Gait Posture. The effect of positive heel inclination biomechanical study. Foot Ankle. 2008;27:51-9. on posture in young children training 1988 Apr;8(5):254-63. 30. Nigg BM, Stefanyshyn D, Cole G, et in flamenco dance. J Dance Med Sci. 20. Albers D, Hu R, McPoil T, Cornwall al. The effect of material characteris- 2003;7(3):85-90. MW. Comparison of foot and plan- tics of shoe soles on muscle activation 8. Pedersen ME, Wilmerding V. Injury tar pressures during walking and en and energy aspects during running. J profiles of student and professional pointe. Kinesiology and Medicine for Biomech. 2003;36(4):569-75. flamenco dancers. J Dance Med Sci. Dance. 1992;15(1):25-32. 31. Oleson M, Adler D, Goldsmith P. A 1998;2(3):108-14. 21. Dozzi PA, Winter DA. Biome- comparison of forefoot stiffness in 9. Downs SH, Black N. The feasibil- chanical analysis of the foot during running and running shoe bending ity of creating a checklist for the rises to full pointe: implications stiffness. J Biomech. 2005;38:1886- assessment of the methodological for injuries to the metatarsal-pha- 94. quality both of randomised and non- langeal joints and shoe redesign. 32. von Tscharner V, Goepfert B, Nigg randomised studies of health care Kinesiology and Medicine for BM. Changes in EMG signals for the interventions. J Epidemiol Com- Dance.1993;16(1):1-11. muscle tibialis anterior while run- munity Health. 1998;52:377-84. 22. Miller CD, Paulos LE, Parker RD, ning barefoot or with shoes resolved 10. Colucci LA, Klein DE. Development Fishell M. The ballet technique shoe: by non-linearly scaled wavelets. J of an innovative pointe shoe. Ergon a preliminary study of eleven differ- Biomech. 2003;36(8):1169-76. Des. 2008 Summer;16(3):6-12. ently modified ballet technique shoes 33. Wakeling JM, Pascual SA, Nigg BM. 11. Cunningham BW, DiStefano AF, using force and pressure plates. Foot Altering muscle activity in the lower Kirjanov NA, et al. A compara- Ankle. 1990 Oct;11(2):97-100. extremities by running with differ- tive mechanical analysis of the 23. Picon AP, Lobo da Costa PH, De ent shoes. Med Sci Sports Exerc. pointe shoe toe box. An in vitro CN, et al. Biomechanical approach 2002;34(9):1529-32. study. Am J Sports Med. 1998 Jul- to ballet movements: a study of the 34. Walther M, Herold D, Sinderhauf A, Aug;26(4):555-61. effects of ballet shoe and musical Morrison R. Children sport shoes – a 12. McGuinness D, Doody C. The in- beat on the vertical reaction forces. systematic review of current litera- juries of competitive Irish dancers. J Presented at the 22nd International ture. Foot Ankle Surg. 2008;14:180- Dance Med Sci. 2006;10(1-2):35-9. Symposium on Biomechanics in 9. 13. Nunes NM, Haddad JJ, Bartlett Sports, Ottowa, Canada, August 35. Robbins S, Waked E. Balance and DJ, Obright KD. Musculoskeletal 8-12, 2004. vertical impact in sports: role of injuries among young, recreational, 24. Picon AP, Lobo Da Costa PH, shoe sole materials. Arch Phys Med female dancers before and after danc- De Sousa F, et al. Biomechanical Rehabil. 1997;78(5):463-7. ing in pointe shoes. Pediatr Phys approach to ballet movements: a 36. Denton J. Overuse foot and ankle Ther. 2002 Summer;14(2):100-6. preliminary study. Presented at the injuries in ballet. Clin Podiatr Med 14. Tuckman AS, Werner FW, Bayley JC. XVIII International symposium on Surg. 1997 Jul;14(3):525-32. Analysis of the forefoot on pointe in biomechanics in sports. Hong Kong, 37. Dozzi PA, Winter DA, Ishac MG. the ballet dancer. Foot Ankle. 1991 2000. Relative role of ankle and metatarsal- Dec;12(3):144-8. 25. Galea V, Norman R. Bone-on-bone phalangeal muscles in ballet pointe 15. Weiss DS, Shah S, Burchette RJ. forces at the ankle joint during a work. J Biomech. 1989;22(10):1005- A profile of the demographics and rapid and dynamic movement. In: 9. training characteristics of profes- Winter DA, Norman RW, Wells 38. Greer JM, Panush RS. Musculoskel- sional modern dancers. J Dance Med RP, et al (eds): Biomechanics IX-A etal problems of performing artists. Sci. 2008;12(2):41-6. International Series on Biomechanics Baillieres Clin Rheumatol. 1994 16. Bentley-Phillips B, Bayles MA. Occu- Proceedings of the 9th International Feb;8(1):103-35. pational koilonychia of the toe nails. Congress of Biomechanics. Cham- 39. Kadel NJ. Foot and ankle injuries Br J Dermatol. 1971;85(2):140-4. paign, IL: Human Kinetics Publish- in dance. Phys Med Rehabil Clin N 17. Kravitz SR, Murgia CJ, Huber S, et ers, 1985, pp. 71-76. Am. 2006;17(4):813-26. al. Bunion deformity and the forces 26. Kadel N, Boenisch M, Teitz C, Trep- 40. Kennedy JG, Baxter DE. Nerve dis- generated around the great toe: a man E. Stability of Lisfranc joints in orders in dancers. Clin Sports Med. biomechanical approach to analysis ballet pointe position. Foot Ankle 2008;27(2):329-34. of pointe dance, classical ballet. In: Int. 2005 May;26(5):394-400. 41. Markinson BC, Root JA. Irish Shell CG (ed): The Dancer as Athlete: 27. Burdett R. Forces predicted at the jig shoes. Podiatry Management. The 1984 Olympic Scientific Congress ankle joint during running. Med Sci 2006;25(9):26. Proceedings, Vol. 8. Champaign, IL: Sports Exerc. 1982;14(4):308-16. 42. Milan KR. Injury in ballet: a review Human Kinetics Publishers, Inc., 28. Oeffinger D, Brauch B, Cranfill S, of relevant topics for the physical 1986, pp. 43-51. et al. Comparison of gait with and therapist. J Orthop Sports Phys Ther. 18. Teitz CC, Harrington RM, Wi- without shoes in children. Gait Pos- 1994 Feb;19(2):121-9. 92 Volume 15, Number 2, 2011 • Journal of Dance Medicine & Science

43. Stretanski MF. Classical ballet: the 1985;7(3):10. 51. Reid DC. Prevention of hip and full-contact sport. Am J Phys Med 48. Hardaker Jr WT, Erickson L. The knee injuries in ballet dancers. Sports Rehabil. 2002 May;81(5):392-3. pathogenesis of dance injury. In: Med. 1988 Nov;6(5):295-307. 44. Stretanski MF, Weber GJ. Medical Shell CG (ed): Dancer as Athlete 52. Marr SJ. The ballet foot. J Am Podia- and rehabilitation issues in classical 1984 Olympic Congress Proceedings. try Assoc. 1983 Mar;73(3):124-32. ballet. Am J Phys Med Rehabil. 2002 Champaign, IL: Human Kinetics 53. Contompasis JP. The classical ballet May;81(5):383-91. Publishers, 1984, pp. 11-29. shoe. Clin Podiatr Med Surg. 1986 45. Taunton JE, McKenzie DC, Clem- 49. Hardaker Jr WT, Moorman CT. Foot Oct;3(4):631-6. ent DB. The role of biomechanics in and ankle injuries in dance and ath- 54. Novella TM. Pointe shoes: fitting and the epidemiology of injuries. Sports letics: similarities and differences. In: selection criteria. J Dance Med Sci. Med. 1988 Aug;6(2):107-20. Shell CG (ed): The Dancer as Athlete 2000;4(2):73-7. 46. Wilson M, Kwon Y. The role of The 1984 Olympic Scientific Congress 55. Spilken T. Young dancers and biomechanics in understanding Proceedings. Champaign, IL: Human their feet. Podiatry Management. dance movement. J Dance Med Sci. Kinetics Publishers, 1986. pp. 31-41. 2007;26(3):133-5. 2008;12(3):109-16. 50. Macintyre J, Joy E. Foot and ankle 56. Quirk R. Common foot and ankle 47. Galea V. Foot and ankle forces in injuries in dance. Clin Sports Med. injuries in dance. Orthop Clin North pointe shoes. Kinesiology for Dance. 2000;19(2):351-68. Am. 1994 Jan;25(1):123-33.