Pressures on the foot in pointe shoes

The Effects of Pointe Shoes on Ballet Dancers' Biomechanics, Muscle Activity, Movement and Symptoms: A Scoping Review

Introduction: Dancing en pointe requires ballet dancers to stand on the tips of their toes while wearing a structured pointe shoe. Understanding the effect of pointe shoes on ballet dancers' biomechanics, function, symptoms and skin health is essential to guide shoe development and ultimately improve dancer performance. Therefore, the purpose of this scoping review was to map the evidence and identify knowledge gaps related to the effect of wearing pointe shoes on professional and recreational ballet dancers. Method: A scoping review was conducted by searching 6 electronic databases and the International Association for Dance Medicine and Science Bibliography. Results: Thirty-five studies were grouped into 5 categories: pointe shoe factors (eg, toe box and shank, pointe shoe status; 9 studies), shoe types (eg, flat shoes vs demi pointe vs pointe; 10 studies), ballet movements (11 studies), symptoms (5 studies), and intrinsic dancer factors (eg, foot type/toe length; 7 studies). Studies were published between 1979 and 2023, with 72% (n = 23) published between 2006 and 2020. Most (86%) of the studies were cross-sectional. Most studies explored biomechanical outcomes and the most common data collection device was force plates (19 studies). Overall, there was an insufficient volume of evidence for specific research aims. Significant gaps in knowledge exist regarding functional and performance-based outcomes, injury outcomes including exploration of factors such as shoe age/usage, and pointe shoe treatment factors. Conclusions: Currently the field of research suffers from threats to ecological validity, with many study methods not reflecting ballet-specific demands or environments. The impact of pointe shoes on ballet dancers is a developing research area, and this scoping review can help guide future research decisions. Studies need to target the knowledge gaps and employ rigorous ecologically valid study designs and ensure that findings inform shoe design and dancer education to minimize injury and maximize comfort and performance.

Footwear comfort: a systematic search and narrative synthesis of the literature

OBJECTIVE

To provide a narrative synthesis of the research literature pertaining to footwear comfort, including definitions, measurement scales, footwear design features, and physiological and psychological factors.

METHODS

A systematic search was conducted which yielded 101 manuscripts. The most relevant manuscripts were selected based on the predetermined subheadings of the review (definitions, measurement scales, footwear design features, and physiological and psychological factors). A narrative synthesis of the findings of the included studies was undertaken.

RESULTS

The available evidence is highly fragmented and incorporates a wide range of study designs, participants, and assessment approaches, making it challenging to draw strong conclusions or implications for clinical practice. However, it can be broadly concluded that (i) simple visual analog scales may provide a reliable overall assessment of comfort, (ii) well-fitted, lightweight shoes with soft midsoles and curved rocker-soles are generally perceived to be most comfortable, and (iii) the influence of sole flexibility, shoe microclimate and insoles is less clear and likely to be more specific to the population, setting and task being performed.

CONCLUSION

Footwear comfort is a complex and multifaceted concept that is influenced not only by structural and functional aspects of shoe design, but also task requirements and anatomical and physiological differences between individuals. Further research is required to delineate the contribution of specific shoe features more clearly, and to better understand the interaction between footwear features and individual physiological attributes.

Readiness for Dancing En Pointe

Advancing to pointe requires sufficient maturity, strength, and flexibility and adequate ballet training to develop the skills which usually occurs between the ages 11 and 13. Health practitioners can provide studios with an objective assessment to determine if a young dancer is ready to transition to en pointe. The evaluator should be proficient in ballet, because the evaluation largely is dance based and includes a history and physical examination as well as a comprehensive assessment. The plan includes health improvement tips and summarizes technique flaws as well as exercises to improve these and other deficits. The goal is to transition dancers safely to pointe.

The Validity of the Session Rating of Perceived Exertion Method for Measuring Internal Training Load in Professional Classical Ballet Dancers

The aim of this study was to investigate the convergent validity of session rating of perceived exertion (s-RPE) with objective measures of internal training load (TL) in professional classical ballet dancers. Heart rate and s-RPE data were collected in 22 professional classical ballet dancers across a total of 218 ballet class or rehearsal sessions. Eleven participants completed at least 9 sessions, and were therefore included in analyses of individual relationships between s-RPE and objective measures. To calculate s-RPE, the session duration was multiplied by the RPE, measured using the modified Borg CR-10 scale. The Edwards summated heart rate zones (Edwards TRIMP) and Banister training impulse (Banister TRIMP) methods were used as criterion measures of internal TL. Pearson product-moment correlation coefficients were used to determine intra-individual relationships between s-RPE and objective measures. Repeated measures correlations were used to identify intra-individual relationships common across the cohort. Positive linear relationships were seen between s-RPE and objective measures across all session types [Edwards TRIMP: r_{rm (195)} = 0.81, p < 0.001; Banister TRIMP: r_{rm (195)} = 0.79, p < 0.001], in ballet class [Edwards TRIMP: r_{rm (58)} = 0.64, p < 0.001; Banister TRIMP: r_{rm (58)} = 0.59, p < 0.001], and in rehearsals [Edwards TRIMP: r_{rm (119)} = 0.82, p < 0.001; Banister TRIMP: r_{rm (119)} = 0.80, p < 0.001], as well as across both males [Edwards TRIMP: r_{rm (136)} = 0.82, p < 0.001; Banister TRIMP: r_{rm (136)} = 0.80, p < 0.001], and females [Edwards TRIMP: r_{rm (57)} = 0.80, p < 0.001; Banister TRIMP: r_{rm (57)} = 0.78, p < 0.001]. Intra-individual correlation coefficients ranged from 0.46–0.96 [Edwards TRIMP: mean r = 0.81 ± 0.11, p = 0.051 – < 0.001; Banister TRIMP: mean r = 0.78 ± 0.14, p = 0.13– < 0.001]. These results demonstrate that s-RPE is a valid and practical method for measuring internal TL in professional classical ballet dancers.

Acute Effect of Toe Cap Choice on Toe Deviation Angle and Perceived Pain in Female Professional Ballet Dancers

Several classical dance complex movements, such as pointe, require body weight to be supported properly to avoid risk of foot injury. Regarding the choice of toe cap for pointe shoes, it is unclear which type can better alleviate pain symptoms and toe deviation angle in dancers. The aim of the current crossover study was to investigate the acute effect of using different types of toe caps among well-trained professional dancers on pain perception and toe deviation angle. Ten young female professional dancers volunteered to participate in the study. Each participant was tested during two separate sessions with an interval of 72 h in between. Participants were tested in the two sessions with a standard commercial or a customized prototype toe cap, always with pointe shoes, and in randomized order. An anteroposterior X-ray examination was performed separately for each participant and a visual analogue scale for pain perception was administered following each situation (with a standard commercial or a customized prototype toe cap). Significant amelioration was obtained when a customized toe cap prototype was used both for toe deviation angle and for visual analogue scale. Use of a customized toe cap prototype compared to a standard one may acutely reduce both toe deviation angle and pain in elite female professional dancers.

Premature Growth Plate Closure in a Ballet Dancer en Pointe

A 13-year-old ballet dancer who had been dancing en pointe (on the tips of the toes) since 10 years presented to the clinic with a shortened right second toe. She had no previous history of pain or trauma. She was diagnosed with premature growth arrest of the second metatarsal head physes resulting in a shortened metatarsal. This is the first reported case of premature growth arrest in a ballet dancer as a result of dancing en pointe.

Mechanics of Jazz Shoes and Their Effect on Pointing in Child Dancers

There has been little scientific investigation of the impact of dance shoes on foot motion or dance injuries. The pointed (plantar-flexed) foot is a fundamental component of both the technical requirements and the traditional aesthetic of ballet and jazz dancing. The aims of this study were to quantify the externally observed angle of plantar flexion in various jazz shoes compared with barefoot and to compare the sagittal plane bending stiffness of the various jazz shoes. Sixteen female recreational child dancers were recruited for 3D motion analysis of active plantar flexion. The jazz shoes tested were a split-sole jazz shoe, full-sole jazz shoe, and jazz sneaker. A shoe dynamometer measured the stiffness of the jazz shoes. The shoes had a significant effect on ankle plantar flexion. All jazz shoes significantly restricted the midfoot plantar flexion angle compared with the barefoot condition. The split-sole jazz shoe demonstrated the least restriction, whereas the full-sole jazz shoe the most midfoot restriction. A small restriction in metartarsophalangeal plantar flexion and a greater restriction at the midfoot joint were demonstrated when wearing stiff jazz shoes. These restrictions will decrease the aesthetic of the pointed foot, may encourage incorrect muscle activation, and have an impact on dance performance.

[Weight bearing upright magnetic resonance imaging of pointe dancing]

Weight-bearing upright Magnetic resonance imaging (MRI) "en pointe" is the ideal tool for research in the field of functional anatomy of pointe dancing and pointe dancing related medicine.

The influence of second toe and metatarsal length on stress fractures at the base of the second metatarsal in classical dancers

BACKGROUND

Stress fractures at the base of the second metatarsal frequently occur in female classical dancers. There is a strong belief that a foot shape in which the first metatarsal or toe is shorter than the second metatarsal or toe increases the risk of this injury in dancers. However, there is a lack of empirical evidence to support this theory. The objective of this study was to examine the influence of the relative length difference between the first and second metatarsals and first and second toes on the frequency of stress fractures at the base of the second metatarsal in elite, female classical dancers.

METHODS

Both feet of 50 elite female classical dancers were measured for length differences between the first and second toes and first and second metatarsals. Retrospective analysis of dancers' medical histories revealed 17 feet with stress injury and 83 without. The mean of the difference between the metatarsal and toe length for the stress-injury group was compared to that of the control group.

RESULTS

No difference between the groups was identified for first and second toe length difference (p = 0.865) and the relative difference between the ends of the first two metatarsals (p = 0.815).

CONCLUSIONS

Dancers who had a stress injury at the base of the second metatarsal displayed similar variances in the two independent variables as dancers who had not had such an injury.

Foot and Ankle Injuries in Dance

Although dancers develop overuse injuries common in other athletes, they are also susceptible to unique injuries. This article reviews common foot and ankle problems seen in dancers and provides some basic diagnosis and treatment strategies.

Stability of Lisfranc joints in ballet pointe position

BACKGROUND

Ballerinas develop stress fractures at the second metatarsal base associated with dancing en pointe. The purpose of this study was to evaluate the relative importance of the pointe shoe and the tarsometatarsal ligaments in Lisfranc joint stability en pointe.

METHODS

Eleven cadaver feet were dressed with pointe shoes, loaded in foot flat with ligaments intact, and loaded en pointe before and after sequential sectioning of the dorsal, interosseous, and plantar ligaments between the first and second metatarsals and cuneiforms. Relative motion between the first and second metatarsals and cuneiforms was determined radiographically.

RESULTS

No significant displacement of the Lisfranc joints occurred when the shod foot with intact ligaments was loaded in the foot flat or en pointe positions. Serial sectioning of the ligaments from dorsal to plantar in the shod foot en pointe demonstrated no change in alignment after the dorsal and interosseous ligaments were cut, but a significant change in alignment between the second metatarsal and second cuneiform was noted after the plantar ligament was cut (p < 0.0001). Removal of the pointe shoe after cutting the ligaments and applying a minimal (1 to 2 kg) load resulted in complete subluxation and diastasis through the first-second intermetatarsal and intercuneiform region. Replacing the shoe improved alignment en pointe with similar loading.

CONCLUSIONS

Both the pointe shoe and Lisfranc ligaments are important for Lisfranc region stability in feet en pointe. The plantar ligaments are major stabilizers of the Lisfranc region in the loaded, shod foot en pointe. Selection of a pointe shoe with adequate support may limit susceptibility to stress fracture of the second metatarsal base in ballerinas.

Central metatarsal head-neck osteotomies: indications and operative techniques

The author presents the history and indications of various central metatarsal head-neck osteotomies with special emphasis on the radiographic assessment, vascular supply, and regional anatomy. The surgical techniques described include (1) minimal incision osteotomy; (2) Weil metatarsal osteotomy and various modifications; and (3) a novel "telescoping" osteotomy. Ancillary soft-tissue and osseous digital procedures as well as the prevention and management of potential complications are presented in detail.

Predicting articular erosion in hallux valgus: clinical, radiographic, and intraoperative analysis

The authors present a prospective intraoperative evaluation of the articular wear pattern of the first metatarsal, tibial and fibular sesamoids, and base of the proximal phalanx of 166 feet undergoing hallux valgus surgery. The collected data were compared with various clinical parameters and radiographic measurements to determine if any of these variables can predict the incidence and location of articular erosion. The incidence and predictability of the location of the articular erosion increased significantly as the patient's age ( P = .000), intermetatarsal angle 1-2 ( P = .004), hallux abductus angle ( P = .000), tibial sesamoid position ( P = .016), and proximal articular set angle ( P = .02) increased. The association of foot type (ie, digital length pattern), metatarsal protrusion distance, metatarsal head shape, and hallux abductus interphalangeus was not significant. Therefore, preoperative clinical parameters (ie, age) and radiographic measurements (ie, intermetatarsal angle 1-2, hallux abductus angle, tibial sesamoid position, and proximal articular set angle) can directly define the incidence and location of articular erosion and are helpful in the preoperative assessment of the hallux valgus deformity. In addition, nearly every first metatarsophalangeal joint evaluated had some degree of articular erosion and, in certain circumstances (ie, advanced age and increased proximal articular set angle), it was universal and extensive.

Toe flexor forces in dancers and non-dancers

Toe flexor force (hallux and second toe) was determined in the right and left feet of 24 dancers and 29 non-dancers (sitting and standing positions) using a commercially-available pressure sensor connected to a voltmeter. For the hallux and second toe combined (all trials combined), average toe flexor force was slightly greater for dancers than non-dancers (dancers, 7 +/- 4 N; non-dancers, 6 +/- 4 N; P<0.049). For dancers and non-dancers combined (all trials), the average toe flexor force of the hallux was more than twice that of the second toe (hallux, 9 +/- 4 N; 2nd toe, 4 +/- 1 N; P<0.0001); average toe flexor force was slightly greater in standing than sitting positions (standing, 7 +/- 4 N; sitting, 6 +/- 3 N; P<0.0001); and the average toe flexor force was slightly greater for the right than left foot (right, 7 +/- 4 N; left, 6 +/- 4 N; P<0.012). The average toe flexor force was greatest for the first repetition and slightly decreased for the second and third repetitions (first repetition, 7 +/- 4 N; second and third repetitions each, 6 +/- 4 N; P<0.0013). Toe flexor force measurement may potentially be applicable to clinical practice as a guide to rehabilitation after injury or as a screening parameter for readiness to advance dance or other athletic training, performance, or competition.

A comparative mechanical analysis of the pointe shoe toe box. An in vitro study

Dancing en pointe requires the ballerina to stand on her toes, which are protected only by the pointe shoe toe box. This protection diminishes when the toe box loses its structural integrity. The objectives of this study were 1) to quantify the comparative structural static and fatigue properties of the pointe shoe toe box, and 2) to evaluate the preferred shoe characteristics as determined by a survey of local dancers. Five different pointe shoes (Capezio, Freed, Gaynor Minden, Leo's, and Grishko) were evaluated to quantify the static stiffness, static strength, and fatigue properties (cycles to failure) of the shoes. Under axial loading conditions, the Leo's shoe demonstrated the highest stiffness level, and the Freed shoe exhibited the least strength. Under vertical loading conditions, the Leo's and Freed shoes demonstrated the highest stiffness levels, and the Gaynor Minden and Freed shoes exhibited the highest strength. Fatigue testing highlighted the greatest differences among the five shoes, with the Gaynor Minden demonstrating the highest fatigue life. Dancers rated the top five shoe characteristics, in order of importance, as fit, comfort, box/platform shape, vamp shape, and durability and indicated that the "best" shoe is one that "feels right" and permits artistic maneuvers, not necessarily the strongest or most durable shoe.

The foot in ballet dancers: the importance of second toe length

Ballet dancers are prone to foot injuries. Our hypothesis was that the length of the second toe in relation to the big toe affected the distribution of stresses on the foot, correlating with calluses, injuries, and pain. Fifty-nine ballet dancers were examined for second toe length with respect to great toe, calluses, and metatarsophalangeal inflammation. Daily foot pain, limitation of work hours because of this, injuries, age, sex, and rank in the company were considered. The dancers' feet had an incidence of shorter, equal, or longer second toes which was comparable to a non-ballet-dancing cohort (N = 60). In female dancers (N = 34), total callus counts and pain scores were significantly lower in the group with shorter second toes versus those with equal or longer second toes. Counts were unrelated to age or rank. Longer second toes were related to hallux rigidus. Limitation of practice hours, ankle sprains, and foot/ankle fractures and sprains were comparable across the groups. The male dancers (N = 25) had significantly fewer calluses than did the women, but had equal pain scores and number of injuries. There were no significant differences among the males in total callus counts, pain scores, limitation of practice hours, or injuries between groups based on toe length, age, or rank. We conclude that there is no significantly more ideal pattern of toe lengths for male ballet dancers, but females with shorter second toes have fewer calluses and less daily foot pain. Those with a longer second toe had a higher incidence of hallux rigidus and correspondingly increased pain scores.

A technique for measuring absolute toe pressures: evaluation of pressure-sensitive film techniques

Although a number of pathologies of the forefoot in ballet dancers on pointe have been described, pressures and deforming forces have not been adequately measured. To evaluate the possible use of pressure-sensitive film (PSF) in measuring the pressures on the external soft tissues in such a confined space as the dancer's toe shoe, it was tested and calibrated with 20 cadaver toes. Each cadaver toe was internally stabilized and loaded longitudinally against PSF on a flat surface. The resultant films were analyzed with a video imaging system and the pressures and total forces were determined. Results showed that the linearity of the PSF to pressure had a regression value of 0.98. By using two sensitivity ranges of films, the total force measured by the PSF was found to be within 10% of the known applied force on each toe. The PSF, therefore, may very well be a useful and accurate method of measuring external soft tissue pressures on the forefoot.

Analysis of the forefoot on pointe in the ballet dancer

The forefoot positions of nine ballet dancers standing on pointe were determined using a mold technique. These molds revealed three positions of the toes: (1) no crossing of the three medial toes; (2) crossing of the third toe behind the second; and (3) crossing of the hallux partially in front of the second. Almost half of all the toes seen on the molds had some deformation of the toenails. These molds also indicated a wide variability in the amount and location of contact between the shoes and toes.

Musculoskeletal demands on flamenco dancers: a clinical and biomechanical study

The flamenco dancer acts on the floor like a drummer. The percussive footwork and vibration patterns created during dancing impose unusual demands on the musculoskeletal system. This study investigated the clinical and biomechanical aspects of this task. Using the electrodynogram and skin-mounted accelerometers, foot pressures as well as hip and knee vibrations were recorded in 10 female dancers after a thorough clinical evaluation. A health questionnaire was also distributed to 29 dancers. Foot pressures and acceleration data reveal the percussive nature of the dance. Some clinical findings, like calluses, are related to pressure distribution. Urogenital disorders, as well as back and neck pain, may be related to the vibrations generated by the flamenco dance form. The hip joint seems to absorb most of the impacts. "Vibration-pressure" diagrams are suggested as a useful tool for evaluating a dancer's biomechanical behavior, as well as the effect of floors and footwear on this behavior.