Eversion. Noé Serrano 22 April 2007 The Center Studio San Francisco, CA

Transcription

1 Eversion Noé Serrano 22 April 2007 The Center Studio San Francisco, CA

2 Summary When one is trying to apply the mechanics of the ankle and foot to dance, there are several technique areas that deserve more discussion. One of these is the issue of achieving the desired aesthetics and placement in demi-point or pointe positions. Another issue is achieving desired foot placement when the knees bends, such as in plies. In ballet, still another important concern is the introduction of point work. The peroneus brevis shares a similar proximal line of pull to the peroneus longus, and so it also assists with ankle-foot plantar flexion and is a prime mover for foot eversion. The peroneals line of pull also enables them to produce abduction of the forefoot, a motion used by dancers to create a beveled foot, a commonly used position in many ballet and some modern schools of dance. The use of the stirrup muscle for a proper function for inversion and eversion is crucial for ankle-foot action in dancing. This case study presents a corrective approach to strength of the stirrup muscle to aid the many actions of the feet in a balanced manner. The surgical procedure was the right foot osteotomy 1 st metatarsal, arthodesis 2 nd digit right foot, arthosplasty right 3 rd & 4 th digits, tenotomy and capulatomy right 2 nd, 3 rd & 4 th metatarsals phalengeal joints. 2

3 Contents Summary 02 Table of contents 03 Anatomical description 04 Introduction 05 Case study 08 Conclusion 10 Bibliography 11 3

4 Anatomical description Lateral crural muscles Lateral crural muscles are located on the lateral portion of the lower leg in the lateral compartment of the leg. The lateral crural muscles are composed of the peroneus longus and peroneus brevis. These muscles are closely associated in terms of origin and function and are sometimes jointly referred to as the peroneals muscles. These lateral crural muscles cross the lateral portion of the ankle behind malleolus and both produce eversion of the foot and ankle-foot plantar flexion. Attachments and Primary Actions of Peroneal Muscles Muscle Proximal attachment(s) Distal attachment(s) Primary action(s) Peroneus longus Lateral tibia condyle Lateral aspect of upper 2/3 of fibula Lateral aspect of first cuneiform Proximal first Foot eversion A-F plantar flexion Depresses head of Peroneus brevis Lateral aspect of lower 2/3 of fibula metatarsal Tuberosity at proximal en of 5 th metatarsal first metatarsal Foot eversion A-F plantar flexion Peroneus Longus (perone, fibula + longus, long) originates from the lateral and upper portions of the tibia and fibula. It courses superficially along the lateral lower leg and then continues under the foot to insert on the undersurface of the first cuneiform and first metatarsal (at the base of the great toe). Peroneus Brevis (perone, fibula + brevis, short) originates lower on the fibula than the longus and runs deep to the longus for much of its upper course. It s attaching distally onto the lateral foot (proximal 5 th metatarsal). When weight bearing, both the peroneus longus and brevis are considered important dynamic stabilizers of the foot and the lower leg relative to the foot. These muscles provide and important counterbalance for the invertors of the foot such as the tibialis anterior and posterior, and flexor hallicus longus and are essential for preventing ankle inversion sprains. 4

5 Introduction Eversion of the foot involves lifting the outer border of the foot. When the foot is unweighted, eversion usually combined with the forefoot abduction. This combination of movements is considered a desired aesthetics in some dance forms such as ballet, and is often referred to as winging or beveling the foot and often encouraged when the foot is pointed or in demi-pointe. The peroneus longus appears to be particularly important in creating this combined movement of forefoot abduction, slight eversion, and plantar flexion. This movement of eversion is also very important when the foot is weight bearing. Here, the everters (the primary muscles: peroneus longus and peroneus brevis and the secondary muscles: extensor digitorum longus, and peroneus tertius) can be used to shift the weight very slightly or extremely medially to create the beveled line desired by many ballet schools when on demi-pointe or pointed. To achieve this latter aesthetic, the everters can be used to shift the body weight and position the forefoot and midfoot relative to the rearfoot while co-contraction of the plantar flexor and inverters is used to help maintain balance, especially in slow inwards turns or to finish an inward turn in balance. The everters perform the important function of limiting supination of the foot. This latter function is very important for maintaining balance, preventing falling out of turns, and preventing ankle sprains. The repetitive use of demi-pointe and pointe in dances places great demands on the foot and requires specialized strength, flexibility, and technique development. In terms of flexibility, extreme ankle-foot plantar flexion is required to achieve the desire aesthetic of these positions and allow the body weight to be appropriately placed over the ball of the foot (demi-pointe) or toes (pointe). In terms of plantar flexion strength and range, the ankle-foot plantar flexors have to contract forcefully to achieve and maintain this position of the foot, and ballet dancers have been reported to have very 5

6 high levels of plantar flexor strength. Although the triceps surae muscles produce a large percentage of the plantar flexor torque, other plantar flexors can help slightly reduce the demands on the triceps surae and help achieve the desired aesthetic. Two such plantar flexors are the flexor hallucis longus and flexor digitorum longus. The flexor hallucis longus and flexor digitorum longus have been shown to have a shortening effect on the foot in a front-to-back direction, and so can help achieve the desire high arch look on pointe. Three other plantar flexors the tibialis posterior, tibialis anterior, and peroneus longus function together to lift the arch and help maintain balance on demi-pointe and pointe. These three muscles can be termed the stirrup muscles because they run behind the medial and lateral malleoli to converge to attach onto the undersurface of the medial longitudinal arch on a stir-up like arrangement. All tree muscles have attachments onto the plantar surface of the cuneiforms, with the tibialis anterior and peroneals also both attaching onto the base of the first metatarsal, while the tibialis posterior has additional attachments on the navicular and other metatarsal bases. Their attachments put them in a perfect position to lift the midfoot higher up in a perfect position to lift the midfoot higher up in plantar flexion, in respective of the position of the toes. In terms of stability, the stirrup muscles can be used to keep the body weight appropriately positioned in a medial-lateral direction over the axis of the foot. Their co-contraction (in combination with other muscles) can be used to allow the weight to rise to the toes and lower from the toes without undesired inversion or eversion, and to make subtle adjustments of the body weight to enhance balance and dance aesthetics. For example, contraction or pulling up, with lateral stirrup muscles will shift the body weight medially on the foot (eversion) and prevent excessive rolling out (inversion) on the foot, such as is commonly seen in falling out of multiple pirouettes. In terms of these medial stirrup muscles, theoretically, the tibialis anterior when on demi-point or pointe due to its additional desired action of ankle-foot plantar flexion. 6

7 Hallux valgus (L. great toe + turned out outward) is a lateral deviation of the distal end of the great toe (hallux) at metatarsophalangeal (MTP) joint, also involving a deviation of the first metatarsal toward the midline of the body (metatarsus primus varus). This bony deviation changes the line of pull of the muscles that cross the MTP joint, such that many of these muscles will tend to have a bowstring effect that further increases the valgus deformity, and in more advance cases causes the sesamoids to displace to the lateral side of the head of the first metatarsal. This valgus deviation if the hallux also tends to make the medial aspect of the hallux also to become more prominent, and the resultant friction and trauma from overlying footwear can readily lead to a bony outgrowth (exostosis), an inflamed bursa between the exostosis and skin, and a callus on the overlying skin. This bony and soft tissue enlargement on the inside of the head of the first metatarsal is termed a bunion. 7

8 Case Study Cross training, as a training tool is key to use while recuperating from an injury or recovering from surgery in downtime and to stay upbeat. A well-rounded dancer can benefit from Pilates training. Although Pilates excels as a torso toner, its exercises require contribution from various muscle groups, so comprehensive, all-over strength and agility are the results. Pilates works deep, finding those hard-to-target muscles so essential to ballet technique. Pilates discovers and corrects imbalances and misalignments that can hinder a dancer s progress. The exercises are designed to ensure that both sides work equally; they will not let the strong side compensate the weaker one. They build dancer s powerhouse abdomen and lower back creating a super strong core that supports all other movement. For example, a long legged dancer, or a teenager who just had growth spurt, may have trouble holding his/her lower back still during grand battement front. By targeting those abdominal muscles and back extensors, Pilates can develop the strength and control needed to perform the ballet exercise correctly. Mat work and selective apparatus exercises have been selected accordingly to the needs of the person, tailored to surgery recovery process. The feet are the foundation of the body when upright: standing, walking, running, and jumping. Any misalignment of the feet, in a static position or in motion, results in postural deviations and compensations all the way up the kinetic chain. It is imperative to strength and re-educate the stirrup muscles to avoid bad habits and create new ones as early as possible. One advantage of this method is that the work can be performed out of the feet without bearing weight in them getting the benefit of specific targeted muscle group aided by the Block System. Special attention needs to be put to the subtalar joint, due to its importance to achieve correct foot alignment, during the Foot Work in the apparatus to achieve correct motion (supination and pronation), which will lead to a neutral alignment. 8

9 The following is a Comprehensive Program for this case study. This program is constructed upon the Block System and BASI approach with the whole concept as a guidance to ensure that the program will achieve its goal. The program includes apparatus and mat work. BLOCK WARM UP FOOT WORK (CADILLAC/REFORMER/WUNDA) ABDOMINAL WORK (REFORMER) HIP WORK (REFORMER) SPINAL ARTICULATION (WUNDA CHAIR) STRETCHES (STEP BARREL) FULL BODY INTEGRATION I ARM WORK (ARM CHAIR) LEG WORK (WUNDA CHAIR) LATERAL FLEXION/ROTATION (MAT WORK) BACK EXTENSION (REFORMER) EXERCISES Pelvic Curl, Supine Spine Twist, Chest Lift, w/rotation, Leg Changes, Roll-up Parallel Heels, Open V Heels, Single Leg Heel, Hip Opener (CADILLAC) Calf Raises (WUNDA CHAIR) Hundred Prep Hundred Frog, Down & Up Circles, Openings Pelvic Curl Hamstrings, Adductors, Hip Flexors Elephant Chest Expansion, Hug-a-Tree, Up & Down Circles, Salute, Biceps, Rhomboids Hamstring Curl, Hip Opener Side Lifts, Side Kick Breaststroke Prep MAT WORK BLOCK SUPINE WARM UP ABDOMINAL SECTION HIP EXTENSION BRIDGING I SUPINE SPINAL ARTICULATION SITTING SPINAL ARTICULATION SITTING STRETCHES SUPINE ROTATION HIP EXTENSION BRIDGING II LATERAL FLEXION/ROTATION BACK EXTENSION FULL BODY INTEGRATION SPINAL MASSAGE RELAXATION & FOCUS EXERCISES Pelvic Curl, Supine Spine Twist, Chest Lift, Chest Lift w/rotation, Single Leg Lifts/Leg Changes Hundred Prep, Roll Up, Leg Circles, Rolling (Roll-like-a-ball), Hundred Shoulder Bridge Prep Roll Over Spine Stretch Saw, Spine Twist Corkscrew Scissors Side Lifts, Side Kick Back Extension, Swimming Teaser Prep, Back Support Seal Puppy Rest Position 9

10 Conclusion While pronation and supination are normal foot movement, excessive amounts of either can easily lead to foot problems. Learning to use optimal placement of the foot when standing, desired knee-foot alignment, and coordinated use of the stirrup muscles can aid with development of desired dance skill. Similarly, strengthening of the stirrup and other key muscles and stretching to achieve both adequate dorsiflexion and plantar flexion can help enhance ankle and foot function and prevent injuries. If any injury does occur, effective treatment and aggressive rehabilitation are vital to prevent recurrence or instability and to allow a successful return to dance. 10

11 Bibliography Body Arts and Science International Study Guide (6): 62 Clippinger, Karen. (2007). Dance anatomy and kinesiology. Champaign, IL: Human Kinetics. (6): , , 333, Isacowitz, Rael. (2006). Pilates. Champaign, IL: Human Kinetics. (1): 17-19, 25, 29-30, (12): Kirstein, Lincoln. (1987). The Classic Ballet. New York, NY: Knopf , (1): 74-77, (4): Minden, Eliza. (2005). The ballet companion. New York, NY: Fireside. (2): 80-81, (3): 108, 115 (4): , 249,