[中][英] 柔軟度訓練：伸展的觀念
Flexibility in Dance: Stretching a Rigid Notion
舞動潛能
Optimizing Dancers’ Performance
文﹕余曉彤
查看社交媒體上的舞蹈內容時，我們的眼球很快就會被大量看似完美、超伸的（hyperextended）身體、過度伸展的姿勢、大膽、甚至危險的動作所吸引。這些相片或者影片充斥著舞者常用的社交平台。但若我們仔細觀察，當中不乏忽視了合適的身體校準（alignment）和安全幅度的動作，令人擔憂會有受傷的風險。更甚是，當年輕的舞者試圖照樣模仿時，往往有可能置於巨大的風險之中。有人可能不同意以上的說法，認為這些圖片和影片只是描繪了訓練有素的優秀舞者與其應有的表現，或認為高柔軟度的身體是舞蹈訓練的必然結果，甚至覺得擁有高柔軟度的人自然地投身舞蹈訓練。可是，現實與這個願景相去甚遠。
主動關節活動 active range of motion／Photo Provided by The Hong Kong Academy for Performing Arts 照片由香港演藝學院舞蹈學院提供
在舞蹈訓練裡，柔軟度被普遍視為組成良好身體素質的重要元素之一。這驅使許多舞者花大量的時間，採取不同的方法，試圖取得成果。例如在課堂開始前或排練之間，常常能見到舞者在做拉伸的動作，或保持伸展的姿勢休息，像是趴在大字馬的姿勢使用電話。舉一個稍微極端但真實的例子，相信你一定見過這個畫面：老師或同學借用自身的重量，長時間加壓在舞者（尤其是年幼的）正在伸展的身體上，以此提高他們的柔軟度。可是增加柔軟度是如此簡單的嗎？這些練習是最佳方法嗎？我們首先需要了解甚麼是柔軟度，才能回答這些問題並找到安全有效的方法進步。
甚麼是柔軟度？
在運動機能學的角度，柔軟度是指關節的活動幅度（ROM）以及與肌肉柔韌性的配合。影響柔軟度的因素有很多，包括遺傳、年齡、性別、肌肉骨骼和神經系統等。與大眾的認知相反，增加柔軟度並不是強行地將自己或他人推壓到目標位置那麼簡單。一個有效的、安全的伸展，必須要嚴謹控制、循序漸進，和有明確的方向。要在特定的關節獲得更高的柔軟度，便需增加所牽涉的肌肉的彈性。舉例，當我們拉伸膕繩肌（大腿後側的肌肉群）時，這將拉長膕繩肌的纖維，進行髖關節屈曲（前腿抬高）時便有更大的幅度。相鄰的肌腱和韌帶在拉伸肌肉的同時，所受到的張力也會加大。肌腱作為槓桿，連接肌肉與骨骼，當肌肉收縮時拉動附著的骨骼；而韌帶將骨骼連接骨骼，穩定並限定關節運動的方向。假使在伸展時用力過大，而肌肉已經達到最大長度，周遭的肌腱和韌帶便會受到額外的壓力。這可導致韌帶撕裂、或關節不穩定等，大大增加受傷的風險。因此我們必須控制伸展的幅度，了解並尊重每個人的身體特徵和限制，才能從伸展中充分受益。即使看到其他舞者的伸展幅度比自己更大，你也必須記住每個人的身體都是獨特的，有些人生來就柔軟度更高——基於上面提到的遺傳因素。
然而，這並不等於柔軟度愈高的舞者身體條件必然是更好的。不同的身體條件都有各自的長處和短處。柔軟度高的人用少許努力便能提升柔軟度，但同時由於缺乏穩定性，他可能更容易受傷；反之，柔軟度低的人擁有更強的穩定性，可是相比較下，更難提升柔軟度。若舞者經常過度伸展，可能會令身體組織過於鬆馳或變弱，這些因素將增加受傷的風險，威脅到他們的職業生涯。為避免這種情況出現，我們需要結合伸展運動與強化運動，增強關節的穩定性和控制力。
為了確保安全的舞蹈練習，我們必須了解伸展運動背後的複雜性，根據每個舞者的身體條件和需求，設計合適、有效的訓練計劃。日常訓練中，在不同時間使用不同類型的伸展運動除了可以提高柔軟度，還可以顯著地提升整體的舞蹈表現。
被動關節活動 passive range of motion／Photo Provided by The Hong Kong Academy for Performing Arts 照片由香港演藝學院舞蹈學院提供
伸展運動的類型
首先是靜態伸展（保持固定的姿勢），一個在傳統舞蹈訓練中最常用的方法。雖然這是提升柔軟度最有效的方法之一，但其普遍的應用並不理想。舞者通常都會在上課或表演前進行靜態拉伸，為即將到來的舞蹈做準備。可是，在一般情況下，這都是錯誤的。靜態拉伸應該在舞蹈活動之後進行，作為緩和運動（cool down）的一部分。每個伸展姿勢應保持三十到六十秒，重複三至五次，便能將所針對的肌肉，拉伸到最大的幅度。由於這樣的動作對肌肉的負荷較高，最好在肌肉有充分的熱身後再進行靜態伸展。
第二類是動態拉伸（持續運動的）。動態拉伸適合在所有舞蹈活動之前進行，因為這可以增加血液流動並激活神經系統，讓身體能為最佳表現作好準備；同時也在喚醒和延伸肌肉，所以動態伸展應該包含在我們的熱身（warm up）中。
第三類是本體感覺神經肌肉促進術（PNF），這種伸展包括了在同一塊肌肉上進行收縮及放鬆的運動。由於它需要藉助外部阻力，因此最好在有經驗的同伴或老師的幫助下完成。
第四類是彈震式伸展（例如快速踢腿等）。這類型的動作涉及很高的爆發性，在達到關節活動幅度的極限時經常會失去控制，這可能會導致肌肉酸痛，或因過度伸展而受傷，因此不被建議在柔軟度的訓練中採用。
若想從拉伸訓練中取得進步，還需要懂得識別主動和被動關節活動幅度的區別。用一個例子來說明，想像一下我們想要增加développé devant（芭蕾舞中的前抬腿）的高度。首先我們要找到產生此動作所需的主動肌群和對抗肌群，分別為髖屈肌和膕繩肌。然後單獨拉伸對抗肌群（膕繩肌），注意不要不自覺地借用下背的幅度來代替！如果前腿在有幫助的情況下能夠達到超過90°（無論是靠手臂拉動還是扶把幫助﹝ 被動的關節活動﹞），但無法僅使用主動肌群將前腿控制抬在相同的高度時（主動的關節活動），我們則需要通過加強髖屈肌（主動肌群）的力量，縮小被動和主動關節活動幅度的差距。若只進行膕繩肌伸展（對抗肌群），那進步會非常有限。
總結
本文介紹了安全、有效地提高柔軟度所需的基本知識。重要的是，切記舞蹈需要眾多元素配合，包括力量、協調性和一系列心理技能等，柔軟度只是其中一方面。更高的柔軟度並不等於是更好的舞者。我們應該訂立全面的整體訓練計劃，在安全的舞蹈環境中涵蓋技術、造詣和其他技能。以下列出的提示和問題，可供你在計劃伸展訓練之前參考。
安全、有效的伸展貼士
伸展要在熱身後進行。 伸展時要保持良好的姿勢和身體排列，配合呼吸以緩慢的速度，溫和地拉伸。
切勿在難以忍受的疼痛、或麻痺的情況下拉伸。加入休息和恢復的時間也很重要。
提升柔軟度要訂立清晰和具體的目標。記住同時要包括相關的力量訓練。
問問自己：為甚麼要做這個伸展運動？它是否有助於我達到目標？
建議閱讀
Clippinger, K. (2016). Chapter 2 The Muscular System. In Dance anatomy and kinesiology: Principles and exercises for improving technique and avoiding common injuries. essay, Human Kinetics.
Irvine, S., Redding, E., Rafferty, S., & IADMS Dance Educators' Committee. (2011). Dance Fitness. International Association for Dance Medicine and Science. Retrieved January 26, 2022, from https://iadms.org/media/5777/iadms-resource-paper-dance-fitness.pdf
Quin, E., Rafferty, S., & Tomlinson, C. (2015). Chapter 4 Training Principles and Supplementary Fitness. In Safe dance practice (pp. 320–332). Human Kinetics.
Flexibility in Dance: Stretching a Rigid Notion
Text: Heidi Yu
If we look at the dance content being shared nowadays on social media platforms, very quickly we find ourselves enticed by eye-catching pictures and videos of seemingly perfect, hyperextended bodies, showing overstretched positions, daring poses and risky movements… These are all commonly seen when going through the Instagram or Facebook—to name just two—feeds of a dancer. However, when observing many of these displays more carefully, we can infer that proper alignment and safety were heavily compromised (or even completely disregarded!) when these images were captured, and that the risk of injury may have been at a worrying level. Even more, when young dancers try to copy these models with their own bodies, they are often putting themselves at significant risk. Some teachers or dancers, however, after reading the preceding sentences, may feel compelled to argue that this is not the case, that those pictures and videos simply depict properly trained, good dancers. They may also claim that this is natural, how flexible bodies are an inherent consequence of dance training, or explain that these bodies are automatically, almost magically, drawn to dance. Unfortunately, though, the reality is far removed from this vision.
Flexibility is widely accepted to be one of the major fitness components of dance training. This drives numerous dancers to spend sizeable portions of their daily schedule on attempting to achieve gains in this area, an endeavour in which they resort to different methods. For example, a common sight in dance studios before the start of a class, or between rehearsals, is that of dancers actively stretching, or resting in a passive stretched position—such as sustaining a side split while looking at their smartphone. To take a more extreme but all-pervasive example, we can recall the practice where a teacher or student leans their bodyweight on a dancer (especially a young one) for prolonged periods of time, in the hope of improving the dancer’s flexibility. But is gaining flexibility as simple as this? Are these practices the best way to increase it? To answer these questions, and to discover safe and effective ways to enhance flexibility, we need first to understand what flexibility is.
主動關節活動 active range of motion／Photo Provided by The Hong Kong Academy for Performing Arts 照片由香港演藝學院舞蹈學院提供
WHAT IS FLEXIBILITY?
Flexibility, in kinesiology, refers to the range of motion (ROM) of a joint in association with the pliability (elasticity] of a muscle. Various factors can affect flexibility, including genetics, the musculoskeletal and nervous systems, age, gender, etc.... Gaining flexibility, contrarily to the general assumptions, is not as simple as forcefully pushing yourself (or someone else) into the desired end-goal position. A stretch, to be effective and safe, has to be measured, progressive, and directed. To achieve greater flexibility in a particular joint, we need to work on increasing the elasticity of the muscles involved, in order to elongate the fibres. Let us take the concrete example of a hamstring stretch. This will lengthen the muscle fibres of the hamstring muscles, allowing for a greater ROM when performing hip flexions (front leg lifts). While the hamstring muscles are being stretched, the tendons and ligaments adjacent to the muscle are also under tension. Tendons, which connect our muscles to our bones, work as levers that pull the attached bones when the muscles contract. Ligaments, on the other hand, connect bone to bone, stabilizing the joints and defining the direction of our movement. If we apply too much force in our stretch, and the hamstring muscle has already reached its maximum length, then there will be stress on the tendons and ligaments, which could result in torn ligament injuries or unstable joints—which also increases the risk of injury significantly. To obtain the full benefit from a stretch, we must work in a controlled capacity, respecting our individual physical characteristics and limitations. Even if we see a fellow dancer stretching much further than we can, we must remember that everyone has a unique body, and that some bodies are naturally more flexible than others—see the genetic and other factors mentioned above.
The closing lines of the above paragraph, however, should not lead us to the wrong conclusion that the dancer who is more flexible is simply better. Both body types have their own strengths and weaknesses. While one type may be able to gain flexibility with less effort, it may at the same time be more prone to injury due to a lack of stability, whereas the other type is built for greater stability, which may render flexibility gains harder to achieve. Dancers who overstretch regularly may develop loose and weakened tissues. These factors will substantially increase the risk of injury, threatening their professional careers. To avoid this, it is important to pair stretching with strengthening exercises, as these will enhance stability and control in the joints.
被動關節活動 passive range of motion／Photo Provided by The Hong Kong Academy for Performing Arts 照片由香港演藝學院舞蹈學院提供
To ensure safe dance practice, we must understand the complex elements that are involved in stretching. At the same time, we need to acknowledge the particular characteristics and needs of each dancer, in order to design suitable and effective exercise programmes. Knowing and using different types of stretching at different times throughout the training schedule can not only help us to develop flexibility, but also noticeably improve overall dance performance.
TYPES OF STRETCHING
The first is static stretching (holding a fixed position), which is the most common technique used in traditional dance training. While this is one of the most effective ways to gain flexibility, the way it is usually applied to dance training is not ideal. Often, dancers engage in static stretching before the class or performance, in preparation for the activity to come. This, however, is generally a mistake. Instead, static stretching should be done after the dance activity or exercise, as part of the cooling down routine. Ideally, each position should be held between 30 and 60 seconds, 3 to 5 times. The reason for this is that static stretching works the full range of the muscles it targets. As this places a relatively high demand on them, it is better to allow the muscles to warm up adequately before submitting them to this kind of effort.
The second is dynamic stretching (moving through the stretch). Dynamic stretching presents some benefits that make it ideal for practice before engaging in any dance activity. Due to its nature, it increases blood flow and activates the nervous system, preparing the body to perform optimally. As it helps engage and lengthen the muscles, this type of stretch should be included in our warm-up routine.
A third type is proprioceptive neuromuscular facilitation (PNF), which includes movements of both contraction and relaxation in the same muscle. As this requires external resistance, it is best done with the assistance of a partner.
While there is a fourth type, ballistic stretching (bouncing and kicking movements), these are considered ineffective for flexibility training. This is because, due to the explosive nature of the movements involved, control is often lost at the limit of the ROM, which can lead to muscle soreness and injury due to overextension.
To fully benefit from stretching, it is important to understand also the difference between passive and active ROM. To illustrate these with an example, let us imagine that we want to increase the height of a développé devant [a leg lift to the front in ballet]. First, we need to identify the agonist and antagonist muscles involved. In this case, the hip flexors would be the agonists, and the hamstrings the antagonists. Then, we will isolate and stretch the antagonist muscles (the hamstrings)—without unconsciously compensating with the lower back! If we are able to reach beyond 90° with assistance (either from our arms pulling or the barre helping us hold our position [passive ROM]), but are unable to hold the leg at the same height using only our leg muscles without assistance [active ROM], the next step will be to reduce the gap between passive and active ROM. If we focus solely on stretching, progress will be minimal, as improvements in the active range can only be made by strengthening the hip flexors (the agonist muscles).
CONCLUSION
In this article, we have covered the basic knowledge required to work safely and effectively on improving flexibility. However, it is important to remember that flexibility is just one among many components necessary for dance; others include strength, coordination, and a whole array of psychological skills. Having greater flexibility does not equate to being a better dancer. Instead, we should aim for a well-rounded holistic training programme, where technique, artistry, and other skills are all covered in a safe dance practice context. To conclude, I would like to list a few tips and questions to take into account before planning stretching sessions.
TIPS FOR STRETCHING EFFICIENTLY AND SAFELY
Always stretch when you are warm. Stretch with a good alignment. Keep a slow and gentle pace with a coordinated breathing pattern.
Never stretch to the point of unbearable pain or numbness. Rest and recovery are also important.
Be precise and specific with your flexibility goals. Remember that you must also include strengthening exercises.
Ask yourself: why am I doing this stretch? Will it help me to reach my specific goal?
REFERENCES AND FURTHER READING
Clippinger, K. (2016). Chapter 2 The Muscular System. In Dance anatomy and kinesiology: Principles and exercises for improving technique and avoiding common injuries. essay, Human Kinetics.
Irvine, S., Redding, E., Rafferty, S., & IADMS Dance Educators' Committee. (2011). Dance Fitness. International Association for Dance Medicine and Science. Retrieved January 26, 2022, from https://iadms.org/media/5777/iadms-resource-paper-dance-fitness.pdf
Quin, E., Rafferty, S., & Tomlinson, C. (2015). Chapter 4 Training Principles and Supplementary Fitness. In Safe dance practice (pp. 320–332). Human Kinetics.
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余曉彤 (MSc, MFA)
Heidi Yu (MSc, MFA)
香港演藝學院講師（舞蹈科學）
余氏擁有豐富的芭蕾舞背景和經驗，近年將重心投放於舞蹈科學研究在舞蹈訓練中的應用和實踐，全方面關注舞者的身心健康，希望透過教育和知識普及，幫助舞者預防傷患並提升表現。
Lecturer (Dance Science) at the Hong Kong Academy for Performing Arts.
With an extensive background in ballet training and performance, she currently dedicates her enthusiasm to Dance Science research, advocating for its application to dance training and promoting a holistic approach for performance enhancement, injury prevention, and dancers' health and well-being.
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