The phrase “range of motion” is used by the medical and fitness communities to describe the distance and directions in which a joint or body part can move. For each joint there is an established normal range of motion, measurable in degrees. Range of motion can be compromised by muscular tension, movement habits, and/or injuries. A frequent aim of fitness training and physical therapy is restoring joints to normal range of motion, or as close to it as possible.
Before I get into a discussion about how range of motion relates to vocal range, I invite you to perform this simple toe-touch assessment:
-Grab a ruler with your right hand.
-Remove your shoes and stand with your feet about hip width apart and your toes and knees pointing straight forward.
-Without flexing your knees, fold forward at your hips and reach for your toes with the fingers of your left hand. Keep your neck relaxed.
-Hang comfortably in this position without making an effort to reach any farther than you can.
-If your fingers do not reach all the way to your toes, use the ruler in your right hand to measure the distance between your fingertips and the floor.
-Carefully return to an upright position.
-Jot down how close your fingertips were to the floor.
Measuring the distance between your fingertips and the floor is a simple way to assess the range of motion of your hips and lumbar vertebrae. No need to judge your results—after all, some people are more naturally flexible than others, and you can be a vibrantly healthy person and a magnificent singer while not being able to touch your toes. The point I want to make is that your range of motion with this exercise is not an immutable given. If you wish to improve it, you can perform some stretches to release and lengthen your hamstrings and your back muscles, periodically assessing your progress.
The joints and muscles that comprise your vocal anatomy are subject to the same principles as the rest of your body. You may not be able to measure their range of motion, but if you view your vocal range of motion from this perspective, it is possible to conduct the equivalent of a toe-touch assessment and devise means to increase your laryngeal range of motion.
Let’s examine how laryngeal range of motion contributes to vocal pitch range.
The resting length of the vocal folds is between .50 and .75 inches for women and .75 to 1.0 inch for men. Our primary means of tuning pitch with the voice is varying the length of the vocal folds, which will produce higher pitches when relatively stretched and lower pitches when relatively relaxed. Your lowest viable pitch is achieved when the vocal folds are near to their default, relaxed length; your highest viable pitch depends largely on the maximum length to which you are capable of stretching them.
Your ability to maximally lengthen your vocal folds is determined by range of motion at the cricothyroid joints. These joints connect the two major cartilages of the larynx: the thyroid cartilage and the cricoid cartilage. When you contract the cricothyroid muscles, they cause the thyroid cartilage to pivot forward at these joints, increasing the distance between the vocal folds’ point of attachment to the thyroid cartilage and the arytenoid cartilages, causing the vocal folds to lengthen. When you contract the thyroarytenoid muscles and release the cricothyroids, it has the opposite effect: decreasing the distance between the vocal folds’ points of attachment and causing them to shorten.
If this were all there were to it, it would seem that all you need to do to optimize range of motion at the cricothyroid joints is to strengthen the cricothyroid muscles, expanding the angle at which the thyroid cartilage can tilt forward, thus increasing the potential length the vocal folds can be stretched to.
There are numerous additional factors, however, that impact range of motion for the cricothyroid joints. Most of them have to do with the fact that the laryngeal cartilages can move only so far before they bump into something else. Your larynx is housed inside your throat, attached to many other structures and nestled against still others. All of these structures must be carefully conditioned and coordinated for the larynx to enjoy the fullest possible range of motion.
The following are several factors that can influence laryngeal range of motion.
Laryngeal Position
Many voice teachers emphasize the advantages of a low laryngeal position. One important advantage is maximizing the length of the supraglottal tract, thereby optimizing resonance. But another advantage is that when the larynx is settled and low it facilitates good range of motion at the cricothyroid joints. Conversely, the higher the larynx, the greater the potential for surrounding structures to crowd it and impede range of motion.
It is not the purpose of this article to propose strategies for lowering the larynx, a topic that would require an article of its own. Suffice it to say that because the muscles capable of elevating the larynx are stronger and more numerous than those that lower it, and because actively depressing the larynx generates tension, my opinion is that the best way to maintain a low laryngeal position is to refrain from elevating it (rather than doing something to hold it down). Excessive breath pressure can also cause the larynx to elevate.
Alignment of the Cervical Spine
One very common postural distortion is an exaggerated lordosis, or curve, of the neck. This can result from a habit of slouching at the computer, driving, etc. The upper trapezius becomes shortened and tight and the shoulders rotate internally. The exaggerated curve distorts and compresses the room available inside the throat, potentially limiting range of motion for the larynx.
Articulatory Efficiency
Poor articulatory coordination can impinge on laryngeal movement in a variety of ways. Retracting the tongue to help stabilize or lower the larynx creates tension that can limit mobility. A jaw that is held too closed or too open may distort what little internal space is available for not only laryngeal movement but also resonance and articulation. Inadequate expansion and vowel “height” within the oropharynx, especially on higher pitches, can lead to a compensatory elevation of the larynx and a sideways spread of the lips.
A Word on Compensations
If you can’t easily touch your toes when folding forward at the hips, there are other ways to manage it. You could compensate for a lack of flexibility by grabbing your ankles and using upper-body strength to pull yourself down, or you could simply bend your knees. This subverts the point of the toe-touch assessment, however, which is to track flexibility in your legs and back.
Any pitch you sing demonstrates your success in adjusting your vocal folds to the requisite length thereby navigating the necessary range of motion at the cricothyroid joints. If you cannot manage full range of motion with ease, however, you are undoubtedly doing the vocal equivalent of pulling on your ankles in order to reach your toes. You are engaging in compensatory strategies that can make singing far more effortful than necessary—with likely consequences for freedom of phonation, stamina, and comfort.
Assessing Your Laryngeal Range of Motion
Here is a simple assessment that will enable you to troubleshoot some of the issues that can limit vocal range and identify compensations that can mask the need for improved coordination.
-With a warmed-up voice, perform a slow siren on [a] that traverses your entire range, ascending and descending, without breaking into falsetto. Jot down the lowest and highest pitches.
-Place one hand on your sternum and your other hand high on your abdomen. Repeat the siren, starting on the same low note, but ascend only as high as you can without either engaging your abdominal muscles or depressing your sternum. Jot down the top pitch.
-Allow your jaw to relax and observe yourself in a mirror. Repeat the siren, but ascend only as high as you can without opening your jaw any farther or spreading your lips sideways. Jot down the top pitch.
-Allow your jaw to relax and gently press a thumb against the underside of your chin to monitor the base of your tongue. Repeat the siren, but ascend only as high as you can without feeling the base of your tongue stiffen and retract. Jot down the top pitch.
-Compare the results of your initial siren with the subsequent ones.
If you were capable of reaching a higher (or even a much higher) pitch on your initial siren, it’s a sign that you are compensating for some tensions or weaknesses that are limiting laryngeal range of motion. But don’t despair—in fact, I’ve got very good news for you. If you have been able to access your highest pitches only with the assistance of these compensations, there’s a good possibility that when you alleviate any issues with laryngeal position, alignment, and articulatory efficiency, you will enjoy even greater range of motion at the cricothyroid joints than these compensations were facilitating. In other words, you’ll be able to not only sing those high notes more freely but you may also end up extending your range.
The toe-touch assessment provides only a general sense of hip range of motion. Similarly, my siren assessment offers a very basic guide for investigating laryngeal range of motion and identifying factors that may be limiting your vocal range. Be sure to view all of these ideas within the context of your vocal technique.
Developing excellent alignment, avoiding excessive abdominal activity, and resolving articulatory tensions and habits are fundamental aims of any good technique. Devote some attention to these issues, and you are likely to see an improvement in your vocal range and freedom.
