Training Muscles for Joint Stability

Small, deep muscles around a joint are key to its dynamic stability and safety, but clients may not train them enough. Here’s why those muscles matter in recovery and how to work them every day.

Whether you’re working with clients to help them recover from an injury, stay fit or improve their performance, your attention to their joint stability and mobility will play a pivotal role in their success.

The small muscles that cross a single joint are typically responsible for holding the joint together and creating dynamic stability as the joint moves. Developing appropriate joint stability and endurance of these muscles creates a necessary foundation for adding load, repetition and multidirectional challenges. In other words, the small, deep muscles of the joint must be primed and strengthened to allow the joint to safely take an increased load or manage a full range of motion.

When clients are recovering from an injury or returning from a hiatus, they can benefit from a program that focuses on training these small, deep muscles first. This will help (establish or re-establish) the coordination and control of the joint before they progress to larger loads and more functional ranges of motion. In turn, such training can help prevent re-injury, enable clients to build confidence (especially if they have expressed concerns about “weak” or “unstable” joints), and provide them with a deeper understanding of how all the muscles work together to produce the best results.

Let’s look at two areas where creating dynamic control of the joints through training the small stabilizing muscles can decrease the likelihood of injury, speed up recovery and increase functional capacity: the lower back (deep lumbar spinal muscles) and the shoulder (rotator cuff muscles). These two areas are both common sources of injury and often overlooked in training programs. When the deep lower back and rotator cuff muscles are trained, clients can see improvement in strength, joint stability and functional skills.

The Deep Lumbar Spinal Muscles

The deep muscles of the lumbar spine have small ranges of motion and limited strength, but they play an essential role in stabilizing and positioning the vertebrae so the larger, more superficial muscles can move the body without causing undue stress on the vertebrae or the intervertebral discs.

The deep muscles of the lumbar spine include the interspinales, intertransversarii and multifidi, all of which work together to create a complex web of interconnections that can position and support the vertebrae as required by a particular movement. The muscles cross one, two, three, four or five joints and create dynamic segmental joint stability and control of the lumbar vertebrae.

The interspinales are paired on either side of the spinous process of each vertebra, and the lumbar intertransversarii connect each transverse process. Because the interspinales and intertransversarii connect each vertebra to its neighbors above and below they can move individual joints.

The multifidi cross multiple joints and connect each vertebra to the vertebra two, three, four or five levels above. (There is some disagreement in different anatomy texts about the number of levels of the multifidi.) The multifidi fill in the space between the transverse processes and the spinous processes and create columns of support on either side of the spine.

These three groups of deep muscles work together as spinal extensors and position the vertebrae so the erector spinae, latissimus dorsi, abdominals and other large muscle groups can move the spine while maintaining the integrity of the intervertebral joints.

These muscles are not ones we typically train. When the body is working well, they fire reflexively and respond appropriately to the demands placed on them. When they are not working properly due to injury, fatigue or poor habitual movement patterns, they may not fire when needed to connect and stabilize the vertebra, which can result in injury. Actively recruiting them along—with the transverse abdominis and other deep stabilizers—can create more balanced musculature around the spine and decrease the likelihood of injury.

Lower Back: Training Principles and Sample Exercises

These muscles activate when the spine moves out of the line of gravity with simple hip flexion from a standing position or in suspension training exercises when leaning into the straps with the body in a straight line.

Both of the following exercises are simple ways to awaken the deep back muscles and should be performed early in the workout so the deep spinal support is ready when needed. When training, keep these principles in mind:

• Pay attention to the activation of the muscles using the hands of the client or the instructor, as directed in the instructions for each exercise shown here.
• If you identify an imbalance (see “Assessment,” right), have the client perform one set of 5–10 reps on the less active side, then one set on the more active side, and finish with an extra set on the first side.
• Because deep back muscles are so critical to everyday functioning and are designed for endurance (not strength), give the client homework to do every day to keep these muscles strong and to minimize imbalances.

1. Standing Hip Flexion

• Stand upright with the body in a straight line and the feet parallel and in line with the hips.
• Place hands on either side of the spinous process at approximately waist level (or you can place your hands on the client’s back, if appropriate).
• Flex the hips so the torso and pelvis tip forward while maintaining a relatively neutral position of the lower back.

Assessment. The deep spinal muscles fire eccentrically or isometrically to support the spine in a neutral position and keep the torso from falling forward. With the hands on the back muscles, it is possible to identify what the muscles are doing. As the torso leans forward, the muscles should firm up and expand under the fingers. If they are firing evenly, they should expand and contract at roughly the same rate on each side. If there is an imbalance in the musculature, one side will feel larger than the other or one side will fire more quickly.

Corrective variation. If one side is firing faster or stronger than the other, switch the stance to a straight-leg lunge with the leg of the less active side in back. Shift the weight from the back leg to the front leg by pushing off the back foot while leaving the ball of the back foot on the floor. Pushing off the back foot creates some extension in the back hip, which usually helps the less active side to fire.

2. Suspension Training Forward Lean

• Stand upright with the body in a straight line and the hands in the handles of the suspension trainer.
• Lean forward maintaining the straight line of the body. Move in and out of the position at a steady pace for 10 reps; then hold the position for 10 seconds. Build up to longer holds of up to 1 minute or repeat the 10-second hold, 3–5 times.

Assessment. For this exercise, you’ll need to use your hands to feel what the muscles are doing.

Corrective variation. Lift one foot off the ground and perform the forward lean. Typically, the lower back on the same side as the supporting leg will fire.

The Rotator Cuff

Creating endurance and coordination of the rotator cuff is critical to the upper body performing at its best. The four small muscles of the rotator cuff—subscapularis, supraspinatus, infraspinatus and teres minor—work together to position the humeral head in the glenoid fossa so the larger mover muscles can move the arm efficiently.

The subscapularis connects the underside of the scapula (subscapular fossa) to the lesser tubercle on the front of the humeral head. The supraspinatus fills in the supraspinous fossa on top of the scapula and attaches to the top of the greater tubercle. The infraspinatus fills in the infraspinous fossa covering the back of the scapula below the scapular spine and attaches to the greater tubercle behind and below the supraspinatus. And the teres minor attaches the lateral border of the scapula to the greater tubercle below the infraspinatus.

Rotator Cuff: Training Principles and Sample Exercises

The rotator cuff muscles are responsible for maintaining congruency of the glenohumeral joint. Congruency means that the ball of the humeral head remains relatively centered within the glenoid fossa as it moves. Imagine that the glenoid fossa is like a shallow bowl and the humeral head is like a soup spoon stirring something in the bowl. When the joint is congruent, the spoon stays centered in the bowl as it stirs (rather than sliding up the sides and over the rim of the bowl).

To maintain the position of the humeral head, the rotator cuff acts like four fingers on a dial, gently positioning the humeral head so the larger muscles of movement—such as the deltoid, latissimus dorsi and pectoralis major—can move the arm without causing impingement between the humeral head and the acromion process or damaging the joint capsule.

When training the rotator cuff, four elements are key:

• Encourage clients to do some rotator cuff exercises every day—and especially before working out—to activate the joint stability system before loading the shoulders.
• It is important to train for endurance rather than strength, so lighter weight and more reps is preferable.
• Have the client vary the position of the arm during the exercise to train coordination of the entire muscle group.
• For the resistance band exercises, the band should be light enough so the client can perform 10–20 reps with minimal fatigue.

Here are three classic exercises for creating joint stability, strength and endurance of the rotator cuff.

1. No Excuses Rotation Exercise

This is easy for anyone to do anywhere and helps develop endurance of this muscle group.

• Sit or stand with both arms relaxed at the sides of the body.
• Slowly rotate the arm from medial to lateral rotation with no resistance. Keep the scapula relatively stable so the movement is focused on the rotator cuff.

Progressions. To challenge the muscles to create joint stability in different positions, move the arm into any range of flexion, extension or abduction, and add rotation. To add a dynamic challenge for the rotator cuff to respond to, have the client hold a small half-full bottle of water in the hand and rotate the arm.

2. Resistance Band Lateral Rotation

• Stand upright with the body in a straight line holding the resistance band in front of the body between both hands, keeping the elbows tucked against the sides.
• Stretch the band by rotating the shoulders outward (as if opening a coat).

3. Resistance Band Medial Rotation

• With one end of the resistance band secured just below chest height, stand upright with the body in a straight line holding the other end of the band in one hand, with the elbow close to the body and the hand pointing forward.
• Stretch the band by rotating the arm toward the body without rounding or hunching the shoulders.

Work Those Small Muscles in Post-Recovery, Too

Both the deep spinal muscles and the rotator cuff are examples of muscle groups whose purpose is to create dynamic joint stability. When training clients, help them understand how these muscles help the large muscles of movement perform effectively and efficiently, and you may help them prevent future injuries, too.