This post originally appeared in early December 2008 as my top 5 LEAST favorite rehabilitation exercises and has proven to be one of the most popular posts I have written so far. I guess controversy sells! I have enhanced and reposted to also include recommendations on how to achieve similar (if not better) results using other exercises. So, to begin, I want to clarify:
- This purely just my opinion
- I may be wrong
- You may get great results with these exercises
- Or you may get great results despite these exercises!
The Empty Can Exercise
I have been trying real hard the last several years to provide enough evidence that we shouldn’t be using the empty can exercise. Still, it comes up and I suspect is still a fairly common exercise. The legendary Dr. Frank Jobe was the first to recommend this exercise for the supraspinatus. Since then it was widely popular as an exercise to isolate the supraspinatus. To clarify, it is a good exercise for the supraspinatus, but not the best. Jobe did discuss the empty can exercise in his classic 1983 article on shoulder exercises but he never mentioned that it “isolated” the supraspinatus. As we all know, we can’t isolate the supraspinatus like this.
So why do I dislike this exercise? Have you tried it? It hurts. Why does it hurt? It is simple actually. My EMG paper a few years ago discussed that EMG of the supraspinatus was the same between the empty can and full can exercise, but that the middle deltoid was significantly more active during the empty can. This articles is free to read from the Journal of Athletic Training.
Simply said, if the deltoid overpowers the supraspinatus, the rotator cuff can not keep the humeral head centered within the glenoid fossa and superior migration occurs. Superior humeral head migration = impingement. Not good, and that is why it hurts. There are numerous other anatomical and biomechanical reasons to not use the empty can exercise, but if the full can has the same EMG activity I don’t see the controversy.
Solution: The Full Can Exercise
This is a simple solution. The empty can should be a thing of the past at this time. I am not sure if there is any place for it as an exercise, though I still use it as a provocative test. As described above, the full can exercise produces the same amount of EMG of the supraspinatus but has the least amount of surrounding muscle activity. In patients with shoulder pain, weakness of the rotator cuff, or inefficient dynamic stabilization, activities that produce higher levels of deltoid activity in relation to supraspinatus activity, such as the empty can exercise, may be detrimental. This is due to the increased amount of superior humeral head migration that may be observed when the rotator cuff does not adequately compress the humerus within the glenoid fossa to counteract, or oppose, the superior pull of the deltoid.
In addition to the altered ratio of supraspinatus to deltoid muscle activity, there are several reasons why the full can exercise may be preferred over the empty can exercise during rehabilitation and supraspinatus testing. Anatomically, the IR of the humerus during the “empty can” exercise does not allow the greater tuberosity to clear from under the acromion during arm elevation, which may increase subacromial impingement risk because of decreased subacromial space width.
Biomechanically, shoulder abduction performed in extreme IR progressively decreases the abduction moment arm of the supraspinatus from 0-90° of abduction. A diminished mechanical advantage may result in the supraspinatus needing to generate more force, thus increasing the tensile stresses in the injured or healing tendon. This may also make the exercise more challenging for patients with weakness, facilitating compensatory movements such as a shoulder “shrug.”
Scapular kinematics are also different between these exercises, with scapular IR (winging, which occurs in the transverse plane with the scapular medial border moving posterior away from the trunk) and anterior tilt (which occurs in the sagittal plane with the scapular inferior angle moving posterior away from the trunk) being greater with the “empty can” compared to the “full can” exercise. This occurs in part because IR of the humerus in the “empty can” position tensions both the posteroinferior capsule of the glenohumeral joint and the rotator cuff (primarily the infraspinartus). Tension in these structures contribute to produce anterior tilt and IR of the scapula, which contribute to scapular protraction. This is clinically important because scapular protraction has been shown to decrease the width of the subacromial space, increasing the risk of subacromial impingement.
Prone Hangs for Knee Extension
What do you do when your patient has some tightness and can’t achieve full knee extension? That is a common dilemma as a knee flexion contracture is not good for our patients. One option is prone hangs over the edge of the table.
Why do I dislike this exercise? When someone can’t achieve full knee extension, there knee typically hurts and is uncomfortable stretching, especially when performing a low-load, long-duration stretch for 10+ minutes. It is difficult for the patient to relax, avoid compensation, and sit still in this position. What happens is the patient ends up rotating and flexing his hip to decrease knee extension, and thus minimize any potential benefit from the stretch. Interestingly, I couldn’t even find a picture of this without a clinician in the photo holding their hip down, which isn’t very realistic for a stretch.
Solution: Supine Knee Extension
By placing the patient supine, they can relax their lower extremity and assume a more normal and comfortable position. To get the most out of this exercise, I place a rolled up ankle weight under the heel of the patient. This alone will provide a gentle load into extension from gravity.
Next, another ankle weight is draped over the distal thigh, just above the knee. Why not right on the knee? You don’t want to compress the patellofemoral joint. I use anywhere from 5 to 15 pounds depending on the situation. To help the patient relax, you can place another weight on the outside of the leg to let the patient relax their groin and allow the hip to not sag into external rotation. If you still find that the patient is compensating proximally, you can use a strap along the ASISs and under the table, though I very rarely have to do this.
Also, don’t underestimate the use of a Joint Active Systems brace for the knee, these things work like a charm and are great for stretching at home. Rather than use a dynamic brace, the JAS brace allows you to just dial in a stretch and maintain for a long duration of time. In my opinion we use these tools too infrequently.
Working Through a Shoulder Shrug
Many times after shoulder surgery, we want to try to work on both passive and active range of motion. When a patient is either tight (usually tight inferior capsule) or does not have adequate rotator cuff function (see empty can description above), a shrug may occur. This can occur during many active and active-assisted ROM exercises such as rope and pulley, L-bar exercises, or simply just during arm elevation.
Why do I dislike this exercise? It comes down to what is actually happening with the shrug. If the inferior capsule is tight or the cuff can’t center the humeral head, again, superior humeral head migration occurs. And what does that cause? That’s right, impingement. Over the years I have seen patients try to work through a shrug by working through the exercise or even by watching themselves in a mirror. Unfortunately, this isn’t a neuromuscular pattern that needs to be relearned. You need to solve the cause of the shrug first and foremost.
Solution: Train the Cuff to Dynamically Stabilize
I will disregard the solution to the tight inferior capsule, obviously you work on restoring mobility of the inferior capsule. When a patient can not elevate their arm without shrugging you need to work the cuff below 90 degrees and restore adequate posterior rotator cuff (ER) strength. I work on rhythmic stabilizations and ER strength predominately and eventually the shrug goes away. You can also eliminate gravity and perform elevation in the sidelying position.
Unfortunately, there isn’t a quick fix, but if you start to elevate before strength returns, the shrug will likely cause even worse problems. I have discussed this previously and have a video demonstrating some of these techniques on my post on rehabilitation following rotator cuff repair. Be sure to follow the link and watch that video.
Stool Scooting for Hamstrings
Many patients need to work on hamstring strength. One rehab exercise I see is stool scooting, where the patient sits and digs their heels into the ground, scooting around your clinic.
Why do I dislike this exercise? This one isn’t too low down the list for me, I don’t think it is that bad. But, I really don’t think it is good either. You really are not getting a lot of hamstring strengthening, you are basically just work on endurance. But, I tend to not use this because it really irritates patients. I have seen hamstring tendonitis, pes irritation, and other annoyances that could be avoided. Sorry, I don’t use this exercise so I didn’t even have a picture of it, nice stool, though!
Solution: Work the Hamstrings Functionally
Realistically, how many times a day do you stand there and flex your knee with your legs together? Traditional hamstring strengthening exercises are fine when baseline strength is needed, but they should be progressed to train the hamstring more functionally once a fair amount of strength is restored. Two exercises perfect for this are single leg deadlifts and physioball hamstring curls
I know deadlifts sounds intimidating for a rehabilitation patient, but I am not talking Olympic lifting here, I am talking about hamstring strength and eccentric control of hip flexion. Really a great exercise. Here is an excellent video from Michael Boyle:
For physioball curls, there are several variations that work on core stability, hip extension, and trunk control. The below video is a decent example, there are better example on Youtube, but I this video is well produced and clear:
Behind the Back Internal Rotation Stretching
The winner of my least favorite rehabilitation exercise is hand down the behind the back stretch for shoulder internal rotation. This is performed by the patient actively, with the assist of a towel, or even manually by a clinician.
Why is this my least favorite common rehabilitation exercise? It places the rotator cuff at an extremely disadvantageous position, placing considerable torque on the rotator cuff insertion. This can lead to even more irritation or worse for the cuff. This really isn’t a pure IR stretch, either, it is a combined motion of shoulder extension, adduction, and IR. My thought is that if the patient is limited in that motion, there must be a reason. Rather than just jam my hand behind my back and try to push harder or use a towel to torque even more, I would rather try to address cause, not the effect.
Solution: IR and Cross Body Horizontal Adduction Stretching
I am a firm believer that if you have a loss of IR, you can restore this motion easily with simple horizontal adduction stretching and IR stretching at 90 degrees abduction. For many patients, this will not be enough and you will have to stretch out the inferior capsule. Notice I didn’t say the posterior capsule. Limitations in IR at 90 degrees of abduction are from the inferior capsule, and the posterior-band of the inferior capsule. Perform standard inferior and posteroinferior mobilizations and you should see improvement.
Sorry for the controversy! I want to hear your thoughts, do you agree or disagree? What else would you add to this list? How would you solve these 5 exercises? To view the original discussion from this original post, follow this link to my Top 5 LEAST Favorite Rehabilitation Exercises.