Effects of tactile
feedback on lumbar multifidus muscle activity in asymptomatic healthy adults
and patients with low back pain
S, Zafereo J, Brizzolara K, Anderson E. Journal of Bodywork and Movement
Therapies. 2017; 1-7
Message: Continuous and direct
tactile feedback on the lumbar multifidus fails to facilitate muscle activation
in people with and without low back pain.
with low back pain have smaller and more atrophied lumbar multifidus muscles on
the involved side. Clinicians often include lumbar multifidus activation
training in rehabilitation programs and use multiple strategies to teach and
facilitate lumbar multifidus activation; including, tactile feedback through
direct hand contact of the clinician. Surprisingly, there is little evidence that
tactile feedback improves lumbar multifidus activation. The authors conducted a
descriptive study to investigate the association between tactile feedback and lumbar
multifidus activation at rest and during a contracted state in healthy people and
those with low back pain. The authors recruited 20 adults with low back pain
and 20 healthy adults from a physical therapy clinic and affiliated
institutions. Muscle activation was measured using surface electromyography
with electrodes placed at the level of the L5 spinous process. The authors normalized
muscle activation to a maximal voluntary isometric contraction, which they
assessed while the participant performed a bilateral arm lift. The authors measured
each participant three times while resting in the prone position, with and
without the applied direct continuous contact for 5 seconds. Each participant
then performed five contralateral arm lifts in the prone position, lasting 8
seconds with just verbal feedback and then with verbal and tactile feedback. The
authors found that all people in the study, regardless of low back pain, had less
lumbar multifidus activation when using tactile feedback during a rested (14%
vs 17%) and contracted state (30% vs 32%). Despite, the lack of benefit many
participants thought the tactile feedback was helpful (healthy: 35%, people
with low back pain: 50%).
study is important because the authors suggest that direct-contact tactile
feedback may be ineffective for increasing activation of the lumbar multifidus.
This article also shows the disconnect between what is happening and what people
perceive because many participants thought the tactile feedback helped them better
activate the lumbar multifidus. Although direct contact tactile feedback was
used in this study a more applicable application of tactile feedback is light
tapping or deep pressure. It would be interesting to replicate this study with
intermittent-tapping tactile feedback. Furthermore, it may be beneficial to
randomize the order of the trials to ensure that issues like muscle fatigue
don’t alter the results. In the meantime, clinicians should incorporate some
repetitions of tactile feedback into their rehabilitation programs for low back
pain so the patient perceives the benefit, followed by repetitions without
for Discussion: Do you think the
outcome would be different for a recreationally active asymptomatic and low
back pain population? Do you think that multiple trials of direct contact
tactile feedback would better activate the lumbar multifidus? Do you use direct
contact tactile feedback in your rehabilitation of low back pain? If so would
you consider altering the technique or otherwise not using it after reading
by: Kaitlyn Hill
by: Jeffrey Driban
Great summary Kaitlyn. Thank you for sharing!
You mentioned that light tapping or deep pressure is more applicable application of tactile feedback. I am curious as to why the pressure of the feedback would affect muscle activation? I also think there would be a stronger activation in an asymptomatic athletic population when compared to a LBP group. I currently would use tactile feedback in rehabilitation for LBP patients to help them understand where I want them to feel the activation. I would be open to using other techniques but would like to know more about which ones show the highest activation.
For this study in particular, I'm not necessarily surprised with the results. The multifudus is relatively deep (and small) and there are many larger, more powerful muscles that lay over the top of it. I'm not certain that by using tactical feedback I would increase its activation. What is surprising is that that tactile feedback actually inhibited the LM activation.
Tactical feedback can definitely help to specify where I want my patients to be focusing their attention to, but I think that if I wanted to increase the activation of the multifudus I would have to implement better exercises. I also think it's interesting that only 35% and 50% of the healthy and LBP patients found the tactical feedback to be helpful. This means that 65% and 50% found it to not be helpful. That's definitely more than I would have expected because anecdotally tactical feedback has seemed to be very beneficial when I have used it in the past.
I don’t think this article is enough for me to stop using tactile feedback. I will keep using tactical feedback for postural cueing/motor control purposes but may have to use caution if I use it with the hopes of increasing muscle activation, specifically in the lumbar multifidus.
I found this article to be very interesting, especially considering that I use a lot of tactile feedback, especially when working with LBP patients to help cue them for activation. As you mentioned, my feedback is more frequently more light tapping than constant pressure. Do you think in a way that would mimic firing patterns of a muscle, altering which portions of the muscle are firing as the muscle starts to fatigue?
I would also think that multiple trials of tactile feedback would help with the activation. I am also wondering if activation of muscles with tactile feedback would be better for different muscles, such as the TrA. I know that I use that a lot in my practice and I seem to have good results. I think this is particularly useful because the athletes themselves can feel when they are activated versus when they are not.
The fact that people feel better & is documented as a result is very positive in my opinion. Often, interventions are applied that are intended to make someone feel better, and then we can apply a higher intensity of ther ex. K-Tape for example, is a tactile stimulus (the tape pulls the skin when you move); it is unlikely to have physiologically measureable effects but patients generally "feel" better.
Hi Juli, good questions and thoughts. According to the authors the constant light contact actually produced an inhibitory effect meaning the muscle was relaxed. One possible explanation could be that the muscle was exposed to the tactile feedback and got used to the stimulus and adapted. I do agree with you though that I would like to know which tactile feedback method is the best and there should be more research done.
Hi Dan, good point, The LM is a very deep muscle and I too am a bit skeptical whether tactile feedback actually gets to that muscle. And the fact that more of the patients did not think the tactile feedback helped is disappointing, considering like you said its seemed to be beneficial in the past. I definitely will keep using tactile feedback, but like I stated previously I think the best method of tactile feedback needs more research.
Sarah that is an interesting thought, and it is possible that the light tapping may mimic the firing pattern of the muscle and the muscle never gets used to the stimulus and cannot adapt and relax like in the study. I do agree with you that I would have liked to see this tactile feedback method used over a longer period of time to see if that would have affected the results.
Hi Kaitlyn, Thank you for sharing. I agree with Dan that this evidence is not enough for me to stop using tactile feedback because it has worked in the past when teaching exercises to patients. I think that more research on this topic is needed to determine if it is detrimental or if it is more subjective. I also agree with Sue that it is very important to use positive subjective information as a result. There are many things we use in Athletic Training that we cannot back up with much more research than our own personal success and patient satisfaction, so I believe more information is needed. I think it would be interesting to see if the results of this study would change if completed on other muscles of the lumbopelvic hip complex.