Foam rolling has become a popular modality used both in warm ups and as a method to assist in recovery from hard training. Little is known about how foam rolling works but the main goal and reason for its use is to decrease muscular tension and improve range of motion, similar to the way in which massage is often used.
A recent study in the Journal of Strength and Conditioning Research by MacDonald and colleagues aimed to understand the effects of an acute bout of foam rolling on knee joint range of motion and muscular force.
The subjects, 11 healthy recreational resistance training males (ages 18-25) participated in the study and were asked to report to the lab on four different occasions, separated by 24-48hrs of rest, each occasion focusing on either baseline measurements or a foam rolling intervention.
- Test Day 1 – A Range of Motion (ROM) assessment was followed by 2min of rest and then the assessment was taken again at 2min and 10min post rest
- Test Day 2 – Muscle force production was measured using maximal voluntary contraction (MVC) and evoked muscle activation and was followed by 2min of rest and then the assessment was taken again at 2min and 10min post rest
- Test Day 3 – A Range of Motion (ROM) assessment followed by 2min of foam rolling and then the assessment was taken again at 2min and 10min post foam rolling
- Test Day 4 – Muscle force production was measured using maximal voluntary contraction (MVC) and evoked muscle activation and was followed by 2min of foam rolling and then the assessment was taken again at 2min and 10min post foam rolling
Foam Rolling Protocol
Foam rolling was performed on a foam roller constructed from hollow PVC pipe surrounded by a neoprene foam of 1cm thickness. The subjects were taught to roll their quadriceps from origin to insertion for 1min. They then rested for 30sec and then rolled for another minute – 2minutes of total foam rolling.
Some Key Findings
- Foam rolling did not produce significant differences in either voluntary or evoked muscular force output
- Acute foam rolling significantly increased knee flexion ROM at both 2 and 10min post foam rolling
The increase in joint ROM is a promising finding of this study as improving joint mobility is often a goal of warming up for activity/training. Additionally, athletes who lack joint ROM in certain areas may find foam rolling to be a beneficial modality to help assist with limitations. While most associate foam rolling with relaxation its application has been used significantly in warm ups over the past several years and if often followed with some form of stretching activity or mobility activity where the muscles are taken through a range of motion, held of a second or two, and then brought back to their starting position, this sequence repeating for several repetitions. As I discussed in a blog article 3 years ago, Stretching As A Part of the Warm Up: Can We Make It Work?, when these two modalities are followed by a more active/dynamic warm up that prepares the nervous system there does not seem to be the performance decrement that most research notes when stretching is immediately followed by a test of maximal power.
Interestingly there was not a decrease in force output of the muscle, as one would assume that foam rolling would cause a greater amount of relaxation in the tissue similar to the findings of other massage research (Wiktorsson-Moller, et al). McKechnie, et al. did find a similar result – improved ankle joint ROM without a decrease in power output – using a 3 minute massage treatment of either Petrissage or Tapotement to the calf musculature.
I do wonder if some of this has to do with the fact that in massage research the subjects are at the mercy of the therapist and the therapist can adjust their touch and depth of pressure to “meet the subject’s nervous system where it is at” rather than trying to force things and go too deep, too fast, and hoping that this produces the results they would like. Perhaps the density of the foam roller in this study was too hard or maybe the subjects leaned too aggressively into the foam roller and really pushed, as many do with the “no pain, no gain” approach that is often taken with foam rolling? Or perhaps there is just something about human touch that allows for more relaxation, comfort, and an ease of tension? Additionally, time may be an issue when it comes to decreasing muscular force, as indicated in Wiktorsson-Moller et al’s study which used a 7-15min massage protocol administered by a therapist and showed a decrease in quadriceps isometric force and hamstring isokinetic force. Additionally, Crane et al have shown that longer periods of time on one area (10min on the quadriceps alone) produced a positive influence on inflammation following an intense bout of exercise (HERE is my write up of that paper from last year).
The time piece is a critical element, in my opinion, as everyone adapts at different rates and their nervous systems ability to adapt may be related to a variety of factors – fitness level, stress, perception, nutrition/hydration, etc – which is why I find it odd that some therapists will perform a few passes on a muscle and expect things to be normalized in 2min. I believe that to be truly comprehensive you need to take a holistic approach, think big picture, and consider how you want to influence more than just a few muscles within a treatment session. So, perhaps the subjects in the study just needed more time in order to see a favorable result in terms of decreased muscle force output?
This was an interesting study and shows some promise that foam rolling may have something beneficial to offer besides the anecdotal praises that it currently enjoys. We still don’t know how it exactly works, what it exactly does, and we don’t know all of the things that rolling your muscles on a piece of PVC may actually influence within the body. Regardless, it seems to do something and if that something improves a client’s ability to perform or feel better and does not have negative effects on health then I am all in!