The term “Full Range of Motion” (FRM) is often used in critiquing resistance training technique, but it is actually a misleading and misused term. Partial range of motion (PRM) is often considered cheating, or just downright WRONG and FRM is “always right”!
Range of Motion
Range of Motion (ROM) varies from one person to the next anyway, so what IS FRM? I’ll just go ahead and say it – FRM in weight training is very rarely desirable. What’s that you say? I thought I was supposed to use full range of motion, you say? Range of motion is determined by several factors – joint flexibility, muscle and connective tissue elasticity, injury, and any number of other genetic or structural issues. But for the sake of argument let’s make the completely ignorant assumption that everyone possesses or can develop the exact same ranges of motion, that their joints and muscle tissues are all genetically identical, of equal relative length, with identical connective tissue strength and muscle insertion points. Even with that completely ignorant premise, not everyone has the same goals or needs! The truth is that the term “Optimal Range of Motion” (ORM) is much more correct, and accounts for several possibilities NOT considered in the FRM concept.
Optimal Range of Motion
Let’s look at some examples of FRM in an exercise or two. The fallacy of FRM can easily be demonstrated with an exercise such as the seated cable row. Now, I’m being literal here, but in a seated reach and touch flexibility test it is not uncommon for an individual to be able to reach several inches past their toes. This would constitute the full forward aspect of their RoM. Are we to assume then, that in a seated cable row, one should reach all the way forward past their toes? I mean, that WOULD be FRM!! Or conversely, that they should lay all the way back at the concentric completion of the pull/row? Ridiculous. Yet that would constitute “full range of motion” in the absolute sense. Since that is obviously ridiculous, the term itself is misleading. Even in the bench press, FRM would mean extension of the shoulders at the top of the press, which is undesirable and even dangerous to the joints.
Obviously, in the seated row example, the full reach forward and full reach back would also recruit muscles that were not the desired target of the exercise, specifically the glutes and hamstrings for instance, as well as placing unnecessary stress on the lower back at both the complete extension and completed flexion stage of the over exaggerated row. It would also limit the amount of weight to be used based on the potential of the auxiliary muscles of the lower back or hamstrings (especially at their weakest point in full extension) rather than the target muscles of the mid an upper back, which are much stronger. Of course, you could lighten up on the weight to account for the low back, glutes and hamstrings, but then you’re essentially doing a completely different exercise and it’s no longer a seated row.
The squat is another perfect example. A movement screen will show broad variables in individuals’ flexibility or movement patterns at several points, from the ankles to the upper vertebrae of
the neck and every joint in between, including both horizontal and lateral movement at the knees and hips. Some consider FRM to be parallel while others insist on “bottoming out” the squat. But neither of these are even physically possible for everyone. Extending the exercise beyond the capability of the lifter’s joints is a sure recipe for injury! Further, EMG examination of the squat at partial (45 degrees), parallel (90 degrees), and full range (125 degrees) or “below parallel” demonstrated different levels of muscle recruitment at each depth, with more gluteus maximus activation at below parallel. Various stance widths also affected muscle recruitment and ROM potential. Too close with the feet, and stability is sacrificed, too wide and depth is more difficult. Wider stances recruit more adductors and glutes, while narrower stances emphasize the vastus lateralus or “sweep” of the quads. Which is optimal? Depends on your desired outcome.
So if we examine the idea of FRM, it really is a false premise on the face of it, as it can be dangerous, inefficient, and ineffective!
In an article on FRM vs. PRM in the bench press, comparing pro’s and con’s, the Pro side of the argument stated “there are specific cases where partial ROM movements are desirable. In order to rehabilitate certain shoulder injuries, to prevent particular injuries, and to enhance overload and increase strength, athletes and coaches should consider performing partial ROM bench presses.” Even in the contrary opinion, the author admitted the caveat “…unless there are functional abnormalities that would not allow movement through the full ROM. In this case, limiting the full, functional ROM would be prudent, and by doing this we maintain a ROM below the anatomically specified ROM, yet we are still performing within that individual’s full, functional ROM.” In other words, individual capacity and safety are always overriding considerations!
ORM is a much better term as it allows for joint safety considerations, but just as importantly, goal specificity! PRM (partial range of motion) is very often ORM (optimal range of motion)!!! Even given the generally accepted concept that a) strength development is range of motion specific, and b) optimal strength development is generally require complete use of a joint’s potential movement, at least a few studies have indicated that even partial range of motion can be just as effective for developing strength as the so-called FRM. A Journal of Strength and Conditioning Research article studied exactly that concept and tested groups performing partial range, full range, or a combination of both in the bench press. The conclusion was that “Each of the 3 groups demonstrated statistically significant increases in strength from pre- to post-test. No differences were found between groups. These findings appear to suggest that partial range of motion training can positively influence the development of maximal strength.”
Ever see a power lifter train do board bench presses with 1, 2, or even 3 boards! That limits his range of motion considerably!! How about the bottom half only and the top half only barbell curls in performing 21’s? Is there a point? Of course there is!! Strength is range of motion specific to within 10 or 15 degrees on either side of a movement. This accounts for what is known as the “strength curve” wherein an exercise is either easier or more difficult at various points in the movement, either at the start, finish, or middle where there is a “sticking point”, which are all the result of the biomechanically weak point in a given movement. Even isometrics, which is NO range of motion, are beneficial in working on sticking points and improving concentric strength at full
contraction (such as helping those who can’t do full pull-ups by starting with a static hold at the top.) There is an old bodybuilding saying that says, “Full range of motion = Full muscle development. Partial range of motion = Partial muscle development.” While there is truth in the statement, it merely emphasizes the fact that there are times when you WANT focus on a particular part, and therefore partial range is appropriate.
One last thought on FRM vs. ORM. Under which condition is it more likely that you are stimulating your muscles, nerves and fuel system such that you’re maximizing your potential to get the desired result? Is it if your goal is to simply move the weight from point A to point B because that’s considered FRM, or is it if you’ve carefully considered and determined through your own study and experience that a particular way of moving is best suited to you and your desired outcomes and is therefore OPTIMAL? And where does that leave a casual observer unaware of someone else’s needs, limitations, and experience when judging that person’s technique?
I once saw a gym member performing a short, jerky, cross-body 6 inch ROM cable curl. Inwardly I laughed because it looked silly and ineffective. But I kept it on the inside and later talked to him. Turned out he was a competitive arm wrestler, and on further analysis, his jerky little motion was PERFECT for the initial move in arm-wrestling! So next time you feel to critique someone for not using FRM, consider that FRM is a stupid term anyway, and they may very well be using ORM for their goals, body type, age, injuries, and personal capacity! And it may well be the PERFECT, OPTIMAL technique for THEM!