Muscle release technique improved dorsiflexion ROM without loss of force production

Research Review: Self-administered Release Technique Improves Dorsiflexion ROM Without Loss of Force Production

By Stefanie DiCarrado DPT, PT, NASM CPT & CES

Edited by Brent Brookbush DPT, PT, MS, PES, CES, CSCS, ACSM H/FS

Original Citation: Halperin, I., Aboodarda, S.J., Button, D.C., Andersen, L.L., Behm, D.G. (2014). Roller massager improves range of motion of plantar flexor muscles without subsequent decreases in force parameters. The International Journal of Sports Physical Therapy. 9(1): 92 -102 - ARTICLE

Subject using roller massager on his plantarflexors

Why is this relevant?: Previous research identified decreased dorsiflexion (DF) as a contributing factor to lower extremity injuries within an athletic population (1-3). Specifically, decreased DF has been linked to anterior cruciate ligament (ACL) injury. The inability to advance the tibia in closed chain may result in eversion, tibial external rotation and femoral internal rotation - i.e. collapse of the lower extremity into a functional valgus. Unfortunately, research (inconclusive) has also been promoted that demonstrates maximal power and force production decreases for a period of several hours after stretching techniques are administered. Some professionals have implied that these same findings would apply to foam rolling. This has lead to a puzzling question in regard to practice, "Do we enhance mobility in restricted segments prior to athletic activity, or should we only use flexibility techniques post exercise?" This study addresses the question of whether a decrease in max strength and power is noted immediately following self-administered release techniques (SMR, Foam Rolling, Etc.).

Study Summary

Subject performing the static stretching intervention

Review & Commentary: This study was unique at the time of publication; being the only study to compare static stretching to the use of a self-administered roller type massage tool for release of the plantarflexors (gastronemius and soleus ) and even more unique to include the effects on single limb balance. This study implemented a strong methodology using standard practices. Researchers evaluated subjects on two separate days, 3-6 days apart. At the start of each session, subjects performed the same warm-up consisting of 10 single leg heel raises (the pace of was set by a metronome). Subjects performed two pretests of each outcome measure in the same order with barefeet, using their dominant leg. The authors clearly defined how they determined the dominant leg, the order of the outcome measures assessed, and the settings of the metronome. The two pretests were intended to assess the effect of the warm-up on muscle activation; researchers evaluated subjects immediately after the warm-up and again after a 10 minute rest. The 10 minute rest was thought to reduce any post activation excitation caused by the warm-up. After completing the second pretest, subjects performed either static stretching or self-massage with a Theraband roller massage which was assigned randomly. Regardless of which intervention, subjects performed the same protocol of 30s repetitions with 10s rest between each repetition. The session concluded with 2 post tests: immediately after the intervention and after a 10 minute rest. Researchers ensured understanding of the protocols by instructing each subject on each intervention prior to the warm-up and required they practiced with the roller massage on the non-tested plantarflexors. Researchers attempted to standardize the pressure applied to the plantarflexors and the stretch force by instructing subjects to apply enough pressure or stretch hard enough to reach a 7 out of 10 on a pain scale. The authors clearly described all equipment used, subject positioning, equipment placement, and settings so that future research studies can replicate and examine the effects of other muscle release techniques.

However, this study is not without weaknesses. The EMG electrode placement was described sufficiently, but it would have been beneficial to have a picture of the placement. The authors described a clever way to monitor whether the subject's heel lifted off the floor during the static lunge test; however, their method of monitoring compensatory movement at the subtalor joint (aka eversion or flattening of the feet) was lacking. The authors noted that subjects were asked to stand perpendicular to a wall, cuing the individual to move the knee toward the wall in a straight line, but did not add additional cuing or methodology to reduce compensation at the subtalar joint. The standard supine measurement for DF ROM may have been a more reliable test. Last, the protocol used for releasing the soleus was not a static hold on trigger points, but a continuous roll up and down the length of the soleus. More study should be done to define the most effective methodology for self-administered release techniques.

Why is this study important?

This study compares a muscle release technique to static stretching. Typical flexibility programs focus on static stretching which may have an inhibitory effect on the muscle being stretched. This inhibitory affect may result in a decrease of maximal force and power output. This study provides evidence to support release technique prior to activity to enhance ROM while maintaining normal force output of the plantar flexors. This study, also provides evidence that increased ROM may not increase balance.

How does it affect practice?

The lesson here is twofold. If a clinician intends to inhibit and and lengthen a muscle that is short and over-active, they should incorporate both release techniques and static stretching. However, if a clinician intends to increase range of motion while maintaining maximal force output for activities immediately following a flexibility program, then release techniques alone may be appropriate.

How does it relate to Brookbush Institute Content?

This study supports the practices of the Brookbush Institute relative to restrictions in dorsi-flexion. Lack of dorsiflexion ROM is part of the predictive model of Lower Leg Dysfunction (LLD) and results in "feet flatten ", "feet turn out ", "knees bow in ", "knees bow out ", and/or excessive forward lean , during an overhead squat assessment (OHSA). LLD can affect motion at the Lumbo Pelvic Hip Complex and/or the Sacroiliac Joint , especially if dorsiflexion is asymmetrical. Asymmetrical LLD will result in an "asymmetric weight shift" during the OHSA . The Brookbush Institute's predictive model of LLD notes the lack of dorsiflexion ROM can be caused by overactivity in the plantarflexors (Gastrocnemius and Soleus ), resulting in reciprocal inhibition the dorsiflexors (mainly tibialis anterior ), and possibl hypomobility at the talocrual joint. Joint hypomobility can be addressed using self-mobilization techniques, muscle overactivity requires release and lengthening interventions and muscle under-activity is addressed with activation exercises . The videos below demonstrate how to better address movement impairment related to decreased DF ROM; however, this routine would only be appropriate if a decrease in dorsiflexion was determined through movement assessment and static stretching may be omitted prior to max strength and power routines.

Gastroc / Soleus Static SA Release

Ankle Mobilization

Dynamic Calf Stretch

Tibialis Anterior Isolated Activation

Single Leg Touchdown with Anterior to Posterior Pull

Tibialis Anterior Reactive Activation

Tibialis Anterior Activation Taping

Bibliography:

1. Padua, D. A., Bell, D. R., & Clark, M. A. (2012). Neuromuscular characteristics of individuals displaying excessive medial knee displacement. Journal of athletic training, 47(5), 525.
2. Mauntel, T., Begalle, R., Cram, T., Frank, B., Hirth, C., Blackburn, T., & Padua, D. (2013). The effects of lower extremity muscle activation and passive range of motion on single leg squat performance. Journal Of Strength And Conditioning Research / National Strength & Conditioning Association, 27(7), 1813-1823.
3. Bell, D. R., Oates, D. C., Clark, M. A., & Padua, D. A. (2013). Two-and 3-dimensional knee valgus are reduced after an exercise intervention in young adults with demonstrable valgus during squatting. Journal of athletic training,48(4), 442-449

© 2015 Brent Brookbush

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