18 I Fall 2018 www.anjc.info Legislative Update Legal Ease Chiro Assist TECHNIQUE Council REHABILITATION Council Legal Q&A By Dr. Kenneth T. Cieslak Clinicians often use stretching programs as part of their patient care plans. Stretching has long been accepted as an effective method to increase range of motion and improve mobility. Often, doctors prefer to incorporate stretching protocols that involve pre-stretch contractions. This includes such protocols as: proprioceptive neuromuscular facilitation (PNF), post- isometic relaxation (PIR), and active isolated stretching (AIS). It is believed that these approaches capitalize on influencing neurological pathways to facilitate improved range of motion through mechanisms such as autogenic inhibition, and/or reciprocal inhibition (Page, 2012; Law, 2009). Proprioceptive neuromuscular facilitation can be further divided into: “contract- relax” (C-R), “hold-relax” (H-R), and “contract-relax agonist contract” (CRAC). In regard to the first two methods, it is believed the muscle will temporarily relax and allow for greater range of motion immediately post contraction. This draws upon the concept of autogenic inhibition. In the case of CRAC, the isometric hold is immediately followed by a contraction of the agonist to allow for an increase in effective range of motion. This is rooted in the concept of reciprocal inhibition. Post-isometric relaxation (PIR) is similar to the “contract-relax” form of PNF, however, it relies on a smaller amplitude contraction (approx. 25% MVC), followed by an immediate stretch (Page, 2012). A further variation of this technique, referred to as Post- Facilitation Stretch (PFS) was developed by Dr. Vladimir Janda, and involves a near-maximal contraction at mid-range, followed by a rapid movement to maximal length followed by a 15 second static hold (Page et al, 2010). In each of these protocols, it has been believed that the increase in range of motion was mediated by inhibitory effects via various neurological pathways, such as the previously mentioned modes of autogenic inhibition and reciprocal inhibition. Etnyre and Abraham (1988) found evidence of reciprocal inhibition of target muscle activity using indwelling electrodes into the soleus muscle. However, emerging research has begun to challenge these concepts of neurological inhibition (Hindle, 2012). Mitchell (2009) found, in a study of 18 subjects utilizing PNF stretching patterns, that EMG activity increased immediately post contraction, at the same time that tissue extensibility increased. Studies by Osternig (1990), Moore (1980) and Cornelius (1983) had similar findings. There does appear to be some evidence that Hoffman reflex (H-reflex) excitability is lowered with a pre-contraction stretch. This may allow muscle to relax via influencing the gamma motor neuron system, despite increased activation of the alpha system (Condon, 1987; Moore, 1991). However, more research is needed before this mechanism can be definitively supported. Over the last decade, clinicians and fitness enthusiasts have increasingly included implements, such as foam rollers into their mobility routines. It is theorized that self myofascial release utilizing foam rollers and handheld roller devices is an effective method to increase mobility, decrease injury risk, and mitigate the effects of delayed onset muscle soreness (DOMS). However, does the research support this belief? In a study by MacDonald and colleagues (2013), foam rollers were used to examine the effects on knee range of motion. Eleven subjects performed two 60-second bouts of foam rolling on the quadriceps. Knee ROM improved, and those improvements were still evident at 10 minutes post treatment. Furthermore, there was no reduction in force output of the muscle. This is important, as static stretching has been shown to reduce force output for as long as 30 minutes post stretch. In a similar study by Mohr and colleagues (2014), foam rollers were compared to static stretching in a larger cohort of 40 participants. It was found that the group that combined foam rolling with static stretching experienced the greatest improvements in range of motion at the hip. A study by Pearcey, et al (2015) attempted to explore whether foam rolling would enhance tissue recovery following application of a 10 x 10 squat protocol. The group that utilized foam rolling post squat protocol, and at 24 and 48 hours post, had less soreness and better scores on a 3-meter sprint test, long jump, and strength endurance tests versus the group that did not foam roll. Finally, in a study by Junker and Stoggl (2015), an attempt was made to compare the effects of foam rolling to PNF stretching to improve hamstring flexibility. Forty males participated. Results indicated that both groups had similar overall improvements in range of motion. This suggests that foam rolling may be as effective as clinician-assisted stretching protocols in enhancing tissue extensibility and range of motion. This is important, because foam rolling is less Examining the Mechanisms behind Assisted Stretching Methods and Foam Rolling: Options for clinical practice