Soleus Muscle Electromyographic Activity and Ankle Dorsiflexion Range of Motion During Four Stretching Procedures

Abstract

Volitional muscle contractions are used frequently in some combination with muscle stretching to promote muscle relaxation and to increase range of motion. In this study, muscle lengthening procedures were evaluated in the ankle plantar flexors. Four soleus muscle stretching procedures--static stretch (SS), hold relax (HR) (isometric plantar flexor contraction before stretch), agonist contract (AC) (dorsiflexor contraction assisting stretch), and hold relax-agonist contraction (HR-AC)--were performed in the sagittal plane by 12 physically active adults. The dorsiflexion angle, soleus muscle electromyogram, and soleus muscle motoneuron excitability as determined by the Hoffmann-reflex (H-reflex) amplitude were measured throughout the duration of each stretch. The range of dorsiflexion achieved at the end of the stretch did not differ significantly between stretching procedures, although in 8 of the 12 subjects and in the subject group as a whole, the AC and HR-AC procedures were associated with higher levels of soleus muscle EMG than the levels in the SS and HR procedures (p less than .01). The H-reflex amplitudes during the AC and HR-AC procedures were smaller than the amplitudes during the SS and HR procedures (p less than .001), suggesting the possibility of reciprocal inhibition during the agonist contraction. Increased tonic EMG levels produced by input from other neural pathways affecting alpha motoneurons in the AC and HR-AC procedures may have masked this inhibitory reflex. In healthy adults, a complicated procedure, involving muscle contractions for decreasing active resistance to stretch, may be unnecessary because active resistance to stretch is minimal and muscle relaxation during stretch appears to have little or no direct effect on the ROM achieved.

Acute effects of muscle stretching on physical performance, range of motion, and injury incidence in healthy active individuals: a systematic review

“…A number of studies report greater ROM improvements after PNF compared with SS within a single session (Etnyre and Lee 1988;Ferber et al 2002;O'Hora et al 2011). On the other hand, SS has also been shown to provide ROM increases similar to those of PNF within a single session (Condon and Hutton 1987;Maddigan et al 2012). There is also conflict in the DS literature, with some studies reporting that an acute bout of DS provides either similar (Beedle and Mann 2007;Perrier et al 2011) or greater (Duncan and Woodfield 2006;Amiri-Khorasani et al 2011) increases in flexibility than does SS, whereas many other studies have reported that DS was not as effective as SS within a single preactivity routine (Samuel et al 2008;Bacurau et al 2009;Sekir et al 2010;Barroso et al 2012;Paradisis et al 2014).…”

The Relationship between Hip Extension Force Measured by Using a Hand-held Dynamometer and the Effect of Proprioceptive Neuromuscular Facilitation Stretching on Hamstring Flexibility

“…Various stretching techniques are used to improve flexibility (Chang et al, 2002), among which the PNF technique is known to be highly effective in increasing ROM; however, there is still some controversy regard this technique. During stretching, resistance is affected by both the viscoelastic properties of the tissues and the contractile components (Condon et al, 1987). The PNF technique is considered to increase flexibility by decreasing active resistance (Osternig et al, 1990).…”

Effect of Previous Standing-up Exercise on Forward Bending Test in the Elderly

“…It is possible that the activities of the quadriceps femoris muscles and simultaneous contraction of the hamstring muscles (as agonistic muscles if they are to be stretched) induced relaxation of the muscles surrounding the hip and knee joints. Condon et al 32) and Ostering et al 33) also reported on the usefulness of relaxation involving contraction of agonistic muscles.…”