Network Magazine summer 2015 | Page 53

The 30-second article • The versatility and portability of suspension training apparatus has made it very popular among PTs who can train clients with it both indoors and outdoors • Studies using EMG have found mixed but generally favourable results with regards muscle activation, particularly in the trunk and torso • Evidence suggests that suspension training may help people with low back pain by causing thicker contraction of some abdominal muscles • Results show that while suspension training elicits a degree of cardio benefit, it is not highly effective in this area of fitness. have a very real place in research, and as long as you understand the limitations of this type of research you will still find value in reading these types of studies. Many studies have utilised EMG techniques with suspension training. Nearly all studies have shown that when comparing the use of a suspension training system to traditional exercises, there is increased surface muscle EMG activity, especially of the trunk or torso muscles to support the unstable nature of the activity. This has been shown frequently in the following research: • Comparing suspension push ups to normal push ups; McGill et al. 2014 • Comparing EMG of Rectus Abdominis across different exercises; Snarr et al. 2013 • Comparing EMG in inverted rows with and without suspension devices; Snarr and Esco 2013 • EMG of plank variations; Snarr and Esco 2014 • Core muscle activity during suspension exercises; Mok et al. 2014 It would be easy to take this to infer that suspension training exercises are more effective than non-suspension-based activities. However, a word of caution on the generalisation of such studies and use of EMG data: science still lacks consensus regarding a precise methodology that can be widely used to quantify muscle strength based on EMG. In fact, very few EMG studies actually measure muscle force output, instead simply reporting the EMG activity and comparing amplitude of the signals. Further, the effect of gravity and the effects of joint stiffness are also ignored, and these can be significant. The evidence does support the use of suspension training to activate muscles of the trunk and torso in developing increased tension of this area, and to offer variety of exercises outside of the traditional approach to core training. Further, through the use of the unstable environment, research has shown that these muscles are more active during suspension training when compared to traditional forms of the same exercises. Evidence does suggest that to develop increased strength, traditional methods of strength training are superior, but in my opinion suspension training may be a great tool for simply adding variety or working clients who do not have elite strength-based goals. Effect on low back pain A number of interesting studies have used subjects with low back pain to compare the changes in thickness of the transverse abdominis after performing exercises both in suspension equipment and on stable surfaces. Very few studies included long term interventions, so it’s hard to determine the effect of such a program outside of the single session period used across most studies, which were often contradictory to each other. Guthrie et al (2012) found that neither traditional- nor suspensionexercise-bridge progression has an immediate clinical effect on external oblique (EO), internal oblique (IO), or transverse abdominis (TrA) activation immediately after a single exercise intervention. Saliba et al (2010) showed the suspension exercise progression resulted in higher TrA activation during exercise than the traditional-bridging exercise. Min Yong Eom concluded that bridging exercises on a sling support surface would increase the thickness of the transverse abdominis and lower extremity muscle activities in rehabilitation programs for patients with back pain, due to the increased thickness of TrA contraction recorded in a single session of suspension training. Overall this is still a relatively poorly supported field of study, and while current evidence suggests use of suspension training may cause thicker contraction of some abdominal muscles, the effect of long term use has not been ve &