1. Abdominal Muscle Activity and Lower Limb Forces When Walking With Nordic Walking Poles Valerie Sparkes, Lucy Warren Katie Whitehouse

2. Background Research into the effects of walking for patients with low back pain has been shown to be beneficial Callaghan et al (1999) Abdominal muscles appear to influence the stability of the spine via their connection to the thoracolumbar fascia

3. Walking and abdominal Abdominal muscle activity has been shown to change when patients have LBP Theories: (i)changes in muscle activity cause spinal pain (muscle-tension or pain-spasm-pain model) or (ii) changes in muscle activity serve to restrict spinal motion (pain adaptation model) Hodges and Moseley (2003) Disturbed muscle function seems to be a risk factor for developing LBP Anders et al (2005)

4. Abdominal muscles All trunk muscles play a role on supporting spine Internal and external oblique play an equally important role in maintaining spinal stability and trunk rotation Kavcic et al, (2004), Ng et al, (2006).

5. Internal and external obliques Internal and external oblique show relatively constant activity throughout the gait cycle White and McNair (2002). IO being most active during the late- stance phase and EO most active at mid- stance Waters and Morris, (1972), Dofferhof and Vink, (1985), Krebs et al, (1992) Callaghan et al (1999)

6. Forces through lower limb effect of supervised NW compared to unsupervised NW or advice to remain active (126 LBP subjects). no differences between 8 weeks of supervised or unsupervised NW and advice to remain active all groups experienced some improvement in pain and disability during the intervention period Hartvigsen et al (2010)

7. Forces through lower limb Walking with NW poles provides 30-50% load reduction to joints of the lower limb Geyer (2005) and INWF (2009)

8. Effects of walking poles on lower extremity gait mechanics All walking with poles conditions significantly increased walking speed, stride length, and stance time compared with the no poles condition. decrease in average vertical GRF walking with poles decrease in vertical (compressive) knee joint reaction force (13 subjects) Willson et al (2001)

9. Forces when walking with Nordic walking poles No-significant reductions in knee-joint loading when comparing walking with NW poles with normal walking, Schwameder and Ring (2006), Jöllenbeck et al (2006) and Grüneberg et al (2006)

10. Aim There is no evidence to date on the effect of walking with Nordic Walking Poles on abdominal muscle activity Conflicting evidence regarding the effect on lower limb forces Aim: To determine effect of walking with Nordic Walking Poles on: Internal & External oblique muscle activity Lower limb vertical ground reaction forces

11. Nordic Walker® Trainer CR

12. Method Crossover experimental study 15 (10F, 5M) Healthy subjects, 21.06 (± 0.88) years All provide informed consent Subjects underwent training period from International Nordic Walking Trainer, Karen Ingram

13. Outcome measures Surface EMG Maximum Voluntary contractions of IO & EO (% MVC) Kistler force platform Vertical Ground reaction forces (Newtons)

14. Method Study conducted in Research Centre of Clinical Kinaesiology Split group into 2. Group 1 were tested walking without poles first then with poles Group 2 were tested walking with poles first and without poles Practice time walking with and without NW poles in the Lab placing right foot on force plate

15. Method Walked at a self selected speed along eight metre walkway during both conditions Three sets of data were collected for each condition The mean muscle activities of IO & EO over the last five seconds of each condition were measured. Data processing:MATLAB 71 Data analysis (SPSS) Version 16 Paired t test as data normally distributed.

16. Results: Muscle activity and forces Significant Increases IO & EO walking with poles p=0.002 Internal oblique No poles 31.94 (39.9) With Poles 53.05 (40.6) External oblique No poles 46.45 (30.9) With Poles 87.93 (60.5) Significant Increase in VGRF walking with poles p=0.008 (11.13%) No poles 871.6 (237.00) Newtons With Poles 968.33 (210.8) Newtons

17. Summary Increased IO & EO activity may be of value for some LBP patients where increases in muscle activity are the objectives of treatment. EO largest values when walking with poles ?due to rotational component of walking pattern or arm activity VGRF increased ? due to novice walkers lack of practice subjects concentration on hitting force platform

18. Limitations & further research Small numbers of subjects Novice walkers Laboratory data collection Collect speed of gait data Forces through ankle/knee/hip Erector spinae muscles as well as abdominals Walking further distance

19. http://www.nordicwalking.co.uk/