ISOLATED LUMBAR EXTENSION RESISTANCE EXERCISE REDUCES LUMBAR KINEMATIC VARIABILITY DURING GAIT IN CHRONIC LOW BACK PAIN PARTICIPANTS

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1 ISOLATED LUMBAR EXTENSION RESISTANCE EXERCISE REDUCES LUMBAR KINEMATIC VARIABILITY DURING GAIT IN CHRONIC LOW BACK PAIN PARTICIPANTS BSc (Hons) a, Stewart Bruce-Low Ph.D a, Dave Smith Ph.D b, David Jessop Ph.D a, Neil Osborne Ph.D c Centre for Health, Exercise and Sport Science, Southampton Solent University a, Department of Exercise & Sport Science, Manchester Metropolitan University b, AECC Clinic, Anglo European College of Chiropractic c

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3 Walking not causally associated with CLBP (Roffey et al., 2010) The Spinal Engine (Gracovetsky, 1985) Normal lumbar movement in gait Consistent waveform pattern (Thurston & Harris, 1983; Crosbie et al. 1997; Callaghan et al. 1999; Whittle & Levine, 1999) Such fine control undoubtedly aided by musculature (Callaghan et al. 1999; Winter et al. 1993) In CLBP; Poor adaptability trunk/pelvis co-ordination (Seay et al., ; Seay et al., ) Stride to stride variability in all planes (Vogt et al., 2001) Poor lumbar extensor activity adaptability (Lamoth et al., 2004)

4 Exercise programs and Gait; Improvement related to strength gains (Hausdorff et al., 2001) Varied programs used in CLBP (Carpes et al., 2008; Tsao & Hodges, 2008; Da Fonseca et al., 2009) Pilates Trunk extension Stability programs Tranverse Abdominus activation But, not every exercise program is equal (Steele et al., 2013 a ) Effective in conditioning lumbar extensors and reducing pain and disability (Steele et al., 2013 b ) What effect does it have upon gait?

5 Study Purpose Rationale The lumbar spine plays an important role in normal gait control. In those with CLBP there is evidence of associated gait variability and lumbar extensor deconditioning. Therefore conditioning this musculature with specific exercise may confer improvement in kinematic control during gait in CLBP participants. Hypothesis Isolated lumbar extension resistance training produces significant improvement in lumbar spine control during gait in symptomatic CLBP participants in addition to increasing strength and decreasing pain and disability.

6 Study Design Randomised controlled trial Methodology Ethics approval granted by CHESS programme ethics committee as well as NHS Research Ethics Service Southampton B committee. Participants Identified and recruited by posters, group and word of mouth from Southampton Solent University. Direct referral was also provided from a local private chiropractor in addition to posters in their practice. All participants cleared by Chiropractor (Dr Neil Osborne, AECC) before participation Participant numbers determined by power analysis from previous research (Choi et al., 2005) 7 per group based on lumbar extension strength ES

7 Equipment & Testing Isometric ILEX strength testing, ROM and training performed using the MedX lumbar extension machine (MedX, Ocala, Florida). Reliable in asymptomatic (r = 0.81 to 0.97) (Graves et al, 1990) and symptomatic participants (r = 0.57 to 0.93) (Robinson et al. 1992), and valid in measurement (Pollock et al. 1991; Inanami, 1991). Standing ROM measured using the modified Schober s test in both flexion (Gill et al. 1988) and extension (Beattie et al. 1987) using a flexible ruler Pain measured using a 100mm point visual analogue scale (VAS; Ogon et al. 1996) Disability measured using the revised Oswestry questionnaire (ODI; Fairbanks et al. 1980)

8 Gait data collected using 10 camera 3D motion capture system (VICON) at 500hz Marker set-up (Schache et al., 2002) Low pass Butterworth filter (fourth order, cutoff frequency determined for each individual participant as sum of residuals closest to zero using 4Hz, 6Hz, 8Hz, 10Hz, and 12Hz) and normalised RHC to RHC (100%)

9 Data Analysis Independent variables Training condition (Training [FullROM & Lim ROM], Control) Dependent variables Group means for angular displacements Stride to stride intrasubject variability Ensemble average CV (Winters CV) Waveform pattern variability (CV p ) Offset variability (CV o ) For details of CV p and Cv o calculations see O Dwyer et al., (2009) Kinematic data did not meet assumptions of normality or homogeneity of variance Baseline group comparison (Mann Whitney-U exact test) Intervention comparison from pre to post (Wilcoxon Signed Ranks Exact test)

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11 Movement Amplitude Transformed to Zero (o) Movement Amplitude Transformed to Zero (o) Movement Amplitude Transformed to Zero ( o ) Movement Amplitude Transformed to Zero (o) Intervention effect Significant changes from pre to post only for sagittal plane CV p (W (16), Z = , p = 0.044) in the training group only Group mean ( %) Suggests improvement in stride to stride waveform pattern replication after the intervention. Gait Cycle (%) Gait Cycle (%) Pre = % CV p Post = % CV p Gait Cycle (%) Gait Cycle (%)

12 Discussion Winters CVs show similar gait variability to other studies (Vogt et al., 2001) Saggital plane being the exception CV p offers a better presentation of pattern consistency Saggital CV P highest of three movement planes Saggital pattern normally very consistent in healthy participants Saggital CV p significantly improved (~20%) after intervention Specificity of lumbar extension exercise? Other exercise improves gait control (Carpes et al., 2008; Tsao & Hodges, 2008;Da Fonesca et al., 2009) Further evidence for deconditioning's role in CLBP as a multifactorial condition?

13 Practical Implications ILEX exercise can improve saggital CV p Potential for reducing need for costly multi-intervention approaches

14 Thank you for listening