Body posture or posture control in back pain patients André Ljutow Centre for Pain Medicine, Nottwil
What is this lecture about? Due to the possibility to measure human posture questions like «What is a normal posture?» and «Is bad posture responsibel for low back pain?» arose. Our data show, that posture itself is not different in healthy individuals and persons with chronic low back pain (clbp), body sway on the contrary is enlarged but proprioception seems not to be altered.
Questions The myth of bad posture as a reason for low back pain: Do persons suffering from chronic low back pain have different body postures compared to healthy controls? Do persons with chronic low back pain have different body sway as a sign of altered posture control?
Literature Recent literature seems to demonstrate in persons with low back pain increased body sway in quiet standing position. This increase is due to a shift in posture control from hip compensation to ankle compensation. Impairment of proprioception as a cause is suggested.
Literature Hamaoui, A (Neuroscience Letters) 2004 Mok, N (Spine) 2004 Bouche, K (Eur Spine J) 2005 Ratzon, N (Work) 2006 della Volpe, R (Gait and Posture) 2006 Popa, T (Exp Brain Res) 2007 Brummage, S (Eur Spine J) 2008 Lafond, D (Gait & Posture) 2009 Mazaheri, M (Gait & Posture) 2010 Lee, A S (Arch Phys Med Rehabil) 2010 Claeys, K (Eur J Appl Physiol) 2011
Measurements in Literature Author Bouche, K. 2005 N o of patients N o of controls Closed eyes Special conditions 15 + 23 72 + One-legged stand 10 sec. (3x) Other criteria than body sway Body sway changed in study group Sway increased Explanatory notes Sign. Increase in clbp group with eyes closed Brummage, S. 2008 21 24 + Stand on foam, vibration on muscles Sway increased Proof of ankle compensation Byle, N. 1991 20 25 - One-legged stand, standing on toes/heels, instable sole Sway increased Additional use of hip compensation Hamaoui, A. 2004 Leinonen, V. 2003 Luoto, S. 1998 10 10 + 20 15 + 99 61 + Feet close together versus normal distance With and without vibration at erector spinae and calves, onelegged stand Velocitiy of change of COP position Velocitiy of change of COP position Sway increased Velocitiy of sway increased Velocitiy of sway increased Mientjes, M.I.V. 1993 Mok, N. 2004 Popa, T. 2007 Ratzon, N. 2006 8 8 + 24 24 + Head in different positions, stand on foam, stand bent forward One-legged stand, shortened base 13 13 + Moving pressure plate 41 + 12 28 + Stand on foam, head in different positions Densitiy of sway: time COP stays in a certain area, number and intervall of spikes Sway increased in mediolateral direction Sway increased Sway increased Sway increased correlation with results from Oswestry and Roland Morris With shortened base use of hip compensation, clbp didn`t meet demands 4 times more frequent della Volpe, R. 2006 12 12 + Moving pressure plate Sway increased
How to approach our questions Body posture can be measured in different ways, but a measurement in no touch technique seemed to have the smallest bias. Body sway is the measurement of body posture over time. Measuring foot pressure is an indirect proportion to the movement of the body.
How to measure body posture Optical impressions may be sometimes puzzling. Under standardized conditions optical measurement is highly more precise than any other measure.
Technical principle Parallel light lines are projected on the body In an oblique view due to the shape of the body these lines are converted into waves By trinagulation the three dimensional shape of the surface can be calcualted precisely
Just take a photograph Measurement is performed quick and easy, a minimum of instructions lessens bias effects Measurement over time allows measurement of body sway Measurements can be repeated (e.g. for therapy control)
What happens in hip or ankle compensation? hip compensation / ankle compensation
Rationale of measurements During quiet stand the body position is controlled by the sense of balance (which gives little information without movement) optical control proprioception By comparing measurements with the patient s eyes open and closed, deficits of proprioception, maybe due to low back pain, should become obvious by an increase in body sway
Measurement with DIERS Formetric 4D Screenshot of sway measurement
Our study We performed measurements in 50 persons with chronic low back pain (clbp) and 50 healthy controls. The patient group consisted of 20 men and 30 women, the control group of 28 men and 22 women. All patients completed a pain questionnaire, the relevant questions were also given to the control persons. Measurement was performed with Diers formetric 4D.
Our study Inclusion criteria for clbp persons: age 18 to 70 y., good communication in german language, pain for more than 3 months, clbp is major pain, chronicitiy (MPSS) II or III, no shortfalls in cognitive abilities, ability to stand without support, medium pain intensity 4 + (nrs 0 10), no sensory or motor deficit, consent to participate in the study Exclusion criteria for clbp persons: disease of nervous system, vertigo, disturbance of equilibrium, radicular pain, unability to stand upright, limited movement in hip-, knee- or ankle joint, foot problems, known pathology like spondylitis, previous low back surgery, severe scoliosis, drug or alcohol abuse Inclusion/exclusion criteria for control persons: as above, but no low back pain more than 3 nrs at the time of measurement or within the last three months
Study approval The study was approved by the ethical commitee of the state of Lucerne (no 845). There are no affiliations (financial or otherwise) with a commercial organization. The presented data have been elaborated without any financial help of any kind.
Outcome measures Body posture was recorded in all participants and compared between the two groups. Body sway was recorded during 30 sec. at level C7, level L5 and COP and compared between the two groups.
Characteristics of the two groups [median] clbp controls sign. diff. (p<0.05) age [y] 45.5 34.5 height [cm] 169 175 weight [Kg] 70.5 69.5 n.s. BMI 25.6 23.2
Characteristics of the two groups [median] clbp controls sign. diff. (p<0.05) number of pain sites 2 0 lbp since [y] 5 0 average pain intensity 6 0 pain before exam 5 0 pain after exam 6 0 pain chronicity [MPSS]( I / II / III ) 3 / 14 / 33 15 / 0 / 0 35 n.a. chronic pain grad. Scale [ 1 /../ 4 ] 2 / 12 / 18 / 18 3 / 0 / 0 / 0 47 n.a. HADS A 8 2 HADS D 9 0 SF-12 phys 29.1 55.5 SF-12 mental 42.4 57.8 FW-7 13.5 31 Oswestry 20 0
Body posture Body posture can be characterised by pelvis tilt, the angles of lordosis and kyphosis and the overall inclination of the trunk. [median] clbp controls sign. diff. (p<0.05) pelvis tilt [ ] 15.7 18 n.s. lordosis [ ] 37 38.5 n.s. kyphosis [ ] 50 50.4 n.s. trunk inclination [ ] 2 1.8 n.s.
No difference in body posture in persons with or without clbp
Body sway [median] clbp controls sign. diff. (p<0.05) a-p movement level C7 eyes open 19.7 18.6 n.s. eyes closed 29.7 22.5 a-p movement level L5 eyes open 14 10.5 eyes closed 16.9 14.6 a-p movement COP eyes open 9.1 6.1 eyes closed 10.8 9.5 n.s. (p=0.067)
Body sway Body sway in quiet stand is significantly different between persons with clbp and healthy individuals (exept measurement at C7 with open eyes). The clbp group shows bigger body sway. The reason for this difference might be a stiffening strategy in the lumbar region, which leads to more ankle compensation of body sway.
Body sway COP eyes open COP eyes closed L5 eyes open L5 eyes closed C7 eyes open C7 eyes closed a-p move [mm] controls clbp
Proprioception The ratio of increase in body sway with eyes closed versus eyes open may be a measure for impairment of proprioception. Ratio_COP Ratio_L5 Ratio_C7 controls median 1.4 1.1 1.1 sd 1.7 0.6 0.6 clbp median 1.6 1.1 1.4 sd 0.9 0.6 0.7 Wilcoxon test showed no significant difference betwen the ratio of sway increase. No difference in proprioception can be supposed.
Conclusions Posture is not different between clbp and controls Body sway in clbp is somehow different Disturbed proprioception might not be the cause The discussion about what kind of measure shows us relevant differences is still open The presented method gives in very short time a lot of useful informations, which we will have to interpret for therapeutical consequences
Thank you for your attention Special thanks to Angela Frotzler from the clinical trial unit for statistical calculations