Reliability of movement control tests in the lumbar spine

Abstract

Background: Movement control dysfunction [MCD] reduces active control of movements. Patients with MCD might form an important subgroup among patients with non specific low back pain. The diagnosis is based on the observation of active movements. Although widely used clinically, only a few studies have been performed to determine the test reliability. The aim of this study was to determine the inter- and intra-observer reliability of movement control dysfunction tests of the lumbar spine.

Methods: We videoed patients performing a standardized test battery consisting of 10 active movement tests for motor control in 27 patients with non specific low back pain and 13 patients with other diagnoses but without back pain. Four physiotherapists independently rated test performances as correct or incorrect per observation, blinded to all other patient information and to each other. The study was conducted in a private physiotherapy outpatient practice in Reinach, Switzerland. Kappa coefficients, percentage agreements and confidence intervals for inter- and intra-rater results were calculated.

Results: The kappa values for inter-tester reliability ranged between 0.24 - 0.71. Six tests out of ten showed a substantial reliability [k > 0.6]. Intra-tester reliability was between 0.51 - 0.96, all tests but one showed substantial reliability [k > 0.6].

Conclusion: Physiotherapists were able to reliably rate most of the tests in this series of motor control tasks as being performed correctly or not, by viewing films of patients with and without back pain performing the task.

Figures

Figure 1

Test protocol – "Waiters bow". Flexion of the hips in upright standing without movement (flexion) of the low back. A. Correct -Forward bending of the hips without movement of the low back (50–70° Flexion hips). B Not correct Angle hip Fx without low back movement less than 50° or Flexion occurring in the low back. Rating protocol: As patients did not know the tests, only clear movement dysfunction was rated as "not correct". If the movement control improved by instruction and correction, it was considered that it did not infer a relevant movement dysfunction.

Figure 2

Test protocol – Sitting knee extension. Upright sitting with corrected lumbar lordosis; extension of the knee without movement (flexion) of low back A. Correct – Upright sitting with corrected lumbar lordosis; extension of the knee without movement of LB (30–50° Extension normal). B Not correct Low back moving in flexion. Patient is not aware of the movement of the back. Rating protocol: As patients did not know the tests, only clear movement dysfunction was rated as "not correct". If the movement control improved by instruction and correction, it was considered that it did not infer a relevant movement dysfunction.

Figure 3

Test protocol Rocking backwards. Transfer of the pelvis backwards ("rocking") in a quadruped position keeping low back in neutral. A. Correct -120° of hip flexion without (Fx) movement of the low back by transferring pelvis backwards. B Not correct Hip flexion causes flexion in the lumbar spine (typically the patient not aware of this). Rating protocol: As patients did not know the tests, only clear movement dysfunction was rated as "not correct". If the movement control improved by instruction and correction, it was considered that it did not infer a relevant movement dysfunction.

Figure 4

Test protocol Dorsal tilt of pelvis. Actively in upright standing. Correct – Actively in upright standing (Gluteus activity); keeping thoracic spine in neutral, lumbar spine moves towards Fx. B Not correct Pelvis doesn't tilt or low back moves towards Ext./No gluteal activity/compensatory Fx in Thx. Rating protocol: As patients did not know the tests, only clear movement dysfunction was rated as ''not correct''. If the movement control improved by instruction and correction, it was considered that it did not infer a relevant movement dysfunction.

Figure 5

Test protocol -Prone lying active knee Flexion. A. Correct – Active knee flexion at least 90° without extension movement of the low back and pelvis. B Not correct By the knee flexion low back does not stay neutral maintained but moves in Ext. Rating protocol: As patients did not know the tests, only clear movement dysfunction was rated as "not correct". If the movement control improved by instruction and correction, it was considered that it did not infer a relevant movement dysfunction.

Figure 6

Test protocol – Rocking forwards. A. Correct – Rocking forwards without extension movement of the low back.B Not correct Hip movement leads to extension of the low back Rating protocol: As patients did not know the tests, only clear movement dysfunction was rated as "not correct". If the movement control improved by instruction and correction, it was considered that it did not infer a relevant movement dysfunction.

Figure 7

Test protocol -One leg stance. From normal standing to one leg stance: measurement of lateral movement of the belly button. (Position: feet one third of trochanter distance apart). Correct – The distance of the transfer is symmetrical right and left. Not more than 2 cm difference between sides. B Not correct Lateral transfer of belly button more than 10 cm. Difference between sides more than 2 cm. Rating protocol: As patients did not know the tests, only clear movement dysfunction was rated as ''not correct''. If the movement control improved by instruction and correction, it was considered that it did not infer a relevant movement dysfunction.

Figure 8

Test protocol – Prone lying active knee flexion. A. Correct – Prone lying active knee flexion at least 90° without (rot) movement of the low back and pelvis. B Not correct Pelvis rotates with knee flexion. Rating protocol: As patients did not know the tests, only clear movement dysfunction was rated as "not correct". If the movement control improved by instruction and correction, it was considered that it did not infer a relevant movement dysfunction.

Figure 9

Test protocol -Crook lying. (supine, knees bent), A. Correct – Active abduction of the hip without rotational movement of the pelvis and low back. B Not correct Belly button moves sidewards, pelvis rotates or tilts. Rating protocol: As patients did not know the tests, only clear movement dysfunction was rated as "not correct". If the movement control improved by instruction and correction, it was considered that it did not infer a relevant movement dysfunction. Rating protocol: As patients did not know the tests, only clear movement dysfunction was rated as "not correct". If the movement control improved by instruction and correction, it was considered that it did not infer a relevant movement dysfunction.

Figure 10

Results overview. The kappa values for inter-rater and intra-rater reliability per pair or person, confidence interval 95% and average value 4 a. Waiter bow; 4 b. Pelvic tilt; 4 c. One leg stance right; 4 d. One leg stance left; 4 e. Sitting knee extension; 4 f. Rocking backwards; 4 g. Rocking forwards; 4 h.Prone knee bend extension; 4i. Prone knee bend rotation; 4 j. Crook lying : Kappa values for: inter-rater first pair of raters (inter 1), second pair (2), average of pair 1 and 2 (Ø), intra-rater for the first rater (intra 1), for the second rater (2) and average of both (Ø). The kappa value should be over 0.4 to be good (bar) and the lower bound of confidence interval at least 0.2 to be fair (line).