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  • Research article
  • Open Access

Pre- and post-operative gait analysis for evaluation of neck pain in chronic whiplash

Journal of Brachial Plexus and Peripheral Nerve Injury20094:10

  • Received: 22 April 2009
  • Accepted: 17 July 2009
  • Published:



Chronic neck pain after whiplash is notoriously refractory to conservative treatment, and positive radiological findings to explain the symptoms are scarce. The apparent disproportionality between subjective complaints and objective findings is significant for the planning of treatment, impairment ratings, and judicial questions on causation. However, failure to identify a symptom's focal origin with routine imaging studies does not invalidate the symptom per se. It is therefore of a general interest both to develop effective therapeutic strategies in chronic whiplash, and to establish techniques for objectively evaluation of treatment outcomes.


Twelve patients with chronic neck pain after whiplash underwent pre- and postoperative computerized 3D gait analysis.


Significant improvement was found in all gait parameters, cervical range-of-motion, and self reported pain (VAS).


Chronic neck pain is associated with abnormal cervical spine motion and gait patterns. 3D gait analysis is a useful instrument to assess the outcome of treatment for neck pain.


Serious persistent problems after whiplash trauma to the neck, sometimes referred to as Whiplash Associated Disorders (WAD)[1] is a common and costly condition; estimates indicate an incidence of over 250,000 in the United States, at an annual cost in 2002 of $2.7 billion or close to $10,000 per incident. [2] Although initial symptoms from acceleration-deceleration trauma to the neck may improve spontaneously or with physical therapy over the course of weeks-to-months, [1] chronic and potentially disabling symptoms persist in a significant percentage of all cases. [3, 4] A complicating factor, which is also a reason for controversy, is the frequent failure of routine clinical laboratory investigative methods including MRI and electrodiagnostic studies, to objectively identify the cause of pain and other symptoms. [5, 6]

Although not a universal finding, stiffness of the neck and shoulders is a common sequela of whiplash. [510] Using 3D motion analysis techniques, Dall'Alba et al. [11] identified significant limitations with a particular pattern of cervical range of motion among patients with WAD, but also pointed out that their results do not provide an explanation for the loss of neck mobility. In a study where similar techniques were applied, Gargan et al found that cervical range of motion and psychological scores at three months were predictive of clinical outcomes at 2 years. [11] Their findings were confirmed by Tomlinson et al in a follow-up study on the same cohort, 7.5 years later. [9]

Existing data suggest that neck stiffness in WAD may be an expression of pain inhibition from soft tissue injury and painful muscle spasm without pathology of the spine. Thus, injections of Botox® to trigger points in superficial neck muscles have been shown to provide temporary but significant decrease in pain and increase in cervical ROM,[8] with similar effect of short duration from injections of local anesthetic to myofascial trigger points in the neck. [12] While rarely a definitive solution to problems associated with the chronic whiplash syndrome, such injections may be helpful in identifying focal origin(s) of soft-tissue pain. [12, 13]

3D motion analysis represents the diagnostic gold standard for conditions that affect the kinematics of the lower extremities, pelvis and trunk. Using this technology, several investigators have confirmed that deviations from normal gait mechanics also affect the compensatory movements of the head and neck. [14, 15] Other studies have demonstrated that temporal and spatial changes in gait are complimented in the neck through input from the vestibulo-ocular reflex (VOR) for stabilization of gaze during angular movements, [16] while head position is controlled by the cervicocollic reflex (CCR), vestibulocollic reflex (VCR) and optocollic reflexes (OCR) through proprioceptive, vestibular and ocular mechanisms. [14, 16] Whether variations in gait parameters are voluntary (due to changes in terrain, gait speed, direction, etc.) or represent deviations from "normal" kinematics (changes in temporal distance measures of walking or joint movement from disease, injury, or surgery), they will, through reflex mechanisms, result in adaptive changes in the kinematics of the cervical spine.

The effect of lower segment dysfunction on the upper body kinematics has been previously investigated in normal controls and in patient groups with musculoskeletal disorders. [1719] We have not, however, found any studies exploring if standard gait parameters are impaired as a result of upper body dysfunction, The present investigation was designed for that purpose and, secondly, to assess the usefulness of computerized 3D gait analysis to objectively monitor outcomes of treatment for neck pain.



Participants were recruited among patients referred to University of Nebraska Medical Center for treatment of chronic neck pain after whiplash (WAD II–III, Table 1). Inclusion criteria are summarized in Table 2.
Table 1

Classification of Whiplash Associated Disorders (WAD)


No complaints. No objective physical signs


Pain. No objective physical signs.


Pain. Objective musculoskeletal signs, e.g. stiffness.


Pain. Objective neurological signs, e.g. weakness, numbness, absent tendon reflexes.


Pain. Radiological evidence of skeletal injury or dislocation.

Table 2

Inclusion criteria

Age 19 or older

Neck pain precipitated by whiplash trauma

Failure of conservative treatment for more than one year

Absence of gross neurologic signs

Absence of gross radiological (MRI) pathology

The study group consisted of twelve consecutive patients (10 F, 2 M) ages 26 to 67 (mean 44.9 ± 12.8). All subjects were able to understand simple commands and ambulate independently with or without assistive devices.


Areas of intense focal tenderness, generally in the lower cervical paraspinal musculature or horizontal segment(s) of the trapezius muscle(s), were preoperatively mapped through diagnostic injections of local anesthetic (Marcaine® 0.25 mg/ml). In a surgical procedure designed to identify and eliminate focal pain generators, the 'tender points' were thereafter addressed during an operation that generally included exploration, neurolysis and decompression of the spinal accessory nerve and/or dorsal sensory branches of cervical nerve roots at their passage through fibrotic trapezius fascia, and trapezius fasciectomy.[13, 20] In order to optimize the outcome of treatment, all patients participated actively with the surgeon in the operating room to identify focal areas of pain. No sedation, analgesia or local anesthetic was used during these key portions of the procedure.

Data collection

Three dimensional motion analyses were carried out using a six camera Vicon system (60 Hz), Vicon Workstation and Polygon software, and the Vicon Plug-In-Gait full body biomechanical model to collect pre- and postoperative data pertaining to gait (speed, cadance and step length), and cervical range-of-motion (degrees from resting position). Pain was assessed with a linear Visual Analogue Scale (VAS) graded 0–1. The evaluations were performed one week before, and 1–10 weeks (27.7 ± 21.6 days) after surgery.

Marker positioning and objective measurements. Four markers, placed at the left and right temporal and occipital regions, respectively, defined a 'head' segment. Additional markers over the sternal notch, xiphoid process, and spinous processes of C7 and T10, defined a 'thorax' segment to allow calculation of orthogonal angles between the two segments. The standard Vicon marker set was used for the lower extremities with a marker on each of the anterior iliac spines, centered between the posterior superior iliac spines, lateral on the thigh and shank, lateral on the knee joint and lateral malleolus and on the dorsum of the foot over the head of the second metatarsal. Figure 1. A static trial using a knee-alignment device was used to estimate knee joint centers.
Figure 1
Figure 1

Marker placement for computerized 3-D motion analysis.

A standard lower body marker set and Plug-In-Gait modeling software was used for precise calculation of repeated angle measurements from gait. [21] The precision of angle measurements for the cervical spine using the Plug-in gait modeling software has not been determined, but is assumed to be as valid as measures for the lower body. Precision of centroid position of the markers has been demonstrated to be accurate to within a millimeter (Vicon, Oxford, England).

During data collection, subjects were asked to move the head along three planes of the neck (flexion-extension, left-right rotation, left-right lateral flexion) to the point of maximum ability or tolerance. Angles between the thorax and head segments were calculated using the Plug-In-Gait full body model, and the maximum angle for each of three trials was identified for each direction of movement. The average of the three trials was used as outcome measure for maximum active range of motion in each direction.

Prior to the measurements of cervical mobility, subjects performed 10 to 15 walking trials at their self selected usual velocity. Walking speed was calculated for each trial, and the three trials closest to the subject's average walking speed were selected for analysis of the temporal distance parameters. Outcome measures included average walking speed, cadence, and bilateral step lengths.

Pain assessment. Participants rated their overall pain before and after each evaluation session, on a linear visual analog scale (VAS) with 0 representing no pain and 10 representing the most severe pain the subject had ever felt. Using the same scale, participants also rated their pain in relation to a typical day during the previous week.

Statistical analysis

Analysis of data was performed using Student's paired t-test. Statistical significance was set at p < 0.05. Intraclass correlation coefficient (ICC) was used to assess intra-session reliability for each of the six cervical spine motion measures taken during both pre and post sessions. [22] The data were compared using ICC (2,1) where time was modeled as a random effect since we were interested in the reliability between any repeated measurements measured not on the same time per session.


Excellent reliability of the cervical spine measures were observed with ICC values consistently above 0.9 as detailed in Table 3.
Table 3

Cervical Spine Measure ICC Values


ICC Value

C-Spine Motion Variables

Pre-Session Measure

Post-Session Measure







Left Lateral Flexion



Right Lateral Flexion



Right Rotation



Left Rotation



The analysis of data confirmed statistically significant (p < 0.005) improvement in cervical range of motion in all six planes following treatment, with the greatest average improvements in flexion-extension (54%), followed by rotation (53.5%). Table 4.
Table 4

Maximum Active Neck Range of Motion (degrees)




Mean change

Paired t-test


Mean ± SD

Mean ± SD



t statistic



25.2 ± 11.9

39.6 ± 12.9






29.3 ± 13.8

44.4 ± 20.2





L Rotation

36.1 ± 21.0

54.1 ± 18.2





R Rotation

37.3 ± 16.3

59.1 ± 16.1





L Lat Flexion

19.4 ± 14.1

25.9 ± 16.2





R Lat Flexion

22.9 ± 1201

32.7 ± 10.2





At follow-up, walking speed had increased by an average of 13.9 centimeters/second, with a 5.2 centimeter average increase in step length. Table 5.
Table 5

Temporal-Distance Gait Parameters




Mean Difference

Paired t-test


Mean ± SD

Mean ± SD



t statistic


Walking speed (cm/sec)

98.5 ± 29.1

112.4 ± 17.4





Cadence (steps/min)

105.9 ± 13.8

112.1 ± 7.6





Step length (cm)

54.5 ± 11.1

59.7 ± 7.9





All patients gave postoperative neck pain ratings that were significantly lower than before surgery, both for daily pain, and for how much their pain increased during exertion. Table 6.
Table 6

Pain Ratings (Visual-Analog Scale 0–10)




Mean change

Paired t-test


Mean ± SD

Mean ± SD



t statistic


Typical day average

6.2 ± 2.0

2.5 ± 1.8





Increase during test

1.6 ± 2.4

0 ± 1.9





No major complications related to treatment were documented among the participants during surgery or the postoperative period.


Significant improvement in three gait parameters were documented after treatment for neck pain from whiplash, a condition that because of a purported lack of diagnostic laboratory findings has been described by some authors as a social or emotional disorder in need of no treatment. [2325]

Pain-related neck stiffness is a cardinal component of the chronic whiplash syndrome, but reliable assessment of cervical range-of-motion is highly dependent on the subject's voluntary effort. Inclinometer- or observation based techniques, or even computer-guided three-dimensional measurement systems are therefore not ideal tools to objectively confirm or monitor chronic whiplash.[26] In contrast, gait is a complex but highly automated function and therefore better suited for standardized analysis.

A clinically validated marker system [27, 28] was adopted for the purpose of this investigation, and the consistency of cervical range-of-motion was confirmed through repeated measurements in each participant since kinematic reproducibility has been established as a method to differentiate healthy subjects simulating neck pain from patients with true whiplash injuries.[7, 12, 29] With these precautions, we consider the present findings reliable and valid.

Various kinematic abnormalities have been reported in chronic whiplash syndrome, often without conclusive evidence of their underlying cause(s). Thus, even though imaging evidence of abnormal cervical [30] or craniocervical [31] motion patterns have lead to recommendations to fuse the cranio-cervical joint complex, [32, 33] it has not been shown that a causative relation exists between such radiological findings and the clinical whiplash syndrome. Other investigators have interpreted patterns of oculomotor dysfunction in whiplash patients as evidence of brainstem injury, or "disorganized neck proprioceptive activity" leading to distortion of the posture control system. [3437] While none of the participants in this investigation had undergone specific diagnostic studies to assess brain stem function or cervical stability, the significant improvements in pain, cervical range-of-motion, and temporal-distance gait parameters illustrate that soft tissue surgery may alleviate considerable symptoms after whiplash in carefully selected patients. The findings also allow the following conclusions: (1) Upper segment pain, e.g. in chronic whiplash syndrome, may be expressed as gait and posture abnormalities;and (2) Computerized 3D gait analysis provides objective data for diagnosis or outcome studies in chronic whiplash.


Authors’ Affiliations

Department of Orthopaedic Surgery and Rehabilitation, University of Nebraska Medical Center, Omaha, NE 68198, USA
Division of Plastic and Reconstructive Surgery, University of Nebraska Medical Center, Omaha, NE 68198, USA
Munroe-Meyer Motion Analysis Laboratory, University of Nebraska, Lincoln, NE 68588, USA


  1. Spitzer WO, Skovron ML, Salmi LR, Cassidy JD, Duranceau J, Suissa S, Zeiss E: Scientific monograph of the Quebec Task Force on Whiplash-Associated Disorders: redefining "whiplash" and its management. Spine 1995, 20:1S-73S.View ArticlePubMedGoogle Scholar
  2. United Nations Economic and Social Council Proposal to Develop a Global Technical Regulation Concerning Head Restraints TRANS/WP.29/AC.3/13 2005.Google Scholar
  3. Carette S: Whiplash injury and chronic neck pain. N Engl J Med 1994, 330:1083–1084.View ArticlePubMedGoogle Scholar
  4. Rosenfeld M, Seferiadis A, Gunnarsson R: Active intervention in patients with whiplash-associated disorders improves long-term prognosis: a randomized controlled clinical trial. Spine 2003, 28:2491–2498.View ArticlePubMedGoogle Scholar
  5. Rauschning W, Jónsson H: Injuries of the cervical spine in automobile accidents: pathoanatomical and clinical aspects. In Whiplash injuries. Current concepts in prevention, diagnosis, and treatment of the cervical whiplash syndrome. Edited by: Gunzburb R, Szpalski M. Philadelphia, PA: Lippincott-Raven Publishers; 1998:33–53.Google Scholar
  6. Yoganandan N, Cusick JF, Pintar FA, Rao RD: Whiplash injury determination with conventional spine imaging and cryomicrotomy. Spine 2001, 26:2443–2448.View ArticlePubMedGoogle Scholar
  7. Antonaci F, Bulgheroni M, Ghirmai S, Lanfranchi S, Dalla Toffola E, Sandrini G, Nappi G: 3D kinematic analysis and clinical evaluation of neck movements in patients with whiplash injury. Cephalalgia 2002, 22:533–542.View ArticlePubMedGoogle Scholar
  8. Juan FJ: Use of botulinum toxin-A for musculoskeletal pain in patients with whiplash associated disorders. BMC Musculoskelet Disord 2004, 5:5.View ArticlePubMedGoogle Scholar
  9. Tomlinson PJ, Gargan MF, Bannister GC: The fluctuation in recovery following whiplash injury 7.5-year prospective review. Injury 2005, 36:758–761.View ArticlePubMedGoogle Scholar
  10. Gargan MF, Bannister G, Main C, Hollis S: The behavioural response to whiplash injury. J Bone Joint Surg Br 1997, 79:517–518.View ArticleGoogle Scholar
  11. Dall'Alba PT, Sterling MM, Treleaven JM, Edwards SL, Jull GA: Cervical range of motion discriminates between asymptomatic persons and those with whiplash. Spine 2001, 26:2090–2094.View ArticlePubMedGoogle Scholar
  12. Freeman MD, Nystrom A, Centeno C: Chronic whiplash and central sensitization; an evaluation of the role of a myofascial trigger points in pain modulation. Brachial Plex Peripher Nerve Inj 2009, 4:2.View ArticleGoogle Scholar
  13. Duffy MF, Stuberg W, DeJong S, Gold KV, Nystrom NA: Case Report: Whiplash-Associated Disorder from a low velocity bumper car collision. History, evaluation, and surgery. Spine 2004, 29:1881–1884.View ArticlePubMedGoogle Scholar
  14. Mulavara AP, Verstraete MC, Bloomberg JJ: Modulation of head movement control in humans during treadmill walking. Gait Posture 2002, 16:271–282.View ArticlePubMedGoogle Scholar
  15. Menz HB, Lord SR, Fitzpatrick RC: Acceleration patterns of the head and pelvis when walking on level and irregular surfaces. Gait Posture 2003, 18:35–46.View ArticlePubMedGoogle Scholar
  16. Chen KJ, Keshner EA, Peterson BW, Hain TC: Modeling head tracking of visual targets. J Vestib Res 2002, 12:25–33.PubMedGoogle Scholar
  17. Kavanagh JJ, Barrett RS, Morrison S: Upper body accelerations during walking in healthy young and elderly men. Gait Posture 2004, 20:291–298.View ArticlePubMedGoogle Scholar
  18. Frigo C, Carabalona R, Dalla Mura M, Negrini S: The upper body segmental movements during walking by young females. Clin Biomech (Bristol, Avon) 2003, 18:419–425.View ArticleGoogle Scholar
  19. Bartonek A, Saraste H, Eriksson M, Knutson L, Cresswell AG: Upper body movement during walking in children with lumbosacral myelomeningocele. Gait Posture 2002, 15:120–129.View ArticlePubMedGoogle Scholar
  20. Hagert CG, Christenson JT: Hyperpressure in the trapezius muscle associated with fibrosis. Acta Orthop Scand 1990, 61:263–265.View ArticlePubMedGoogle Scholar
  21. Kadaba MP, Ramakrishnan HK, Wootten ME: Measurement of lower extremity kinematics during level walking. J Orthop Res 1990, 8:383–390.View ArticlePubMedGoogle Scholar
  22. Shrout PE, Fleiss JL: Intraclass Correlations: Uses in Assessing Rater Reliabilty. Psychol Bull 1979, 2:420–428.View ArticleGoogle Scholar
  23. Ferrari R, Shorter E: From railway spine to whiplash – the recycling of nervous irritation. Med Sci Monit 2003, 9:HY27–37.PubMedGoogle Scholar
  24. Ferrari R, Russell AS, Carroll LJ, Cassidy JD: A re-examination of the whiplash associated disorders (WAD) as a systemic illness. Ann Rheum Dis 2005, 64:1337–1342.View ArticlePubMedGoogle Scholar
  25. Ferrari R, Kwan O, Russell AS, Pearce JM, Schrader H: best approach to the problem of whiplash? One ticket to Lithuania, please. Clin Exp Rheumatol 1999, 17:321–326.PubMedGoogle Scholar
  26. Schaufele MK, Boden SD: Physical function measurements in neck pain. Phys Med Rehabil Clin N Am 2003, 14:569–588.PubMedGoogle Scholar
  27. Wilk B, Karol LA, Johnston CE 2nd, Colby S, Haideri N: The effect of scoliosis fusion on spinal motion: a comparison of fused and nonfused patients with idiopathic scoliosis. Spine 2006, 31:309–314.View ArticlePubMedGoogle Scholar
  28. Engsberg JR, Lenke LG, Uhrich ML, Ross SA, Bridwell KH: Prospective comparison of gait and trunk range of motion in adolescents with idiopathic thoracic scoliosis undergoing anterior or posterior spinal fusion. Spine 2003, 28:1993–2000.View ArticlePubMedGoogle Scholar
  29. Berger M, Lechner-Steinleitner S, Hoffmann F, Schönegger J: Akzelerations-Dezelerations-Trauma der Halswirbelsäule. Diagnose schmerzbedingter und simulierter zervikaler Bewegungsstörungen. Schmerz 1998, 12:400–405.View ArticlePubMedGoogle Scholar
  30. Kristjansson E, Leivseth G, Brinckmann P, Frobin W: Increased sagittal plane segmental motion in the lower cervical spine in women with chronic whiplash-associated disorders, grades I-II: A case-control study using a new measurement protocol. Spine 2003, 28:2215–2221.View ArticlePubMedGoogle Scholar
  31. Krakenes J, Kaale BR, Moen G, Nordli H, Gilhus NE, Rorvik J: MRI assessment of the alar ligaments in the late stage of whiplash injury-a study of structural abnormalities and observer agreement. Neuroradiology 2002, 44:617–624.View ArticlePubMedGoogle Scholar
  32. Johansson BH: Whiplash injuries can be visible by functional magnetic resonance imaging. Pain Res Manag 2006, 11:197–199.PubMedGoogle Scholar
  33. Volle E, Montazem A: MRI video diagnosis and surgical therapy of soft tissue trauma to the craniocervical junction. Ear Nose Throat J 2001, 80:41–4. 46–8PubMedGoogle Scholar
  34. Prushansky T, Dvir Z, Pevzner E, Gordon CR: Electro-oculographic measures in patients with chronic whiplash and healthy subjects: a comparative study. J Neurol Neurosurg Psychiatry 2004, 75:1642–4.View ArticlePubMedGoogle Scholar
  35. Gimse R, Tjell C, Bjørgen IA, Saunte C: Disturbed eye movements after whiplash due to injuries to the posture control system. J Clin Exp Neuropsychol 1996, 18:176–186.Google Scholar
  36. Kristjansson E, Hardardottir L, Asmundardottir M, Gudmundsson K: A new clinical test for cervicocephalic kinesthetic sensibility: "the fly". Arch Phys Med Rehabil 2004, 85:490–495.View ArticlePubMedGoogle Scholar
  37. Hildingsson C, Wenngren BI, Bring G, Toolanen G: Oculomotor problems after cervical spine injury. Acta Orthop Scand 1989, 60:513–516.View ArticlePubMedGoogle Scholar


© Nystrom et al. 2009

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