Changes in apparent leg length”(leg retraction) have been used by many as a means of locating subluxation in various Joints. The leg assessment is based on the assumption that unequal muscular contraction (e.g. hyper irritable muscles) about the spine and pelvis have the ability to retract one leg relative to the other. Despite Claims of usefulness, many problems are inherent in the prone leg assessment such as: a) measurement error; b) subject positioning by the examiner (expectancy bias) and; c) interference with die surface of the examining table. There have been prior attempts to quantify the amount of leg length changes that occur during a treatment session, but most have suffered due to the lack of a measurement technique which provides the necessary accuracy in the recording of slight changes in heel position. The purpose of this study was to quantify involuntary, movements that result from neck flexion and extension maneuvers. Five subjects exhibiting involuntary leg reactions were tested using an optoelectric motion analysis system. During each testing session, the subject lay prone on an adjusting table while infrared light emitting diodes (IREDs) were affixed to the heels of fracture boots. In the rest position, the neck was in neutral flexion so the face rested on the surface of the table. Prior to testing, the examination area was in neutral flexion so the face rested on the surface of the table. Prior to testing, the examination area was calibrated resulting in RMS errors of less than 0.3 mm. Data were collected for ten seconds by three cameras positioned to record movement of the IREDs. During each testing session, each subject preformed two movements; a head-up movement, during which the subject extended the neck and then returned to a resting position, and a chin-tuck movement, in which the subject flexed the neck and then returned to a resting position. A testing session consisted of three no-movement baseline trials, followed by three head-up trials and three chin-tuck trials. Examination of output displacement histories showed that during all trials, movement occurred at the heels in the direction of the subject’s longitudinal axis. During the head-up trials, a majority of cases showed a net shortening in heel position during head movement.
Reference: John K. Dewitt. B.Sc.E, Paul J. Osterbauer, D.C., George E. Stelmach, Ed.D., & Arlan W. Fuhr. D.C.; Optoelectric Measurement of Leg Length Changes During Isolation Tests; Proceedings of the CCR’s 8th Annual Conference on Chiropractic Science in Health Policy and Research, Monterey, CA, June 18-20, 1993, pp. 156-7.
Affiliation: Arizona State University, Phoenix. Arizona and National Institute for Chiropractic Research, Phoenix, AZ.
More in this category: A Prospective, Randomized, Double Blind, Placebo Controlled Clinical Trial Assessing the Effects of Applying a Force to C5 by a Mechanically Assisted Instrument (MAI) on Referred Pain to the Shoulder » Characteristics of Paraspinal Muscle Spindle Response to Mechanically Assisted Spinal Manipulation: A Preliminary Report » Clinical Trials » Attenuation Effect of Spinal Manipulation on Neuropathic and Postoperative Pain Through Activating Endogenous Anti-Inflammatory Cytokine Interleukin 10 in Rat Spinal Cord » A Randomized Controlled Trial to Measure the Effects of Specific Thoracic Chiropractic Adjustments on Blood Pressure and Pulse Rate » Neural Response During a Mechanically Assisted Spinal Manipulation in an Animal Model: A Pilot Study » Comparison of spinal manipulation methods and usual medical care for acute and subacute low back pain: a randomized clinical trial. » In Vitro Biomechanical Evaluation of Single Impulse and Repetitive Mechanical Shockwave Devices Utilized for Spinal Manipulative Therapy » Safety & Effectiveness: The Foundations of Success » The Chiropractic Report – May 2014 » Neural responses to the mechanical parameters of a high-velocity, low-amplitude spinal manipulation: effect of preload parameters. » A pilot study of a chiropractic intervention for management of chronic myofascial temporomandibular disorder. » Review of methods used by chiropractors to determine the site for applying manipulation. » The Activator Story: Development of a New Concept in Chiropractic. » Effects of thrust amplitude and duration of high velocity low amplitude spinal manipulation on lumbar muscle spindle responses to vertebral position and movement. » Comparison of paraspinal cutaneous temperature measurements between subjects with and without chronic low back pain. » Chiropractic management of a veteran with lower back pain associated with diffuse idiopathic skeletal hypertrophy and degenerative disk disease » Changes in pressure pain thresholds and Basal electromyographic activity after instrument-assisted spinal manipulative therapy in asymptomatic participants: a randomized, controlled trial. » Clinical effectiveness of the Activator adjusting instrument in the management of musculoskeletal disorders: a systematic review of the literature. » Chiropractic spinal manipulative therapy for a geriatric patient with low back pain and comorbidities of cancer, compression fractures, and osteoporosis » Resolution of Breech Presentation Confirmed by Ultrasound Following Webster’s Technique » Evaluation of Mechanical Allodynia in an Animal Immobilization Model using the Von Frey Method » Cerebral Metabolic Changes in Men After Chiropractic Spinal Manipulation for Neck Pain » Interexaminer Reliability of Supine Leg Checks for Discriminating Leg-Length Inequality » Diagnostic Accuracy of the Clinical Examination in Identifying the Level of Herniation in Patients with Sciatica » Measuring the Effects of Specific Cervical Chiropractic Adjustments on Blood Pressure and Pulse Rate: A Randomized Controlled Trial » Intermittent low back pain referred from a uterine adenomyosis: a case report » Fall Risk Profile and Quality-of-Life Status of Older Chiropractic Patients » Immediate Effects of the Audible Pop from a Thoracic Spine Thrust Manipulation on the Autonomic Nervous System and Pain: A Secondary Analysis of a Randomized Clinical Trial » The relationship between pelvic torsion and anatomical leg length inequality: a review of the literature. » Relative effectiveness and adverse effects of cervical manipulation, mobilisation and the activator instrument in patients with sub-acute non-specific neck pain: results from a stopped randomised trial. » Chiropractic management of a 5-year-old boy with urinary and bowel incontinence » Chiropractic care of a 6 year old girl with neck pain; headaches; hand, leg and foot pain; and other nonmusculoskeletal symptoms » The safety and effectiveness of pediatric chiropractic: a survey of chiropractors and parents in a practice-based research network » Heart Rate Variability Modulation After Manipulation in Pain-Free Patients vs Patients in Pain » Interexaminer Reliability of a Leg Length Analysis Procedure Among Novice and Experienced Practitioners » Technique Systems used by post-1980 graduates of the Canadian Memorial Chiropractic College practicing in five Canadian provinces: a preliminary survey » Relative Immediate Effect of Ischaemic Compression and Activator Trigger Point Therapy on Active Upper Trapezius Trigger Points: A Randomized Trial » Treatment of Paroxysmal Supraventricular Tachycardia using Instrument-Assisted Manipulation of the Fourth Rib: A 6 Year Study » Effects of a Manually Assisted Mechanical Force on Cutaneous Temperature » Interexaminer Reliability of the Prone Leg Length Analysis Procedure » Variability of Force Magnitude and Force Duration in Manual and Instrument-Based Manipulation Techniques » Three-Dimensional Vertebral Motions Produced by Mechanical Force Spinal Manipulation » Activator as a theraputic instrument: Survey of usage and opinions amongst members of the British Chiropractic Association » A Hypothesis of Chronic Back Pain: Ligament Subfailure Injuries Lead to Muscle Control Dysfunction » Spinal Manipulation Reduces Pain and Hyperalgesia after Lumbar Intervertebral Foramen Inflammation in the Rat » Chiropractic Treatment of Temporomandibular Disorders Using the Activator Adjusting Instrument and Protocol » Spinal Manipulation Alters Electromyographic Activity of Paraspinal Muscles: A Descriptive Study » A Randomized Clinical Trial of the Relative Effectiveness of Manual Versus Mechanical Force Chiropractic Adjustments in the Management of Sacroiliac Joint Syndrome » Status of Activator Methods Chiropractic Technique, Theory and Practice » A review of the literature pertaining to the efficacy, safety, educational requirements, uses and usage of mechanical adjusting devices. Part 2 of 2 » Active Trunk Extensor Contributions to Dynamic Posteroanterior Lumbar Spinal Stiffness » A review of the literature pertaining to the efficacy, safety, educational requirements, uses and usage of mechanical adjusting devices. Part 1 of 2 » Neuromechanical Characterization of in Vivo Lumbar Spinal Manipulation. Part II. Neurophysiological Response » Neuromechanical Characterization of In Vivo Lumbar Spinal Manipulation. Part I. Vertebral Motion » Chiropractic Management of Ehlers-Danlos Syndrome: A Report of Two Cases » Chiropractic Treatment of Temporomandibular Disorders Using the Activator Adjusting Instrument: A Prospective Case Series » Lateral Cervical Curve Changes in Patients Receiving Chiropractic Care After A Motor Vehicle Collision: A Retrospective Case Series » Comparison of Dynamic Posteroanterior Spinal Stiffness to Plain Film Radiographic Images of Lumbar Disk Height » Chiropractic Name techniques in Canada: a continued look at demographic trends and their impact on issues of jurisprudence » A Review of Activator Methods Chiropractic Technique » A Novel Method For Assessing Elbow Pain Resulting From Epicondylitis » Force-deformation response of the lumbar spine: a sagittal plane model of posteroanterior manipulation and mobilization » Chiropractic Treatment of Postsurgical Neck Syndrome With Mechanical Force, Manually Assisted Short-Lever Spinal Adjustments » The Effective Forces Transmitted by High-Speed, Low-Amplitude Thoracic Manipulation » Stiffness and Neuromuscular Reflex Response of the Human Spine to Posteroanterior Manipulative Thrusts In Patients With Low Back Pain » Rating Specific Chiropractic Technique Procedures for Common Low Back Conditions » The diagnostic performance of vertebral displacement measurements derived from ultrasonic indentation in an in vivo model of degenerative disc disease » Fibromyalgia & Chronic Myofascial Pain Syndrome – A Survival Manual » Chiropractic “Name Techniques”: A Review of the Literature » A Pilot Randomized Clinical Trial on the Relative Effect of Instrumental Versus Manual Thrust Manipulation in the Treatment of Cervical Spine Dysfunction. » In Vivo Transient Vibration Assessment of the Normal Human Thoracolumbar Spine » Muscular and Soft-Tissue Contributions of Dynamic Posteroanterior Spinal Stiffness » Lumbar Erector Spinae Reflex Responses to Mechanical Force, Manually- Assisted Thoracolumbar and Sacroiliac Joint Manipulation in Patients with Low Back Pain » Correlation of L5 Dynamic Posteroanterior Spinal Stiffness to Plain Film Radiographic Images of Lumbosacral Disc Height » Neurophysiological Response to Intraoperative Lumbosacral Spinal Manipulation » Name techniques in Canada: current trends in utilization rates and recommendations for their inclusion at the Canadian Memorial Chiropractic College » The mechanics of spinal manipulation » Dynamic Response of the Human Lumbar Spine: A 5 DOF Lumped Parameter Time and Frequency Domain Model » Evaluating Teaching Effectiveness of the Activator Methods Chiropractic Technique Leg Check Based on Interexaminer Reliability » Electromyographic Responses To Mechanical Force, Manually Assisted Spinal Manipulative Therapy » Chiropractic Care for Patients Aged 55 Years and Older: Report from a Practice-Based Research Program » Mechanical Force Spinal Manipulation Increases Trunk Muscle Strength Assessed By Electromyography: A Comparative Controlled Clinical Trial » Reflex Responses Associated with Activator Treatment » Theory of small vertebral motions: an analytical model compared to data » Activator hand-held manual device included as part of the Medicare Carriers Manual Part 3 Chapter II Coverage of Chiropractic Services. » Interexaminer Reliability of Activator Method’s Relative Leg-Length Evaluation in the Prone Extended Position » Chiropractic Treatment of Coccygodynia via External Instrumental Adjusting Procedures utilizing Activator Methods Chiropractic Technique. » Muscular and Mechanical Behavior of the Lumbar Spine in Response to Dynamic Posteroanterior Forces » Validation of the Force and Frequency Characteristics of the Activator Adjusting Instrument: Effectiveness as a Mechanical Impedance Measurement Tool » Grand Rounds Discussion: Patient with acute low back pain » Treatment of Cervical Disc Protrusions Via Instrumental Chiropractic Adjustment. » Treatment of Symptomatic Lumbar Disc Herniation Utilizing Activator Methods Chiropractic Technique » Measurement of Soft Tissue Strain in Response to Consecutively Increased Compressive and Distractive Loads on a Friction-Based Test Bed » Movements of Vertebrae During Manipulative Thrusts to Unembalmed Human Cadavers » Safety in chiropractic practice. Part II: Treatment to the upper neck and the rate of cerebrovascular incidents. » The effects of spinal manipulation on the intensity of emotional arousal in phobic subjects exposed to a threat stimulus: a randomized, controlled, double-blind clinical trial. » Letters to the Editor | Safety in chiropractic practice. Part II: Treatment to the upper neck and the rate of cerebrovascular incidents. » Technique Overview: Activator Methods Chiropractic Technique » Engineering ─ In Vivo Transient Vibration Analysis of the Normal Human Spine » Activator Methods Chiropractic Technique » Comparison of Two Chiropractic Techniques on Pain and Lateral Flexion in Neck Pain Patients: a Pilot Study » Manipulation and mobilization of the cervical spine. A systematic review of the literature. » Three-Dimensional Head Kinematics and Cervical Range of Motion in the Diagnosis of Patients with Neck Trauma. » Oscillations of the Vertebrae in Spinal Manipulative Therapy » On Sounds and Reflexes of Cavitation » Back to Basics…Technology Assessment of the Chiropractic Subluxation » A Biomechanical Model of the Lumbar Spine During Upright Isometric, Flexion, Extension, and Lateral Bending » Comparison of Leg Length Inequality Measurement Methods as Estimators of the Femur Head Height Difference on Standing X-ray » The Immediate Effect of Activator vs. Meric Adjustment on Acute Low Back Pain: A Randomized Controlled Trial » Posterior Calcaneal Subluxation: An Important Consideration in Chiropractic Treatment of Plantar Fasciitis (Heel Spur Syndrome) » Instrumental Chiropractic Treatment of Frozen Shoulder Associated With Mixed Metastatic Carcinoma » Chiropractic Treatment of Frozen Shoulder Syndrome (Adhesive Capsulitis) Using Mechanical Force Manually Assisted Short Lever Adjusting Procedures. » Description and Analysis of Activator Methods Chiropractic Technique » Leg Length Inequality and the Side of Low Back Pain – A Pilot Study » Reflex Responses Associated with Manipulative Treatments on the Thoracic Spine: A Pilot Study » The Audible Release Associated with Joint Manipulation » Optoelectric Measurement of Changes in Leg Length Inequality Resulting from Isolation Tests » Conservative Treatment of Torn Medial Meniscus via Mechanical Force, Manually Assisted Short Lever Chiropractic Adjusting Procedures. » Measurement and Analysis of the In Vivo Posteroanterior Impulse Response of the Human Thoracolumbar Spine: A Feasibility Study » Dependence of the Delivered Force on the Force Setting on the Activator Adjusting Instrument » Instantaneous Helical Axis Estimation From 3-D Video Data in Neck Kinematics for Whiplash Diagnostics. » Optoelectric Measurement of Leg Length Inequalities Before, During, and After Isolation Tests. » The Activator Story: Development of a New Concept in Chiropractic » Biomechanical Characterization (fingerprinting) of Five Novel Methods of Cervical Spine Manipulation » Relationship between Preload and Peak Forces during Spinal Manipulative Treatments » Three-Dimensional Head Axis of Rotation During Tracking Movements: A Tool for Assessing Neck Neuromechanical Function » Responsiveness of leg alignment changes associated with articular pressure testing to spinal manipulation: the use of a randomized clinical trial design to evaluate a diagnostic test with a dichotomous outcome. » Reactivity of Leg Alignment to Articular Pressure Testing: Evaluation of a Diagnostic Test using a Randomized Crossover Clinical Trial Approach » Measurement and Analysis of Interspinous Kinematics » Evaluating Mechanical Force Manually Assisted Short Lever adjusting using an Anthropomorphic model » Treatment and biomechanical assessment of patients with chronic sacroiliac joint syndrome. » Treatment of Bell’s Palsy by Mechanical Force, Manually Assisted Chiropractic Adjusting and High-voltage Electrotherapy » Treatment of Bell’s Palsy by Mechanical Force, Manually Assisted Chiropractic Adjusting and High-voltage Electrotherapy » Three-dimensional Head Kinematics and Clinical Outcome of Patients with Neck Injury Treated with Spinal Manipulative Therapy: a Pilot Study » Vertebral Subluxation and Otitis Media: A Case Study » Motion Analysis as a Means to Objectify Changes in Apparent (Prone) Leg Length Inequality » Treatment of Chronic Sciatica by Mechanical Force, Manually Assisted, Short Lever Adjusting and a Video Assisted Stretching Program: A Quantitative Case Study » Non-Specific Short and Long Lever Chiropractic Adjusting: Principles and Practice » Mechanical Force, Manually Assisted, Short Lever Chiropractic Adjustment » Chiropractic Treatment Of Chronic Mechanical Low Back Pain In A Geriatric Population: A Practitioner-Scientist Protocol » Cervical spine: manipulative skill and performance considerations » The current status of Activator Methods Chiropractic Technique, theory, and training » Interexaminer Reliability of Eight Evaluative Dimensions of Lumbar Segmental Abnormality » Spinal learning: central modulation of pain processing and long-term alteration of interneuronal excitability as a result of nociceptive peripheral input. » Low Force Chiropractic Care of Two Patients with Sciatic Neuropathy and Lumbar Disc Herniation » Precise measurement of functional leg length inequality and changes due to cervical spine rotation in pain-free students. » Interexaminer Reliability of an Isolation Test for the Identification of Upper Cervical Subluxation » Interexaminer Reliability of Relative Leg Length Evaluations in the Prone Extended Position » Skin Accelerometer Displacement and Relative Bone Movement of Adjacent Vertebrae in Response to Chiropractic Percussion Thrusts » Effects of Chiropractic Treatment on Blood Pressure and Anxiety: A Randomized Controlled Trial » Reliability of the Derifield-Thompson test for leg length inequality, and use of the test to demonstrate cervical adjusting efficacy. » Effects of altered afferent articular input on sensation, proprioception, muscle tone and sympathetic reflex responses. » A model for the evaluation of chiropractic methods. » Accuracy of Piezoelectric Accelerometers Measuring Displacement of a Spinal Adjusting Instrument » The Force of the Activator® Adjusting Instrument » Inter- and intra-examiner reliability of leg-length differential measurement: a preliminary study. » Activator Adjusting For Acute Torticollis »