Nick


 * Nick's part of ethics:**
 * 8. Nature of research, including methodology and a list of all procedures to be used on human participants. Please include a statistical power analysis statement if applicable **

**__Participants: __** how will the patients contact gary? Telephone in persion ie. Information session The following inclusion and exclusion criteria will be assessed by Kymberley Sayers BSc (Clinical science) – student investigator, Shaun Richardson BSc (Clinical science) – student investigator, Claire Richardson BSc (Clinical science) – student investigator, Melanie Taylor BSc (Clinical science) – student investigator and Nicholas Wittenberg BSc (Clinical science) – student investigator. //A) ////Inclusion criteria // Healthy?  participants of either gender without current low back pain, aged between 18 and 50 years.

//B) ////Exclusion criteria // Participants will be excluded from this study if they are currently suffering from lower back pain. A neurological screening examination will be performed by Dr. Gary Fryer ( insert credentials ) to exclude subjects with radiculopathy or peripheral neuropathy. Participants will also be excluded if they exhibit any history signs that are contraindicative to HVLA as defined in (Gibbons and Tehan, 2010). Pregnancy/possibility of being pregnant and medications to also be exclusion criteria

**//C) //****//Withdrawal criteria //** Patients will be withdrawn from the study if they exhibit any apparent aggravation of pain from the intervention, or any other complications to the interventions (Gibbons and Tehan, 2010).

**__Experimental design: __** The study will be a controlled cross-over design where participants will be undergo both the control and experimental intervention, tested one week apart. The order of the treatment intervention will be randomised. When taking MEP readings pre and post intervention, won’t the patient have to be supine? Sitting them up again after a Lx manip will change biomechanics and is not logical. After determining the optimal stimulation site and individual motor threshold (defined as the lowest stimulation to evoke an MEP above 50 μV in 50% of MEPs), 10 MEP's (spaced 4 - 5 s apart) will be recorded at 20% above motor threshold as baseline values. Participants will then relocate to a treatment table and an intervention will be randomly allocated and performed. Immediately after the intervention, MEP's will be measured at 20 s intervals within the first 120 s to determine the acute time course of post manipulation effects on central motor pathways. MEP's will also recorded at 5 and 10 minutes after manipulation. Participants will return for a second session one week later and will receive the same procedures with the alternative intervention. //B) ////Interventions // //HVLA // The HVLA interventions will consist of either of the following (Gibbons and Tehan, 2010): 1 or 2 thrusts?? What if we can’t get cavitation on first thrust? <span style="font-family: 'Arial','sans-serif'; font-size: 10pt;">A right sided L5-S1 side-posture HVLA manipulation will be administered. The patient is placed in a side-lying position, with hips in approximately 20 degrees of flexion. The lower left leg is left straight, with the upper right hip and knee are slightly flexed. The upper body is rotated to the right until the level of L5-S1. The clinician then manually contacts the tissues overlying the zygapophyseal joint, reinforcing both the lower and upper body rotation. The practitioner ensures that the participant is relaxed, and once tissue tension is maximised, a HVLA thrust is applied. The thrust is applied in the direction of the apophyseal joint plane, usually in a direction of a line along the long axis of the patient's right femur (Gibbons & Tehan, 2008).
 * __<span style="font-family: 'Arial','sans-serif'; font-size: 10pt;">Procedure: __**
 * //<span style="font-family: 'Arial','sans-serif'; font-size: 10pt;">A) Measurement of MEP //**
 * · <span style="color: #00b0f0; font-family: 'Arial','sans-serif'; font-size: 10pt;">L5-S1 will be adjusted in neutral positioning with patient sidelying; direction of thrust is dependent on apophysial joint plane
 * · <span style="color: #00b0f0; font-family: 'Arial','sans-serif'; font-size: 10pt;">L5-S1 will be adjusted in flexion positioning with patient sidelying; direction of thrust is dependent on apophysial joint plane

<span style="background: white; font-family: 'Arial','sans-serif'; font-size: 10pt; margin-bottom: 0pt;">The operator will assist the participant into a side posture; however no truncal torque will be applied and no manual contact will be made with the spine. **__<span style="font-family: 'Arial','sans-serif'; font-size: 10pt;">Statistical Analysis: __** <span style="background: white; font-family: 'Arial','sans-serif'; font-size: 10pt; margin-bottom: 0pt;">Data will be collated using Microsoft Excel and analysed using SPSS version 18. Analysis of within and between group changes in MEP from baseline, immediately after intervention and 5 minutes after intervention will be performed using a split plot ANOVA (SPANOVA). Cohen’s d effect sizes will also be calculated on the pre-post data. The alpha level will be set at 0.05
 * 1) **//<span style="font-family: 'Arial','sans-serif'; font-size: 10pt;">Control group: //**

The monosynaptic Hoffmann Reflex (H-Reflex) is the electrically induced version of the spinal stretch reflex, also known as the myotatic reflex. Eliciting the H-reflex involves electrical stimulation of the Ia afferent fibers proximal to their origin in the muscle spindle, thereby bypassing the muscle spindle. The stimulus travels in the Ia afferent fibers through the motoneuron pool of the corresponding muscle to the efferent (motor) fibers. The H-reflex is an estimate of alpha motoneuron ( a MN) excitability when presynaptic inhibition and intrinsic excitability of the a MNs remain constant. (Palmieri et al., 2004)
 * Nick's part of Proposal:**
 * 1)** <span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 11pt;">**theories of HVLA. ie h - reflex, osteo theories, chiro theories**

An early study involving H-reflex changes following spinal manipulation was conducted by Dishman et al., 2000. The study investigated the effect of lumbosacral manipulation versus spinal mobilization on tibial nerve H-reflexes recorded from the gastrocnemius muscle. The authors found that there was a significant decrease in the H/Mmax ratio measured 10 seconds after the spinal manipulation, which returned to baseline 30 seconds after the manipulation. Dishman et al. published a paper in 2002 contrasting the different effects of cervical versus lumbar spinal manipulation on the tibial nerve H-reflex recorded from the gastrocnemius muscle. The authors found that the H/Mmax ratio was significantly depressed with respect to baseline values for 60 seconds after the L5/S1 spinal manipulative procedure; however, the there was no concomitant change after C5-6 spinal manipulation. This led them to conclude that SMT inhibition of motoneuron activity involves a local segmental response rather than an integrative central response. Another study on the effects of H-reflex changes following sacroiliac joint manipulation was conducted by Murphy et al., 1995. The study investigated H-reflex responses from the soleus muscle after ipsilateral sacroiliac joint manipulation. The authors found that H-reflex amplitude was significantly decreased in the ipsilateral leg (p < 0.001) post manipulation while there was no significant alteration following the sham intervention or in the contralateral leg.
 * Studies involving spinal manipulation and H-Reflex:**

A number of papers have demonstrated the existence of reflex muscular activity following spinal manipulation. An EMG study on reflex muscular responses to HVLA was published by (Herzog et al., 1999). The study demonstrated a consistent and systematic reflex response both in muscles local to the manipulated joint and also in more distant muscles. The estimated latency of the reflex response was 50ms. (Symons //et al//., 2000) conducted a similar experiment using an activator device to deliver the manipulation. More localized, mainly ipsilateral reflexes with a latency of 4ms were noted. An additional study on the effect of activator induced thrusts was conducted on low back pain patients by (Colloca and Keller, 2001). This paper also demonstrated reflex responses with a latency of 4ms and found that patients with the greatest degree of pain and disability had the largest amplitude of reflex response.
 * Studies involving spinal manipulation reflex muscular activity:**

Colloca CJ, Keller TS. Electromyographic reflex responses to mechanical force, manually assisted spinal manipulative therapy. //Spine// 2001;**26**:1117–24 Dishman JD, Bulbulian R. Transient suppression of alpha motoneuron excitability following lumbosacral spinal manipulation. Spine 2000;25:2519-25 Dishman JD, Cunningham BM, Burke J. Comparison of tibial nerve H-reflex excitability after cervical and lumbar spine manipulation. J Manipulative Physiol Ther 2002;25:318-25 Herzog W, Scheele D, Conway PJ. Electromyographic responses of back and limb muscles associated with spinal manipulative therapy. //Spine// 1999;**24**:146–52; discussion 153 Murphy BA, Dawson NJ, Slack JR. Sacroiliac joint manipulation decreases the H-reflex. Electromyogr Clin Neurophysiol 1995;35:87-94 Palmieri RM, Ingersoll CD, Hoffman MA. The Hoffmann reflex: methodologic considerations and applications for use in sports medicine and athletic training research. //Journal of Athletic Training// 2004;39(3):268–277 Symons BP, Herzog W, Leonard T, Nguyen H. Reflex responses associated with activator treatment. //J Manipul Physiol Therap// 2000;**23**:155–9

<span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 11pt;">This article has __shitloads__ on the theory behind why we do hvla. <span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 11pt;">http://hvlaandtms.wikispaces.com/file/view/Maigne+2002+Mechanisms+of+SMT.pdf <span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 11pt;">Can you maybe include stuff about the stretch reflex? i haven't gone into it really..

<span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 11pt;">Possible reason for paradoxical inhibition/excitation given in 2002 Dishman article:

<span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 11pt;">"The H-Reflex is highly susceptible to presynaptic inhibition of 1a afferents that mediate the reflex. If SMT produces inhibition of 1a afferent fibres by means of stimulation of presynaptic inhibitory interneurons, the decrease in amplitude of of the H-reflex may be independent of changes in the excitability of the alpha motoneuron pool." <span style="color: #ff0000; font-family: Arial,Helvetica,sans-serif; font-size: 11pt;">**<--- Answered in red below** <span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 11pt;">H-Reflex is not the best way to assess motoneurone excitability because it is a "summation of both pre and post-synaptic mechanisms." Therefore stimulation of the presynaptic inhibitory neurons by hvla could theoretically give the decreased h-reflexes found in the 2000 dishman article. <span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 11pt;">TMS can make "an accurate assessment of overall central motor system excitability". TMS generates post-synaptic MEP's, the amplitude of which can reflect changes in the alpha motoneurone pool excitability.

<span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 11pt;">"The paradoxical effects of L5-S1 SM procedure <span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 11pt;">on H-reflex and MEP responses may be best explained by <span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 11pt;">evidenced by H-reflex inhibition that may adversely affect <span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 11pt;">the stability of the increased recruitment gain of the <span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 11pt;">motoneuron pool subsequent to SM, as evidenced by MEP <span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 11pt;">facilitation. In support of this mechanism, **<span style="color: #ff0000; font-family: Arial,Helvetica,sans-serif; font-size: 11pt;">presynaptic **
 * <span style="color: #ff0000; font-family: Arial,Helvetica,sans-serif; font-size: 11pt;">presynaptic gating **<span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 11pt;"> of peripheral feedback mechanisms, as
 * <span style="color: #ff0000; font-family: Arial,Helvetica,sans-serif; font-size: 11pt;">inhibition does not influence corticospinal inputs to the α **
 * <span style="color: #ff0000; font-family: Arial,Helvetica,sans-serif; font-size: 11pt;">motoneuron pool, which is the descending pathway **
 * <span style="color: #ff0000; font-family: Arial,Helvetica,sans-serif; font-size: 11pt;">measured with TMS **<span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 11pt;">" - Dishman 2008 MOTOR-EVOKED POTENTIALS RECORDED FROM LUMBAR ERECTOR SPINAE MUSCLES: A STUDY OF CORTICOSPINAL EXCITABILITY CHANGES ASSOCIATED WITH SPINAL MANIPULATION

<span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: 11pt;">http://hvlaandtms.wikispaces.com/file/view/First+prize+central+motor+excitability+changes+after+spinal+manipulation.pdf -love from pasty.

Alpha motor neurons: • Each muscle fibre only supplied by 1 alpha LMN • 1 alpha LMN may supply multiple muscle fibres • 1 alpha LMN and the muscle fibres it supplies is known as a motor unit • All of the alpha motor neurons required to supply an entire muscle is known as a motor neuron pool
 * GLOSSARY:**