Previous article Next article Full AccessLetters to the Editor-in-ChiefDecember 2011 Letters to the Editor-in-ChiefAuthorsJournal of Orthopaedic & Sports Physical TherapyPublished Online:December 1, 2011Volume41Issue12Pages983-987https://www.jospt.org/doi/10.2519/jospt.2011.0202SectionsPDFPDF PLUSAbstract ToolsAdd to FavoritesDownload CitationsTrack CitationsPermissions ShareShare onFacebookTwitterLinkedInRedditEmail AboutAbstractLetters to the Editor-in-Chief of JOSPT as follows: ‘Early Prognostic Factors in Patients With Whiplash’ and Author's Response‘Staying Current in the Use of Ultrasound Imaging’ and Author's Response‘Differentiating the Soleus From the Gastrocnemius With the Heel Raise Test’ and Author's ResponseJ Orthop Sports Phys Ther 2011;41(12):983–987. doi:10.2519/jospt.2011.0202Early Prognostic Factors in Patients with WhiplashRobert Ferrari, , MD, MSc (Med), FRCPC Clinical Professor, Department of Medicine, University of Alberta, Edmonton, Alberta, CanadaResponseDavid Walton , PT, PhDAssistant Professor, School of Physical Therapy, The University of Western Ontario, CanadaStaying Current in the Use of Ultrasound ImagingDouglas M. White, , DPT, OCS President, Imaging Special Interest Group, Orthopaedic Section, APTAResponseJackie Whittaker , BScPT, FCAMPT PhD candidate, Faculty of Health Sciences, University of Southampton, Southampton UK.The Practice; Physiotherapy and Pilates, White Rock, British Columbia, Canada and Maria Stokes , PhD, MCSP Professor of Neuromusculoskeletal Rehabilitation, Faculty of Health Sciences, University of Southampton, Southampton, UKDifferentiating the Soleus from the Gastrocnemius with the Heel Raise TestDamien Howell, , PT, DPT, OCS Bon Secours Physical Therapy, Richmond, Va.ResponseKim Hébert-Losier, , PT School of Physiotherapy, University of Otago, Dunedin, New Zealand, Anthony G. Schneiders, , PT, PhD School of Physiotherapy, University of Otago, Dunedin, New Zealand and S. John Sullivan, , PhD School of Physiotherapy, University of Otago, Dunedin, New ZealandWalton et al6 have further opened up a useful research avenue in terms of identifying early prognostic factors in patients with whiplash. While their results need to be confirmed in population-based samples, with additional data gathered on confounders, the data are promising. Central sensitization has been associated with chronic pain in patients with whiplash, although the extent to which it is a result or a cause of chronic pain (or both) has not been fully elucidated.3 At the same time that Walton and colleagues are showing how a measure of central sensitivity may be prognostic, the answer to a single question that asks patients with whiplash about their expectations of recovery is also a predictor of rate of recovery.1 In a large population-based cohort of more than 6000 patients with whiplash in the acute stage, the answer to the question “Do you think that your injury will…,” with response options “Get better soon,” “Get better slowly,” “Never get better,” or “Don't know,” was prognostic. After adjusting for the effect of sociodemographic characteristics, postcrash symptoms and pain, prior health status, and collision-related factors, those who expected to get better soon recovered over 3 times more quickly (hazard rate ratio, 3.62; 95% confidence interval: 2.55, 5.13) than those who expected that they would never get better.1 Findings were similar for resolution of pain-related limitations and resolution of neck pain intensity.There are many methods reported to assess central sensitization,1 but most require specialized equipment. One method reported to be useful includes the brachial plexus provocation test (BPPT).5 Although there is in fact no standard single test or combination of tests that represent the gold standard for a determination of central sensitization, the BPPT has been shown to be abnormal (compared to controls) in patients with whiplash, who also have other abnormal (compared to controls) test results for measures such as cold and heat sensitivity.4 In a recent study2 that examined 91 patients with whiplash within 1 week of their collision for their expectations of recovery and 3 months later with the BPPT as a sign of central sensitization, it was found that, after adjusting for a number of predictors, expectation of recovery predicted the results of the BPPT. In summary, those patients with whiplash who expect “never to get better” or “don't know” have a much higher likelihood of developing at least 1 sign of central sensitization 3 months later. It would thus be of interest in the future to examine the correlation, in the acute stage, between measures like pressure pain thresholds and expectations for recovery, to understand the interrelation between these seemingly prognostic factors. We thank Dr Ferrari for his comments and interest in our recently published paper evaluating the association between pressure pain threshold and outcomes in the short-intermediate term following whiplash.1 In his letter to the editor, Dr Ferrari addresses an important limitation of observational studies, which is that only variables that have been observed can be found to be predictive. This means that countless other variables remain unobserved, which may in fact be better predictors of outcome than those collected in any given study.We agree that patients often can provide an excellent “prognosis” about their recovery, as Dr Ferrari has pointed out in work that he has conducted with colleagues. Similar findings have been demonstrated in other patient populations, and for other outcomes like return to work. However, one of the limitations of patient expectations of recovery as a predictor is that it is not helpful in directing patients to specific interventions that might optimize recovery. We are uncertain which patients have reasonably calibrated their current physical health, injury manifestation, occupational demands, and life circumstances, in comparison to patients in whom potentially treatable hypersensitivity, fear of pain, etc, might be driving expectations. For this reason, when identifying predictors, important to consider those which are valued mainly for their accuracy in prediction (predictive) versus those that might contribute to clinical pathways that optimize treatment for individuals (explanatory).Although better understanding of predictors may eventually lead to refining treatment pathways, we urge caution in drawing conclusions regarding the mechanisms behind our findings, or any findings from observational research. Dr Ferrari raises the concept of central sensitization as a mechanism, which is certainly one possible pathway. Of course other mechanisms may also be at play. In our publication, we address the possibility of fear of pain as a mechanism. One might expect that a person fearful of pain would be more likely to halt a respondent-controlled pain threshold test early, and fear has also shown prognostic ability in whiplash and low back pain. In fact, a spectrum of biological and psychological factors contributes to pain perception. At this point, all we have shown is an association; but other criteria need to be addressed before we are confident in endorsing pressure pain threshold as an important prognostic factor. We also agree that the consistency of this association in different contexts and larger populations should be explored.We believe this is a promising avenue of research, and are heartened by the results obtained through the use of less resource-intensive measurement devices than those used previously. This step brings us closer to moving the assessment of pain thresholds into clinical practice. Further research in clinical settings may lead to a clearer understanding of the meaning and usefulness of these measures. At present, prognosis is a muddy swamp through which we wade, and it will take some time before the waters become clear.The clinical commentary, Ultrasound Imaging and Muscle Function,1 published in the August 2011 issue of the Journal of Orthopaedic & Sports Physical Therapy, is both interesting and timely. The description of ultrasound imaging (USI) of muscles describes this application of USI well. The use of USI by physical therapists has increased significantly in recent years. So have the applications of USI in physical therapist practice. As the availability of lower cost and portable ultrasound equipment has increased, it has become a practical adjunct to physical therapist patient management. It is anticipated that the scope of application of USI will continue to broaden as more physical therapists become aware of the value of USI in aiding patient management.Appropriate training in the use of USI is important for all healthcare practitioners who seek to employ this tool in practice and research. Considerations such as professional preparation, advanced training, intended applications of USI, and scope of practice, as defined by government bodies, all factor into both the qualifications necessary and the ability to employ USI in practice. Thus the authors' recommendation to use the World Health Organization's 1998 report2 on training in diagnostic ultrasound is no longer current or universally applicable to all physical therapists. Nor do training recommendations for diagnostic USI apply to physical therapists' use of USI to evaluate muscle function. Organizations such as the Imaging Special Interest Group Orthopaedic Section American Physical Therapy Association, the American Institute of Ultrasound in Medicine, and the American Registry for Diagnostic Medical Sonography are all in the process of developing guidance on the use of USI in musculoskeletal conditions. As these organizations move forward with their initiatives, physical therapists should consider applicability to their professional development in the use of USI.We thank Dr White for his letter regarding our commentary, Ultrasound Imaging and Muscle Function,5 in which he endorses our promotion of the use of ultrasound imaging (USI) by physical therapists and recognition of the urgent need for training. Dr White questions our recommendation to ensure that physical therapy training in USI be consistent with that proposed by the World Health Organization's 1998 report7 on training in diagnostic imaging and appears to have misunderstood our intention. We stated that “specialized training (consistent with the World Health Organization recommendations) is recommended,”7 not that the WHO approach, as it stands, meets the needs of the physical therapy profession. Our intention was to point out that the framework for training outlined in the report contains a template and guidelines that can be adapted to meet the specific needs of the physical therapy profession. The WHO report recognizes the need for prerequisite specific allied health training, additional didactic and practical training in USI, as well as supervised scans. It also acknowledges that the acquisition of USI skills occurs in stages and defines 3 levels of practice with curricular content that would be useful to expand upon for developing training to meet our needs.As the profession moves forward in its initiatives surrounding USI use by physical therapists, it is critical to keep in mind that current applications of USI in physical therapy essentially fall into 2 distinct areas of musculoskeletal imaging: rehabilitative USI (RUSI) and diagnostic imaging. The former, which includes evaluation of muscle structure (morphology) and behavior, as well as using USI as a biofeedback tool, is almost exclusive to physical therapy and of little interest to other disciplines.6 Conversely, diagnostic imaging, which involves examining the effects of injury, lesion, or disease on various musculoskeletal structures, is more established and of interest to multiple disciplines.4 Consequently the professional issues and barriers associated with specialized training of these 2 applications differ. For instance, diagnostic imaging has established standardized criteria (generally nation specific) for training, competent use, and regulation. Therefore, physical therapists need only undertake training consistent with these standards if they wish to become skilled in diagnostic musculoskeletal USI. In contrast, the emerging field of RUSI lacks overseeing professional bodies, standard curricula, and governance for training. Consequently, training opportunities and standards for clinical use are lacking, and there is little standardization for performing and reporting RUSI research.1–3 It is our belief that, although the needs of RUSI training are unique and specific, it is critical that the framework for this training be consistent with those of other imaging specialties if it is to be recognized as a legitimate specialty of imaging.Ultimately, the use of USI by physical therapists worldwide is dependent upon the development of comprehensive and effective RUSI training programs, access to existing diagnostic musculoskeletal USI training, and the evolution of healthcare policy related to the use of USI by allied health professionals. Underpinning this is the need for a strong foundational evidence base supporting the role of USI in the delivery of musculoskeletal physical therapy. Another important ingredient to achieving success is the dedication of individuals, such as Dr White and others, who devote a great amount of time and effort to the evolution of our profession as it relates to the integration of imaging technology.I commend the authors of Analysis of Knee Flexion Angles During 2 Clinical Versions of the Heel Raise Test to Assess Soleus and Gastrocnemius Function, on their contribution to an area where there is very little published evidence.1 There are a limited number of papers that examine the process of differentiating the soleus from gastrocnemius in a non-weight-bearing situation, and there are even fewer papers differentiating the soleus from gastrocnemius in a weight-bearing situation. The results suggest that 2 different knee flexion angles did not distinguish between 2 clinical versions of the heel raise test. The methodology used in the investigation asked the subjects to perform a heel raise on 1 foot “as high as possible.” The end point of the heel raise test of “as high as possible” may not reach the threshold required to affect the muscle length-tension relationship to achieve active insufficiency of the gastrocnemius required to differentiate the soleus from the gastrocnemius.Kendall2 proposed that ankle plantar flexion with the knee flexed leads to active insufficiency of the gastrocnemius. Kendall2 also proposed that the monoarticular soleus is expected to complete the full range of motion of the joint over which it crosses, and to exert a strong effective force at completion of this range of motion sufficient to a grade of normal.There is variance about standardization of the height of the heel raise test. A review by Losier1 identified the following heights that a unilateral heel raise test should achieve: as high as possible, 5 cm, 50% of maximum height of unilateral heel raise, or 90% of maximum height of unilateral heel raise test. The authors of the current investigation choose maximum height of a unilateral heel raise. I would suggest a different standard for the height of a unilateral heel raise test: the height achieved when performing a bilateral heel raise test. The height of a bilateral heel raise is likely closer to the end range of plantar flexion and closer to position of shortest length for muscles responsible for plantar flexion.A 1-repetition unilateral heel raise test to a height equal the height of a bilateral heel raise test may provide better differentiation between soleus and gastrocnemius. If the subject can perform a unilateral heel raise to the height equal to the height of a bilateral heel raise, then the subject can lift body weight through the full range of plantar flexion. If the subject cannot perform a 1-repetition unilateral heel raise test to a height equal to the height of a bilateral heel raise test, then a standing break test for plantar flexion is indicated. The subject positions the ankles and feet in a position of maximum plantar flexion by performing a bilateral heel raise to a maximum height, then, lifting 1 foot off the ground, the subject is asked to hold the position of maximum height. This process is similar to standard non-weight-bearing manual muscle testing procedure, in which the joint is positioned by the examiner so that the muscle is in a position of shortest length, and the subject is asked to hold the test position if possible. Failure to hold the test position infers that there is an “overstretch weakness” or length-associated muscle strain.3 Inability to hold the test position achieved by performing a maximum height bilateral heel raise will result in a break from the test position, and a sag in a relative movement of the ankle and foot in the direction of dorsiflexion will occur.If the subject is able to maintain a heel raise at a height equal to the height of a bilateral heel raise, the plantar flexor muscles are strong enough to isometrically hold body weight when the muscles of plantar flexion are in a shortened position. The 1-repetition unilateral heel raise test to a height equal the height of a bilateral heel raise test can be performed with the knee in 30° of flexion and with the knee in full extension, so that inferences of active insufficiency of either the soleus or gastrocnemius can occur.I find it curious that manual muscle testing of ankle and foot plantar flexion is the only manual muscle testing procedure which has evolved to include a test parameter for endurance and fatigue of multiple repetitions.Like the authors, I believe it is important to validate clinical examination methods to differentiate the muscle performance of the gastrocnemius from the soleus and to identify additional muscle performance tests to corroborate existing clinical examinations of muscle length (alignment and range-of-motion tests). Given the results of this study, I am curious to hear from the authors what future research questions need to be answered relative to clinically differentiating the muscle performance of gastrocnemius from the soleus.We are grateful to have the opportunity to reply to the comments made by Dr Howell in regard to our recent article published on the heel raise test (HRT).4 We agree with Dr Howell that there are few empirical reports on clinical procedures used in physical therapy to differentiate between soleus and gastrocnemius function, particularly in a weight-bearing position. We also agree that the numerous administrative protocols and parameters suggested for the HRT1 may influence the contribution of the soleus and gastrocnemius muscles relative to the task.3Dr Howell suggests that a unilateral HRT may not reach the threshold required for differentiation between soleus and gastrocnemius and proposes to standardize the heel raise height of a unilateral HRT to that of a bilateral HRT. This approach appears sensible in a nonpathological population; however, there is no current evidence that heel raise height or end-range plantar flexion is different between unilateral and bilateral HRT conditions. This is certainly an area for further investigation. Nevertheless, we emphasize that requiring healthy subjects to reach the highest height possible during a unilateral HRT does entail relative end-range plantar flexion that is task specific. Additionally, while Kendall suggests that soleus exerts a strong and effective force at end-range with the knee bent,6 it has also been reported that the amount of soleus relative to gastrocnemius activity decreases in this terminal position.5We appreciate Dr Howell's proposal that a single maximal effort unilateral test performed in both knee positions may provide a better differentiation between soleus and gastrocnemius. However, recent research findings from our laboratory suggest that a unilateral end-range plantar flexion “break” test with the knee straight is not specific to maximal gastrocnemius activity, nor is it to soleus with the knee bent.2 A unilateral standing break test in select knee positions may, therefore, not be an appropriate clinical indicator of specific triceps surae muscle function in healthy individuals. Whether it is useful in groups with pathological conditions warrants further research consideration.Finally, in response to Dr Howell's interest in what research we consider needs to be conducted to clinically differentiate the muscle performance of gastrocnemius from soleus, we have recently completed an EMG analysis of the muscle activity of these 2 muscles in different knee angles, different populations, and under fatigued and nonfatigued conditions. Like Dr Howell, we believe in the importance of systematic experimentation to establish the continuing role and clinical value of the HRT and similar tests in sports and orthopaedic clinical practice.1. Carroll LJ, , Holm LW, , Ferrari R, , Ozegovic D, , Cassidy JD. and Recovery in whiplash-associated disorders: do you get what you expect? J Rheumatol. 2009; 36: 1063– 1070. http://dx.doi.org/10.3899/jrheum.080680 Crossref Medline Google Scholar2. Ferrari R. and Predicting central sensitisation - whiplash patients. Aust Fam Physician. 2010; 39: 863– 866. Medline Google Scholar3. Nijs J, , Van Oosterwijck J, , De Hertogh W. and Rehabilitation of chronic whiplash: treatment of cervical dysfunctions or chronic pain syndrome? Clin Rheumatol. 2009; 28: 243– 251. http://dx.doi.org/10.1007/s10067-008-1083-x Crossref Medline Google Scholar4. Sterling M. and Testing for sensory hypersensitivity or central hyperexcitability associated with cervical spine pain. J Manipulative Physiol Ther. 2008; 31: 534–539. http://dx.doi.org/10.1016/j.jmpt.2008.08.002 Crossref Medline Google Scholar5. Sterling M, , Jull G, , Vicenzino B, , Kenardy J. and Sensory hypersensitivity occurs soon after whiplash injury and is associated with poor recovery. Pain. 2003; 104: 509–517. Crossref Medline Google Scholar6. Walton DM, , Macdermid JC, , Nielson W, , Teasell RW, , Reese H, , Levesque L. and Pressure pain threshold testing demonstrates predictive ability in people with acute whiplash. J Orthop Sports Phys Ther. 2011; 41: 658– 665. http://dx.doi.org/10.2519/jospt.2011.3668 Link Google ScholarReference1. Walton DM, , Macdermid JC, , Nielson W, , Teasell RW, , Reese H, , Levesque L. and Pressure pain threshold testing demonstrates predictive ability in people with acute whiplash. J Orthop Sports Phys Ther. 2011; 41: 658– 665. http://dx.doi.org/10.2519/jospt.2011.3668 Link Google Scholar