The ‘jumpers knee paradox,’

The ‘jumpers knee paradox,’ where symptomatic athletes appear to perform better in measures of vertical jump height compared to asymptomatic individuals, has not been thoroughly explored. The aim of the current study was to investigate whether jumping ability and change of jumping ability may predispose an athlete to the onset of jumper’s knee [A&P: patellar tendinitis]. 

150 elite volleyball players were followed prospectively over a 5-year period. Vertical jump height –determined via counter movement jump (CMJ) and standing jump (SJ) – was assessed at the time of inclusion and semiannually. 28 athletes developed jumper’s knee over this period. Retrospective analysis revealed that symptomatic male athletes performed significantly better in CMJ compared with asymptomatic males at the time of inclusion, while no differences were detected in SJ. All athletes improved their jump performance over the duration of the study, with no significant differences observed in change in jump ability between symptomatic and asymptomatic athletes. 

These findings suggest that male volleyball players who naturally jump high are at greater risk at developing jumper’s knee, independent of subsequent improvements in jumping skills resulting from higher training loads > Visnes et al.; Br J Sports Med. (2012). All rights reserved to BJSM.

Lumbar instability is clinically characterized by a painful arc in a certain direction

Lumbar instability is clinically characterized by a painful arc in a certain direction, rather than end range pain or limitations in range of motion (ROM); often segmental shifts are visible in the painful direction, neural tissue provocation is generally normal. Movement dysfunctions can be divided into several directional patterns: patterns towards flexion or extension, lateral shift patterns and multidirectional patterns. The physical examination of patients presenting chronic low back pain (CLBP) due to instability should be targeted at identifying the symptomatic segment and possible directional specificity of the problem. Furthermore, the neuromuscular strategy of dynamic stabilization should be determined and a relationship must be found between the symptoms and local muscle control. When specific motor deficits are present, a motor learning model encompassing specific training of local muscles is appropriate: if an incorrect movement pattern is identified, components of this movement should be isolated and retrained in functional tasks > from O'Sullivan; Manual Therapy (2000) 2-12. All rights reserved to Harcourt Publishers Ltd.

The differentiation between nociception and pain is often ignored

The differentiation between nociception and pain is often ignored. Pain emerges from the brain according to apparent danger to body tissues. Nociception is the neural processes of processing noxious stimuli (mechanical, thermal or chemical changes above a certain threshold) that have the potential to damage tissue. 
Increased central sensitization is an (mal)adaptation that occurs when the body experience persisted pain. This optimizes the likelihood of tissue healing and minimize the risk of secondary injury in the beginning. Over time, sensitization may lose its value and become a problem of its own (chronic pain). Changes on cortical level occur. Certain strategies can treat people with central sensitization due to the plasticity of the brain. The main strategy within CLBP-patients is the cognitive and behavioral strategies: 
- Reduce feelings of helplessness and uncontrollability (establish a sense of control over pain)
- Change pain coping strategies
- Attention to activity planning and pacing
- Give education about pain and the factors that modulate it 

> from Moseley et al.; Neurorehabilitation and Neural Repair 26 (2012) 646-652. All rights reserved to the American Society of Neurorehabilitation.

Spinal manipulative therapy

Spinal manipulative therapy (SMT) is an intervention that is widely practiced by a variety of health care professionals worldwide. The effectiveness of this form of therapy for the management of chronic low-back pain has come under dispute. 

The results of this Cochrane review demonstrate that SMT appears to be as effective as other common therapies prescribed for chronic low-back pain, such as, exercise therapy, standard medical care or physiotherapy. However, it is less clear how it compares to inert interventions or sham (placebo) treatment because there are only a few studies, typically with a high risk of bias, which investigated these factors. Approximately two thirds of the studies had a high risk of bias, which means we cannot be completely confident with their results. Furthermore, no serious complications were observed with SMT. In summary, SMT appears to be no better or worse than other existing therapies for patients with chronic low-back pain > from Rubinstein et al.; The Cochrane Library - Cochrane Back Group (2012) DOI: 10.1002/14651858.CD008112.pub2. All rights reserved to The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.

A considerable amount of surgical reattachments of rotator cuff tendons to bone fails

A considerable amount of surgical reattachments of rotator cuff tendons to bone fails: the cellular and molecular processes responsible for tendon-to-bone healing are unable to form of functional attachment of sufficient strength. The insertion of platelet-rich fibrin (PRFM) might accelerate and increase quality of tendon healing. In this study, 79 patients - 40 of which were allocated to the experimental group and 39 to the control group - underwent arthroscopic repair techniques; tendon healing was evaluated by ultrasound at 6 and 12 weeks. Secondary outcome measures were standardized shoulder outcome scales and muscle strength, measured with a handheld dynamometer. 

Insertion of autologous PRFM at the tendon-bone junction during surgery did not have positive effects on tissue healing, tendon vascularity, muscle strength or symptoms. Linear regression analyses even suggested a possible detrimental effect of the application of PRFM on tendon healing; this finding however should be interpreted with caution due to the relatively small number of patients > from Rodeo et al.; Am J Sports Med 40 (2012) 1234-1241. All rights reserved to the author(s).

Acute hamstring injuries

Acute hamstring injuries are the most prevalent muscle injuries reported in sport. Despite a thorough and concentrated effort to prevent and , injury occrehabilitate hamstring injuriesurrence and re-injury rates have not improved over the last three decades. 

Previous injury, fatigue, strength, flexibility, core stability and architecture of the hamstring muscles have all been suggested to be involved in hamstring strains. However, there exists some contradiction within the scientific literature to indicate one single factor as possible cause of this injury. The authors of this article suggest that all of these factors are connected with each other and the combination of those factors can results in hamstring strain instead of one single factor. The model that they suggest should serve as a foundation for future research in developing a prevention method to decrease the high incidence of hamstring strains > from Mendiguchia et al.; British Journal of Sports Medicine 46 (2012) 81-85.. All rights reserved to BMJ Publishing Group Ltd.

The way attention and emotion modulates pain is a complex but relevant topic

The way attention and emotion modulates pain is a complex but relevant topic. Several studies focused on the interaction between the performance of a (non-painful) task and concurrent painful stimuli, which mainly resulted in disruptive performance i.e. reduced accuracy and increased recognition times. The aim of this study was to investigate the interaction between the task complexity nd the stimulus intensity, therefore salience, of phasic nociceptive stimulation. 

The main results of this study where: 
- Pain ratings can be reduced by increasing the load of attentional resources at the perceptual level of a pain-unrelated task.
- Nevertheless, the disruptive effect of highly intensive nociceptive stimuli on the performance of the perceptual task was only evident under high load. Which is an example of dissociation between the perception induced by the stimulus (i.e. pain) and the attentional effect it produces on the behavior. 

Important to note is that (like most studies), For RT (recognition times) analysis, only correct responses were analyzed > from Romero et al.; Pain (2012) article in press. All rights reserved to the Authors.

The purpose of this study was to determine examine the effects of Kinesio Tex tape (KT) on normal tissue

The purpose of this study was to determine examine the effects of Kinesio Tex tape (KT) on normal tissue. 20 female subjects were assigned to one of three groupings: facilitation taping using KT’s post-ACL taping protocol, placebo taping (cross-fiber) or no taping. The peak quadriceps torque was then examined using isokinetic testing to determine peak torque both concentrically and eccentrically at 60 and 240 degrees/second. 

The results suggest that application of KT on the anterior surface of the thigh, in the direction of vastus medialis, laterallis and rectus femoris fascia may increase the eccentric muscle strength (isokinetic eccentric peak torque) in healthy adults. It is not clear yet, if the results presented in this study, are related to skin or fascia mechanoreceptors, or to the biomechanical support of the muscle through the application of the tape at the direction of the fascia. It is not also known, if the increased muscle contraction observed immediately after the positioning of KT last for a long duration. These questions require further researches directed at the efficacy of KT for the relief of pain, the improvement of microcirculation and the decrease of muscle spasm > from Vithoulka et al.; Isokinetics and Exercise Science 18 (2010) 1-6. All rights reserved to IOS Press and the authors.

Trapezius muscle in patients with chronic mechanical neck pain

The purpose of this study was to compare the behavior of the trapezius muscle in patients with chronic mechanical neck pain (MNP) and clinical signs of scapula dysfunction to healthy controls.

Eighteen volunteers with chronic MNP and 20 healthy controls participated in the study. Participants performed isometric shoulder abduction, external rotation, and flexion at 3 intensities of effort (maximum voluntary contraction [MVC], 50% MVC, and 20% MVC). Electromyographic signals were recorded unilaterally from the upper, middle, and lower portions of the trapezius muscle during isometric shoulder contractions. Significantly greater levels of lower trapezius electromyographic signals were observed in patients with MNP compared with controls for the abduction and external rotation conditions but not for the flexion condition. No differences in activity were observed in the upper or middle portions of trapezius between groups during any of the isometric shoulder girdle conditions. 

These findings represent a change in the behavior of the lower trapezius muscle in individuals with MNP who exhibit clinical signs of scapular dysfunction. Clinicians should consider the potential involvement of the axioscapular muscles when assessing patients with chronic neck pain, as retraining scapular function may be required for the successful management of these patients > from Zakharova-Luneva et al.; Journal of Manipulative and Physiological Therapeutics 35 (2012) 346-353. All rights reserved to Elsevier Ltd.

Physical therapists routinely assess scapular position and motion

Physical therapists routinely assess scapular position and motion of the symptomatic shoulder taking as reference for the contralateral asymptomatic side. A different positioning between sides (scapular asymmetry) is often assumed as pathological, however, the symmetry of scapular kinematics in healthy individuals is yet to be demonstrated. 

The purpose of this study was to describe and compare 3D scapular kinematics of dominant and non-dominant shoulders in healthy individuals. The 3D scapular positioning of the dominant and non-dominant shoulders of fourteen healthy young adults was measured by an electromagnetic tracking device at three positions of arm elevation: rest, hands on hips, and 90 degree of shoulder abduction with internal rotation. The scapula on the dominant shoulder showed greater retraction and upward rotation at all positions of arm elevation. 

This study showed that at rest and throughout shoulder abduction, scapular positioning differs between dominant and non-dominant arms. This should be taken into consideration when comparing scapular position and motion of symptomatic and contralateral shoulders > from Morais et al.; Manual Therapy (2012) Epub ahead of print. All rights reserved to Elsevier Ltd.

A large body of evidence shows that chronic pain

A large body of evidence shows that chronic pain is associated with disruption of a range of body-related cortical representations. There is some evidence that this disruption contributes to, or maintains, chronic pain. The theory that the disruption reflects maladaptive neuroplastic changes underpins treatments that aim to normalize cortical representations as a way of treating chronic pain. 

This review has touched briefly on some of the changes that occur in the brain when pain persists, and which present barriers to successful recovery. The relation between pain and cortical reorganization has been observed in many chronic pain states. It is not only limited to sensory and motor representations but it could result in disruption across many efferent systems. 

Knowledge about these changes as a result of persistent pain, could provide more insight in why in some patients recovery is delayed. Although the mechanisms behind are not always as clear and straight forward, Treatments that target sensory and cognitive representations using sensory and motor strategies show functional and symptomatic benefits > from Moseley et al.; Neurorehabil Neural Repair 26 (2012) 646 652 . All rights reserved to Sage Journals.

We – medical doctors – are seeing an increasing number of dance-related injuries

Dance is becoming more popular especially with the advent of numerous dancing reality shows, not to mention popular dance-based workouts such as Zumba. As a result, we – medical doctors – are seeing an increasing number of dance-related injuries. 

This study looked at 500 dancers at the dance festival of Joinville (Brasil) over a period of 12 months. Dancers were broken into 4 groups: classical ballet, jazz/contemporary, tap/folk dance and street dance, based on biomechanical characteristics, the degree of motor demand and physiological aspects related to training in each group. 627 injuries were reported in 377 dancers, with overall incidence of dance injury being 70%. The most common anatomical region injured in the different groups was ankle/foot in classical dance, thigh/leg in contemporary/jazz, knee in tap/folk dance while there was no significant injury occurrence in different anatomical regions with street dance. 

The following were identified as risk factors for dance injuries: age and weight in jazz/contemporary dance; greater height in classical ballet; shorter height in tap/folk dance; and greater weekly frequency of practice in classical ballet and jazz/contemporary dance > from Soares Campoy et al.; Clin J Sport Med. 21 (2011) 493-498. All rights reserved by Lippincott Williams & Wilkins.

The Active Straight Leg Raise

The Active Straight Leg Raise (ASLR) is an important test in diagnosing pelvic girdle pain (PGP). This study investigated normal EMG activity during the ASLR in healthy subjects. During leg raising the Rectus Femoris (RF) was ipsilaterally active, Biceps Femoris (BF) contralaterally, and the abdominal muscles bilaterally. Hip flexion causes forward pull of the ipsilateral ilium. This is counteracted by contralateral BF activity. However this is only useful when the two sides of the pelvis act as a single unit, so when they are pressed together by force closure. Problems with this force closure can unable patients to perform the ASLR. Abdominal wall activity (ipsilateral Transverses abdominis and Obliquus abdominis internus) counteracts forward rotation of the ilium as well > from Hu et al.; Manual Therapy 17 (2012) 531-537. All rights reserved to Elsevier Ltd.