The objective of this observational cross-sectional study was to investigate the normal motion of the median nerve when stretched during a neurodynamic exercise. In recent years, ultrasonography has been increasingly accepted as an imaging technique for examining peripheral nerves in vivo, offering a reliable and noninvasive method for a precise evaluation of nerve movement. Transverse motion of the median nerve in the arm during a neurodynamic test was measured. A volunteer sample of 22 healthy subjects (11 women) participated in the study. Nerve displacement and deformation were assessed by dynamic ultrasonography. Excellent interobserver agreement was obtained, with kappa coefficient of .7–.8. Ultrasonography showed no lateral motion during wrist extension in 68% of nerves, while 73% moved dorsally, with statistically significant differences between sexes (ORlat = 6.3; 95% CI = 1.4–27.7 and ORdor = 8.3; 95% CI = 1.6–44.6). The cross-sectional area was significantly greater in men (3.6 mm2). Quantitative analysis revealed no other statistically significant differences. Our results provide evidence of substantial individual differences in median nerve transverse displacement in response to a neurodynamic exercise.
Jacinto Javier Martínez-Payá, José Ríos-Díaz, María Elena del Baño-Aledo, David García-Martínez, Ana de Groot-Ferrando and Javier Meroño-Gallut
Mindi Fisher, Ryan Tierney, Anne Russ and Jamie Mansell
Clinical Question: In concussed patients, will having attention deficit hyperactivity disorder (ADHD) or learning difficulties (LD) versus not having ADHD or LD cause higher symptom severity scores or invalid baseline protocols? Clinical Bottom Line: Research supports the concept that there is a difference at baseline for individuals with ADHD and/or LD compared with those who do not.
Y.L. Lo, H.H. Zhang, C.C. Wang, Z.Y. Chin, S. Fook-Chong, C. Gabriel and C.T. Guan
In overt reading and singing tasks, actual vocalization of words in a rhythmic fashion is performed. During execution of these tasks, the role of underlying vascular processes in relation to cortical excitability changes in a spatial manner is uncertain. Our objective was to investigate cortical excitability changes during reading and singing with transcranial magnetic stimulation (TMS), as well as vascular changes with nearinfrared spectroscopy (NIRS). Findings with TMS and NIRS were correlated. TMS and NIRS recordings were performed in 5 normal subjects while they performed reading and singing tasks separately. TMS was applied over the left motor cortex at 9 positions 2.5 cm apart. NIRS recordings were made over these identical positions. Although both TMS and NIRS showed significant mean cortical excitability and hemodynamic changes from baseline during vocalization tasks, there was no significant spatial correlation of these changes evaluated with the 2 techniques over the left motor cortex. Our findings suggest that increased left-sided cortical excitability from overt vocalization tasks in the corresponding “hand area” were the result of “functional connectivity,” rather than an underlying “vascular overflow mechanism” from the adjacent speech processing or face/mouth areas. Our findings also imply that functional neurophysiological and vascular methods may evaluate separate underlying processes, although subjects performed identical vocalization tasks. Future research combining similar methodologies should embrace this aspect and harness their separate capabilities.
Kym J. Williams, Dale W. Chapman, Elissa J. Phillips and Nick Ball
Purpose: To establish the influence of athlete-dependent characteristics on the generation and timing of system and individual joint powers during a countermovement jump (CMJ). Methods: Male national representative athletes from volleyball (n = 7), basketball (n = 6), and rugby (n = 7) performed a set of 3 CMJs at relative barbell loads of 0%, 10%, 20%, 30%, and 40% of absolute back-squat strength. Ground-reaction forces and joint kinematics were captured using a 16-camera motion-capture system integrated with 2 in-ground force plates. Limb lengths and cross-sectional areas were defined using 3-dimensional photonic scans. A repeated-measures analysis of variance determined the interaction between system and joint load–power profiles, whereas a multiregression analysis defined the explained variance of athlete-dependent characteristics on the load that maximized system power. Results: System and isolated hip, knee, and ankle peak powers were maximized across a spectrum of loads between and within sports; power values were not significantly different across loads. A positive shift in the timing of hip and ankle peak powers corresponded to a significant (P < .05) positive shift in the timing of system peak power to occur closer to toe-off. An optimal 3-input combination of athlete-dependent characteristics accounted for 68% (P < .001) of the explained variance in the load that maximized system peak power. Conclusion: The load maximizing system power is athlete-dependent, with a mixture of training and heredity-related characteristics influencing CMJ load–power profiles. The authors recommend that a combination of relative loads be individually prescribed to maximize the generation and translation of system CMJ power.
Melissa Jack, Ryan Tierney, Jamie Mansell and Anne Russ
Focused Clinical Question: In patients with myofascial trigger point pain, does dry needling result in greater decreases in pain compared to sham needling? Clinical Bottom Line: The evidence supporting dry needling as more effective than sham needling in reducing patients’ pain is mixed.
Tessa Gordon, Esther Udina, Valerie M.K. Verge and Elena I. Posse de Chaves
Injured peripheral but not central nerves regenerate their axons but functional recovery is often poor. We demonstrate that prolonged periods of axon separation from targets and Schwann cell denervation eliminate regenerative capacity in the peripheral nervous system (PNS). A substantial delay of 4 weeks for all regenerating axons to cross a site of repair of sectioned nerve contributes to the long period of separation. Findings that 1h 20Hz bipolar electrical stimulation accelerates axon outgrowth across the repair site and the downstream reinnervation of denervated muscles in rats and human patients, provides a new and exciting method to improve functional recovery after nerve injuries. Drugs that elevate neuronal cAMP and activate PKA promote axon outgrowth in vivo and in vitro, mimicking the electrical stimulation effect. Rapid expression of neurotrophic factors and their receptors and then of growth associated proteins thereafter via cAMP, is the likely mechanism by which electrical stimulation accelerates axon outgrowth from the site of injury in both peripheral and central nervous systems.
Joanne E. Folker, Bruce E. Murdoch, Louise M. Cahill, Kristin M. Rosen, Martin B. Delatycki, Louise A. Corben and Adam P. Vogel
Electropalatography (EPG) was used to describe the pattern of linguopalatal contact and the consonant phase durations exhibited by a group of seven individuals with dysarthria associated with Friedreich’s ataxia (FRDA). A group of 14 non-neurologically impaired individuals served as controls. The Reading Electropalatograph (EPG3) system was used to record linguopalatal contact during production of the target consonants (/t/, /l/, /s/, /k/) elicited in five words of CV and CVC construction, with the target consonants in word initial position. These words were embedded into short sentences and repeated five times by each participant. The FRDA group exhibited significantly increased consonant durations compared with the controls while maintaining normal linguopalatal contact patterns. These findings suggest that the articulatory impairment in FRDA manifests as a temporal rather than spatial disturbance.
Francesca Wightman, Suzanne Delves, Caroline M. Alexander and Paul H. Strutton
Descending bilateral control of external oblique (EO) and latissimus dorsi (LD) was investigated using transcranial magnetic stimulation. Contralateral (CL) motor evoked potential (MEP) thresholds were lower and latencies were shorter than for ipsilateral (IL) MEPs. Hotspots for EO were symmetrical; this was not the case for LD. The volumes of drive to the left and right muscles were not different. The laterality index was not different between the left and right muscles. The average index for the EO muscles was closer to zero than that for LD, suggesting a stronger IL drive to EO. The symmetry of drive to each muscle did not differ; however, the symmetry of drive varies within a subject for different muscles and between subjects for the same muscle. The findings may be useful in understanding a number of clinical conditions relating to the trunk and also for predicting the outcome of rehabilitative strategies.
Andrzej Kochanowicz, Bartłomiej Niespodziński, Jan Mieszkowski, Stanisław Sawczyn, Paweł Cięszczyk and Kazimierz Kochanowicz
Purpose: To determine neuromuscular and torque kinetic changes after 10 months of explosive sport training in the elbow of prepubertal gymnasts compared with untrained age-matched controls. Methods: In 15 young gymnasts (9.02 [0.41] y) and 15 age-matched untrained males (8.76 [0.51] y), the rate of torque development (RTD) using the Biodex System 4 and the coactivation index were evaluated using electromyography. Explosive strength variables were normalized to the peak torque. Measures were determined twice: before and after a 10-month period of gymnastic training. Covariation analysis was used to account for differences in baseline values between gymnasts and controls. Results: After 10 months of training, gymnasts demonstrated a significantly (P < .05) greater increase in normalized peak RTD values in elbow flexion compared with controls (7.76% vs 0.65%). Covariation analysis also revealed a significantly (P < .05) greater reduction in the coactivation index of elbow extension in the gymnasts (−7.81% [5.44%] points) compared with controls (−1.23% [6.32%] points). Conclusions: Compared with physical development alone, 10 months of explosive-strength training of young gymnasts is sufficient to increase torque-normalized RTD in the elbow joint of prepubertal boys. The RTD changes the authors observed in antagonistic elbow functions vary among gymnasts due to the specific demands of gymnastic training.
Neil Maguire, Paul Chesterton and Cormac Ryan
that a 70-minute PNE session for undergraduate physiotherapy students improved pain neurophysiology knowledge, improved attitudes, and increased the likelihood of delivering appropriate treatment recommendations to patients with chronic pain. Given the prevalence of low back pain in the athletic