Inflatable penile prosthesis technique and outcomes after radial forearm free flap neophalloplasty.

The aim of this study was to describe the technical aspects and short-term outcomes of inflatable penile prosthesis (IPP) implantation after neophallus reconstruction at a single institution. Nine men with previously constructed radial forearm neophalli underwent IPP implantation. The etiologies of their penile anomaly were bladder exstrophy complex in five, disorder of sexual differentiation in two and genital obliteration secondary to ballistic trauma in two. Median follow-up was 9.6 months (range 1.5-139.7). The records for these patients were retrospectively reviewed and outcomes recorded. Mean age was 23.6 (range 18-31) years, and mean time interval from neophalloplasty to IPP implantation was 22.1 months (range 3-48). In all cases, 3-piece IPPs were employed, with eight of patients having one cylinder implanted in the native corporal body and extending into the neophallus. Mean surgical time was 222 min (range 142-409). Median length of implanted device was 22 cm. No intraoperative complications were observed. At the most recent follow-up, six patients (66.7%) had functional devices, with acceptable surgical outcomes. Three patients (33.3%) sustained device infections, and three (33.3%) sustained cylinder erosion. In three patients in whom neo-tunica albuginea were fashioned by ensheathing the cylinder with allograft human dermal tissue matrix, no erosions occurred. One patient underwent two revisions, the first for the associated erosion and infection and the second for genital pain, and was left with a semi-rigid prosthesis. IPP implantation affords the best opportunity for functionality for patients with a radial forearm free flap neophallus. Caution must be taken to ensure viability of the neophallus intraoperatively, and protocols to minimize the risk of infection should be followed. Fashioning neo-tunica albuginea using graft material may reduce risk of erosion.

Modern utilization of penile prosthesis surgery: a national claim registry analysis.

The objective of this study was to evaluate the modern utilization of penile prosthesis surgery based on data derived from national claim databases and contrast to an analysis of patients similarly treated at an academic center during a contemporaneous period. A retrospective claim analysis utilizing a national database (MarketScan, Thomson Reuters) was performed for Commercial insurer and Medicare databases between January 2000 and March 2011. A retrospective analysis of contemporaneous penile prosthesis implantation at the Johns Hopkins Hospital (JHH) was done. Population demographics, comorbidities, previous (ED) therapies and time from ED diagnosis to surgery were assessed. Median ages for patients undergoing penile prosthesis implantation were 58, 70 and 63 years for the Commercial, Medicare and JHH cohorts, respectively. For the claim databases (Commercial, Medicare, respectively), hypertension (72%, 78%), dyslipidemia (71%, 56%) and diabetes mellitus (45%, 40%) were predominant comorbidities, whereas for the JHH database prostate cancer (51%) and its management by prostatectomy (45%) or radiation (12%) were predominant. Previous use of PDE5 inhibitors was similar across databases (60, 58 and 69% for Commercial, Medicare and JHH cohorts, respectively), although previous use of non-oral ED therapies was greater in the JHH database. Median time to surgery from initial ED diagnosis was 2, 2 and 4 years for the Commercial, Medicare and JHH patients, respectively. Demographic variables and ED risk factors associated with penile prosthesis surgery at a national population-based level over a contemporary period were defined. Some differences in utilization trends of penile prosthesis surgery exist at a single institutional level.

Penile straightening maneuvers employed during penile prosthesis surgery: technical options and outcomes.

Straightening maneuvers (SM), including manual penile modeling, tunical relaxing incisions and corporal reconstruction using grafting techniques, are occasionally required during inflatable penile prosthesis (IPP) implantation to ensure functional penile straightness. The aim of this study was to compare the outcomes of men undergoing SM employed during IPP implantation compared with those wherein these maneuvers were not required. A retrospective review of 391 patients undergoing IPP implantation at the Johns Hopkins Hospital from January 2000 to December 2011 was performed. Patients in whom some SM was employed (SM, n=93, 23.9% of the overall cohort) were compared with those for whom SM was not required (IPP group, n=298). Seven patients were excluded from final analysis (6 patients with IPPs inserted in neophalli (SM group), and 1 patient with incomplete data (IPP group). Patients in whom a SM was used were younger (55.4 vs 62.3 years), more likely to have Peyronie's disease, and less likely to have prostate cancer, radical prostatectomy or to have previously used erectile aids (all P<0.05). Mean operating room time in the SM group was longer (173.8 vs 152.9 min, P=0.003). Within the SM group, modeling was performed in 40 (43%), tunical relaxing incisions in 37 (39.8%) and tunical reconstruction in 16 (17.2%) (most commonly using allograft dermis or pericardium, or synthetic gore-tex grafts). There were no significant differences in terms of device infection (P=0.15), mechanical failure (P=0.23) or erosion (P=0.96). Although limited in size, this cohort study suggests that IPP implantation in men with penile deformity requiring complex reconstruction to achieve straightening may be done proficiently and without increased adverse outcome risk.

Leg muscles differ in spatial activation patterns with differing levels of voluntary plantarflexion activity in humans.

BACKGROUND/AIMS: The purpose of this study was to investigate the differential activity between and within individual muscles commonly grouped as plantarflexors. Much of the previous information gathered on plantarflexor activity has been attained using electromyographic recordings. In this study, we used magnetic resonance imaging which allowed us to look at spatial differences in activation. METHODS: Twenty-two human subjects exercised under four different conditions - combinations of loads of 25 or 65% of maximum voluntary contraction (MVC) and the direction of plantarflexion at a sagittal and off-sagittal angle. Before and after each exercise condition, T2-weighted magnetic resonance images were collected. Regions of interest were drawn around the lateral gastrocnemius (LG), medial gastrocnemius (MG), soleus (SOL), peroneus longus (PER) and tibialis anterior (TA) muscles and analyzed for differences. RESULTS: Significant increases in T2 relaxation times during 25% MVC conditions were found for PER and, during the 65% MVC, for all four muscles considered plantarflexors (LG, MG, SOL, PER). No significant differences were found between sagittal and off-sagittal conditions. Within LG and MG, greater increases in T2 times with exercise were found in proximal regions compared with distal regions. CONCLUSION: These results are consistent with suggestions that individual members of muscle groups are capable of differential activity and that for at least some muscles, such differential activity may exist within subvolumes of individual muscles.

Functional activation of the extensor carpi radialis muscles in humans.

OBJECTIVES: To assess activity of radial wrist extensors caused by isometric radial deviation and extension by using magnetic resonance imaging (MRI) and to assess measures that might be used to normalize T2-weighted data. DESIGN: Two-way analysis of variance (ANOVA) design. SETTING: Laboratory and children's hospital. PARTICIPANTS: Three healthy volunteers. INTERVENTIONS: Ten repetitions of 10-second randomly ordered 30% or 60% of maximum voluntary isometric contractions toward wrist extension or radial deviation. MAIN OUTCOME MEASURES: Average T2 values from T2-weighted MR images of the extensor carpi radialis brevis (ECRB) and the extensor carpi radialis longus (ECRL), flexor digitorum profundus (FDP), and radius marrow were determined across 7 sections and 4 exercise bouts and a preexercise condition. RESULTS: Significant differences across task and across sections were determined. Post hoc analysis revealed differences in activity between proximal and distal ECRB and ECRL during an exercise and differential activation of the same muscle across the 2 exercise tasks. Bone marrow and FDP did not show task-related changes. The range of average T2 values of bone marrow across sections was greater than a muscle (FDP) that was not the target of the exercise protocol. However, FDP did show small but significant differences across sections. CONCLUSIONS: T2-weighted MR images can be used to study muscle activation at 30% and 60% of maximum voluntary contractions. The use of inactive muscle and bone marrow for normalizing data requires further investigation.

Plasticity in the Central Nervous System: Operant Conditioning of the Spinal Stretch Reflex.

Studies in monkey models have demonstrated that spinal stretch reflexes (SSRs) can be conditioned to be smaller or larger. Results of H-reflex conditioning studies further support the concept that operant conditioning alters the anatomical and biophysical properties of targeted alpha motoneurons. Results from able-bodied human subjects are strikingly similar to results from monkey models. Conditioning paradigms appear successful in downtraining the SSR of spinal-cord-injured patients who present with some residual control of a hyperactive biceps brachii. The conditioning may also affect movement control of spinal-cord-injured patients. Initial attempts at conditioning hyperactive SSRs of stroke patients have been equivocal. The site of lesion probably influences whether a stroke patient can successfully condition the SSR.

Long latency ankle responses to dynamic perturbation in older fallers and non-fallers.

OBJECTIVE: The purpose of this study was to examine the effects of falling history and aging on the latency and magnitude of long latency responses in the lateral gastrocnemius (LG) and tibialis anterior (TA) muscles of older adults. DESIGN: Single observation study. SETTING: Emory University School of Medicine, Center for Rehabilitation Medicine, serving the greater Atlanta, Georgia, area. PARTICIPANTS: There were 62 community-dwelling adults aged 60 or older, 32 with a history of two or more unexplained falls in the past year and 30 with no history of falls in the past year. MEASUREMENTS: The electromyographic activity of the gastrocnemius and tibialis anterior muscles was recorded bilaterally during repeated 10 degree dorsiflexion perturbations to standing subjects at the acceleration of gravity and a velocity of approximately 100 deg/sec. The latency and magnitude of the long latency EMG responses (LLR) of both muscles were determined and compared between individuals by falls history and by decades of age. MAIN RESULTS: No significant differences between falls status groups existed for mean LLR latencies or magnitudes of either LG or TA. Attenuation of the LLR throughout the trials was significantly different between groups. Non-fallers demonstrated attenuation of the LG magnitude over the first five stretches. Fallers showed maladaptation of the LG response, with the latency becoming shorter over 25 trials. More than half of the subjects in both groups had one or more instances of temporal reversal of the response latencies, with the TA response occurring earlier than the LG response during the first five stretches. No differences existed in the LLR between age decades within faller or non-faller groups. A timed measure of mobility (Up & Go) showed a significant difference between falls status, but not between age decades in either group. CONCLUSIONS: Lack of differences between falls status and age decade groups over all trials suggests that LLRs remain intact between older fallers and non-fallers and between older age groups. The mechanism of perturbation is a distinguishing feature of this study and probably contributes to our findings. The appearance of an atypical response strategy in both groups, where the TA response often occurs before the LG response, has raised the question of whether there is always a stereotypical pattern of LLRs during postural perturbations outside the experimental setting.

Determining consistency of elbow joint threshold angle in elbow flexor muscles with spastic hypertonia.

BACKGROUND AND PURPOSE: Threshold angle, the point in passive range of motion where a muscle response or torque change is elicited, may be a potentially valid measure of hypertonus. Because the relationship of initial muscle length to threshold angle has not been addressed previously, this preliminary study examined whether starting elbow joint position and speed of stretch to elbow flexor muscles affect threshold angle. SUBJECTS: Five subjects with stroke-induced hypertonia of the elbow flexor muscles participated. METHODS: Two starting angles and two designated stretch speeds were applied randomly by a torque motor at each of three testing sessions. RESULTS: Starting angle, subject, and session affected threshold angle. A 90-degree starting angle at a stretch speed of approximately 1.0 radian/s produced the most consistent threshold angles between sessions within subjects, and threshold angle was relatively consistent for some subjects, irrespective of speed. CONCLUSION AND DISCUSSION: If future research indicates that these data can be generalized, the use of threshold angle as a consistent measure of hypertonia will require comparison within individuals, use of a consistent starting angle, and a movement condition of a 90-degree starting angle and an approximate movement speed of 1.0 radian/s across sessions.

Reducing human biceps brachii spinal stretch reflex magnitude.

1. Nine subjects received 6 baseline and 24 training sessions, each consisting of 250 elbow joint stretch perturbations into extension. The training sessions were designed to reduce the subjects' biceps brachii spinal stretch reflexes (SSR). Changes in longer-latency responses and short-latency brachioradialis responses were also monitored. Background electromyogram activity was recorded from the lateral head of triceps brachii during the biceps sampling intervals. These data were compared with those form 12 control subjects who received equal numbers of stretches over an extended baseline (i.e., without application of a training paradigm). 2. Training subjects reduced their mean biceps SSR responses by 24%, whereas control subjects increased their responses by 12% When changes in activity were grouped by sets of six consecutive sessions following the baseline interval, group-by-time interaction was observed. Training subjects showed significant reductions from baseline after the first raining set. The increased magnitude of biceps SSR for control subjects was significantly larger than baseline in sets 2-5. After the first training interval, all subsequent differences between groups were statistically significant. 3. The brachioradialis showed greater response variability, but these responses paralleled those seen in biceps brachii. The training group reduced their brachioradialis responses by 18%, whereas the control group increased their responses by 12%. Background activity recorded over the lateral head of triceps brachii during the biceps brachii SSR window became smaller in both groups. 4. Comparison of data between control subjects and subjects who had undergone biceps SSR up-training in previous studies suggests that the small increase seen among the present control subjects was probably not the result of a direct training effect. 5. Baseline differences in longer-latency response onset time were seen between groups. Over extended baseline sessions, longer-latency responses showed only a 1% onset, representing a change of 0.3 ms, in the control group. A 1.3% later onset, equaling a change of 1.1 ms, was observed over conditioning sessions in the training group. When analyzed by sets following baseline, neither group showed significant within- or between-group changes over time. 6. The magnitude of the longer-latency biceps brachii response showed 7% and 37% reductions for the control and training groups, respectively. No difference in set averages was seen within groups, but a significant difference was measured over sets 2-4 between groups. Reductions in the magnitude of longer-latency responses in training subjects were more obvious in later training sessions. 7. These data suggest that 1) the biceps brachii SSR can be reduced in human subjects; 2) concurrent changes are often observed in the synergist brachioradialis; and 3) the reduced biceps SSR magnitude is not linked to a compensatory increase in antagonist muscle activity. Reductions in the magnitude of longer-latency biceps brachii activity seen in parallel with the decreased SSR may imply that some degree of supraspinal processing is required to achieve this task.

Contralateral and long latency effects of human biceps brachii stretch reflex conditioning.

Results from previous studies on monkeys and human subjects have demonstrated that the biceps brachii spinal stretch reflex (SSR) can be operantly conditioned. The extent to which conditioning paradigms influence contralateral SSRs or longer latency responses in the same limb has not been examined. Nine subjects were given 10 training sessions to either increase or decrease the size of their biceps brachii SSR. Group changes were compared to the mean of six baseline (control) sessions. Both groups showed progressive SSR changes over the training sessions. Up-trained subjects increased their SSR responses by an average of 135.3% above baseline, with the last three sessions showing a 237.5% increase, while down-trained subjects reduced their average SSR responses by 43.4%, with a 52.7% reduction over the last three sessions. ipsilateral longer latency responses showed average changes of 68.9% and -68.7% for up- and down-trainers, respectively. As in the case of SSRs, these responses changed progressively over sessions, with a 131.5% increase seen in the last three up-training sessions and an 82.4% reduction over the same period for down-trainers. Correlation coefficients between SSR and longer latency responses were high (R = 0.90, up-trainers; R = 0.87, down-trainers). Contralateral SSR and longer latency responses, measured in the absence of feedback and at least 10 min after ipsilateral conditioning, showed directional changes that were similar to the trained side, but their magnitudes were not as profound. Collectively, these data suggest that unilateral SSR conditioning affects spinal circuits controlling contralateral SSRs and influences longer latency responses.

Operant conditioning of spinal stretch reflexes in patients with spinal cord injuries.

Hyperactive spinal stretch reflexes (SSRs) often occur with spinal cord injuries (SCI). These altered SSRs may impair movement. Recent studies in monkeys and human subjects have indicated that the magnitude of SSRs can be modulated using operant conditioning. The purpose of this study was to determine whether hyperactive biceps brachii SSRs could be operantly conditioned downward. Seventeen chronic (> 1 year postlesion) spinal cord-injured patients participated. Subjects were trained to keep biceps background (prestretch) electromyographic (EMG) activity and elbow angle at predetermined levels prior to having the elbow rapidly extended by a torque motor to elicit the biceps SSR. All subjects participated in six baseline sessions over a 2-week period. Then, subjects were randomly assigned to either control or training groups for the next 24 sessions over an 8-week period. By the end of the study, training subjects had significantly reduced biceps SSRs (t test, P < 0.001), while control subjects SSRs were not significantly reduced (t test, P > 0.05). The reduced SSRs persisted for up to 4 months following cessation of training. The results of this study support the hypothesis that hyperactive SSRs can be operantly conditioned downward in SCI patients.

Immediate effects of the toe spreader on the tonic toe flexion reflex.

BACKGROUND AND PURPOSE: The purpose of the study was to determine whether the use of a toe spreader to inhibit the tonic toe flexion reflex (TTFR) immediately alters temporal-distance gait characteristics, plantar surface contact, or muscle activity in the limb exhibiting the TTFR of subjects with hemiparesis secondary to supraspinal lesion. SUBJECTS: Eighteen adults with hemiparesis secondary to supraspinal lesions served as subjects for the standing portion of the study. Sixteen of the subjects participated in the gait portion of the study. METHODS: The study was a randomized, within-subject, between-conditions comparison consisting of standing and gait phases, with four conditions for each phase (shoe off, toe spreader off/on, shoe on, toe spreader off/on). Measures performed were ink footprint gait analysis and integrated electromyography from the limb exhibiting the TTFR. RESULTS: Presence of the TTFR was reduced significantly with the use of the toe spreader. Velocity and cadence were increased significantly by use of the toe spreader. CONCLUSION AND DISCUSSION: The toe spreader may be a useful treatment option for improving gait. The clinical significance of these findings, however, will depend on the functional context of toe-spreader use.

Compartmentalization of muscles and their motor nuclei: the partitioning hypothesis.

This review article is designed to expose physical therapists to an examination of muscle organization and the implications that this organization has for therapeutic applications. The partitioning hypothesis is based on the fact that an individual muscle is arranged in a more complex array than simply fibers attaching at aponeuroses, tendons, or bones with a single muscle nerve innervation. Neuromuscular compartments, which are distinct subvolumes of a muscle, each innervated by an individual muscle nerve branch and each containing motor unit territories with a unique array of physiological attributes, are described. In addition, the organization of individual muscles into these subunits is paralleled by the organization of their parent motoneurons within the spinal cord. These notions are detailed in a review of data derived from studies performed primarily in cat and rat models. Recent data derived from morphological and anatomical study of human muscles support the existence of similar neuromuscular partitions. These data are complemented by physiological studies, the results from which suggest that partitions may have functional or task-oriented roles; that is, different portions of one muscle may be called into play depending on the task demands of the situation. The importance of these observations for reconsidering how we provide clinical applications, such as neuromuscular stimulation or kinesiological monitoring, is discussed.

Genioglossi muscle activity in response to changes in anterior/neutral head posture.

Clinicians have acknowledged swallowing, tongue activity, and head posture as interdependent variables that must be concurrently examined. The purpose of this study was to evaluate genioglossus activity during swallowing, rest, and maximal tongue protrusion in two head positions (HPs) with a noninvasive recording device. Eight Angle Class I subjects were evaluated. Repeated measures were performed in a single session to record surface intraoral electromyographic (EMG) activity of the genioglossus muscles. Head position was measured in angular degrees from photographs. Three variables were measured in both the neutral-head position (NHP) and anterior-head position (AHP): (1) duration of genioglossus EMG during swallowing, (2) genioglossus EMG with the tongue at rest, and (3) genioglossus EMG during maximal isometric tongue protrusion. A Wilcoxin matched-pair signed-rank statistic was used for EMG analysis, and a paired sample t test statistic was used for head posture analysis. The angles measured for NHP and AHP within each subject were significantly different verifying two different head positions. Duration of swallowing was not significantly different between head positions. Resting genioglossus EMG and maximal isometric genioglossus EMG were statistically greater in the AHP. The data suggest that head positional changes may have an effect on genioglossus muscle activation thresholds. However, small differences in resting EMG activity between head positions suggests that the clinical significance needs further investigation.

Variability of human biceps brachii spinal stretch reflexes: Control conditions.

The variability of the human biceps brachii spinal stretch reflex (SSR) elicited by rotational stretches is not known. Data obtained by others using tendon taps suggests considerable variability of biceps stretch reflex. The purpose of this study was to determine the variability of the biceps SSR across and within sessions in able-bodied subjects. In addition, we wanted to determine if four baseline sessions was a sufficient number against which to compare an intervening variable. Ten able-bodied subjects participated in this study, which included four baseline sessions and eight additional baseline sessions among five of these subjects. Five bins of 50 stretches were elicited at each session (i.e., a total of 250 stretches per session). Subjects were provided no feedback of SSR magnitude during any session. Means, standard deviations, and coefficients of variation (standard deviation/mean) were calculated. A nested analysis of variance was used in assessing relative contributions to the total variance. Within-session variance contributed at least five times the amount to the total variance as day-to-day variability in both baseline and extended baseline phases. During the baseline phase within-session coefficients of variation were approximately 60%, whereas across-session coefficients of variation were approximately 30%. The within-session coefficients of variation increased during the extended baseline phase, whereas the across-session coefficients were similar to the baseline phase. In addition, the mean SSR decreased during the extended baseline phase. We conclude that biceps SSRs elicited by rotational stretches are highly variable, particularly within sessions. Thus, multiple trials and sessions are necessary if meaningful data are to be gathered.

Task-oriented EMG activity recorded from partitions in human lateral gastrocnemius muscle.

Twenty normal human subjects (mean age: 25.9, range: 22-40) performed specific lower extremity functional tasks while integrated electromyographic (IEMG) activity was recorded from the lateral gastrocnemius (LG) muscle. The electrode placements used corresponded with sites known to have distinct patterns of innervation based upon previous anatomical microdissections. These sites were defined as proximal medial, proximal lateral, distal medial, and distal lateral. Myoelectric activity from each site was normalized against maximal voluntary efforts. Quantitative analyses of records made from these distinct sites, which we call 'partitions', revealed significant differences both within and across specific tasks. The distal lateral site showed greatest activity during a step-up task with the test leg in knee flexion while the proximal lateral site tended to show the least activity for most tasks. No consistent pattern was observed across all eight leg tasks at any one site thus suggesting that motor units contributing to total electromyographic (EMG) activity in each partition did so differentially. Spike triggered averages were obtained from motor units within partitions of these muscles. Little synchrony could be demonstrated between units and averaged electrical activity in other partitions. This observation implies some degree of electromyographic isolation. Collectively these data suggest that partitions within a human two-joint muscle display selectively different levels of muscle activity depending upon the motor task. While these observations require further explanation, they also indicate that a more comprehensive understanding of the organization of muscles and their outputs is a necessary prerequisite to the establishment of therapeutic regimens.

Neuromuscular compartments in the human biceps brachii muscle.

Electrophysiological evidence suggests that the human biceps brachii muscle is organized into functional neuromuscular compartments. The purpose of this study was to determine whether there was an anatomical basis for these compartments. Dissection of the biceps revealed both architectural and nerve branching pattern compartmentalization within the muscle. Although the biceps brachii is grossly subdivided into long and short heads, these heads are further subdivided into roughly parallel architectural compartments. Moreover, these architectural compartments usually receive a private nerve branch, thus supporting the notion that the human biceps brachii has neuromuscular compartments.

Hyperthyroidism in patients treated with lithium: report of nine cases.

Nine cases of hyperthyroidism which developed in patients on lithium therapy are presented and analyzed and the literature is briefly reviewed. The findings strongly suggest that lithium therapy does not cause hyperthyroidism.

Wrist movements in able-bodied and brain injured individuals.

The purpose of this study was to compare movement velocity characteristics during targeted wrist movements between able-bodied individuals and a sample of individuals with spasticity secondary to closed head injury. Two amplitudes (30 degrees and 60 degrees) of movement were performed at slow and fast velocities, with the forearm either passively supported or actively supported by elbow extension and shoulder flexion. Variables measured were the following: (1) average velocity of entire movement, (2) velocity for 10 degrees increments of a movement, and (3) ratio of average peak 10 degrees increment velocity to average velocity. In addition, qualitative examination of velocity profiles was performed. Slow movements were performed in a discontinuous manner by both groups; however, observable differences in peak/average velocity were noted between groups in the unsupported position during slow and fast movements. Able-bodied individuals performed seven of eight fast movements with greater velocity (p less than .05) than brain injured individuals, and the fast movements of the able-bodied subjects were continuous.

Quantitative analysis of surface and percutaneous electromyographic activity in lumbar erector spinae of normal young women.

Bilateral surface and fine-wire electromyographic activity from the erector spinae at the L4-5 interspace was recorded from 10 female subjects during flexion, extension, rotation to right/left, and sidebending to right/left. Fine-wire electrodes demonstrated significant left-right electromyographic differences during terminal flexion. Surface and fine-wire electromyographic recordings demonstrated a symmetric pattern of activity during extension. A symmetric pattern of erector spinae activity was observed during rotation using fine-wire electrodes but not from surface electrodes. Increased electromyographic activity from the contralateral erector spinae was detected by the surface electrodes during sidebending to neutral movements.