Corticomotor Control of Lumbar Erector Spinae in Postural and Voluntary Tasks: The Influence of Transcranial Magnetic Stimulation Current Direction.

Lumbar erector spinae (LES) contribute to spine postural and voluntary control. Transcranial magnetic stimulation (TMS) preferentially depolarizes different neural circuits depending on the direction of electrical currents evoked in the brain. Posteroanterior current (PA-TMS) and anteroposterior (AP-TMS) current would, respectively, depolarize neurons in the primary motor cortex (M1) and the premotor cortex. These regions may contribute differently to LES control. This study examined whether responses evoked by PA- and AP-TMS are different during the preparation and execution of LES voluntary and postural tasks. Participants performed a reaction time task. A Warning signal indicated to prepare to flex shoulders (postural; n = 15) or to tilt the pelvis (voluntary; n = 13) at the Go signal. Single- and paired-pulse TMS (short-interval intracortical inhibition-SICI) were applied using PA- and AP-TMS before the Warning signal (baseline), between the Warning and Go signals (preparation), or 30 ms before the LES onset (execution). Changes from baseline during preparation and execution were calculated in AP/PA-TMS. In the postural task, MEP amplitude was higher during the execution than that during preparation independently of the current direction (p = 0.0002). In the voluntary task, AP-MEP amplitude was higher during execution than that during preparation (p = 0.016). More PA inhibition (SICI) was observed in execution than that in preparation (p = 0.028). Different neural circuits are preferentially involved in the two motor tasks assessed, as suggested by different patterns of change in execution of the voluntary task (AP-TMS, increase; PA-TMS, no change). Considering that PA-TMS preferentially depolarize neurons in M1, it questions their importance in LES voluntary control.

Effects of elastic kinesiology taping on shoulder proprioception: a systematic review.

BACKGROUND: Shoulder injuries are associated with proprioceptive deficits. Elastic kinesiology tape (KT) is used for treating musculoskeletal disorders, including shoulder injuries, as it arguably improves proprioception. OBJECTIVE: To synthesize the evidence on the effects of elastic KT on proprioception in healthy and pathological shoulders. METHODS: Four databases (PubMed, WoS, CINAHL, SPORTDiscus) were searched for studies that investigated the effects of elastic KT on shoulder proprioception. Outcome measures were active joint position sense (AJPS), passive joint position sense (PJPS), kinesthesia, sense of force (SoF), and sense of velocity (SoV). Risk of bias (RoB) was assessed using the Cochrane Collaboration RoB tool for randomized controlled trials (RCTs), and the ROBINS-1 for non-RCTs, while the certainty of evidence was determined using GRADE. RESULTS: Eight studies (5 RCTs, 3 non-RCTs) were included, yielding 187 shoulders (102 healthy and 85 pathological shoulders). RoB ranged from low (2 studies), moderate (5 studies), to high (1 study). Elastic KT has a mixed effect on AJPS of healthy shoulders (n=79) (low certainty). Elastic KT improves AJPS (subacromial pain syndrome and rotator cuff tendinopathy, n=52) and PJPS (chronic hemiparetic shoulders, n=13) among pathological shoulders (very low certainty). Elastic KT has no effect on kinesthesia among individuals with subacromial pain syndrome (n=30) (very low certainty). CONCLUSION: There is very low to low certainty of evidence that elastic KT enhances shoulder AJPS and PJPS. The aggregate of evidence is currently so low that any recommendation on the effectiveness of elastic KT on shoulder proprioception remains speculative.

Within-Session Test-Retest Reliability of Pressure Pain Threshold and Mechanical Temporal Summation in Chronic Low Back Pain.

OBJECTIVES: To determine the absolute and relative within-session test-retest reliability of pressure pain threshold (PPT) and temporal summation of pain (TSP) at the low back and the forearm in individuals with chronic low back pain (CLBP) and to test the impact of different sequences of measurements on reliability metrics. MATERIALS AND METHODS: Twenty-eight adults with CLBP were recruited. Relative (intraclass correlation coefficient [ICC] and coefficient of variation) and absolute reliability (standard error of measurement and minimal detectable changes) were quantified at 4 sites (back: sacrum and lumbar erector spinae; wrist: hand dorsum and wrist flexors) for PPT and 2 sites (hand and low back) for TSP, for various sequences of measurements. RESULTS: Systematic differences were found between within test and retest for most PPT sequences at the lumbar erector spinae site and 1 TSP sequence (1-2-3) at back and hand sites, precluding reliability analyses for these data. Within-session PPT relative reliability was excellent at low back (ICC = 0.83 to 0.94) and wrist (ICC = 0.88 to 0.97) sites, whereas TSP showed good to excellent reliability at hand (ICC = 0.80 to 0.90) and low back (ICC = 0.73 to 0.89). In general, 2 and 3 measurements optimized absolute and relative reliability for TSP and PPT, respectively. DISCUSSION: Within-session reliability was generally excellent for PPT and TSP at the low back and hand sites among individuals with CLBP. We recommend using 3 measurements for PPT and 2 for TSP to optimize reliability. Caution is recommended when testing PPT of the painful lower back area since a systematic difference was present between the test and retest.

Immediate Effect of Lumbosacral Orthosis and Abdominal Drawing-In Maneuver on Postural Control in Adults With Nonspecific Chronic Low Back Pain.

OBJECTIVE: The purpose of this study was to examine the immediate effects of lumbosacral orthosis and the abdominal drawing-in maneuver on the trunk postural control of adults with chronic low back pain compared with asymptomatic controls during 1-legged and semi-tandem stances. METHODS: An experimental and comparative study (cross-sectional design) was conducted in a laboratory setting. Twenty adults with chronic low back pain and 20 asymptomatic controls randomly performed 2 postural balance tasks over a force platform, considering 3 experimental conditions: (1) natural posture (baseline-control), (2) lumbosacral orthosis, and (3) abdominal drawing-in maneuver. Linear variables (mean amplitude, ellipse area, and sway velocity) derived from the center of pressure were computed, and 2-way analysis of variance (group × condition) for repeated measures were conducted. RESULTS: No group × condition interactions (.139 ≤ P ≤.938) were detected in any center of pressure parameters. No condition effect was detected, but a group effect (P = .042) was observed for 1 center of pressure parameter. The chronic low back pain group presented with a lower mean anteroposterior center of pressure amplitude than asymptomatic controls (∆ = 0.31 ± 0.66 cm [95% confidence interval, 0.05-0.56], P = .019) during the semi-tandem stance balance task. CONCLUSION: Neither lumbosacral orthosis nor the abdominal drawing-in maneuver showed immediate improvement in trunk postural control in any group. Thus, clinicians should not expect immediate benefits or improvements yielded by lumbosacral orthosis or the abdominal drawing-in maneuver when patients with chronic low back pain undergo these interventions.

Association between the level of partial foot amputation and gait: a scoping review with implications for the minimum impairment criteria for wheelchair tennis.

OBJECTIVE: This scoping review examines how different levels and types of partial foot amputation affect gait and explores how these findings may affect the minimal impairment criteria for wheelchair tennis. METHODS: Four databases (PubMed, Embase, CINAHL and SPORTDiscus) were systematically searched in February 2021 for terms related to partial foot amputation and ambulation. The search was updated in February 2022. All study designs investigating gait-related outcomes in individuals with partial foot amputation were included and independently screened by two reviewers based on Arksey and O'Malley's methodological framework and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews. RESULTS: Twenty-nine publications with data from 252 participants with partial foot amputation in 25 studies were analysed. Toe amputations were associated with minor gait abnormalities, and great toe amputations caused loss of push-off in a forward and lateral direction. Metatarsophalangeal amputations were associated with loss of stability and decreased gait speed. Ray amputations were associated with decreased gait speed and reduced lower extremity range of motion. Transmetatarsal amputations and more proximal amputations were associated with abnormal gait, substantial loss of power generation across the ankle and impaired mobility. CONCLUSIONS: Partial foot amputation was associated with various gait changes, depending on the type of amputation. Different levels and types of foot amputation are likely to affect tennis performance. We recommend including first ray, transmetatarsal, Chopart and Lisfranc amputations in the minimum impairment criteria, excluding toe amputations (digits two to five), and we are unsure whether to include or exclude great toe, ray (two to five) and metatarsophalangeal amputations. TRIAL REGISTRATION: The protocol of this scoping review was previously registered at the Open Science Framework Registry (https://osf.io/8gh9y) and published.

The immediate effect of two lumbar stabilization methods on postural control parameters and their reliability during two balance tasks.

Background: Lumbosacral orthosis (LSO) and/or the isolated contraction of the transversus abdominis muscle by the abdominal drawing-in maneuver (ADIM) can increase lumbar stiffness, consequently influencing postural control. The purpose of this study was to compare the effects of LSO and ADIM on postural control during two balance tasks and determine their reliability.Methods: Twenty participants (50% men) randomly performed three experimental conditions: 1) without lumbar stabilization, 2) with LSO), and 3) with ADIM. Each experimental condition was tested in two postural tasks: semi-tandem and one-legged stance on a force platform for 30 seconds, while the Center of pressure postural (COP) parameters were computed.Results: The two methods of lumbar stabilization were comparable and did not significantly reduce the COP values across time, even though a few individuals presented a change in their COP data above the levels of measurement errors. The reliability of these measurements was generally acceptable and sometimes excellent (≥ 0.90 and ≤10% error measurement).Conclusions: Both LSO and isolated contraction of the transversus abdominis muscle by ADIM do not change postural control in one-legged stance and in semi-tandem tasks. These results have implications for use or not these methods for postural control on a rehabilitation perspective.

Kinesiotaping for the Rehabilitation of Rotator Cuff-Related Shoulder Pain: A Randomized Clinical Trial.

BACKGROUND: Kinesiotaping (KT) has been widely used in clinical practice. Current evidence is insufficient to support the use of KT for treating rotator cuff-related shoulder pain (RCRSP), as its mid- and long-term effects have not been investigated. HYPOTHESES: Individuals using KT will achieve faster improvements in symptoms and functional limitations compared with those not using it. They will also present a greater increase in pain-free range of motion (ROM) and acromiohumeral distance (AHD) at the end of the treatment. STUDY DESIGN: Randomized controlled trial (NCT02881021). LEVEL OF EVIDENCE: Therapy, level 1b. METHODS: A total of 52 individuals with RCRSP, randomly assigned to 1 of 2 groups (experimental: KT; control: no-KT), underwent a 6-week rehabilitation program composed of 10 physical therapy sessions. KT was added to the treatment of the KT group. Symptoms and functional limitations were assessed using the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire (primary outcome); Brief Pain Inventory (BPI); and Western Ontario Rotator Cuff (WORC) index at baseline, 3 weeks, 6 weeks, 12 weeks, and 6 months. AHD, pain-free ROM, and full ROM were measured at baseline and at week 6. The effects of KT were assessed using a nonparametric analysis for longitudinal data. RESULTS: No significant group × time interactions (0.112 ≤ P ≤ 0.726) were found for all outcomes. Time effects were observed as both groups showed significant improvements for all studied outcomes (DASH, BPI, and WORC, p < 0.0001; AHD, p = 0.017; pain-free ROM, p < 0.0001; and full ROM abduction, p ≤ 0.0001). CONCLUSION: Whereas symptoms, functional limitations, ROM, and AHD improved in both groups, the addition of KT did not lead to superior outcomes compared with exercise-based treatment alone, in the mid and long term, for individuals with RCRSP. CLINICAL RELEVANCE: Clinicians should not expect supplementary mid- or long-term gains with KT to reduce pain, improve shoulder function and ROM, or increase AHD if a rehabilitation program focusing on shoulder neuromuscular control is concurrently provided as treatment for individuals with RCRSP.

Is There a Decrease in the Acromiohumeral Distance Among Recreational Overhead Athletes With Rotator Cuff-Related Shoulder Pain?

CONTEXT: Recreational overhead athletes are exposed to high overload, which increases the risk of shoulder injuries. Reduction of the acromiohumeral distance (AHD) is often associated with rotator cuff-related shoulder pain (RCRSP) among the general population. However, the AHD of symptomatic shoulders of recreational athletes has not yet been compared with their asymptomatic shoulders. OBJECTIVE: To compare the AHD of a symptomatic to asymptomatic shoulder at rest (0°) and 60° abduction. To establish the relationship between AHD, pain, and functional limitations of recreational athletes with RCRSP. DESIGN: Cross-sectional study. SETTING: University laboratory. PARTICIPANTS: A total of 45 recreational overhead athletes with RCRSP were examined. MAIN OUTCOME MEASURES: The AHD was measured by ultrasonography at 0° and 60° abduction (angles). Shoulder pain was assessed using a numeric pain scale, whereas functional limitations were assessed using the The Disabilities of the Arm, Shoulder, and Hand questionnaire. Differences in the between-shoulders condition (symptomatic and asymptomatic) were determined using 2-way analysis of variance for repeated measures. A Pearson correlation established the relationship between AHD, pain, and functional limitations. RESULTS: No angles × shoulder condition interactions (P = .776) nor shoulder condition effects (P = .087) were detected, suggesting no significant differences (P > .05) between asymptomatic and symptomatic shoulders in the AHD at 0° or 60°. The AHD at 60° reduced significantly compared with 0° (3.05 [1.36] mm [2.77-3.33], angle effects: P < .001). The AHD at 0° and 60° was not correlated with pain or functional limitations (-.205 ≤ r ≤ .210, .167 ≤ P ≤ .585). CONCLUSIONS: The AHD of recreational athletes is not decreased in symptomatic shoulders compared with asymptomatic shoulders. Reduction of the AHD in symptomatic shoulders is not associated with an increase in pain or functional limitations of recreational athletes with RCRSP.

Validity and Reliability of 2-Dimensional Video-Based Assessment to Analyze Foot Strike Pattern and Step Rate During Running: A Systematic Review.

CONTEXT: Two-dimensional (2D) video-based analysis is often used by clinicians to examine the foot strike pattern (FSP) and step rate in runners. Reliability and validity of 2D video-based analysis have been questioned. OBJECTIVE: To synthesize the psychometric properties of 2D video-based analysis for assessing runners' FSP and step rate while running. DATA SOURCES: Medline/PubMed, Science Direct, Embase, EBSCOHost/CINAHL, and Scielo were searched from their inception to August 2018. STUDY SELECTION: Studies were included if (1) they were published in English, French, Portuguese or Spanish; (2) they reported at least 1 psychometric property (validity and/or reliability) of 2D video-based analysis to assess running kinematics; and (3) they assessed FSP or step rate during running. STUDY DESIGN: Systematic review. LEVEL OF EVIDENCE: Level 2. DATA EXTRACTION: Studies were screened for methodological (MacDermid checklist) and psychometric quality (COSMIN checklist) by 2 independent raters. RESULTS: Eight studies, with a total of 702 participants, were included. Seven studies evaluated the reliability of 2D video to assess FSP and found very good to excellent reliability (0.41 ≤ κ ≤ 1.00). Two studies reported excellent reliability for the calculation of step rate (0.75 ≤ intraclass correlation coefficient [ICC] ≤ 1.00). One study demonstrated excellent concurrent validity between 2D and 3D (gold standard) motion capture systems to determine FSP (Gwet agreement coefficient [AC] > 0.90; ICC > 0.90), and another study found excellent concurrent validity between 2D video and another device to calculate step rate (0.84 ≤ ICC ≤ 0.95). CONCLUSION: Strong evidence suggests that 2D video-based analysis is a reliable method for assessing FSP and quantifying step rate, regardless of the experience of the assessor. Limited evidence exists on the validity of 2D video-based analysis in determining FSP and calculating step rate during running.

Immediate effects of kinesiotaping on acromiohumeral distance and shoulder proprioception in individuals with symptomatic rotator cuff tendinopathy.

BACKGROUND: Kinesiotaping is widely used for the rehabilitation of rotator cuff tendinopathy. It has been argued to reduce symptoms and functional limitations through improvement of proprioceptive feedback. In addition, kinesiotaping has been reported to increase the subacromial space in healthy subjects. However, its effects on the acromiohumeral distance and shoulder proprioception of individuals with rotator cuff tendinopathy have not been ascertained. This study investigated the immediate effects of kinesiotaping on the acromiohumeral distance and shoulder proprioception in individuals with rotator cuff tendinopathy. METHODS: Twenty-two individuals with chronic rotator cuff tendinopathy were included. The acromiohumeral distance was measured using an ultrasound scanner at rest and 60° shoulder abduction. Proprioception was measured through active joint repositioning in low- (45°-65°) and mid-amplitude (80°-100°) of shoulder flexion and abduction. A wireless inertial measurement unit system was used to quantify shoulder angles. First, measurements were taken without kinesiotaping. Thereafter, kinesiotaping was applied on the symptomatic shoulder, and the same measurements were retaken. Repeated measures ANOVAs were used for statistical analyses. FINDINGS: Kinesiotaping induced a significant increase in acromiohumeral distance at 60° abduction (∆AHD = 0.94 mm; 95%CI: 0.50-1.38, p < 0.001), exceeding the minimal detectable change (0.70 mm). No significant difference was observed in acromiohumeral distance at rest or in proprioception during active joint repositioning in both low- and mid-amplitude (p > 0.05). INTERPRETATION: Kinesiotaping led to an immediate increase in acromiohumeral distance at 60° of abduction that, although it seems a minor change (↑10.5%), it may be significant for symptomatic patients, whereas it had no immediate effect on active joint repositioning.

Effects of kinesiotaping added to a rehabilitation programme for patients with rotator cuff tendinopathy: protocol for a single-blind, randomised controlled trial addressing symptoms, functional limitations and underlying deficits.

INTRODUCTION: Rotator cuff tendinopathy (RCTe) is the most frequent cause of shoulder pain, resulting in considerable losses to society and public resources. Muscle imbalance and inadequate sensorimotor control are deficits often associated with RCTe. Kinesiotaping (KT) is widely used by clinicians for rehabilitation of RCTe. While previous studies have examined the immediate effects of KT on shoulder injuries or the effects of KT as an isolated method of treatment, no published study has addressed its mid-term and long-term effects when combined with a rehabilitation programme for patients with RCTe. The primary objective of this randomised controlled trial (RCT) will be to assess the efficacy of therapeutic KT, added to a rehabilitation programme, in reducing pain and disabilities in individuals with RCTe. Secondary objectives will look at the effects of KT on the underlying factors involved in shoulder control, such as muscular activity, acromiohumeral distance (AHD) and range of motion (ROM). METHODS AND ANALYSIS: A single-blind RCT will be conducted. Fifty-two participants, randomly allocated to one of two groups (KT or no-KT), will take part in a 6-week rehabilitation programme. The KT group will receive KT added to the rehabilitation programme, whereas the no-KT group will receive only the rehabilitation programme. Measurements will be taken at baseline, week 3, week 6, week 12 and 6 months. Primary outcomes will be symptoms and functional limitations assessed by the Disabilities of the Arm, Shoulder and Hand questionnaire. Secondary outcomes will include shoulder ROM, AHD at rest and at 60° of abduction, and muscle activation during arm elevation. The added effects of KT will be assessed through a two-way analysis of variance for repeated measures. ETHICS AND DISSEMINATION: Ethics approval was obtained from the Ethics Committee of Quebec Rehabilitation Institute of the Centre Integrated University Health and Social Services. Results will be disseminated through international publications in peer-reviewed journals, in addition to international conference presentations. TRIAL REGISTRATION NUMBER: Protocol was registered at ClinicalTrials.gov (NCT02881021) on 25 August 2016. The WHO Trial Registration Data Set can also be found as an online supplementary file.

Electromyographic analysis of rotator cuff muscles in patients with rotator cuff tendinopathy: A systematic review.

The shoulder is inherently an unstable joint which heavily relies on the neuromuscular activation of the rotator cuff (RC) complex for stability during movement. Currently, there is no consensus regarding how the activity of RC muscles is affected among individuals with a RC tendinopathy (RCTe). This study reviewed the evidence of studies comparing the electromyographic (EMG) activity of any RC muscle of shoulders with a symptomatic RCTe to asymptomatic shoulders. Eight databases were searched. Data from 343 participants (201 symptomatic and 209 asymptomatic shoulders) were analyzed from 10 out of 402 included studies. Strong evidence for the infraspinatus and supraspinatus during isometric contractions and limited evidence for the supraspinatus and infraspinatus during isokinetic contractions suggest that the muscular activity is not altered among individuals with a RCTe during these types of contraction. Very limited evidence indicates reduced muscle activity for the infraspinatus and subscapularis in the presence of a RCTe during isotonic contractions, and no alterations for the supraspinatus or teres minor were identified. Lastly, conflicting to moderate evidence suggests alterations in RC muscle activity during unrestrained movements and swimming. These findings indicate that EMG deficits associated with a RCTe can best be appreciated during unrestrained movements.

STATIC STRETCHING DOES NOT REDUCE VARIABILITY, JUMP AND SPEED PERFORMANCE.

BACKGROUND: Stretching is often part of the warm-up routine prior to athletic participation; however, controversial evidence exists on the effects of stretching on countermovement jump (CMJ) and sprint performance. Additionally, analysis of variability between repeated tasks is useful for monitoring players, to analyze factors that could affect the performance, and to guide clinical decisions for training strategies. PURPOSE: The purpose of this study was to examine whether static stretching (SS) prior to CMJ and 20-meter (20-m) sprint would affect performance, and to investigate whether SS affects an athlete's ability to perform these tasks consistently. METHODS: Twenty-two trained healthy athletes (23.2 ± 5.0 years) attended, randomly, two testing sessions, separated by 48 hours. At session one, all participants underwent 10 minutes of dynamic running warm-up followed by the experimental tasks (three CMJ and three 20-m sprint), whereas five minutes of stretching was added after the warm-up routine at session two. All participants performed the same experimental tasks in both sessions. The stretching protocol consisted of five stretching exercises for each lower limb. RESULTS: The paired-samples t-test revealed no significant differences between the stretching protocol condition and no stretching condition for the 20-m sprint (t(21)=.920; p=.368) and CMJ (t(21)=.709; p=.486). There were no significant differences in trial-by-trial variability on 20-m sprint (t(21)=1.934; p=.067) and CMJ scores (t(21)=.793; p=.437) as result of SS. CONCLUSION: The SS protocol did not modify jumping and running ability in trained healthy athletes. The SS prior to training or competition may not cause detrimental effects to athletic performance. LEVEL OF EVIDENCE: Level III, Nonrandomized controlled trial.

Sensory Integration during Vibration of Postural Muscle Tendons When Pointing to a Memorized Target.

Vibrating ankle muscles in freely standing persons elicits a spatially oriented postural response. For instance, vibrating the Achilles tendons induces a backward displacement of the body while vibrating the tibialis anterior muscle tendons induces a forward displacement. These displacements have been called vibration induced falling (VIF) responses and they presumably are automatic. Because of the long delay between the onset of the vibration and the onset of the VIF (about 700 ms), and the widespread cortical activation following vibration, there is a possibility that the sensory signals available before the VIF can be used by the central nervous system to plan a hand pointing action. This study examined this suggestion. Ten healthy young participants stood on a force platform and initially were trained to point with and without vision to a target located in front of them. Then, they were exposed to conditions with vibration of the Achilles tendons or tibialis anterior muscle tendons and pointed at the target without vision. The vibration stopped between each trial. Trials with vision (without vibration) were given every five trials to maintain an accurate perception of the target's spatial location. Ankle vibrations did not have an effect on the position of the center of foot pressure (COP) before the onset of the pointing actions. Furthermore, reaction and movement times of the pointing actions were unaffected by the vibration. The hypotheses were that if proprioceptive information evoked by ankle vibrations alters the planning of a pointing action, the amplitude of the movement should scale according to the muscle tendons that are vibrated. For Achilles tendon vibration, participants undershot the target indicating the planning of the pointing action was influenced by the vibration-evoked proprioceptive information (forward displacement of the body). When the tibialis anterior were vibrated (backward displacement of the body), however, shorter movements were also observed. Longer movements would have increased the backward response of the sensed body movement. Thus, it is possible that pointing actions were adjusted on the basis of the expected consequences of the planned pointing action to avoid a response that could have compromised postural stability.