Highlights • Participants with CAI present an increased peroneus longus activity during walking. • Participants with CAI present an inverted rearfoot pattern during gait. • Participants with CAI ...present increased lateral foot pressure during gait. • Further studies with better methodological quality are required
The biomechanical effects of foot orthoses (FOs) with and without a lateral bar compared to a control condition during walking at different speeds are still unknown. The objective of this study was ...to compare the biomechanical effects of functional FOs with and without a lateral bar to a control condition during comfortable walking in individuals with cavus feet and determine if their effects change at a fast speed.
Fifteen individuals with cavus feet (age: 25.3 ± 5.8 yrs) walked under two experimental conditions (FOs with and without a lateral bar) and a control condition (shoes only) at comfortable (CW) and fast (FW) speeds. The outcome measures were ankle and knee angles and gluteus medius, vastus lateralis, gastrocnemius lateralis, gastrocnemius medialis, peroneus longus and tibialis anterior electromyography (EMG) amplitudes during the stance phase of walking and were compared between the FOs and a control condition using one-dimensional statistical parametric mapping.
During CW, both FOs decreased ankle dorsiflexion and increased knee extension angles compared to no FOs. FOs with a lateral bar also decreased peroneus longus EMG amplitudes. During FW, FOs with and without a lateral bar decreased ankle dorsiflexion angles compared to no FOs.
Both types of FOs had different effects on the biomechanics of the lower limb compared to a control condition. The decreased peroneus longus EMG amplitudes during CW in individuals with cavus feet could have important clinical implications in other populations, such as individuals with painful cavus feet. The orthoses only affected the ankle dorsiflexion angles at a fast speed and no EMG amplitude or knee kinematics effects were observed. Further studies assessing the ankle kinematics and kinetics effects of these orthoses are needed to improve our understanding of their mechanism of action and inform future efficacy trials.
Background/Purpose The effects of footwear on the walking kinematics, kinetics and electromyography (EMG) of individuals with chronic ankle instability (CAI) at different speeds are still unknown. ...The objective of this cross-sectional study was to evaluate the kinematic, kinetic and electromyography differences between shod and barefoot walking at comfortable (CW) and fast (FW) speeds in individuals with CAI. Methods Twenty-one individuals with CAI walked on a 5-meter walkway shod and barefoot at CW and FW speeds. A force plate was used to record the ground reaction forces, a 3-D motion analysis system to record the lower limb kinematics and a surface EMG system to collect the gluteus medius, vastus lateralis, gastrocnemius lateralis, gastrocnemius medialis, peroneus longus and tibialis anterior muscles activity. The dependent variables were ankle and knee angles and moments and normalized muscle activity. The shod and barefoot data during CW and FW were compared using a one-dimensional non-parametric mapping analysis. Results The main results of this study were that individuals with CAI exhibited more ankle dorsiflexion angle, knee extension and tibialis anterior muscle activation during the beginning of the stance phase during shod compared to barefoot walking. Also, the biomechanical effects of shoes are similar during walking at FW and CW. Conclusion The biomechanical deficits associated with CAI were partly attenuated during the shod compared to the barefoot condition and these effects were similar at CW and FW. These findings are compatible with the concept that locomotor interventions using suitable shoes may enhance gait abilities in individuals with CAI.
This study aimed to investigate how load expectations modulate neuromuscular and postural strategies in the anticipation of a freestyle lifting task with varying expected loads in individuals with ...and without chronic low back pain (cLBP).
Forty-seven participants, 28 with cLBP pain and 19 without, were recruited and completed a series of freestyle lifting trials (3 sets of box lifted for a total of 36 lifts). Verbal cues were used to modulate their expectations about the boxes' weight: no expectation, lighter or heavier load expectations. Following each set, participants rated their perceived exertion on a visual analog scale. During the lifting protocol, kinematics (time to maximal flexion, angular velocity and joint angles), electromyography muscle activity (erector spinae and quadriceps) and center of pressure displacement were simultaneously recorded.
Results showed that time to maximal knee flexion was modulated by load expectations in both groups (mean lighter load expectations = 1.15 ± 0.32 sec.; mean heavier load expectations = 1.06 ± 0.31 sec.). Results also showed a load expectations X group interaction for that time to maximal hip and lumbar flexion. Time to maximal hip flexion decreased with heavier load expectations (mean lighter load expectations = 1.20 ± 0.36; mean heavier load expectations = 1.16 ± 0.33) for cLBP only. Time to maximal lumbar flexion increased with heavier load expectation (mean lighter load expectations = 1.41 ± 0.27 sec.; mean lighter load expectations = 1.46 ± 0.29 sec.) for participants without LBP. However, no difference in lumbar, hip nor knee angles were observed between groups or conditions. Results highlighted significant load expectation effects for erector spinae electromyography activity, as lower muscle activations was observed for both groups with heavier load expectations (mean = 0.32 ± 0.15), compared to lighter load expectations (mean = 0.52 ± 0.27). Force plates analyses did not reveal any significant load expectation effects.
Present findings showed that load expectations modulate movement strategies and muscle activation similarly but not identically in individuals with chronic low back pain and healthy adults during freestyle lifting. Results of the present study partially differ from previous studies and suggest only minor differences in lifting strategies between healthy individuals and individuals with cLBP experiencing low level of pain and disability. More studies are needed to investigate the potential role of load expectations in the development and persistence of chronic low back pain.
The aim of this study was to identify adaptations in muscle activity distribution to spinal tissue creep in presence of muscle fatigue.
Twenty-three healthy participants performed a fatigue task ...before and after 30 minutes of passive spinal tissue deformation in flexion. Right and left erector spinae activity was recorded using large-arrays surface electromyography (EMG). To characterize muscle activity distribution, dispersion was used. During the fatigue task, EMG amplitude root mean square (RMS), median frequency and dispersion in x- and y-axis were compared before and after spinal creep.
Important fatigue-related changes in EMG median frequency were observed during muscle fatigue. Median frequency values showed a significant main creep effect, with lower median frequency values on the left side under the creep condition (p≤0.0001). A significant main creep effect on RMS values was also observed as RMS values were higher after creep deformation on the right side (p = 0.014); a similar tendency, although not significant, was observed on the left side (p = 0.06). A significant creep effects for x-axis dispersion values was observed, with higher dispersion values following the deformation protocol on the left side (p≤0.001). Regarding y-axis dispersion values, a significant creep x fatigue interaction effect was observed on the left side (p = 0.016); a similar tendency, although not significant, was observed on the right side (p = 0.08).
Combined muscle fatigue and creep deformation of spinal tissues led to changes in muscle activity amplitude, frequency domain and distribution.
Spinal manipulative therapy (SMT) includes biomechanical parameters that vary between clinicians, but for which the influence on the therapy clinical effects is unknown. This parallel-randomized ...controlled trial aimed to investigate the effect of SMT biomechanical parameters on the outcomes of participants with chronic thoracic pain (CTP) following three treatment sessions (follow-up at one week).
Adults reporting CTP (pain within the evaluated region T6 to T8 for ≥3 months) were asked to participate in a four-session trial. At the first session, participants were randomly assigned to one of three experimental groups (different SMT doses) or the control group (no SMT). During the first three sessions, one SMT was executed at T7 for the experimental groups, while a 5-min rest was provided to the control group. SMT were delivered through an apparatus using a servo-controlled linear actuator motor and doses consisted of peak forces, impulse durations, and rates of force application set at 135 N, 125 ms and 920 N/s (group 1), at 250 N, 125 ms and 1840 N/s (group 2), and at 250 N, 250 ms, 920 N/s (group 3). Disability and pain intensity were evaluated at each session (primary outcomes). Spinal stiffness was assessed before-and-after each SMT/rest and at follow-up. Tenderness and muscle activity were evaluated during each spinal stiffness trial. Improvement was evaluated at follow-up. Differences in outcomes between groups and sessions were evaluated as well as factors associated with clinical improvement.
Eighty-one participants were recruited and 17, 20, 20 participants of the three experimental groups and 18 of the control group completed the protocol. In exception of higher pain intensity at baseline in the control group, no between-group differences were found for any of the outcomes. A decrease in pain intensity, disability, spinal stiffness, and tenderness during spinal stiffness were observed (p-values< 0.05). At follow-up, 24% of participants were classified as 'improved'. Predictors of improvement were a greater decrease in pain intensity and in tenderness (p-values< 0.05).
In an experimental setting, the delivery of a SMT does not lead to significantly different outcomes in participants with CTP than a control condition (spinal stiffness assessment). Studies are still required to explore the mechanisms underlying SMT effects.
ClinicalTrials.gov NCT03063177 , registered 24 February 2017).
...in the last section, results of studies focusing on the development of innovative tools and methods to assess and improve gait, balance and cognitive functions in neurological patients are ...reported. Since aging is known to increase the falling risk, the Sensory Organization Test (SOT) applied to old people appears to be a useful tool for assessing postural stability, risk of falling, and balance improvement during rehabilitation. ...Moon et al. stressed that SOT has limitations (high cost, lack of portability etc.) that hinder its use in clinical practice. ...they developed an innovative system, called VR-ComBAT (for “Virtual Reality Comprehensive Balance Assessment and Training”), that provides a safe, feasible, and cost-effective virtual reality environment allowing the investigation of multisensory integration in balance control. ...much attention has been given to the investigation of both gait and postural control in patients with various neuromusculoskeletal conditions, either to establish baseline comparisons with healthy individuals, track natural history of diseases or assess clinical improvement following clinical interventions.
Spinal mobilization (SMob) is often included in the conservative management of spinal pain conditions as a recommended and effective treatment. While some studies quantify the biomechanical (kinetic) ...parameters of SMob, interpretation of findings is difficult due to poor reporting of methodological details. The aim of this study was to synthesise the literature describing force-time characteristics of manually applied SMob.
This study is reported in accordance with the Preferred Reporting Items for Scoping Reviews (PRISMA-ScR) statement. Databases were searched from inception to October 2022: MEDLINE (Ovid), Embase, CINAHL, ICL, PEDro and Cochrane Library. Data were extracted and reported descriptively for the following domains: general study characteristics, number of and characteristics of individuals who delivered/received SMob, region treated, equipment used and force-time characteristics of SMob.
There were 7,607 records identified and of these, 36 (0.5%) were included in the analysis. SMob was delivered to the cervical spine in 13 (36.1%), the thoracic spine in 3 (8.3%) and the lumbopelvic spine in 18 (50.0%) studies. In 2 (5.6%) studies, spinal region was not specified. For SMob applied to all spinal regions, force-time characteristics were: peak force (0-128N); duration (10-120s); frequency (0.1-4.5Hz); and force amplitude (1-102N).
This study reports considerable variability of the force-time characteristics of SMob. In studies reporting force-time characteristics, SMob was most frequently delivered to the lumbar and cervical spine of humans and most commonly peak force was reported. Future studies should focus on the detailed reporting of force-time characteristics to facilitate the investigation of clinical dose-response effects.
Purpose
The aim of this study was to evaluate the effectiveness of an exercise protocol designed to induce delayed-onset muscle soreness (DOMS) in paraspinal muscles and its effects on low back ...functional capacities.
Methods
Twenty-four healthy participants were asked to perform four series of 25 trunk flexion–extension in a prone position (45° inclined Roman chair). The protocol was performed using loads corresponding to participant’s trunk weight plus 10% of their trunk extension maximal voluntary contraction. Perceived soreness and pain were assessed using an 11-point numerical analogue scale three times a day during 5 day post-DOMS protocol. Pressure-pain thresholds (PPT) in paraspinal muscles (L2 and L4 bilaterally) and the vastus medialis (control site), and trunk extension maximal voluntary contraction were assessed 24–36 h post-protocol and compared to baseline (
t
tests).
Results
Muscle soreness (3.8/10) and pain (2.1/10) peak scores were observed 24–36 h post-protocol (mean of 28 h). A significant reduction in trunk extension maximal voluntary contraction was observed post-protocol (
p
= 0.005). Significant reductions in PPT were observed post-protocol for all trunk extensor sites (
ps
< 0.01), but not for the control site (
p
= 0.40).
Conclusions
The exercise protocol efficiently led to low back muscle DOMS, reduced functional capacities, and increased pain sensitivity locally. Such protocol could be used as an efficient and safe experimental low back pain model.
Background The purpose of this study was to investigate how feedback and self-assessment strategies affect performance and retention of manual skills in a group of chiropractic students. Methods ...Seventy-five students participated in two spinal manipulation (SM) learning sessions using a force-sensing table. They were recruited between May and November 2022 during HVLA technical courses. Students were randomly assigned into three different groups: participants in group 1 received visual feedback, those in group 2 received visual feedback after self-assessment, and participants in group 3 (C) received no feedback. During the first session, participants started with one block of 3 familiarization trials, followed by two blocks of 6 SM HVLA (high velocity low amplitude) posterior-to-anterior thoracic SM trials, with 3 trials performed with a target force of 450 N and 3 others at 800 N. They received feedback according to their group during the first block, but no feedback was provided during the second block. All participants were invited to participate in a second session for the retention test and to perform a new set SM without any form of feedback. Results Results showed that visual feedback and visual feedback in addition to self-assessment did not improve short-term SM performance, nor did it improve performance at the one-week retention test. The group that received visual feedback and submitted to self-assessment increased the difference between the target force and the peak force applied, which can be considered a decrease in performance. Conclusion No learning effects between the three groups of students exposed to different feedback and self-assessment learning strategies were highlighted in the present study. However, future research on innovative motor learning strategies could explore the role of external focus of attention, self-motivation and autonomy in SM performance training. Keywords: Motor skills, Motor learning, Spinal manipulation, Feedback
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