Ultrasound imaging of the dorsalis pedis artery as an early indicator of the precursory changes for rheumatoid vasculitis: A case series.

Introduction: Clinical verification of rheumatoid vasculitis (RV) persists as a mid-to-late diagnosis with medical imaging or biopsy. Early and subclinical presentations of RV, in particular, can remain underdiagnosed in the absence of adequate diagnostic testing. In this study, the research demonstrated the precursory changes for RV in patients with rheumatoid arthritis (RA) using non-invasive ultrasound imaging of a peripheral vessel. Method: Six participants were recruited: three participants with (RA) and three age- and gender-matched healthy controls. All participants completed a Foot Health Survey Questionnaire (FHSQ), and participants with RA completed a Rheumatoid Arthritis Disease Activity Index-5 (RADAI-5). Bilateral B-mode and Doppler ultrasound of the dorsalis pedis artery (DPA) was performed. The degree of inflammation, lumen and artery diameters, lumen diameter-to-artery diameter ratio and peak systolic velocity in the proximal DPA were compared between the two groups. Results: The mean RADAI-5 score (5.4 ± 0.8 out of 10) indicated moderate disease activity amongst participants with RA. Inflammation was observed in the DPA wall in all participants with RA, compared to no inflammation observed in the control group (Friedmans two-way analysis: χ2 = 15.733, P = 0.003). Differences between groups for inflammation, lumen diameter and lumen diameter-to-artery diameter ratio were found (P < 0.034), without differences for artery diameter and peak systolic velocity (P > 0.605). DPA wall inflammation did not correlate with FHSQ scores (r = -0.770, P = 0.073). Conclusion: Despite moderate RA disease activity, this is the first study to demonstrate the use of ultrasound to observe inflammation in small vessel disease. Our findings suggest ultrasound imaging may be a viable screening tool to demonstrate arterial wall inflammation, indicating the precursory changes of RV.

Effect of minimalist and maximalist shoes on impact loading and footstrike pattern in habitual rearfoot strike trail runners: An in-field study.

Running-related injuries among trail runners are very common and footwear selection may modulate the injury risk. However, most previous studies were conducted in a laboratory environment. The objective of this study was to examine the effects of two contrasting footwear designs, minimalist (MIN) and maximalist shoes (MAX), on the running biomechanics of trail runners during running on a natural trail. Eighteen habitual rearfoot strike trail runners completed level, uphill and downhill running at their preferred speeds in both shod conditions. Peak tibial acceleration, strike index and footstrike pattern were compared between the two footwear and slopes. Interactions of footwear and slope were not detected for all the selected variables. There was no significant effect from footwear (F = 1.23, p = 0.27) and slope (F = 2.49, p = 0.09) on peak tibial acceleration and there was no footwear effect on strike index (F = 3.82, p = 0.056). A significant main effect of slope on strike index (F = 13.24, p < 0.001) was found. Strike index during uphill running was significantly greater (i.e. landing with a more anterior foot strike) when compared with level (p < 0.001, Cohen's d = 1.72) or downhill running (p < 0.001, Cohen's d = 1.44) in either MIN or MAX. The majority of habitual rearfoot strike runners switched to midfoot strike during uphill running while maintaining a rearfoot strike pattern during level or downhill running. In summary, wearing either one of the two contrasting footwear (MIN or MAX) demonstrated no effect on impact loading and footstrike pattern in habitual rearfoot strike trail runners running on a natural trail with different slopes.

The effect of support surface and footwear condition on postural sway and lower limb muscle action of the older women.

BACKGROUND: Diminished somatosensory function is a critical age-related change which is related to postural instability in the older population. Footwear is a cost-effective way to modulate the postural stability by altering sensorimotor inputs via mechanoreceptors on the plantar surface of the feet. Compared to insoles with indentions in the entire surface, we innovatively developed a textured insole with site-specific nodulous protrudous. This study thus aimed to investigate the immediate effect of the nodulous insole and supporting surface condition on static postural stability and lower limb muscle activation for healthy older women. METHODS: This is a single-session study with repeated measurements. Twenty-three healthy older women stood on the firm (i.e., concrete floor) and foam surfaces with their eyes open in the three footwear conditions, namely barefoot, plain shoes and shoes with an innovative textured insole, for 30 seconds. Static postural sway and muscle activation of biceps femoris (BF), vastus lateralis (VL), tibialis anterior (TA), and lateral gastrocnemius (LG) of the dominant leg were measured during each testing condition. RESULTS: Compared to a firm surface, standing on the foam could significantly increase the body sway and lower limb muscle activation (p<0.05). When standing on the foam, compared to barefoot, wearing footwear significantly decreased the VL and TA muscle activation and minimize the postural sway in medial-lateral and anterior-posterior direction, while the influence is larger for the shoes with nodulous insloe compared to the plain shoes. No significant differences between the footwear conditions for static stability and muscle activation were observed on firm surface condition. CONCLUSIONS: For older women, footwear could improve the postural stability in the unstable surface, particularly the footwear with nodulous insole, with the underlying mechanism as enhancing the mechanoreceptors on the plantar surface of the feet.

Transfer Learning Effects of Biofeedback Running Retraining in Untrained Conditions.

PURPOSE: Running gait retraining via peak tibial shock biofeedback has been previously shown to reduce impact loading and mitigate running-related symptoms. In previous research, peak tibial shock is typically measured and trained for one limb at a single constant training speed during all training sessions. The goal of this study was to determine how runners transfer learning in the trained limb to the untrained limb at different unconstrained speeds. METHODS: Thirteen runners (3 females, age = 41.1 ± 6.9 yr, running experience = 6.8 ± 4.4 yr, weekly running distance = 30.7 ± 22.2 km) underwent running gait biofeedback retraining via continuous tibial acceleration measured at the right distal tibia. Before and after the training, participants were asked to run at their self-selected constrained training speeds (2.8 ± 0.2 m·s) and at 110% and 90% of the training speed. Pretraining and posttraining peak tibial shock values for each limb were compared. RESULTS: Participants reduced peak tibial shock in the trained limb by 35% to 37% (P < 0.05, Cohen's d = 0.78-0.85), and in the untrained limb by 20% to 23% (P < 0.05, Cohen's d = 0.51-0.71) across the three testing speeds. The reduction was not significantly different between the trained and untrained limbs (P = 0.31-0.79, Cohen's d = 0.18-0.45). Similarly, there was no difference in peak tibial shock reduction among the three running speeds (P = 0.48-0.61, Cohen's d = 0.06-0.45). CONCLUSION: Participants demonstrated transfer learning effects evidenced by concomitant reduced peak tibial shock in the untrained limb, and the learning effects were retrained when running at a 10% variance of the training speed.

Placebo effect of facilitatory Kinesio tape on muscle activity and muscle strength.

PURPOSE: Kinesio tape (KT) is claimed to be able to facilitate muscle activation and promote muscle strength. Previous studies have proposed that placebo effect could be a major attributing factor. This study sought to compare the effects of facilitatory KT on muscle activity and performance between regular KT-users and non-users. METHODS: Sixty participants, including 27 regular KT-users and 33 non-users, performed maximal grip assessment with and without facilitatory KT, which was applied to their wrist extensor muscles of the dominant forearm from the direction of origin to insertion at 75% of its maximal tension. Within-subject comparisons of normalized root mean square of the wrist extensors electromyographic activity, maximal grip strength, and perceived performance were conducted. RESULTS: KT-users showed an increase in grip strength with application of facilitatory KT, when compared to tapeless condition (p = 0.030, Cohen's d = 0.16). Non-users demonstrated similar grip strength with and with KT application (p = 0.232). No significant differences were found in the muscle activity (p > 0.198) and perceived performance (p > 0.400) in both groups. CONCLUSIONS: Facilitatory KT promotes maximal grip strength only among regular KT users, but its effect is trivial. Interestingly, such effect is not related to any electrophysiological change in the KT applying muscle, which may indicate an indirect working mechanism leading to the increased grip strength.

Type effect of inhibitory KT tape on measured vs. perceived maximal grip strength.

This study examined the effects of KT tape (KT) applied in an inhibitory manner on muscle activity, measured maximal grip strength, and perceived maximal grip strength in regular KT-users and non-users. This study was a single-blinded crossover study with sixty participants including 27 kT-users and 33 non-users. Participants underwent maximal grip strength tests with and without inhibitory KT applied across the wrist extensors. Muscle activity and maximal grip strength were measured, while perceived maximal grip strength was rated using a visual analogue scale. No significant interaction effect was found between taping conditions and participant KT-experience for muscle activity (F = 0.825, p = 0.367), measured grip strength (F = 1.018, p = 0.317) or perceived grip strength (F = 0.122, p = 0.728). No significant differences were observed in the EMG activity between taping conditions for either KT-users (p = 0.367) or non-users (p = 0.215). A similar trend was found in the measured grip strength (KT-users: p = 0.317; non-users: p = 0.294) and perceived grip strength (KT-users: p = 0.728; non-users: p = 0.063). KT applied in an inhibitory manner does not impede EMG activity, measured maximal grip strength, or perceived maximal grip strength in adults, regardless of their preconceived notions of KT.

Biomechanical Outcomes Due to Impact Loading in Runners While Looking Sideways.

A stable gaze is necessary to optimize visual conditions during running. Head accelerations generally remain stable when looking in front; however, it is unclear if this response is similar when the head is turned sideways, and whether other adaptive strategies are present to maintain this stability. The purpose of this study, therefore, was to examine whether runners maintained stable head accelerations while gazing at fixed targets in front and to their sides. The authors collected biomechanical data from 13 runners as they directed their gaze to visual targets located in front, 45°, and 90° to the sides at a random sequence. Vertical head and tibial accelerations were the primary outcome measures, while vertical loading rate, footstrike angle, contact time, stride length, and stride rate were the secondary measures. A reduction in vertical head accelerations was found in the rightmost direction (P = .04), while an increase in vertical tibial accelerations was found on the same direction (P = .02). No other significant differences were observed for the other variables. The results of this study suggest that the tibia accommodated the increased shock to maintain head stability.

Do running speed and shoe cushioning influence impact loading and tibial shock in basketball players?

BACKGROUND: Tibial stress fracture (TSF) is a common injury in basketball players. This condition has been associated with high tibial shock and impact loading, which can be affected by running speed, footwear condition, and footstrike pattern. However, these relationships were established in runners but not in basketball players, with very little research done on impact loading and speed. Hence, this study compared tibial shock, impact loading, and foot strike pattern in basketball players running at different speeds with different shoe cushioning properties/performances. METHODS: Eighteen male collegiate basketball players performed straight running trials with different shoe cushioning (regular-, better-, and best-cushioning) and running speed conditions (3.0 m/s vs. 6.0 m/s) on a flat instrumented runway. Tri-axial accelerometer, force plate and motion capture system were used to determine tibial accelerations, vertical ground reaction forces and footstrike patterns in each condition, respectively. Comfort perception was indicated on a 150 mm Visual Analogue Scale. A 2 (speed) × 3 (footwear) repeated measures ANOVA was used to examine the main effects of shoe cushioning and running speeds. RESULTS: Greater tibial shock (P < 0.001; η2 = 0.80) and impact loading (P < 0.001; η2 = 0.73-0.87) were experienced at faster running speeds. Interestingly, shoes with regular-cushioning or best-cushioning resulted in greater tibial shock (P = 0.03; η2 = 0.39) and impact loading (P = 0.03; η2 = 0.38-0.68) than shoes with better-cushioning. Basketball players continued using a rearfoot strike during running, regardless of running speed and footwear cushioning conditions (P > 0.14; η2 = 0.13). DISCUSSION: There may be an optimal band of shoe cushioning for better protection against TSF. These findings may provide insights to formulate rehabilitation protocols for basketball players who are recovering from TSF.

Upper limb muscle fatigue during prolonged Boccia games with underarm throwing technique.

This study investigated the acute fatigue pattern in neuromuscular activity after a simulated Boccia game and the effect of fatigue pattern on sport performance. Nine elite Boccia athletes were tested before, during, and after a simulated game. Maximum ball speed was captured with video, and the target hitting rate and rating of perceived exertion (RPE) score were collected and analyzed. Electromyography signals from the upper trapezius, anterior deltoid, posterior deltoid, biceps brachii, triceps brachii, and wrist extensor muscles were collected by surface electrode and were evaluated with mean power frequency (MPF). Only the upper trapezius muscle showed fatigue as demonstrated by a reduction of MPF of 8% (p = 0.027) when comparing the first and last throws in a simulated game. Subjective RPE score increased during the game (118%, p = 0.004), and sports performance in terms of maximum ball speed (-12%, p = 0.004) and target hitting rate (-25%, p = 0.004) also deteriorated. In conclusion, fatigue on the upper trapezius muscle was demonstrated in elite Boccia athletes following a prolonged Boccia game and may have affected Boccia performance. Preventative measures against upper trapezius muscle fatigue and endurance training for synergists of the upper trapezius muscle may be considered in future studies.

Enforced bipedal downhill running induces Achilles tendinosis in rats.

Enforced downhill running has been reported to induce tendinosis in the rat supraspinatus tendon but similar exercise failed to induce Achilles tendinosis in this animal. Due to the presence of acromial arch in the shoulder, accessing the supraspinatus tendon with physical modalities is difficult; thus this model may not be suitable for studying the treatment for tendinosis. To develop a rat model for Achilles tendinosis, we tested 14 mature Sprague-Dawley rats by dividing them into 2 groups of 7 each. The experimental group was subjected to a daily enforced downhill bipedal running program by suspending their upper bodies so that they ran with their hind limbs on a treadmill for 1 hr/day for 8 weeks. The downward inclination was 20 degrees and the speed was 17 m/min. The animals in the control group did not undergo any exercise. After 8 weeks, the Achilles tendons were harvested and subjected to histological and biomechanical analysis. Histological examination revealed tenocyte proliferation, change in tenocytes appearance, and collagen bundle disintegration in the running group. The biomechanical testing revealed significant decrease in stiffness (p = 0.002) and ultimate tensile strength (p = 0.016) in the running group than in the control group. Both the histological and biomechanical findings are suggestive of changes in the tendon of the running group that resembled the pathological changes of tendinosis in human. This new model of Achilles tendinosis in rat will be useful for studying the etiology and subsequent management strategies of this condition.