Lower-Extremity Energetic Distribution During Rate-Controlled Ballet Jumps (Sautés) in Healthy Dancers.

Dancers frequently perform jumps in the context of a prolonged, continuous dance piece. The purpose of this study is to explore the lower-extremity energetics in healthy dancers performing repetitive dance jumps (sautés) before and after typical dance-specific choreography. Lower-extremity kinetic data were collected from 14 healthy female dancers during a series of sautés performed before and after 3 minutes of dance. Percent contributions of the lower-extremity joints to the whole-limb mechanical energy expenditure during ground contact were calculated. The jumps performed at the beginning were compared with the jumps at the end of the dance choreography. Dancers maintained the jump rate and consistent whole-limb mechanical energy expenditure between the jump series. As expected, for both jump series, the sautés had greater relative energetic contribution from the ankle and knee as compared with lesser contribution from the hip and toe. However, we observed lesser contribution from the knee and greater contribution from the hip after a 3-minute dance. After performing typical dance choreography, the dancers demonstrated a distal to proximal redistribution of individual joints' contribution to whole-limb mechanical energy expenditure.

Flexor hallucis longus tendon morphology in dancers clinically diagnosed with tendinopathy.

PURPOSE: The unique demands of dance technique make dancers more prone to certain pathologies especially of the foot and ankle. Flexor hallucis longus (FHL) tendinopathy, colloquially known as "dancer's tendinopathy," is common in dancers and not well studied. The purpose of this study was to assess if morphological alterations in tendon structure occur as an adaptive response to dance activity by comparing the FHL tendon in dancers to non-dancers, and if pathology further alters tendon morphology in dancers clinically diagnosed with tendinopathy. METHODS: Three groups of ten participants were recruited (healthy non-dancers, healthy dancers, and dancers with FHL tendinopathy). Ultrasound images of the FHL tendons were analyzed for macromorphology by measuring the tendon thickness. The micromorphology was analyzed by determining the peak spatial frequency radius of the tendon. Our study did find increased tendon proper and composite tendon thickness in dancers with tendinopathy but no difference between asymptomatic dancers and non-dancers. RESULTS: There was no significant difference in micromorphology found between any of the groups. As expected, dancers with tendinopathy demonstrated increased composite tendon and tendon proper thickness however, there was no evidence of adaptive thickening of the FHL tendon as might be expected for the dance population. There was also no evidence of micromorphological changes in the presence of clinically diagnosed FHL tendinopathy. CONCLUSION: Because of the limited normative data for this pathology, these results can help improve diagnosis and therefore treatment for dancers to decrease the impact of this injury on their careers.

Wearable activity monitors to support physical activity interventions in neurodegenerative disease: a feasibility study.

Aim: To evaluate the feasibility of using activity monitors in a physical activity (PA) intervention in people with Parkinson's (PD) and Huntington's disease (HD). Materials & methods: People with early-stage PD (n = 13) and HD (n = 14) enrolled in a 4-month coaching program, wore a Fitbit, and were guided through a behavioral intervention to facilitate PA uptake. Wear time, wear habits and activity metrics (e.g., steps) were analyzed. Results: Retention rate was 85% and participants had an average 92.3% (±9.2) valid wear days. Daily wear time was 18.4 (±4.5) h. Day & night Fitbit wearers showed improvements in steps (d = 1.02) and MET×min/week (d = 0.69) compared with day-only wearers. Conclusion: Implementing wearables in a coaching intervention was feasible and provided insights into PA behavior.

Trunk control in and out of an episode of recurrent low back pain in young adults during the Balance-Dexterity Task.

We investigated motor control strategies utilized by individuals with recurrent low back pain (rLBP) during active pain and remission periods as well as by back-healthy controls using the Balance-Dexterity Task. Nineteen young adults with rLBP were tested first when they were in pain and then again in symptom remission, and 19 matched controls were also tested. Trunk kinematic coupling and muscle co-activation were examined while participants performed the task by standing on one leg while compressing a spring with a maximum consistent force with the other leg. We found a decreased bilateral external oblique co-activation during the spring condition of the task compared to the stable block condition in people with rLBP compared to back healthy individuals. There was also reduced trunk coupling during the spring condition of the task compared to the stable block condition in both the rLBP active and remission groups, but no group difference between rLBP and back-healthy individuals. When individuals were in active pain, they exhibited more co-activation than when they were in remission, but the co-activation during active pain was not greater than in back-healthy individuals.

Dance interventions for individuals post-stroke - a scoping review.

BACKGROUND: There is a growing body of literature assessing the potential benefits of dance for individuals post-stroke. OBJECTIVES: We conducted a scoping review mapping the state of the literature on feasibility, intervention procedures, and efficacy of dance to improve health-related outcomes for individuals post-stroke. ELIGIBILITY CRITERIA: Included studies were original research that described the use of a dance intervention for individuals post-stroke, included any health-related outcome, and were written in English. SOURCES OF EVIDENCE: Databases selected were Pubmed, Scopus, Google Scholar, Proquest, MedRxiv, and CINHAL. CHARTING METHODS: Two reviewers extracted relevant data and results were organized into themes and categories determined by all authors through discussion. RESULTS: We searched electronic databases were in February 2021. We included 18 publications from 14 studies. Ten were quantitative, five were qualitative, one was mixed-methods, and two were community project descriptions. Twelve publications evaluated in-person dance classes and six evaluated dance exergaming. Based on the limited studies included, evidence suggests dance is a feasible and potentially effective intervention for individuals post-stroke. Studies demonstrate dance may facilitate changes in balance and fall risk, encourage confidence, promote comfort with the changed body, increase rehabilitation motivation, and facilitate community reintegration. Evidence is limited by number of studies, design (lack of control groups and blinded assessments), intervention descriptions, and outcomes reporting. CONCLUSIONS: There is growing interest in dance for stroke interventions. Further research should focus on rigorous study design, optimal intervention timing, consistency of reporting outcomes, key elements of dance classes, and the impact of cultural dance styles.

Physical Activity Coaching via Telehealth for People With Parkinson Disease: A Cohort Study.

BACKGROUND AND PURPOSE: Physical activity (PA) has many known benefits for people with Parkinson disease (PD); however, many people do not meet recommended levels of frequency or intensity. We designed Engage-PD, a PA coaching program delivered via telehealth and grounded in self-determination theory to promote PA uptake and facilitate exercise self-efficacy in people with Parkinson disease. This study aimed to determine the feasibility and preliminary efficacy of Engage-PD, and to explore whether baseline characteristics were associated with outcomes. METHODS: A single cohort of people with PD (n = 62, Hoehn and Yahr I-III) participated in the 3-month Engage-PD program, which consisted of up to 5 telehealth coaching sessions delivered by physical therapists. Feasibility was evaluated based on recruitment and retention rates, along with participants' feedback. Planned and unplanned PA, exercise self-efficacy (ESE), and individualized goals were assessed pre- and post-intervention. Relationships between baseline characteristics and changes in planned PA and ESE were also evaluated. RESULTS: Recruitment (62%) and retention (85%) rates were high, and the intervention was well accepted and perceived by the participants. From pre- to postintervention, participants increased planned PA (d = 0.33), ESE (d = 1.20), and individualized goal performance (d = 1.63) and satisfaction (d = 1.70). Participants with lower baseline planned PA experienced greater improvements in planned PA, and those with lower baseline ESE experienced greater improvements in ESE. DISCUSSION AND CONCLUSIONS: A telehealth PA coaching program for people with PD was feasible and potentially efficacious. Physical therapist-led coaching may be an important component of a consultative model of care starting early in the disease process.Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A393).

Individuals with recurrent low back pain exhibit further altered frontal plane trunk control in remission than when in pain.

BACKGROUND: Movement alterations due to low back pain (LBP) could lead to long-term adverse consequences if they do not resolve after symptoms subside. This study aims to determine if altered trunk control associated with recurrent low back pain persists beyond symptom duration. METHODS: Twenty young adults with recurrent LBP were tested once during an LBP episode and once in symptom remission, and twenty matched back-healthy participants served as controls. Participants walked on a treadmill with five prescribed step widths (0.33, 0.67, 1, 1.33, 1.67 × preferred step width). Motion capture and surface electromyography were used to record trunk kinematics and muscle activation. Thorax-pelvis coordination was calculated using vector coding, and longissimus activation and co-activation were analyzed. FINDINGS: Young adults with recurrent LBP exhibited a "looser" trunk control strategy in the frontal plane during gait that was persistent regardless of pain status across multiple step widths compared to controls. The looser trunk control was demonstrated by a greater pelvis-only, less thorax-only coordination pattern, and decreased bilateral longissimus co-activation in individuals with recurrent LBP compared to controls. The looser trunk control strategy was further amplified when individuals were in symptom remission and exhibited greater trunk excursion and reduced in-phase coordination in the frontal plane. INTERPRETATION: The amplification of aberrant movement during symptom remission may suggest that movement patterns or anatomical factors existing prior to the tested painful episode underlie altered trunk control in individuals with recurrent LBP. The symptom remission period of recurrent LBP may be a critical window into clinical evaluation and treatment.

Young adults with recurrent low back pain demonstrate altered trunk coordination during gait independent of pain status and attentional demands.

Pain influences both attention and motor behavior. We used a dual-task interference paradigm to investigate (1) alterations in attentional performance, (2) the ability to switch task prioritization, and (3) the effect of attentional demand on trunk coordination during narrow-based walking in and out of a painful episode in individuals with recurrent low back pain (LBP). We tested twenty young adults with LBP both in and out of a painful episode and compared them to twenty matched back-healthy individuals. Participants simultaneously performed a narrow step width matching task and an arithmetic task, with and without instructions to prioritize either task. A motion capture system was used to record kinematic data, and frontal plane trunk coordination was analyzed using vector coding on the thorax and pelvis angles. Single-task performance, dual-task effect, dual-task performance variability, task prioritization switch, and trunk coordination were analyzed using paired t tests or repeated measures two-way ANOVAs. Results indicated that active pain has a detrimental effect on attentional processes, indicated by poorer single-task performance and increased dual-task performance variability for individuals with recurrent LBP. Individuals with LBP, regardless of pain status, were able to switch task prioritization to a similar degree as their back-healthy counterparts. Compared to the control group, individuals with recurrent LBP exhibited a less in-phase, more pelvis-dominated trunk coordination during narrow-based walking, independent of pain status and regardless of attentional manipulations. Thus, altered trunk coordination in persons with LBP appears to be habitual, automatic, and persists beyond symptom duration.

Effects of a "toes-off" modified heel raise on muscle coordination in non-dancers, dancers, and dancers with flexor hallucis longus tendinopathy.

BACKGROUND: Tendinopathy of the flexor hallucis longus, commonly called "dancer's tendinitis", is a prevalent injury among female ballet dancers. Limited success of non-surgical interventions leads to many dancers undergoing tenolysis surgeries with risks and recovery times that can be detrimental to a dance career. The purpose of this study was to evaluate lower limb kinematics and muscle coordination during a modified traditional heel raise exercise where the toes hang off the edge of the support surface. We hypothesized this would decrease activation of the flexor hallucis longus and increase activation of larger plantarflexors. METHODS: Healthy non-dancers (n = 11), healthy dancers (n = 10), and dancers with flexor hallucis longus tendinopathy (n = 9) performed traditional ("toes-on") and modified ("toes-off") heel raises with kinematic and electromyographic instrumentation of the lower leg. FINDINGS: Participants maintained ankle excursion with the toes-off modification, while metatarsophalangeal joints had reduced excursion and greater excursion variability. Most healthy dancers (9/10) decreased flexor hallucis longus activation as predicted, but dancers with flexor hallucis longus tendinopathy showed a variable response with some decreasing activation (3/9) but others increasing activation up to 4-times. There were no changes in activation of other plantarflexors. Across groups, intrinsic foot muscle activation decreased with the toes-off modification. INTERPRETATION: The toes-off modification decreased flexor hallucis longus activation in most of the healthy dancers but was insufficient to shift muscle coordination from the flexor hallucis longus to larger plantarflexors in dancers with flexor hallucis longus tendinopathy. Future work should investigate clinical cues or modifications to this "toes-off" heel raise intervention.

Trunk control during gait: Walking with wide and narrow step widths present distinct challenges.

The active control of the trunk plays an important role in frontal plane gait stability. We characterized trunk control in response to different step widths using a novel feedback system and examined the different effects of wide and narrow step widths as they each present unique task demands. Twenty healthy young adults walked on a treadmill at 1.25 m/s at five prescribed step widths: 0.33, 1.67, 1, 1.33, 1.67 times preferred step width. Motion capture was used to record trunk kinematics, and surface electromyography was used to record longissimus muscle activation bilaterally. Vector coding was used to analyze coordination between pelvis and thorax segments of the trunk. Results showed that while center of mass only varied across step width in the mediolateral direction, trunk kinematics in all three planes were affected by changes in step width. Angular excursions of the trunk segments increased only with wider widths in the transverse plane. Thorax-pelvis kinematic coordination was affected more by wider widths in transverse plane and by narrower widths in the frontal plane. Peak longissimus activation and bilateral co-activation increased as step widths became narrower. As a control task, walking with varied step widths is not simply a continuum of adjustments from narrow to wide. Rather, narrowing step width and widening step width from the preferred width represent distinct control challenges that are managed in different ways. This study provides foundation for future investigations on the trunk during gait in different populations.

Interlimb Force Coordination in Bipedal Dance Jumps: Comparison Between Experts and Novices.

Bipedal tasks require interlimb coordination that improves with practice and acquisition of skills. The purpose of this study was to compare interlimb force coordination during dance-specific rate-controlled consecutive bipedal jumps (sautés) between expert dancers and nondancers. To analyze coordination of vertical ground reaction forces recorded under each leg, the vector coding approach was used. Although there were no differences in the patterns of interlimb force coordination between groups, the dancers exhibited less variability of interlimb force coordination during the transition phase from weight acceptance to propulsion as well as during the propulsion phase itself. The interlimb force coordination variability was associated with task performance only during the transition phase, which highlights the potential importance of control during this phase. In conclusion, expert dancers were better at reducing interlimb force coordination variability during the task-relevant transition phase, which was related to better performance at maintaining jump rate and jump height consistency.