Music to Our Ears: Are Dancers at Risk for High Sound Level Exposure?

Enduring exposure to high sound pressure levels (SPLs) can lead to noise-induced hearing loss (NIHL). In the performing arts population, NIHL has been studied primarily in the context of sound exposure experienced by musicians and less so by dancers. This research aimed to identify sound exposure that dancers may experience in some dance classes. Decibel levels were recorded in 12 dance classes (6 ballet, 4 modern, and 1 soft and 1 hard shoe Irish dance) at 8 different studios using the NIOSH SLM app on an iOS smartphone with external microphone. A minimum of five recordings of each class was measured, each collected on a different day, yielding a total of 114 measurements. Results showed that 20.2% of all recordings exceeded the recommended NIOSH sound exposure limits of both 100% projected daily dose and 85 LAeq. Analysis between styles of dance demonstrated significantly lower LAeq (p≤0.05) in soft shoe Irish dance compared to ballet (p=0.023), modern (p=0.035), and Irish hard shoe dance (p=0.009). Irish soft shoe dance demonstrated minimal to no risk of high sound exposure. Conversely, 53.25% of ballet, 90.9% of Irish hard shoe dance, and 68.24% of modern recordings exhibited minimal to moderate risk of high sound exposure. Furthermore, we found wide ranges of projected daily noise doses within classes taught by the same teacher. It is recommended that multiple recordings of dance environments be obtained, as a single sound recording may not accurately represent potential exposure. These findings indicate that dancers of Irish hard shoe, modern, and ballet may benefit from noise intervention such as audiometric testing, noise controls, and hearing protection.

Ultrasound-Guided Intratendinous Injections With Platelet-Rich Plasma or Autologous Whole Blood for Treatment of Proximal Hamstring Tendinopathy: A Double-Blind Randomized Controlled Trial.

OBJECTIVES: To compare the effects of ultrasound-guided platelet-rich plasma (PRP) and whole blood (WB) injections in patients with chronic hamstring tendinopathy. METHODS: In a prospective double-blind randomized controlled trial, PRP or WB was injected under ultrasound guidance into the proximal hamstring tendon in a cohort of patients with clinically suspected hamstring tendinosis. Questionnaires were administered before injection and 2, 6, and 12 weeks and 6 months after injection. Pain and function outcomes were measured via the Modified Harris Hip Score (MHHS), Hip Outcome Scores for activities of daily living (ADL) and sport-specific function, and International Hip Outcome Tool 33 (IHOT-33). Diagnostic ultrasound was used to compare preinjection and 6-month postinjection tendon appearances. RESULTS: The WB group showed greater improvements in pain and function over the PRP group before 12 weeks, whereas the PRP group showed improved outcomes over WB at 6 months. None of these between-group outcome measures, except 6-week IHOT-33, showed statistical significance. Comparing preinjection and 6-month scores, the PRP group showed significant improvements in ADL (P = .018) and IHOT-33 (P = .28) scores, whereas the WB group showed no significant improvements from baseline. The WB group showed significantly decreased pain with 15-minute sitting (P= .008) at 6 months. Ultrasound imaging showed no significant differences between PRP and WB group tendon appearances. CONCLUSIONS: Both PRP and WB groups showed improvements in all outcome measures at 6 months. The PRP group showed significant improvements in 6-month ADL and IHOT-33 scores. The WB group reached significance in 15-minute sitting pain. No significant between-group differences were observed at any time point.

Hallux valgus in dancers: a closer look at dance technique and its impact on dancers' feet.

Hallux valgus is a common deformity of the forefoot. There is no doubt that some dancers develop hallux valgus, but the question remains as to whether dancers are at greater risk than the general population for developing this deformity. Review of the literature reveals on-going debate regarding risk factors for hallux valgus, which may include increasing age, female gender, genetic predisposition, constrictive shoe wear, first ray hypermobility, foot architecture, tight Achilles tendon, and first metatarsal length. There is insufficient evidence to demonstrate conclusively that dancing, specifically pointe work, increases the prevalence or severity of hallux valgus; more research is needed. Treatment of hallux valgus in dancers should be conservative, with delay of surgical correction until retirement if possible.

Dissecting the doctor-dancer relationship: health care decision making among American collegiate dancers.

OBJECTIVE: To examine perceptual influences on dancers' health care-seeking decisions and whether dancers' beliefs correlate with actual use of provider services when they are injured. Secondary aims were to understand how dancers may select physicians and what they consider to be the most important features of the medical consultation. DESIGN: Prospective cohort study. SETTING: University and conservatory dance departments. PARTICIPANTS: Forty American collegiate dancers. ASSESSMENT OF RISK FACTORS: Before the start of the dance semester, all participants completed a retrospective survey that included baseline demographic data, dance experience, a dance-related injury (DRI) inventory, previous health care exposures, and perceptions regarding health care treatment providers. Data regarding new DRIs and health care exposures were then prospectively collected every 2 weeks for 6 months. MAIN OUTCOME MEASUREMENTS: A DRI was defined as any neuromusculoskeletal condition sustained as the result of dancing activity that caused a dancer to stop or modify his or her dancing for more than 3 consecutive days. RESULTS: Dancers perceived dance teachers to be first-line treatment providers (47.5%), followed by physical therapists (PTs; 30%). Physicians were ranked third (12.5%) and only marginally higher than a dance colleague (10%). The dancers expressed a strong preference for nonsurgical rather than surgical physicians (87.5% versus 5.0%), and among physicians, the majority of dancers preferred subspecialists (60%), namely nonsurgical sports medicine doctors and physiatrists. During the 6-month prospective data-collection period, 25 dancers (69.4%) sustained 55 unique injuries, with 22 dancers (88%) and 34 injuries (61.8%) undergoing evaluation. Only 17.7% of injuries were evaluated by a physician. Dancers showed greater incongruity between their preinjury perceptions and postinjury use of physicians than they did with PTs (P = .0002). CONCLUSIONS: Although dancers did not perceive physicians to be first-line treatment providers for DRIs, these perceptions about physicians were poorly correlated with use. Instead, injured dancers' health care-seeking behaviors were more likely related to relatively decreased barriers to other nonphysician providers, as well as pre-existing referral pathways to PTs.

Relationship between Respiratory Load Perception and Perception of Nonrespiratory Sensory Modalities in Subjects with Life-Threatening Asthma.

Subjects with life-threatening asthma (LTA) have reported decreased sensitivity to inspiratory resistive (R) loads. It is unknown if decreased sensitivity is specific for inspiratory R loads, other types of respiratory loads, or a general deficit affecting sensory modalities. This study hypothesized that impairment is specific to respiratory stimuli. This study tested perceptual sensitivity of LTA, asthmatic (A), and nonasthmatic (NA) subjects to 4 sensory modalities: respiratory, somatosensory, auditory, visual. Perceptual sensitivity was measured with magnitude estimation (ME): respiratory loads ME, determined using inspiratory R and pressure threshold (PT) loads; somatosensory ME, determined using weight ranges of 2-20 kg; auditory ME, determined using graded magnitudes of 1 kHz tones delivered for 3 seconds bilaterally; visual ME, determined using gray-to-white disk intensity gradations on black background. ME for inspiratory R loads lessened for LTA over A and NA subjects. There was no significant difference between the 3 groups in ME for PT inspiratory loads, weight, sound, and visual trials. These results demonstrate that LTA subjects are poor perceivers of inspiratory R loads. This deficit in respiratory perception is specific to inspiratory R loads and is not due to perceptual deficits in other types of inspiratory loads, somatosensory, auditory, or visual sensory modalities.

Perception of intrinsic and extrinsic respiratory loads in children with life-threatening asthma.

There is a subpopulation of asthmatic patients with a history of life-threatening asthma (LTA) who have a reduced perception of respiratory loads. The aim of this study was to determine if these patients have a reduced perception of both intrinsic and extrinsic loads. Children with asthma were classified into life-threatening asthma and control asthmatic groups. Perception of extrinsic loads was assessed by magnitude estimation of inspiratory resistive loads. Magnitude estimation was measured with handgrip estimation of resistive load magnitude. Perception of intrinsic loads was by methacholine bronchoprovocation in doses sufficient to a drop to 40% below baseline of forced expired volume in 1 sec (FEV(1)). Chest tightness, breathlessness, and air hunger, as estimated by a Borg scale were, used to rate methacholine perception. Life-threatening asthma subjects had a lower slope than nonlife-threatening asthma subjects for magnitude estimation of resistive loads. Life-threatening asthma patients also had a lower maximum Borg score for all three symptoms. There was no significant difference in magnitude estimation of symptom type.These results suggest that life-threatening asthma subjects have poor perception of extrinsic and intrinsic loads. This suggests that there is a similarity between the sensations elicited by intrinsic and extrinsic loads, allowing for the identification of poor-perceiving patients with either method of assessment and who suffer from life-threatening asthma.