Lower extremity and spine characteristics in young dancers with and without patellofemoral pain

The effect of high-intensity laser therapy on pain and lower extremity function in patellofemoral pain syndrome: a single-blind randomized controlled trial

Patellofemoral pain syndrome (PFPS) is a set of symptoms that negatively affect the daily life activities of the individual, leading to functional disability and significant loss of labor, especially in young adults. PFPS is usually due to weakness of the vastus medialis obliquus (VMO) resulting in abnormal patellar tracking and pain. Our study aims to compare the efficacy of high-intensity laser therapy (HILT) on pain and lower extremity function in the treatment of PFPS with different electrophysical agents (EPAs). The study was designed as a single-blind randomized controlled trial. Forty-five people with PFPS (aged 25-45 years) were included in the study. The patients were randomly divided into three groups and a total of ten sessions of treatment were administered to all three groups for 2 weeks, 5 days a week. High-intensity laser (HILT) and exercise program were applied to group 1. Ultrasound (US), transcutaneous electrical nerve stimulation (TENS), and exercise program were applied to group 2. In group 3, US, interferential current (IFC), and exercise program were applied. Both groups underwent three evaluations: pre-treatment, post-treatment, and 12 weeks after treatment. Outcome measures included the visual analog scale for pain severity (VAS), knee flexion range of motion (FROM), Q angle, pain threshold, muscle strength of quadriceps and hamstring, Kujala patellofemoral scoring, lower extremity functional scale (LEFS), and Timed Up and Go Test (TUG). The ANOVA was used for comparing the data of the groups, and two-way repeated measure ANOVA was used to compare at the pre-post and post-intervention 3rd month. The LSD and Bonferroni post hoc tests were also used to identify the between-group differences. Groups 2 and 3 were statistically effective in pain and functionality (p < 0.05). Group 1 was found to be statistically more effective than other groups in reducing pain (95% confidence interval (CI), 0.000/0.000; p = 0.000), increasing knee flexion angle (95% CI, 127.524/135.809; p = 0.000), and increasing lower extremity function (95% CI, 75.970/79.362; p = 0.000). This study indicated that high-intensity laser therapy was found to be a more effective method in the treatment of patellofemoral pain syndrome after 3 months of follow-up compared to US-TENS combination and US-interferential current combination treatments. Also, HILT can be used as an effective method in combination with an appropriate exercise program including vastus medialis strengthening to reduce pain and increase functionality in the patients with PFPS.

A Systematic Review on Quadriceps Angle in Relation to Knee Abnormalities

Previous studies on the quadriceps (Q) angle and its relation to knee problems have led to conflicting conclusions. In this comprehensive review, we evaluate recent studies on the Q angle and analyze the changes in Q angles. Specifically, we investigate the variation in Q angles when measured under the following conditions: 1) under various measurement techniques; 2) between symptomatic and non-symptomatic groups; 3) between samples of men and women; 4) unilateral versus bilateral Q angles; 5) Q angle in adolescent boys and girls. It is widely believed that Q angles are more significant in symptomatic patients than in asymptomatic individuals or that the right lower leg and left lower limb are equivalent, which is supported by little scientific data. However, research states that young adult females have higher mean Q angles than males.

Does the Foot and Ankle Alignment Impact the Patellofemoral Pain Syndrome? A Systematic Review and Meta-Analysis

Background: A convincing association between the foot and ankle alignment (FAA) and patellofemoral pain syndrome (PFPS) remains debatable in the literature. Therefore, all studies investigating the role of FAA in patients with PFPS were systematically reviewed. Methods: A systematic literature search was performed on the databases PubMed, Embase, Cochrane Library, and Web of Science. Inclusion criteria were all studies investigating static and/or dynamic FAA factors and PFPS. Studies with less than 20 patients or with patellofemoral osteoarthritis were excluded. The quality assessment was based on Cochrane study criteria, and the maximum score was set at eight. Results: Of 2246 articles, only 13 case-control studies were eligible. Considering static FAA factors, two studies found an association with rearfoot eversion and one with rearfoot inversion. While examining dynamic FAA characteristics, one study found an association with rearfoot eversion range of motion and three with gait kinematics. No further associations were reported. The quality assessment mean score was 5.5 (SD = 0.97) corresponding to moderate quality. Conclusions: In contrast to our expectations, a limited number of studies were founded supporting an association between FAA and PFPS. At present, the quality of the literature is still poor and conflicting, thus the need for further studies to determine any association between FAA and PFPS.

Levels of Gnostic Functions in Top Karate Athletes-A Pilot Study

High-quality sensory perception and body scheme (somatognosis) are important aspects for sport performance. This study compares stereognosis, body scheme, and kinesthesia in a group of 36 competitive karate athletes against a control group of 32 general population participants. The stereognosis Petrie test, two body scheme tests, and three kinesthesia tests served as outcome measurement tools. No significant difference was found in the stereognosis Petrie test, for the dominant (p = .389) or the nondominant (p = .791) hand, nor in the kinesthesia test (dominant, p = .661 and nondominant, p = .051). Karate athletes performed significantly better in the body scheme tests, that is, fist width estimation (p = .024) and shoulder width estimation (p = .019), as well as in karate-specific kinesthesia tests, that is, single punch (p = .010) and triple punch (p = .001). This study confirms competitive karate athletes have significantly better somatognosis, and better accuracy when performing quick dynamic movements compared with the general population.

Cross-Sectional Risk Factors of Anterior Knee Pain in Adolescents

Background: Anterior knee pain is a common complaint amongst adolescents, which can both be persistent, and in some cases, disabling. This study investigated a series of potential risk factors potentially linked to the onset of anterior knee pain.

Methods: Questionnaires were distributed amongst 367 10–15 years-olds enrolled in the local school board. These surveys included questions on sex, age, sport participation, and history of anterior knee pain verified by a physician. Bivariate correlations and a binomial logistic regression were conducted. Overall rate of AKP in the population studied was 7.4%. The results indicated that past history of knee pain, age, and increased sports participation significantly correlated with increased risk of AKP. AKP was significantly more common in females than males. While sex, height, age, overall sport participation, participation in specific sports, and history of knee injury all contributed to the binomial model.

Type of Turnout and Injury Rates in Elite Dancers: A Critically Appraised Topic

Clinical Scenario: Dancers commonly stand in hip external rotation due to the esthetics that ballet requires. Increased external rotation is desired which leads dancers to find ways to compensate to increase their external rotation, an action known as compensated turnout. Dancers commonly rotate at the tibiofemoral joint and/or the talocrural joint to increase external rotation of the entire lower body, placing increased stress on these joints. This critically appraised topic focuses on the relationship between types of turn out and lower-extremity injury in dancers. Clinical Question: In elite dancers, does compensated, anatomical, or functional turnout influence lower-extremity injuries? Summary of Key Findings: Three studies met the inclusion criteria and were included in the analysis. One study demonstrated a relationship between compensated turnout and traumatic injuries, low back pain, and number of injuries in modern dancers. Greater compensated turnout in dancers was associated with a greater number of injuries. Two studies showed no relationship between anatomical or functional turnout and injuries in dancers. Clinical Bottom Line: Based on 3 level 2b studies, there is level C evidence to suggest that increased compensated turnout is associated with increased traumatic lower-extremity injuries, low back pain, and number of injuries in university modern dancers compared with dancers with a reduced angle of compensated turnout. This relationship was not found between anatomical or functional turnout and lower-extremity injuries in elite dancers. Strength of Recommendation: There is weak evidence to suggest that compensated turnout, but not anatomical or functional turnout, is related to lower-extremity musculoskeletal injury. More research is needed to study compensatory mechanisms in a broader range of dancers and the relationship to lower-extremity injury.

Do Individuals with History of Patellofemoral Pain Walk and Squat Similarly to Healthy Controls? A 3D Kinematic Analysis During Pain Remission Phase

BACKGROUND

Patellofemoral pain (PFP) is typically accompanied by changes in movement pattern. However, it is unclear if these changes persist in the remission phase of symptoms. Investigating movement patterns in individuals in remission phase of PFP may help to further guide the rehabilitation process and to understand whether changes are due to high levels of pain or related to other factors.

PURPOSE

To compare 3D kinematics during walking and the single leg squat (SLS) between individuals with history of PFP in remission phase and a control group without history of lower limb injuries and PFP.

STUDY DESIGN

Cross-sectional case-control study.

METHODS

Individuals with onset of PFP for at least one year and in phase of remission of symptoms (experimental group [EG]; n=13, 30±8 years) were compared to a control group (CG, n=13, 28±7 years). A 10-camera motion analysis system (Vicon-Nexus®) was used to record 3D ankle, knee, hip and trunk angles during walking and SLS.

RESULTS

The EG presented less ankle dorsiflexion, knee and hip flexion during the stance phase of walking compared to the CG (p=0.005, large effect size ηp2 = 0.141). During the SLS, no between-group differences were observed for the ankle, knee and hip angles at the peak of knee flexion (p>0.05). A trend for increased trunk range of movement in the EG compared to the CG was observed (p=0.075, medium effect size ηp2 = 0.127).

CONCLUSION

The results of this study indicate less movement in the sagittal plane during walking, and a trend towards more movement of the trunk during SLS in the EG compared to the CG. The participants of the EG had minimal symptoms, to the point of not classifying them as pathological. However, the between-group differences suggest that even in the remission phase, kinematic differences persist for some reason and may contribute to the recurring pain in PFP individuals.

LEVEL OF EVIDENCE

Level 3.

Anterior knee pain in runners after a half-marathon race

BACKGROUND

Anterior knee pain has been associated with sports activity, especially long-distance running and endurance sports. It is important to determine the incidence of anterior knee pain (AKP) in runners after a half-marathon race and identify possible risk factors associated.

METHODS

Cross-sectional study where runners from a half marathon race were randomly invited to participate. Participants were recruited at the race kit pickup site the day before the race. Eligible participants completed a survey regarding demographic information, running experience and training details. An orthopedic surgeon performed a physical examination and recorded the medical history. At the finish line, the participants were evaluated again for possible new injuries.

RESULTS

A total of 205 runners were included in the study, with a 98.5% follow-up rate (n = 203). 24% of runners had an injury at the end of the race (n = 49). Anterior knee pain was the most frequent injury (n = 12), followed by iliotibial band syndrome (n = 10), muscle cramps (n = 7) and hamstring tears (n = 4). Anterior knee pain had a statistically significant association with insufficient stretching of the hamstrings (p = 0.048) and finishing the race in more than 2 h (p = 0.014).

CONCLUSIONS

Anterior knee pain was the most frequent new injury in the half-marathon runners after the competition. Spending more than 2 h to finish the race and stretching the hamstrings by less than 70° in the supine position were risk factors for anterior knee pain.

Generalized joint hypermobility, scoliosis, patellofemoral pain, and physical abilities in young dancers

Background

Many young girls with generalized joint hypermobility (GJH) choose to participate in dance because their bodies are suited for this activity. Scoliosis tends to occur often in thin girls, who also are more likely to choose dance. Both anomalies (GJH and scoliosis) may be related to reduced abilities such as diminished strength and insufficient postural balance, with increased risk for musculoskeletal conditions. The main objectives of the present study were to determine the prevalence of dancers with GJH, the prevalence of dancers with scoliosis, and the prevalence of dancers with these two anomalies; and, to determine differences in physical abilities and the presence of patellofemoral pain (PFP) between young female dancers with and without such anomalies.

Methods

One hundred thirty-two female dancers, aged 12–14 years, were assessed for anthropometric parameters, GJH, scoliosis, knee muscle strength, postural balance, proprioception ability, and PFP.

Results

GJH was identified in 54 dancers (40.9%) and scoliosis in 38 dancers (28.8%). Significant differences were found in the proportion of dancers with no anomalies (74 dancers, 56.1%) and dancers with both anomalies (34 dancers, 25.8%) (p < .001). Dancers with both anomalies had reduced dynamic postural balance in the anterior direction (p = .023), reduced proprioception ability (p < .001), and weaker knee extensors (p = .036) and flexors (p = .040) compared with dancers with no anomalies. Among dancers with both anomalies, 73.5% suffered bilateral PFP, 17.6% suffered unilateral PFP, and 8.8% had no PFP (p < .001).

Conclusions

A high prevalence of young girls participating in dance classes had GJH, as the increased joint flexibility probably provides them with some esthetic advantages. The high prevalence of scoliosis found in these young dancers might be attributed to their relatively low body mass, their delayed maturation, and the selection process of dancers. Dancers with both GJH and scoliosis had decreased muscle strength, reduced postural balance, reduced proprioception, with higher risk of PFP. The main clinical implications are the need to reduce the risk of PFP among dancers by developing appropriate strength and stabilizing exercises combined with proprioceptive and postural balance training, to improve the correct alignment of the hyperextended and hypermobile joints, and to improve their supporting muscle strength.

Unilateral and bilateral patellofemoral pain in young female dancers: Associated factors

Aiming to evaluate the prevalence of unilateral/bilateral patellofemoral pain (PFP) among young dancers, and to investigate whether different factors are associated with PFP in young dancers, 132 dancers aged 12-14 years were assessed for PFP. Anthropometric parameters, proprioception ability, dynamic postural balance (DPB), and muscle strength were measured. PFP was found in 64.1% of the dancers. No significant differences in the prevalence of dancers with no, unilateral, or bilateral PFP at different ages were found. Significant age effects were found for anthropometric and developmental measurements, and for intensity of training. PFP effect was found for DPB asymmetry, ankle proprioception, and leg-length %height. A higher hip abductor/adductor ratio was associated with PFP in 14-year-old dancers. Binomial logistic regression showed that increased number of hours per day (h/day) and decreased number of hours per week (h/week), low proprioception scores, greater leg length as %height, and more anterior DPB asymmetry were significant predictors of PFP. In conclusion: unilateral/bilateral PFP is common among young dancers. Body morphology, reduced ankle proprioception ability, DPB asymmetry, and increased h/day of practice are associated with PFP. Dance teachers should start monitoring the impact of training and implement injury modification/prevention strategies when their students are at a young age.

Patellofemoral Pain in Adolescents: Understanding Patellofemoral Morphology and Its Relationship to Maltracking

BACKGROUND

Developing bone is highly adaptable and, as such, is susceptible to pathological shape deformation. Thus, it is imperative to quantify if changes in patellofemoral morphology are associated with adolescent-onset patellofemoral pain, as a pathway to improve our understanding of this pain's etiology.

PURPOSE

To quantify and compare patellofemoral morphology in adolescent patients with patellofemoral pain with matched healthy adolescent controls and determine if a relationship exists between patellofemoral shape and kinematics (measured during active flexion-extension).

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Using 3-dimensional static magnetic resonance images acquired during a previous study, we measured patellar, trochlear, and lateral patellar width; trochlear and patellar depth; Wiberg index; patellar-height ratio; lateral trochlear inclination; cartilage length; and lateral femoral shaft length. Student t test was used to compare shape parameters between adolescents with patellofemoral pain and controls. Pearson correlations and stepwise linear regression models were used to explore the relationship among morphology, kinematics (medial-lateral shift/tilt), and pain.

RESULTS

Relative to controls, adolescents with patellofemoral pain had larger sulci (mean ± SD, 6.6 ± 0.7 vs 6.0 ± 1.1 mm; 95% CI, 0.6 mm; P = .043; d = 0.66), lateral patellar width (23.1 ± 2.4 vs 21.4 ± 2.6 mm; 95% CI, 1.6 mm; P = .033; d = 0.70), and patella-trochlear width ratio (1.2 ± 0.1 vs 1.1 ± 0.1; 95% CI, 0.1; P < .001; d = 1.26). Shape correlated with kinematics in both cohorts and in the entire population. In the patellofemoral pain group, lateral shaft length (r = 0.518; P = .019), Wiberg index (r = 0.477; P = .033), and patellar-height ratio (r = -0.582; P = .007) were correlated with medial shift. A moderate correlation existed between patellar-height ratio and lateral patellar tilt (r = 0.527; P = .017). Half of the variation in patellar shift in the patellofemoral pain cohort was explained by the patellar-height ratio and Wiberg index (R² = 0.487; P = .003). Linear correlations with pain were not found.

CONCLUSION

This study provides direct evidence that patellofemoral morphology is altered and influences maltracking in adolescents with patellofemoral pain, highlighting the multifactorial etiology of this pain. Neither morphology nor kinematics (measured during active flexion-extension) correlated with pain. Both increases and decreases in these parameters likely lead to pain, negating a direct linear correlation.

Patellofemoral Pain

Patellofemoral pain (PFP) is a common musculoskeletal-related condition that is characterized by insidious onset of poorly defined pain, localized to the anterior retropatellar and/or peripatellar region of the knee. The onset of symptoms can be slow or acutely develop with a worsening of pain accompanying lower-limb loading activities (eg, squatting, prolonged sitting, ascending/descending stairs, jumping, or running). Symptoms can restrict participation in physical activity, sports, and work, as well as recur and persist for years. This clinical practice guideline will allow physical therapists and other rehabilitation specialists to stay up to date with evolving PFP knowledge and practices, and help them to make evidence-based treatment decisions. J Orthop Sports Phys Ther. 2019;49(9):CPG1-CPG95. doi:10.2519/jospt.2019.0302.

Patellofemoral pain, body morphology and alignment in female pubertal dancers: One-year follow-up

The aim of this study was to assess changes in body morphology, anatomical alignment and prevalence of patellofemoral pain (PFP) in young female dancers along one year of pubertal growth, and to identify the risk factors related to PFP in these young dancers. Both legs of 60 dancers were evaluated during grade 7 and again after 1-year. At each of these points in time, the dancers were interviewed concerning their background, and anthropometric measurements, lower-limb physical examinations and knee ultrasound scans were performed. Morphological parameters changed significantly from baseline to follow-up. PFP was found in 53.3% of the dancers' knees at baseline. At follow-up, 55.4% of the asymptomatic knees at baseline developed PFP, and only 9.4% of the symptomatic knees at baseline recovered. Lower BMI was identified among dancers who developed PFP during follow-up compared with dancers with no PFP, either at baseline or at follow-up. A positive grinding and positive Patellar Inhibition Test (PIT) were found to be risk factors for PFP at follow-up. A high prevalence of young dancers suffered PFP, from injuries they sustained mostly during the 1-year of dance practice. Parameters predisposing the dancers to PFP should be identified at early stages of dance class.

Screening Tools as a Predictor of Injury in Dance: Systematic Literature Review and Meta-analysis

BACKGROUND

Dance involves movements of complexity and physical intensity which result in stress on the body. As a consequence, dancers are at risk of injury which can impact on their well-being. Screening tools are used for injury prevention to identify those dancers at risk of injury. The aim of this study was to investigate which screening tools can predict injury in dancers, encompassing all dance genres, levels and ages.

METHODS

An electronic search of seven databases from their inception to December 2017 was conducted. The databases were the Allied and Complementary Medicine Database (AMED), CINAHL, eBOOK Collection (EBSCOhost), MEDLINE, Cochrane Database of Systematic Reviews, SPORTDiscus and PEDro: the Physiotherapy Evidence Base. The following search terms were used: (i) Dance AND injury AND Screening, (ii) Screening AND dance and (iii) Musculoskeletal AND Screening AND Dance. Studies were assessed using a 20-point scoring tool, and eligible studies were included in a meta-analysis.

RESULTS

The mean methodological quality score was 12.2 points. Injured dancers had a significantly higher compensated turnout range of motion than non-injured dancers: pooled mean difference of compensated turnout (23.29°; 95% CI 14.85-31.73; P < 0.00001; I² = 0%). Injured dancers had significantly greater functional turnout range of motion when compared to non-injured dancers: pooled mean difference of functional turnout (14.08°; 95% CI 7.09-21.07; P < 0.0001; I² = 0%). There also some evidence for use of hip range of motion as a predictor of dance injury.

CONCLUSIONS

Some evidence exists for the potential use of dance-specific positions as a predictor of injury. A number of studies were limited by a lack of prospective injury design, injury definition and self-reporting of injury.

Possibilities of kinesio taping to prevent injuries of professional dancers

A literature review of the application of kinesio taping in the prevention of professional dancers' injuries indicated frequent dance-related and overuse injuries and a lack of organized information about this issue. This study aimed to assess the impact of kinesio taping on the musculoskeletal system of dancers, based on scientific research data from 2015-2017. The analysis revealed that kinesio taping can effectively reduce muscle spasms, rebuild muscle strength of the injured extremity, improve static and dynamic balance and ease pain, due to its ability to improve proprioception of joints and regulate muscle tone. These effects reduce muscle imbalance and joint instability, thus increasing treatment efficacy and shortening the physical load limitation. Kinesio taping significantly reduces the risk of overuse syndromes and dance-related injuries during dance training and strenuous exercises of people with chronic musculoskeletal diseases. Therefore, kinesio taping has broad utility in primary and secondary prevention of dance-related injuries.

Ultrasonography and clinical examination of knee injuries in pre- and post- menarche dancers

This study aimed at evaluating whether the prevalence of knee injuries and morphological features are different among pre-and-post menarche dancers; Sixty-seven pre-and-post menarche dancers were screened for anthropometric parameters; knee laxity; patella femoral pain syndrome (PFPS), pathologies and anatomical structure of the knees. Both groups showed a high and similar prevalence of PFPS. The post-menarche dancers produced a significantly higher rate of Tanner stages 3-4 (p = .010), greater weight (p < .001) higher BMI (p = .003); and, higher prevalence of MCL pathology, pes planus, and scoliosis compared with pre-menarche dancers (p < .05). The pre-menarche dancers started dance practice earlier (p = .008); and, showed significantly higher prevalence of lateral laxity, patellar laxity, positive Lachman test and positive Drawer test compared with post-menarche dancers (p < .05). Interactions (menarche yes/no by PFPS no/one leg/both legs) were found for BMI (p = .044; η² = .187), trochlear cartilage thickness (p = .020; η² = 0.121) and tip of patella - trochlear groove distance (p = .024; η² = .150). Pre-and-post-menarche female dancers demonstrated similar prevalence of knee injuries, with different body morphology.