Lower Limb Dominance, Morphology, and Sonographic Abnormalities of the Patellar Tendon in Elite Basketball Players: A Cross-Sectional Study

Discipline-specific Torque-Velocity Profiles and Musculotendinous Morphology in Athletes

OBJECTIVES

The aim of this study was to compare torque-velocity profiles, muscle architecture, tendon dimensions, and bilateral-symmetry between competitive cyclists (CY), competitive runners (RN), ice-hockey players (IH), basketball players (BP), and physically-active individuals (CN) (n=10 for each group).

METHODS

Vastus lateralis (VL) muscle and patellar tendon (PT) structures were determined with B-mode ultrasonography, and maximal knee extensor isokinetic torque was assessed at three different velocities.

RESULTS

Optimal torque and velocity were lower in runners than CY, BP and IH (p<0.05). Maximal power was similar between the athlete groups but greater than CN (p<0.05). Furthermore, RN and BP reached their peak-torque at longer muscle lengths compared to IH and CY (p<0.05). RN had the lowest VL muscle thickness and the greatest fascicle length, while CY had the greatest pennation angle (p<0.05). CY had the greatest PT thickness, particularly at the proximal and medial sites, while BP at the distal point (p<0.05), with similar trends observed for PT cross-sectional-area.

CONCLUSIONS

Our findings show that even if power generating capacity is similar between athletic disciplines, there are discipline-specific muscle adaptations, where particularly runners appear to have muscles adapted for speed rather than torque development, while in cyclists, velocity is sacrificed for torque development.

A New Quantitative Tool for the Ultrasonographic Assessment of Tendons: A Reliability and Validity Study on the Patellar Tendon

Ultrasound is widely used for tendon assessment due to its safety, affordability, and portability, but its subjective nature poses challenges. This study aimed to develop a new quantitative analysis tool based on artificial intelligence to identify statistical patterns of healthy and pathological tendons. Furthermore, we aimed to validate this new tool by comparing it to experts' subjective assessments. A pilot database including healthy controls and patients with patellar tendinopathy was constructed, involving 14 participants with asymptomatic (n = 7) and symptomatic (n = 7) patellar tendons. Ultrasonographic images were assessed twice, utilizing both the new quantitative tool and the subjective scoring method applied by an expert across five regions of interest. The database contained 61 variables per image. The robustness of the clinical and quantitative assessments was tested via reliability analyses. Lastly, the prediction accuracy of the quantitative features was tested via cross-validated generalized linear mixed-effects logistic regressions. These analyses showed high reliability for quantitative variables related to "Bone" and "Quality", with ICCs above 0.75. The ICCs for "Edges" and "Thickness" varied but mostly exceeded 0.75. The results of this study show that certain quantitative variables are capable of predicting an expert's subjective assessment with generally high cross-validated AUC scores. A new quantitative tool for the ultrasonographic assessment of the tendon was designed. This system is shown to be a reliable and valid method for evaluating the patellar tendon structure.

Chronic adaptations of the long head of the biceps tendon and groove in professional baseball pitchers

BACKGROUND AND HYPOTHESIS

The long head of the biceps tendon (LHBT) plays a significant shoulder stabilizing role during pitching, with the large forces and repetitions involved in overhead throwing likely contributing to LHBT pathology. Determining whether the LHBT undergoes adaptive changes in baseball pitchers and how these changes relate to bicipital groove morphology can improve our understanding of the biceps function at the glenohumeral joint. Therefore, the purpose of this study was to determine the chronic adaptations of the bicipital groove morphology and the LHBT in professional baseball pitchers, with a secondary purpose of evaluating biceps integrity as it relates to torsional changes of the bicipital groove. We hypothesized that the throwing arm of professional baseball pitchers would exhibit chronic adaptations of the LHBT compared with their nonthrowing arm, and that these adaptations would be related to the bicipital groove morphology.

MATERIALS AND METHODS

Fifty-three professional baseball pitchers were enrolled at the beginning of the 2015 Major League Baseball spring training. Ultrasound was used to bilaterally measure humeral retroversion and to capture images of the bicipital groove and the LHBT. MATLAB software was used to calculate the area of the bicipital groove, and ImageJ software was used to quantify the area, echogenicity, and circularity of the LHBT.

RESULTS

The dominant arm LHBT cross-sectional area was significantly smaller than the nondominant arm (9 mm² vs. 10 mm²; P = .011), whereas the dominant arm LHBT echogenicity was significantly higher than the nondominant arm (65 optical density vs. 59 optical density; P = .002). Pitchers with more bicipital groove rotational adaptation (more retroversion) had significantly more LHBT echogenicity adaptation compared with pitchers with less bicipital groove rotational adaptation (12 vs. 2; P = .023).

CONCLUSION

There are significant bilateral differences in the LHBT of professional baseball pitchers. An adaptation in bony rotation was associated with a larger bilateral difference in LHBT echogenicity but was not related to bilateral differences in LHBT area or circularity. Therefore, the bilateral difference in echogenicity is impacted by bony morphology, whereas the bilateral difference in cross-sectional area may be independent of bony morphology in this healthy population.

Foot and Lower Limb Clinical and Structural Changes in Overuse Injured Recreational Runners Using Floating Heel Shoes: Preliminary Results of a Randomised Control Trial

Foot-strike and the associated load rate are factors related to overuse injuries in runners. The purpose of this study was to analyse structural and functional changes in runners using floating heel running shoes, compared with runners using conventional footwear. A randomised control trial was conducted. Twenty runners with overuse injuries were followed over a 12-week gait retraining programme using floating heel running shoes or their conventional footwear. Pain was measured with pressure pain thresholds (PPTs), structural changes were measured with ultrasonography, and severity and impact of injury was scored on the Oslo Sports Trauma Research Centre Overuse Injury Questionnaire (OSTRC-O). Statistical differences were found between groups after the intervention (p < 0.001), with a medium size effect SE = 0.8, and the floating heel running shoes group reached higher PPTs values. Participants using floating heel running shoes showed higher OSTRC-O scores than those using their conventional footwear (p < 0.05), with higher scores after the intervention (p < 0.05). A 12-week gait retraining programme using floating heel running shoes had positive effects on the injury recovery process when compared to the use of conventional footwear, with significant differences in terms of pain and impact on sports activity.

Bony asymmetry in patellofemoral morphology and risk factors of instability are mostly clinically negligible

PURPOSE

Previous investigations suggested that femoral side-to-side differences were located in the upper femur anatomy. However, little is known about the asymmetry between distal femur and patella. The degree of bony asymmetry in the patellofemoral joint was evaluated using pairs of CT-scans with emphasis on morphometric measurements and risk factors relevant to patellofemoral disorders.

METHODS

Patellofemoral morphometric parameters and anatomical risk factors were analyzed from 345 pairs of CT scans to evaluate side-to-side differences for each patient. All measurements were automatized using previously published algorithm-calculated bone landmarks. We analyzed asymmetry based on absolute differences (AD) and percentage asymmetry (AS%). Significant asymmetry was defined as AS% > 10%.

RESULTS

Patellar height was found to be highly symmetric (mean AD 0.1 for both Insall-Salvatti and Caton-Deschamps methods, AS% 8% and 9%, respectively). Patellar and femoral morphometric parameters were found highly symmetric, except for the trochlear groove depth. Substantial asymmetry was reported in two patellofemoral risk factors: the lateral trochlear inclination (mean AD 2°, AS% 16%) and the tibial tuberosity-trochlear groove distance (1 mm, 116%). Patellar and femoral morphometric asymmetries were independent of demographics, including age, gender, height, weight and ethnicity.

CONCLUSION

Patellar height was found to be highly symmetric and is, therefore, a reasonable index for contralateral templating. While very few patellofemoral morphometric parameters and anatomical risk factors were asymmetric, the mean differences were clinically negligible and independent of demographics.

LEVEL OF EVIDENCE

III.

Stiffness of the Gastrocnemius-Achilles Tendon Complex Between Amateur Basketball Players and the Non-athletic General Population

Muscle and tendon stiffness are related to sports performance, tendinopathy, and tendon degeneration. However, the effects of habitual loading on muscle and tendon mechanical properties are unclear. Using amateur basketball players as examples, we investigated the effects of mechanical loading on the stiffness of the gastrocnemius–Achilles tendon (AT) complex in non-dominant and dominant lower limbs. Then, we evaluated the correlation between gastrocnemius and AT stiffness. Forty participants (20 amateur basketball players; 20 normal non-athletic persons) were recruited for this study. Stiffness of the gastrocnemius–AT complex was assessed using MyotonPRO at neutral position and 10° dorsiflexion of the ankle joint in participants from amateur basketball players and the non-athletic general population. Our results showed a greater stiffness of the gastrocnemius–AT complex in amateur basketball players than that in healthy non-athletic subjects at neutral position and 10° dorsiflexion of the ankle joint (P < 0.05). No significant difference in stiffness was found between the non-dominant and dominant lower limbs either in amateur basketball players or in generally healthy subjects (P > 0.05). A significant positive correlation was obtained between stiffness of the AT and medial gastrocnemius (MG) in amateur basketball players (neutral position: r = 0.726 and P = 0.001; dorsiflexion 10°: r = 0.687 and P = 0.001). The amateur basketball players exhibit significantly higher stiffness value in Achilles and gastrocnemius. This is possibly caused by repeated training effects. The symmetric stiffness of the AT and gastrocnemius exists both in amateur basketball players and generally healthy subjects. A significant correlation between the AT and the MG was found in amateur basketball players.

Ultrasound Characterization of Patellar Tendon in Non-Elite Sport Players with Painful Patellar Tendinopathy: Absolute Values or Relative Ratios? A Pilot Study

Imaging findings in patellar tendinopathy are questioned. The aim of this pilot study was to characterize ultrasound measures, by calculating ultrasound ratio and neovascularization of the patellar tendon in non-elite sport players with unilateral painful patellar tendinopathy. Cross-sectional area (CSA), width, and thickness of the patellar tendon were assessed bilaterally in 20 non-elite sport-players with unilateral painful patellar tendinopathy and 20 asymptomatic controls by a blinded assessor. Ultrasound ratios were calculated to discriminate between symptomatic and asymptomatic knees. The Ohberg score was used for characterizing neovascularization. We found that non-elite sport players with patellar tendinopathy exhibited bilateral increases in CSA, width, and thickness of the patellar tendon compared to asymptomatic controls (Cohen d > 2). The ability of ultrasound ratios to discriminate between painful and non-painful patellar tendons was excellent (receiver operating characteristic, ROC > 0.9). The best diagnostic value (sensitivity: 100% and specificity: 95%) was observed when a width ratio ≥ 1.29 between the symptomatic and asymptomatic patellar tendon was used as a cut-off. Further, neovascularization was also observed in 70% of non-elite sport players with unilateral patellar tendinopathy. A greater CSA ratio was associated with more related-disability and higher tendon neovascularization. This study reported that non-elite sport players with painful unilateral patellar tendinopathy showed structural ultrasound changes in the patellar tendon when compared with asymptomatic controls. Ultrasound ratios were able to discriminate between symptomatic and asymptomatic knees. Current results suggest that ultrasound ratios could be a useful imaging outcome for identifying changes in the patellar tendon in sport players with unilateral patellar tendinopathy.