MOVEMENT VARIABILITY IN PRE-TEEN AND TEENAGE ATHLETES DURING SPORTS RELATED TASKS. Issue 4 (28th April 2020)

• Record Type: Journal Article
• Authors: Edison, Bianca; O'Callahan, Bridget; Mueske, Nicole M.; Conrad-Forrest, Adriana; Katzel, Mia J.; Zaslow, Tracy; Wren, Tishya A. L.
• Is Part Of: Orthopaedic journal of sports medicine. Volume 8:Issue 4(2020)Supplement 3
• Publication Date: 2020-04-28
• Subjects: Sports medicine -- Periodicals; Orthopedics -- Periodicals; Arthroscopy -- Periodicals; Arthroplasty -- Periodicals; Knee -- Surgery -- Periodicals; 616.7
• DOI: 10.1177/2325967120S00151
• Languages: English
• ISSNs: 2325-9671

Abstract

Background: Movement variability may affect injury assessment and may change as athletes mature. Hypothesis/Purpose: We hypothesized that pre-teen athletes would exhibit greater variability than teenage athletes when performing drop jump, heel touch, and single leg hop motions. Methods: 55 uninjured pediatric athletes were divided into pre-teen (age 7-12 years; n=29; 11 female) and teenage (age 13-15 years; n=26; 13 female) groups of similar size. All participants performed 2-3 repetitions per side of three sports related tasks: drop jump (41 cm), heel touch (single-leg squat from 15 cm or 23 cm step, depending on whether subject height <155 cm), and single leg hop for distance. 3D kinematics were recorded using motion capture during the loading phase of each task. To assess intra-individual variability, we examined the standard deviation (SD) and range (maximum-minimum) of key metrics among the multiple repetitions of each task performed by each participant. Variability was compared between age groups using 2-sided t-tests. Results: In the drop jump and heel touch, the younger group was more variable than the older group (Figure 1.1 left). The median within-subject SD of repeat measurements varied from 1-6° in the sagittal plane, 1-3° in the frontal plane, and 1-4° in the transverse plane over both groups (Table 1.2), while the within-subject range of measurements varied from 2-11° in the sagittal, 2-5° in the frontal, and 2-7° in the transverse planes (Table 1.3). Representing a worst-case scenario, the 95th percentile for range of measurements was >15° for many sagittal plane variables and >10° for many frontal and transverse plane variables in the younger group. In the singl- leg hop, the older group was much more variable than the younger group in the sagittal plane, particularly at the trunk, pelvis, and ankle (Figure 1.1 right). The younger group was still more variable than the older group at the trunk and pelvis in the transverse plane. Median within-subject variability ranged from 2-9° for SD and 3-17° for range of repeat measurements. Conclusion: There was substantial within-subject variability in performing sports related tasks for pediatric athletes of all ages. Variability was generally lower for older athletes, but was particularly high in the older group for sagittal plane trunk and pelvis motion during single-leg hop landing, which may reflect the need to adjust for less constrained positioning of a larger proximal mass. The high variability in performing sports tasks suggests that multiple trials should be analyzed for a more complete and representative evaluation. : Figure 1.1. Variability (range of repeat measurements is shown) generally decreased with age during the drop jump and heel touch (left) but was much higher in the older group in the sagittal plane during single leg hop (right) Table 1.2. Median (5 th percentile, 95 th percentile) for standard deviation of within-subject measurements for pre-teen and teenage groups Drop Jump Heel Touch Single Leg Hop Age <12 yr Age ≥12 yr Age <12 yr Age ≥12 yr Age <12 yr Age ≥12 yr Max trunk tilt 5.8 (1.1, 12.1) 3.3 (0.9, 9.2) 2.8 (0.6, 11.0) 2.7 (0.9, 5.6) 4.7 (1.1, 21.6) 7.9 (2.8, 22.1) Max pelvic tilt 2.8 (1.1, 10.7) 1.6 (0.7, 5.7) 2.0 (0.6, 4.8) 1.3 (1.3, 3.3) 3.3 (0.5, 7.2) 8.7 (1.1, 20.8) Max hip flexion 5.0 (1.1, 11.7) 2.8 (1.1, 9.4) 4.4 (0.6, 8.9) 2.8 (0.5, 5.6) 4.3 (0.6, 10.2) 5.1 (1.4, 12.0) Max knee flexion 4.6 (0.6, 16.6) 3.2 (0.8, 8.1) 3.1 (0.4, 7.8) 1.8 (0.4, 4.3) 4.2 (1.9, 9.4) 5.7 (0.5, 11.3) Max ankle dorsiflexion 2.4 (0.6, 5.0) 1.6 (0.3, 3.9) 1.2 (0.3, 2.8) 0.9 (0.2, 2.6) 2.6 (0.9, 10.4) 7.3 (1.2, 17.2) Mean trunk obliquity 2.8 (0.8, 5.9) 1.6 (0.4, 3.1) 2.6 (0.2, 8.3) 1.6 (0.4, 5.3) 4.4 (1.1, 9.1) 3.6 (1.1, 10.5) Mean pelvic obliquity 1.4 (0.4, 4.5) 1.1 (0.3, 2.7) 1.6 (0.6, 3.7) 1.1 (0.3, 2.7) 2.4 (0.4, 8.3) 2.8 (0.6, 6.8) Mean hip adduction 2.6 (0.3, 8.0) 1.5 (0.5, 4.0) 2.1 (0.7, 5.4) 1.3 (0.2, 3.8) 2.7 (1.0, 7.2) 4.0 (0.9, 10.6) Mean knee adduction 1.4 (0.2, 3.4) 0.9 (0.2, 2.6) 1.6 (0.5, 3.5) 1.1 (0.3, 3.1) 1.5 (0.3, 4.7) 1.6 (0.4, 4.4) Mean trunk rotation 2.8 (0.8, 6.2) 1.7 (0.5, 4.0) 3.1 (0.9, 8.0) 1.8 (0.3, 5.3) 5.6 (1.0, 11.4) 3.6 (0.6, 10.6) Mean pelvic rotation 3.7 (0.7, 8.0) 1.8 (0.5, 3.3) 2.8 (1.1, 10.1) 1.7 (0.3, 3.2) 4.9 (0.7, 11.6) 3.5 (0.6, 7.1) Mean hip rotation 2.0 (0.4, 4.5) 1.6 (0.4, 3.1) 2.0 (0.7, 5.7) 1.3 (0.4, 4.0) 2.3 (0.3, 6.7) 2.5 (0.4, 5.9) Bold indicates significant difference between age groups at p<0.05. All measurements are in degrees. Table 1.3. Median (5 th percentile, 95 th percentile) for range of within-subject measurements for pre-teen and teenage groups Drop Jump Heel Touch Single Leg Hop Age <12 yr Age ≥12 yr Age <12 yr Age ≥12 yr Age <12 yr Age ≥12 yr Max trunk tilt 10.5 (1.9, 23.2) 6.1 (1.8, 14.3) 5.2 (1.2, 21.8) 5.0 (1.7, 10.7) 8.6 (2.0, 40.6) 15.2 (5.1, 40.7) Max pelvic tilt 5.3 (1.6, 19.7) 3.1 (1.4, 10.6) 3.0 (1.2, 9.1) 2.3 (0.6, 6.5) 6.2 (0.7, 14.2) 17.1 (1.6, 37.0) Max hip flexion 8.6 (2.2, 23.0) 5.3 (1.9, 18.1) 8.4 (1.1, 16.6) 5.3 (0.9, 11.1) 8.3 (0.9, 17.9) 9.8 (2.3, 23.0) Max knee flexion 8.7 (0.8, 29.3) 6.2 (1.5, 16.3) 5.9 (0.7, 15.1) 3.4 (0.7, 8.2) 7.5 (1.9, 17.3) 9.9 (0.9, 21.7) Max ankle dorsiflexion 4.6 (1.0, 9.8) 3.1 (0.5, 7.7) 2.4 (0.5, 5.5) 1.8 (0.5, 5.1) 5.0 (0.5, 15.4) 13.2 (2.3, 26.3) Mean trunk obliquity 5.2 (1.1, 11.8) 2.9 (0.7, 6.2) 4.7 (0.4, 15.4) 2.9 (0.9, 10.4) 7.9 (1.4, 17.1) 6.3 (1.7, 20.1) Mean pelvic obliquity 2.6 (0.6, 8.1) 2.1 (0.7, 5.4) 3.1 (1.1, 7.3) 2.1 (0.6, 5.4) 4.5 (0.6, 13.5) 4.6 (1.1, 11.5) Mean hip adduction 5.2 (0.5, 15.3) 2.7 (1.0, 7.7) 3.8 (1.2, 10.3) 2.4 (0.4, 7.5) 5.1 (1.3, 13.1) 7.4 (1.7, 19.4) Mean knee adduction 2.4 (0.3, 8.3) 1.8 (0.5, 4.7) 3.1 (0.9, 6.9) 2.2 (0.6, 6.0) 2.8 (0.5, 9.0) 2.8 (0.5, 7.6) Mean trunk rotation 6.8 (3.3, 18.3) 3.3 (0.9, 7.8) 6.2 (1.8, 15.3) 3.3 (0.7, 10.4) 9.9 (1.7, 22.0) 6.8 (1.1, 15.5) Mean pelvic rotation 7.1 (1.3, 15.5) 3.4 (1.0, 6.5) 5.4 (2.1, 20.2) 3.3 (0.5, 6.1) 7.4 (1.3, 16.4) 6.6 (1.1, 14.2) Mean hip rotation 3.8 (0.7, 11.4) 2.8 (0.5, 7.7) 4.1 (1.4, 11.4) 2.4 (0.7, 7.4) 4.5 (0.4, 12.9) 4.2 (0.8, 11.7) Bold indicates significant difference between age groups at p<0.05. All measurements are in degrees.