EFFECTS OF SURFACE ON TRIPLE HOP DISTANCE AND KINEMATICS

Abstract

Background: The single leg triple hop (SLTH) test is often utilized by rehabilitation practitioners as a functional performance measure in a variety of patient groups. Accuracy and consistency are important when measuring the patient progress and recovery. Administering the SLTH test on different surfaces, consistent with the patient's sport, may affect the hop distances and movement biomechanics.

Purpose: The purpose of this study was to examine the effects of court and turf surfaces on the hop distance, limb symmetry index (LSI), and lower extremity kinematics of a SLTH test.

Methods: Recreationally active female participants (n=11, height 163.8 ± 7.1cm, mass 63.1 ± 7.1kg, age 18.9 ± 0.9yrs), without injury, volunteered to participate in the study. Three maximal effort SLTH test trials on two different surfaces (court, synthetic turf) were collected and analyzed using 3D motion analysis techniques. Outcome variables included SLTH test distances and LSI values and sagittal plane kinematics including trunk, hip, knee and ankle range of motion (ROM) during the last two landings of each SLTH test trial. The second landing involves an absorption phase and propulsion phase in contrast to the final landing which involves absorption and final balance on the single leg. Paired t-tests were used to determine differences between surfaces in hop distance and LSI values. Two-way repeated measures ANOVA were used to determine differences between surfaces in kinematic variables.

Results: The total SLTH test distance was not statistically different between the court (4.11 ± 0.47m) and turf (4.03 ± 0.42m, p=0.47) surfaces. LSI for the court surface was 100.8 ± 3.0% compared to 99.7 ± 3.0% for turf surface, which was not statistically different (p=0.30). Knee flexion ROM was significantly less (p=0.04) on the turf compared to the court surface during the second landing. Ankle flexion range of motion was also significantly less (p=0.03) during the second landing on turf compared to court.

Conclusions: Type of surface influenced landing kinematics but not total SLTH test distance. When evaluating the quality of landings during a SLTH test, it may be warranted to observe each type of landing and the type of surface used during single leg tests.

Level of evidence: 2.

Keywords: biomechanics; landing; motion analysis; movement system; rehabilitation; return to sport.

Figure 1.

3D Marker Locations. Anatomical landmarks at the sternum, sacrum, left PSIS, C7, three tracking markers on the upper back, and bilaterally on the shoulder, upper arm, elbow, wrist, ASIS, greater trochanter, midthigh, medial and lateral knee, tibial tubercle, midshank, distal shank, medial and lateral ankle, heel, posterior lateral foot, anterior lateral foot, and toe.

Figure 2.

Single leg triple hop (SLTH) test. Three consecutive maximal forward hops on the same limb without hesitation were performed. The second and third landings were analyzed kinematically.

Figure 3.

Effect of surface on second and final landing for trunk, hip, knee, and ankle excursion during the landing phase. Gray lines indicate the individual change for each participant when comparing court and turf surfaces. Dot represents each participant and square represents mean with standard deviation black error bar. *p<0.05 post‐hoc analysis indicated significant differences in the surface.