•All analyzed tasks differentiate the kinematics between PFP and asymptomatic women.•MDP can be used to differentiate the kinematics of PFP from asymptomatic women.•Step down tests are the tasks that ...most differentiate the kinematics of PFP women.•The LSD has the highest sensitivity to detect the kinematic differences.•PFP kinematic differences are less evident in stair ascent and descent.
Studies evaluating kinematics lead to different conclusions, not all changes appear in all assessed tasks and in all subgroups of patients with patellofemoral pain (PFP). The inconsistencies between studies could be reduced if we knew which task separates patients best from healthy controls.
Identify which functional task, between gait, forward step down (FSD), lateral step down (LSD), stair ascent and descent and propulsion and landing phase of the single leg hop test (SLHT), differentiates the three-dimensional kinematics of women with patellofemoral pain from asymptomatic women.
This cross-sectional study evaluated thirty-five PFP and thirty-five asymptomatic women during the execution of the following tasks: gait, FSD, LSD, stair ascent and descent and the propulsion and landing phase of single leg hop test. Frontal, sagittal and transverse plane angles of the trunk, pelvis and hip, frontal and sagittal plane angles of the knee, ankle dorsiflexion, foot progression angle and hindfoot eversion were analyzed through the Movement Deviation Profile (MDP). To compare the groups, the multivariate analysis with Bonferroni post hoc test were used, with a significance level of p < 0.01. To identify which task presented the most difference between the groups, the Z-score of the mean MDP was calculated.
For all tasks, the groups presented significant differences. According to the Z-score, the groups got farther apart considering the MDP for each task in the following order: LSD (7.97), FSD (7.62), landing phase of SLHT (3.43), gait (2.85), propulsion phase of SLHT (1.64), descending stairs (1.63) and ascending stairs (1.00).
We suggest that step down tests should be included in the assessment of PFP patients, since these tests most differentiate the kinematics of women with and without PFP. Identifying the tasks with the highest sensitivity to detect the kinematic differences is expected to improve clinical decision-making.
Background:
The countermovement jump (CMJ) is a valid and reliable test of lower extremity (LE) muscle power. However, the CMJ may not be appropriate during early-stage rehabilitation of injuries. ...Functional muscle strength tests (FMSTs) could evaluate LE muscle power with lower joint reaction forces.
Hypothesis:
The lateral step-up test (LSUT), 5 times sit to stand (5×STS), and 30-s chair stand test (30CST) could predict CMJ jump height (JHt) and jump peak power (JPow).
Study Design:
Cross-sectional study.
Level of Evidence:
Level 2.
Methods:
Eighty-one young adults performed 3 CMJs to measure JHt and JPow using an electronic jump mat and speed analyzer. Participants also performed three FMSTs: 1 trial of the LSUT and a modified trial of LSUT touching the ground with the heel only (MLSUT); 2 trials of the 5×STS; and 2 trials of the 30CST, in a randomized order. Spearman rho correlations and hierarchal multiple linear regressions were used to determine whether FMST performances predicted JHt and JPow, after controlling for sex, body height, and body mass.
Results:
30CST, LSUT, MLSUT, sex, body mass, and body height were significantly associated with JHt (P < 0.05). LSUT, sex, body height, and body mass were significantly associated with JPow (P < 0.05). Hierarchical regression analyses showed that the 30CST significantly predicted JHt (P < 0.01) and JPow (P = 0.03), independent of sex, body height, and body mass.
Conclusion:
30CST performance predicted JHt and JPow in young adults.
Clinical Relevance:
The 30CST is easy to perform, requires equipment found readily in clinics, and predicts LE muscle power. This test could be used to track progress during the early stages of LE injury rehabilitation.
This study evaluated center-of-pressure (COP) and time-to-boundary (TTB) measures of postural control during a Lateral Step-Down Test in participants with chronic ankle instability (CAI).
Cohort ...study.
Biomechanics laboratory.
Physically active adults with CAI (n = 15) and matched controls (n = 15).
Traditional COP and TTB measures of postural control were computed in the medial/lateral (ML) and anterior/posterior (AP) directions.
No significant results were found for the traditional COP measures (p > 0.05). The CAI group exhibited a lower TTB ML absolute minimum on their affected limb compared to the matched limb of the control group (p < 0.001). Additionally, on average the CAI group displayed significantly lower TTB ML mean of minima (p = 0.004) and TTB standard deviation of minima in the ML (p < 0.001) and AP directions (p = 0.002) regardless of limb.
Sensorimotor impairments associated with CAI negatively alter spatiotemporal postural control and may cause a maladaptive reorganization of centrally mediated motor control strategies that results in bilateral postural control deficits during the Lateral Step-Down Test. In addition, traditional COP measures did not reveal any postural control deficits suggesting that a spatiotemporal analysis should be used when assessing postural control in participants with CAI.
•Deficits in postural control are associated with CAI.•The Lateral Step-Down Test was completed on both limbs to assess postural control.•Center of pressure measures did not reveal any significant differences in postural control.•Spatiotemporal postural control deficts were found in individuals with CAI on both limbs.
The ability to counteract destabilizing external forces while simultaneously executing a complex task presents a novel way to ascertain one's ability to generate adaptive postural control responses ...to avoid a potential fall. In this study, participants performed an upper limb object transport task requiring a lateral change in support on a robotic platform that could remain fixed in space or translated (mimicking a slip or trip perturbation). No significant stability differences were observed at initial recovery step between slip and trip perturbations. Variability measures were greatest during the trip perturbations; though stability was at its greatest level preceding these perturbations. These results will aid in the design of future studies that will investigate adaptive postural control responses generated by older adults when executing similar, ongoing complex upper body tasks interrupted by a destabilizing support surface perturbation.
Highlights • We compared postural strategies following lateral step between young and older adults. • Older adults prioritize control of postural stability in the AP direction after completing a ...lateral step. • Older adults use a strategy similar to young adults in the AP direction, but delayed in time. • Older adults display large ML CoP velocity up to thirty seconds after taking a lateral step. • A perturbation within 30 s would increase risk of falling.
Lower extremity movement patterns have been implicated as a risk factor for various knee disorders. Ankle-dorsiflexion (DF) range of motion (ROM) has previously been associated with a faulty movement ...pattern among healthy female participants.
To determine the association between ankle DF ROM and the quality of lower extremity movement during the lateral step-down test among healthy male participants.
Cross-sectional study.
Training facility of the Israel Defense Forces.
Fifty-five healthy male Israeli military recruits (age = 19.7 ± 1.1 years, height = 175.4 ± 6.4 cm, mass = 72.0 ± 7.6 kg).
Dorsiflexion ROM was measured in weight-bearing and non-weight-bearing conditions using a fluid-filled inclinometer and a universal goniometer, respectively. Lower extremity movement pattern was assessed visually using the lateral step-down test and classified categorically as good or moderate. All measurements were performed bilaterally.
Weight-bearing and non-weight-bearing DF ROM were more limited among participants with moderate quality of movement than in those with good quality of movement on the dominant side (P = .01 and P = .02 for weight-bearing and non-weight-bearing DF, respectively). Non-weight-bearing DF demonstrated a trend toward a decreased range among participants with moderate compared with participants with good quality of movement on the nondominant side (P = .03 adjusted P = .025). Weight-bearing DF was not different between participants with good and moderate movement patterns on the nondominant side (P = .10). Weight-bearing and non-weight-bearing ankle DF ROM correlated significantly with the quality of movement on both sides (P < .01 and P < .05 on the dominant and nondominant side, respectively).
Ankle DF ROM was associated with quality of movement among healthy male participants. The association seemed weaker in males than in females.
The aim of this study was to find the optimal basketball athletic stance which will enable the fastest subsequent action. We compared the reaction (RT), movement (MT), and total response (RST) times ...of a single leg lateral step, performed from starting positions and differentiating in three different heights and two different stance widths. RMANOVA results showed that the RSTs obtained during wide stance positions were clearly shorter when compared to the times obtained during narrow stances (p = 0.000). Interaction of the height (knee angle) and width of stance was also found significant (p = 0.048), while the effect of the height of the stance alone was not (p = 0.098). Similar results were found for MT, while no differences were found for RT. Width of the stance therefore clearly brings about different RSTs; a wide feet position enabled shorter MT when compared to a narrow position and consequently shorter RST, probably due to a more advantageous starting position for lateral movements and due to laws of joint and muscle mechanics. The basic athletic stance with feet double shoulder distance apart and a medium (120°) and small (150°) knee flexion was found optimal in enabling the quickest lateral movement response.
In tennis, a "split-step" is a small vertical jump or hop that is commonly used as a preparatory motion for a lateral step when receiving the ball. The purposes of the present study were (1) to ...determine whether a split-step increases the velocity of the subsequent lateral step, and (2) to investigate when the landing should occur in order to obtain the maximum benefit from a split-step. Ten male collegiate tennis players performed a choice reaction step-and-reach task with and without a split-step. The participants could reach the target earlier by taking a split-step (split: 764 ± 106 ms, no-split: 868 ± 63, P < 0.001). A risk-benefit relationship of a split-step depended on the timing of the landing. If the interval between the activation of the direction signal and the landing was shorter than mean minus standard deviation of the participant's response time, participants sometimes achieved very quick step to the target but could not reach the target in 7.8% of the trials. On the contrary, if the interval between the activation of the direction signal and the landing was within the mean plus-minus standard deviation of the participant's response time, participants achieved quick and reliable (percentage of error: 0.8%) step.
Purpose: The present study examined the concurrent and construct validity of the Lateral Step Up (LSU) test, for adolescents with CP. Method: A total of 35 adolescents, classified as GMFCS Levels I, ...II and III, were examined using LSU, GMFM - 88 (D & E), other functional mobility measures (TUG, STS, TUDS), body structures and functions (strength, ROM and spasticity). Results: LSU inter-correlations with: (i) GMFM - 88 (D & E) (r = 0.656), (ii) functional mobility measures (r = −0.567 to 0.721) and (iii) body structures and functions (r = 0.155 to 0.563) were at the appropriate range. The LSU differentiated adolescents with CP (F = 16.185, p = 0.000, η2 = 0.503), according to their GMFCS (I > II, II > III, I > III). Finally, 50.27% of the LSU variability was explained by GMFCS differences, with 65.7% of adolescents classified correctly across the three levels. Conclusions: The LSU may be perceived as a valid instrument for assessing the functional mobility of adolescents with CP.
Implications for Rehabilitation
LSU is valid for assessing functional mobility and strength in CP adolescents.
LSU may be used in accordance with other functional mobility measures in the school environment.
The LSU may be used from physical therapists to predict the functional mobility of CP adolescents at GMFCS Levels I-III.
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