Matthew R. Patterson

Lower limb kinematic alterations during drop vertical jumps in female athletes who have undergone anterior cruciate ligament reconstruction

The aim of this study was to determine if anterior cruciate ligament reconstructed (ACL‐R) female athletes exhibit altered lower limb kinematic profiles during jump landing when compared to a non‐injured age, sex, and activity matched control group. Fourteen ACL‐R and 14 non‐injured control subjects performed 3 vertical drop jump (DVJ) trials. Lower limb kinematics were recorded at 200 Hz. Peak and time‐averaged angular displacements were quantified and utilized for between‐group analysis. The ACL‐R group displayed altered hip joint frontal and transverse plane kinematic alterations, and knee joint frontal and sagittal plane kinematic alterations. Specifically the ACL‐R group displayed an increased adducted (p < 0.05) and internally rotated (p < 0.05) hip joint position, both peak and time‐averaged, following landing. The ACL‐R group also displayed a decreased adducted (p < 0.05) and flexed (p < 0.05) position of the knee joint following landing. The observed aberrant lower limb kinematics could pre‐dispose ACL‐R athletes to potential future knee joint injuries. Further studies are required to determine in a prospective manner whether such deficits increase the incidence of recurrent ACL injury, and whether specific sensorimotor protocols following ACL reconstruction can minimize these kinematic deficits.

Lower Limb Kinematics and Dynamic Postural Stability in Anterior Cruciate Ligament-Reconstructed Female Athletes

CONTEXT Deficits in lower limb kinematics and postural stability are predisposing factors to the development of knee ligamentous injury. The extent to which these deficits are present after anterior cruciate ligament (ACL) reconstruction is still largely unknown. The primary hypothesis of the present study was that female athletes who have undergone ACL reconstruction and who have returned to sport participation would exhibit deficits in dynamic postural stability as well as deficiencies in hip- and knee-joint kinematics when compared with an age-, activity-, and sex-matched uninjured control group. OBJECTIVE To investigate dynamic postural stability as quantified by the Star Excursion Balance Test (SEBT) and simultaneous hip- and knee-joint kinematic profiles in female athletes who have undergone ACL reconstruction. DESIGN Descriptive laboratory study. SETTING University motion-analysis laboratory. PATIENTS OR OTHER PARTICIPANTS Fourteen female athletes who had previously undergone ACL reconstruction (ACL-R) and 17 age- and sex-matched uninjured controls. INTERVENTION(S) Each participant performed 3 trials of the anterior, posterior-medial, and posterior-lateral directional components of the SEBT. MAIN OUTCOME MEASURE(S) Reach distances for each directional component were quantified and expressed as a percentage of leg length. Simultaneous hip- and knee-joint kinematic profiles were recorded using a motion-analysis system. RESULTS The ACL-R group had decreased reach distances on the posterior-medial (P < .01) and posterior-lateral (P < .01) directional components of the SEBT. During performance of the directional components of the SEBT, ACL-R participants demonstrated altered hip-joint frontal-, sagittal-, and transverse-plane kinematic profiles (P < .05), as well as altered knee-joint sagittal-plane kinematic profiles (P < .05). CONCLUSIONS Deficits in dynamic postural stability and concomitant altered hip- and knee-joint kinematics are present after ACL reconstruction and return to competitive activity. The extent to which these deficits influence potential future injury is worthy of investigation.

Peak knee adduction moment during gait in anterior cruciate ligament reconstructed females

BACKGROUND Recent work has shown that anterior cruciate ligament reconstructed patients exhibit an increased peak knee adduction moment during walking gait compared to healthy controls. An increased peak knee adduction moment has been suggested to be a potential mechanism of degeneration for knee osteoarthritis. The few studies in this area have not considered an exclusively female anterior cruciate ligament reconstructed group. This study tested the hypothesis that female anterior cruciate ligament-reconstructed patients would have higher peak knee adduction moments than controls. METHODS Peak knee adduction moment during walking was compared between a group of anterior cruciate ligament reconstructed females and a group of female activity matched controls over ten 15m walking trials in a laboratory at a self-selected pace. FINDINGS Peak knee adduction moment was lower for the anterior cruciate ligament reconstructed group (N = 17, M = 0.31 Nm/kg · m, SD = 0.08) than for the control group (N = 17, M = 0.41 Nm/kg · m, SD = 0.12; t(32) = 2.483, p = 0.010, one-tailed, eta squared effect size = 0.16). INTERPRETATION A group of female anterior cruciate ligament reconstructed subjects did not exhibit a gait characteristic which has been suggested to be associated with knee osteoarthritis development and has been shown to be present in male and mixed sex anterior cruciate ligament reconstructed populations previously.

Hip and knee joint kinematics during a diagonal jump landing in anterior cruciate ligament reconstructed females

Anterior cruciate ligament (ACL) injury is a common injury encountered by sport medicine clinicians. Surgical reconstruction is the recommended treatment of choice for those athletes wishing to return to full-contact sports participation and for sports requiring multi-directional movement patterns. The aim of ACL reconstruction is to restore knee joint mechanical stability such that the athlete can return to sporting participation. However, knowledge regarding the extent to which lower limb kinematic profiles are restored following ACL reconstruction is limited. In the present study the hip and knee joint kinematic profiles of 13 ACL reconstructed (ACL-R) and 16 non-injured control subjects were investigated during the performance of a diagonal jump landing task. The ACL-R group exhibited significantly less peak knee joint flexion (P=0.01). Significant between group differences were noted for time averaged hip joint sagittal plane (P<0.05) and transverse plane (P<0.05) kinematic profiles, as well as knee joint frontal plane (P<0.05) and sagittal plane (P<0.05) kinematic profiles. These results suggest that aberrant hip and knee joint kinematic profiles are present following ACL reconstruction, which could influence future injury risk.

An Ambulatory Method of Identifying Anterior Cruciate Ligament Reconstructed Gait Patterns

The use of inertial sensors to characterize pathological gait has traditionally been based on the calculation of temporal and spatial gait variables from inertial sensor data. This approach has proved successful in the identification of gait deviations in populations where substantial differences from normal gait patterns exist; such as in Parkinsonian gait. However, it is not currently clear if this approach could identify more subtle gait deviations, such as those associated with musculoskeletal injury. This study investigates whether additional analysis of inertial sensor data, based on quantification of gyroscope features of interest, would provide further discriminant capability in this regard. The tested cohort consisted of a group of anterior cruciate ligament reconstructed (ACL-R) females and a group of non-injured female controls, each performed ten walking trials. Gait performance was measured simultaneously using inertial sensors and an optoelectronic marker based system. The ACL-R group displayed kinematic and kinetic deviations from the control group, but no temporal or spatial deviations. This study demonstrates that quantification of gyroscope features can successfully identify changes associated with ACL-R gait, which was not possible using spatial or temporal variables. This finding may also have a role in other clinical applications where small gait deviations exist.

The effects of visual feedback in therapeutic exergaming on motor task accuracy

Poor exercise technique and lack of adherence during home exercise are implicated in preventing a full recovery to peak physical function during rehabilitation. It is widely believed that therapeutic exergaming has the potential to solve these issues. However, the field is still young and there is little empirical evidence supporting, in particular, its effectiveness in helping the patient to maintain correct technique. In this paper we present preliminary results from a study to examine the effects that visual feedback during exergaming has on a persons accuracy in performing a motor task. Our study showed that interacting with a game incorporating simple visual feedback results in improved accuracy compared to performing exercise from memory or with limited feedback in the form of an instructional video demonstration. These results provide early evidence that exergaming can be used to enhance technique during exercise performance.

Dual-task and electrophysiological markers of executive cognitive processing in older adult gait and fall-risk

The role of cognition is becoming increasingly central to our understanding of the complexity of walking gait. In particular, higher-level executive functions are suggested to play a key role in gait and fall-risk, but the specific underlying neurocognitive processes remain unclear. Here, we report two experiments which investigated the cognitive and neural processes underlying older adult gait and falls. Experiment 1 employed a dual-task (DT) paradigm in young and older adults, to assess the relative effects of higher-level executive function tasks (n-Back, Serial Subtraction and visuo-spatial Clock task) in comparison to non-executive distracter tasks (motor response task and alphabet recitation) on gait. All DTs elicited changes in gait for both young and older adults, relative to baseline walking. Significantly greater DT costs were observed for the executive tasks in the older adult group. Experiment 2 compared normal walking gait, seated cognitive performances and concurrent event-related brain potentials (ERPs) in healthy young and older adults, to older adult fallers. No significant differences in cognitive performances were found between fallers and non-fallers. However, an initial late-positivity, considered a potential early P3a, was evident on the Stroop task for older non-fallers, which was notably absent in older fallers. We argue that executive control functions play a prominent role in walking and gait, but the use of neurocognitive processes as a predictor of fall-risk needs further investigation.

Coordination and symmetry patterns during the drop vertical jump, 6-months after first-time lateral ankle sprain

To evaluate the adaptive movement and motor control patterns of a group with a 6‐month history of first‐time lateral ankle sprain (LAS) injury during a drop vertical jump (DVJ) task. Fifty‐one participants with a 6‐month history of first‐time acute LAS injury and twenty controls performed a DVJ task. 3D kinematic and sagittal plane kinetic profiles were plotted for the lower extremity joints of both limbs for the drop jump (phase 1) and drop landing (phase 2) phases of the DVJ. Inter‐limb symmetry and the rate of impact modulation (RIM) relative to bodyweight (BW) during both phases of the DVJ were also determined. LAS participants displayed bilateral increases in knee flexion and an increase in ankle inversion during phases 1 and 2, respectively. They also displayed reduced ankle plantar flexion on their injured limb during both phases of the DVJ (p < 0.05); increased inter‐limb asymmetry of RIM was noted for both phases of the DVJ, while the moment‐of‐force profile exhibited bilaterally greater hip extensor dominance during phase 1. Participants with a 6‐month history of first‐time LAS display some movement patterns consistent with those observed in chronic ankle instability populations during similar tasks.

Quantifying show jumping horse rider expertise using IMUs

Horse rider ability has long been measured using horse performance, competition results and visual observation. Scientific methods of measuring rider ability on the flat are emerging such as measuring position angles and harmony of the horse-rider system. To date no research has quantified rider ability in show jumping. Kinematic analysis and motion sensors have been used in sports other than show jumping to measure the quality of motor control patterns in humans. The aim of this study was to quantify rider ability in show jumping using body-mounted IMUs. Preliminary results indicate that there are clear differences in experienced and novice riders during show jumping.

A diagonal landing task to assess dynamic postural stability in ACL reconstructed females

BACKGROUND Previous research has used time to stabilization (TTS) from forward landing tasks to assess dynamic postural stability in ACL reconstructed (ACLR) athletes in order to identify impaired sensorimotor control and mechanical stability. This may not be an appropriate test due to the fact that research has suggested that ACL injury has a multi-planar mechanism of injury. The purpose of the present study was to compare TTS values from a forward land and a diagonal land to determine if diagonal landing TTS values are more sensitive to dynamic postural stability deficits in female ACLR athletes. METHODS A group of ACL reconstructed female athletes and a group of female control athletes performed three forward lands and three diagonal lands onto a force-plate and remained still on one foot for 15s. TTS was calculated for the anterior-posterior and medial-lateral ground reaction forces as well as the resultant vector of both forces. RESULTS All three TTS values were significantly increased in the ACLR group from the control group for the diagonal landing task. There was no difference in TTS values between the groups for the forward landing task. CONCLUSION TTS values from a diagonal landing are more sensitive at detecting impaired dynamic postural stability in a group of female ACLR athletes compared to TTS values from a forward land. LEVEL OF EVIDENCE III - Casecontrolled study.