Search Results

You are looking at 1 - 10 of 11 items for

  • Author: Riann M. Palmieri x
Clear All Modify Search
Restricted access

Lindsey K. Lepley and Riann M. Palmieri-Smith

Clinical Scenario:

Interventions aimed at safely overloading the quadriceps muscle after anterior cruciate ligament (ACL) reconstruction are essential to reducing quadriceps muscle weakness that often persists long after the rehabilitation period. Despite the best efforts of clinicians and researchers to improve ACL rehabilitation techniques, a universally effective intervention to restore preinjury quadriceps strength has yet to be identified. A muscle’s force-producing capacity is most optimal when an external force exceeds that of the muscle while the muscle lengthens. Hence, the potential to improve muscle strength by overloading the tissue is greater with eccentric strengthening than with concentric strengthening. Traditionally, the application of early postoperative high-intensity eccentric resistance training to the ACL-reconstructed limb has been contraindicated, as there is potential for injury to the ACL graft, articular cartilage, or surrounding soft-tissue structures. However, recent evidence suggests that the application of early, progressive, high-force eccentric resistance exercises to the involved limb can be used to safely increase muscle volume and strength in ACL-reconstructed individuals. As a result, eccentric strengthening may be another attractive alternative to traditional concentric strengthening to improve quadriceps strength after ACL reconstruction.

Focused Clinical Question:

In patients who have undergone ACL reconstruction, is there evidence to suggest that eccentric exercise positively affects postoperative quadriceps strength?

Restricted access

Abbey C. Thomas, Scott G. McLean and Riann M. Palmieri-Smith

Neuromuscular fatigue exacerbates abnormal landing strategies, which may increase noncontact anterior cruciate ligament (ACL) injury risk. The synergistic actions of quadriceps and hamstrings (QH) muscles are central to an upright landing posture, though the precise effect of simultaneous fatigue of these muscles on landing and ACL injury risk is unclear. Elucidating neuromechanical responses to QH fatigue thus appears important in developing more targeted fatigue-resistance intervention strategies. The current study thus aimed to examine the effects of QH fatigue on lower extremity neuromechanics during dynamic activity. Twenty-five healthy male and female volunteers performed three single-leg forward hops onto a force platform before and after QH fatigue. Fatigue was induced through sets of alternating QH concentric contractions, on an isokinetic dynamometer, until the first five repetitions of a set were performed at least 50% below QH peak torque. Three-dimensional hip and knee kinematics and normalized (body mass × height) kinetic variables were quantified for pre- and postfatigue landings and subsequently analyzed by way of repeated- measures mixed-model ANOVAs. QH fatigue produced significant increases in initial contact (IC) hip internal rotation and knee extension and external rotation angles (p < .05), with the increases in knee extension and external rotation being maintained at the time of peak vertical ground reaction force (vGRF) (p < .05). Larger knee extension and smaller knee fexion and external rotation moments were also evident at peak vGRF following fatigue (p < .05). Females landed with greater hip fexion and less abduction than males at both IC and peak vGRF as well as greater knee fexion at peak vGRF (p < .05). The peak vGRF was larger for females than males (p < .05). No sex × fatigue effects were found (p > .05). Fatigue of the QH muscles altered hip and knee neuromechanics, which may increase the risk of ACL injury. Prevention programs should incorporate methods aimed at countering QH fatigue.

Restricted access

J. Craig Garrison, Joe M. Hart, Riann M. Palmieri, D. Casey Kerrigan and Christopher D. Ingersoll

Context:

Although kinematic analyses are helpful in describing movement differences between genders, kinetic data might further explain the predisposing factors contributing to potential injury during athletic landing maneuvers.

Objective:

To determine whether there are differences in knee moments between male and female varsity college soccer players during a single-leg landing.

Design:

Preexperimental with static group comparison.

Setting:

Motion-analysis laboratory.

Participants:

16 varsity college soccer players (8 men, 8 women).

Intervention:

Subjects performed 5 single-leg landings from a height of 60 cm.

Main Outcome Measures:

Peak internal rotation, valgus, varus, and extension knee moments calculated from raw ground-reaction forces and kinematic data.

Results:

Significant gender differences were present (P = .020), with men exhibiting 31% greater mean peak knee-varus moments than women when landing on a single leg from 60 cm (P = .020).

Conclusions:

Male soccer players demonstrate greater knee-varus moments than female soccer players during single-leg landing. This might be valuable in designing clinical treatment and prevention programs for ACL injuries.

Restricted access

Christine L. Berg, Joseph M. Hart, Riann Palmieri-Smith, Kevin M. Cross and Christopher D. Ingersoll

Context:

If ankle joint cryotherapy impairs the ability of the ankle musculature to counteract potentially injurious forces, the ankle is left vulnerable to injury.

Objective:

To compare peroneal reaction to sudden inversion following ankle joint cryotherapy.

Design:

Repeated measures design with independent variables, treatment (cryotherapy and control), and time (baseline, immediately post treatment, 15 minutes post treatment, and 30 minutes post treatment).

Setting:

University research laboratory.

Patients or Other Participants:

Twenty-seven healthy volunteers.

Intervention(s):

An ice bag was secured to the lateral ankle joint for 20 minutes.

Main Outcome Measures:

The onset and average root mean square amplitude of EMG activity in the peroneal muscles was calculated following the release of a trap door mechanism causing inversion.

Results:

There was no statistically significant change from baseline for peroneal reaction time or average peroneal muscle activity at any post treatment time.

Conclusions:

Cryotherapy does not affect peroneal muscle reaction following sudden inversion perturbation.

Restricted access

J. Craig Garrison, Joe M. Hart, Riann M. Palmieri, D. Casey Kerrigan and Christopher D. Ingersoll

Context:

Gender differences in muscle activity during landing have been studied as a possible contributing factor to the greater incidence of anterior cruciate ligament injuries in women.

Objective:

To compare root-mean-square (RMS) electromyography (EMG) of selected lower extremity muscles at initial contact (IC) and at peak knee internal-rotation (IR) moment in men and women during landing.

Design:

Preexperimental design static-group comparison.

Setting:

Motion-analysis laboratory.

Participants:

16 varsity college soccer players (8 men, 8 women).

Main Outcome Measures:

EMG activity of the gluteus medius, lateral hamstrings, vastus lateralis, and rectus femoris during landing.

Results:

When RMS EMG of all muscles was considered simultaneously, no significant differences were detected between genders at IC or at peak knee IR moment.

Conclusion:

Male and female college soccer players display similar relative muscle activities of the lower extremity during landing. Gender landing-control parameters might vary depending on the technique used to analyze muscle activity.

Restricted access

Joseph M. Hart, J. Craig Garrison, Riann Palmieri-Smith, D. Casey Kerrigan and Christopher D. Ingersoll

Context:

Lower extremity kinetics while performing a single-leg forward jump landing may help explain gender biased risk for noncontact anterior cruciate ligament injury.

Objective:

Gender comparison of lower extremity joint angles and moments.

Design:

Static groups comparison.

Setting:

Motion analysis laboratory.

Patients or Other Participants:

8 male and 8 female varsity, collegiate soccer athletes.

Intervention:

5 single-leg landings from a 100cm forward jump.

Main Outcome Measures:

Peak and initial contact external joint moments and joint angles of the ankle, knee, and hip.

Results:

At initial heel contact, males exhibited a adduction moment whereas females exhibited a abduction moment at the hip. Females also had significantly less peak hip extension moment and significantly less peak hip internal rotation moment than males had. Females exhibited greater knee adduction and hip internal rotation angles than men did.

Conclusions:

When decelerating from a forward jump, gender differences exist in forces acting at the hip.

Restricted access

Jessica E. Digiacomo, Riann M. Palmieri-Smith, John A. Redman III and Lindsey K. Lepley

Context: Modifiable and nonmodifiable risk factors have been identified for sustaining a primary anterior cruciate ligament (ACL) injury; however, less research is available examining risk factors for a second injury. Identifying whether bony morphological factors are different (or more exaggerated) among those that experience a secondary ACL injury is critical to understanding if nonmodifiable risk factors are associated with a second injury. Objective: To determine if bony morphology is different among those that experience a secondary ACL reinjury as compared with those that do not. Design: Case-control. Setting: University laboratory. Participants and Interventions: ACL participants were tracked after return to play following primary reconstruction, and if individuals experienced a second ipsilateral injury (ACLx2; n = 14, 8f/6m, 17.9 ± 4.0 y), the primary clinical MRI was analyzed for bony morphological risk factors. ACLx2 participants were matched to individuals (sex, age, height, graft, gender, and activity level) that had undergone reconstruction but did not experience reinjury (ACLx1, n = 14, 8f/6m, 18.7 ± 4.0 y). Ten controls were also enrolled (5m/5f, 20.8 ± 3.9 y) for the purposes of comparing the authors’ ACL data against healthy knees. Main Outcome Measures: Lateral and medial posterior tibial slopes (LPTS, MPTS), notch shape index (NSI), and medial tibial plateau depth of concavity (MDC). Results: All ACL-reconstructed patients (combined ACLx1 and ACLx2 group) had a steeper LPTS than controls (d = 0.87, 95% CI 0.11–1.60, P = .023); however, no difference in LPTS was found between ACLx1 and ACLx2 (P > .05). No differences in MPTS, NSI, and MDC were found between all ACL participants (combined ACLx2 and ACLx1) and controls or between ACLx1 and ACLx2 (P > .05). Conclusions: Compared to healthy individuals, a steeper LPTS is a common bony abnormality in all ACL-injured participants. Individuals that go on to experience a second ipsilateral ACL injury do not have more exaggerated bony morphology than those that do not suggesting that differences in modifiable risk factors at return to play may contribute to reinjury.

Restricted access

Lindsey K. Lepley, Abbey C. Thomas, Scott G. McLean and Riann M. Palmieri-Smith

Context:

As individuals returning to activity after anterior cruciate ligament reconstruction (ACLr) likely experience fatigue, understanding how fatigue affects knee-muscle activation patterns during sport-like maneuvers is of clinical importance. Fatigue has been suggested to impair neuromuscular control strategies. As a result, fatigue may place ACLr patients at increased risk of developing posttraumatic osteoarthritis (OA).

Objective:

To determine the effects of fatigue on knee-muscle activity post-ACLr.

Design:

Case control.

Setting:

University laboratory.

Participants:

12 individuals 7–10 mo post-ACLr (7 male, 5 female; age 22.1 ± 4.7 y; 1.8 ± 0.1 m; mass 77.7 ± 11.9 kg) and 13 controls (4 male, 9 female; age 22.9 ± 4.3 y; 1.7 ± 0.1 m; mass 66.9 ± 9.8 kg).

Interventions:

Fatigue was induced via repetitive sets of double-leg squats (n = 8), which were interspersed with sets of single-leg landings (n = 3), until squats were no longer possible.

Main Outcome Measures:

2 × 2 repeated-measures ANOVA was used to detect the main effects of group (ACLr, control) and fatigue state (prefatigue, postfatigue) on quadriceps:hamstring cocontraction index (Q:H CCI).

Results:

All subjects demonstrated higher Q:H CCI at prefatigue compared with postfatigue (F 1,23 = 66.949, P ≤ .001). Q:H CCI did not differ between groups (F 1,23 = 0.599, P = .447).

Conclusions:

The results indicate that regardless of fatigue state, ACLr individuals are capable of restoring muscle-activation patterns similar to those in healthy subjects. As a result, excessive muscle cocontraction, which has been hypothesized as a potential mechanism of posttraumatic OA, may not contribute to joint degeneration after ACLr.

Restricted access

Kristof Kipp, Tyler N. Brown, Scott G. McLean and Riann M. Palmieri-Smith

The purpose of this study was to examine the combined impact of experience and decision making on frontal plane knee joint biomechanics during a cutting maneuver. Kinematic and kinetic data were collected from 12 recreationally active and 18 NCAA Division I female athletes during execution of anticipated and unanticipated single-leg land-and-cut maneuvers. Knee joint abduction angles and external knee joint abduction torques were calculated and discrete peak stance-phase variables were extracted. Angle and torque time-series data were also submitted to separate functional data analyses. Variables derived from the functional data analyses indicated that decision making influenced knee abduction angle and torque time series in the recreational group only. Specifically, these variables pointed to greater knee abduction at the end of stance as well as a greater, albeit delayed peak in knee abduction torque at the beginning of landing in the recreational athletes during the unanticipated condition. In addition, the recreational athletes displayed greater discrete peak knee abduction angles than the Division I athletes regardless of condition. Discrete peak knee abduction torque did not differ between groups or conditions.

Restricted access

Riann M. Palmieri, Christopher D. Ingersoll, Marcus B. Stone and B. Andrew Krause

Objective:

To define the numerous center-of-pressure derivatives used in the assessment of postural control and discuss what value each might provide in the assessment of balance.

Data Sources:

MEDLINE and SPORTDiscus were searched with the terms balance, postural control, postural sway, and center of pressure. The remaining citations were collected from references of similar papers. A total of 67 references were studied.

Conclusions:

Understanding what is represented by each parameter used to assess postural control is crucial. At the present time the literature has failed to demonstrate how the variables reflect changes made by the postural-control system. Until it can be shown that the center of pressure and its derivatives actually reveal changes in the postural-control system, the value of using these measures to assess deficits in postural control is minimized.