Increased joint stress and malalignment are etiologic factors in osteoarthritis. Static tibiofemoral frontal plane malalignment is associated with patellofemoral osteoarthritis (PFOA). Patellofemoral joint stress is increased by activities such as sit-to-stand (STS); this stress may be even greater if dynamic frontal plane tibiofemoral malalignment occurs. If hip muscle or quadriceps weakness is present in persons with PFOA, aberrant tibiofemoral frontal plane movement may occur, with increased patellofemoral stress. No studies have investigated frontal plane tibiofemoral and hip kinematics during STS in persons with PFOA or the relationship of hip muscle and quadriceps strength to these motions. Eight PFOA and seven control subjects performed STS from a stool during three-dimensional motion capture. Hip muscle and quadriceps strength were measured as peak isometric force. The PFOA group demonstrated increased peak tibial abduction angles during STS, and decreased hip abductor, hip extensor, and quadriceps peak force versus controls. A moderate inverse relationship between peak tibial abduction angle and peak hip abductor force was present. No difference between groups was found for peak hip adduction angle or peak hip external rotator force. Dynamic tibiofemoral malalignment and proximal lower extremity weakness may cause increased patellofemoral stress and may contribute to PFOA incidence or progression.
Lisa T. Hoglund, Howard J. Hillstrom, Ann E. Barr-Gillespie, Margery A. Lockard, Mary F. Barbe and Jinsup Song
Brittney A. Luc, Adam S. Lepley, Michael A. Tevald, Phillip A. Gribble, Donald B. White and Brian G. Pietrosimone
Alterations in corticomotor excitability are observed in a variety of patient populations, including the musculature surrounding the knee and ankle after joint injury. Active motor threshold (AMT) and motor-evoked-potential (MEP) amplitudes elicited through transcranial magnetic stimulation (TMS) are outcome measures used to assess corticomotor excitability and have been deemed reliable in upper-extremity musculature. However, there are few studies assessing the reliability of TMS measures in lower-extremity musculature.
To determine the intersession reliability of AMT and MEP amplitudes over 14 and 28 d in the quadriceps and fibularis longus (FL).
Descriptive laboratory study.
20 able-bodied volunteers (10 men, 10 women; 22.35 ± 2.3 y, 1.71 ± 0.11 m, 73.61 ± 16.77 kg).
Main Outcome Measures:
AMT and MEP amplitudes were evaluated at 95%, 100%, 105%, 110%, 120%, 130%, and 140% of AMT in the dominant and nondominant quadriceps and FL. Interclass correlation coefficients (ICCs) were used to assess reliability for absolute agreement and internal consistency between baseline and 2 follow-up sessions at 14 and 28 d postbaseline. Each ICC was fit with the best-fit straight line or parabola to smooth out noise in the observations and best determine if a pattern existed in determining the most reliable MEP value.
All muscles yielded strong ICCs between baseline and both time points for AMT. MEPs in both the quadriceps and FL produced varying degrees of reliability, with the greatest reliability demonstrated on day 28 at 130% and 140% of AMT in the quadriceps and FL, respectively. The dominant FL muscle showed a significant pattern; as TMS intensity increased, MEP reliability increased.
TMS can be used to reliably identify corticomotor alterations after therapeutic interventions, as well as monitor disease progression.
Christopher J. Burcal, Alejandra Y. Trier and Erik A. Wikstrom
Both balance training and selected interventions meant to target sensory structures (STARS) have been shown to be effective at restoring deficits associated with chronic ankle instability (CAI). Clinicians often use multiple treatment modalities in patients with CAI. However, evidence for combined intervention effectiveness in CAI patients remains limited.
To determine if augmenting a balance-training protocol with STARS (BTS) results in greater improvements than balance training (BT) alone in those with CAI.
24 CAI participants (age 21.3 ± 2.0 y; height 169.8 ± 12.9 cm; mass 72.5 ± 22.2 kg) were randomized into 2 groups: BT and BTS.
Participants completed a 4-week progression-based balance-training protocol consisting of 3 20-min sessions per week. The experimental group also received a 5-min set of STARS treatments consisting of calf stretching, plantar massage, ankle joint mobilizations, and ankle joint traction before each balance-training session.
Main Outcome Measures:
Outcomes included self-assessed disability, Star Excursion Balance Test reach distance, and time-to-boundary calculated from static balance trials. All outcomes were assessed before, and 24-hours and 1-week after protocol completion. Self-assessed disability was also captured 1-month after the intervention.
No significant group differences were identified (P > .10). Both groups demonstrated improvements in all outcome categories after the interventions (P < .10), many of which were retained at 1-week posttest (P < .10). Although 90% CIs include zero, effect sizes favor BTS. Similarly, only the BTS group exceeded the minimal detectable change for time-to-boundary outcomes.
While statistically no more effective, exceeding minimal detectable change scores and favorable effect sizes suggest that a 4-week progressive BTS program may be more effective at improving self-assessed disability and postural control in CAI patients than balance training in isolation.
Thomas Koesterer, Aaron Blanchard and Patrick Donnelly
To present a unique case of meralgia paresthetica.
A 21-year-old male collegiate lacrosse player fell, twisted his right leg, and felt a “pop” in his hip. Objective fndings included: antalgic gait, mild palpable swelling, and tenderness to touch with limited range of motion due to pain. Joint stability tests were negative.
Right hip abductor strain, hip sprain, trochanteric bursitis, or labral tear.
The physician’s findings included deep hip pain that increased with hip scouring and pain with active and passive motion. The physician’s diagnosis was hip sprain; treatment was to continue with ice and begin active progression for return to play. The athlete was treated over the next several days with warm whirlpools, stretching, and a hip fexor wrap. Ten days postinjury, the athlete played in a game, but in the fourth quarter came off the field stating he couldn’t feel his thigh. The orthopedic physician evaluated the athlete and provided a differential diagnosis of right hip fexor strain and hip capsule sprain with numbness, possibly due to meralgia paresthetica. The physician ordered treatment to continue and began a regimen of 600 mg of ibuprofen three times per day and noted the athlete could continue to play.
The athlete did not show any symptoms of meralgia paresthetica for 10 days post initial injury. The meralgia paresthetica was most likely caused by swelling resulting from the hip sprain, in which the swelling compressed the lateral femoral cutaneous nerve (LFCN) against the inguinal ligament.
Meralgia paresthetica may occur as a result of trauma and subsequent swelling of the inguinal region. A thorough evaluation of the hip must be conducted to ensure no motor neuron involvement is associated with the paresthesia symptoms.
Kyung-Min Kim, Joo-Sung Kim and Dustin R. Grooms
Context: Patients with somatosensory deficits have been found to rely more on visual feedback for postural control. However, current balance tests may be limited in identifying increased visual dependence (sensory reweighting to the visual system), as options are typically limited to eyes open or closed conditions with no progressions between. Objective: To assess the capability of stroboscopic glasses to induce sensory reweighting of visual input during single-leg balance. Design:Descriptive Setting: Laboratory Participants: 18 healthy subjects without vision or balance disorders or lower extremity injury history (9 females; age = 22.1 ± 2.1 y; height = 169.8 ± 8.5 cm; mass = 66.5 ± 10.6 kg) participated. Interventions: Subjects performed 3 trials of unipedal stance for 10 s with eyes open (EO) and closed (EC), and with stroboscopic vision (SV) that was completed with specialized eyewear that intermittently cycled between opaque and transparent for 100 ms at a time. Balance tasks were performed on firm and foam surfaces, with the order randomized. Main Outcome Measures: Ten center-of-pressure parameters were computed. Results: Separate ANOVAs with repeated measures found significant differences between the 3 visual conditions on both firm (P-values =< .001) and foam (P-values =< .001 to .005) surfaces for all measures. For trials on firm surface, almost all measures showed that balance with SV was significantly impaired relative to EO, but less impaired than EC. On the foam surface, almost all postural stability measures demonstrated significant impairments with SV compared with EO, but the impairment with SV was similar to EC. Conclusions:SV impairment of single-leg balance was large on the firm surface, but not to the same degree as EC. However, the foam surface disruption to somatosensory processing and sensory reweighting to vision lead to greater disruptive effects of SV to the same level as EC. This indicates that when the somatosensory system is perturbed even a moderate decrease in visual feedback (SV) may induce an EC level impairment to postural control during single-leg stance.
Lindsay Hunter, Quinette Abigail Louw and Sjan-Mari van Niekerk
Iliotibial-band syndrome (ITBS) is a common overuse running injury. There is inconclusive evidence to support current management strategies, and few advances have been made in the past few years. New management approaches should thus be developed and evaluated.
To assess the effects of a real-time running-retraining program on lower-extremity biomechanics, pain while running, and function.
Single-subject experimental study.
University motion-analysis laboratory.
Female recreational runner with ITBS.
Nine real-time running-retraining sessions were implemented based on the biomechanical alterations of the participant's symptomatic lower limb, including pelvic and knee movement in the transverse plane, as well as foot movement in the frontal plane. Real-time visual feedback of the pelvic-rotation angle was provided during the running-retraining sessions.
Main Outcome Measurements:
3-dimensional lower-extremity running kinematics, pain on a verbal analog scale while running on a treadmill, and the Lower Extremity Functional Scale (LEFS).
Pelvic external rotation decreased, although the aim was to increase pelvic external rotation and knee rotation. The foot-progression angle improved after the intervention and at 1-mo follow-up. There was a 12.5% improvement in running time, and the pain score while running improved by 50% postintervention; these improvements were maintained at 1-mo follow-up. The mean LEFS score, indicative of function, improved by 8.75% and by 10% at the end of the intervention and at 1-mo follow-up, respectively.
The real-time running-retraining program improved pain while running, as well as function, and was effective in addressing the lower-limb biomechanical alterations of the knee and foot in a female runner with ITBS. The application, effectiveness, and feasibility of real-time training should be addressed in larger studies in the future.
Kristina Amrani, Andrew Gallucci and Marshall Magnusen
, styles of play, and court surface, 7 which may explain the differences in volume reported throughout the literature. Despite knowing an approximate shot volume required of an elite tennis player, only one IHP describes a progression based on preestablished volume. 8 In fact, there are no existing IHPs
Cameron Haun, Cathleen N. Brown, Kimberly Hannigan and Samuel T. Johnson
. However, there was no control or comparison group included in the study. • Two of the 3 studies reported a decrease in ND following an SFE intervention. While the studies used different intervention volumes and progressions, the SFE instructions were consistent across the publications. This suggests that
Power Patterns during Obstacle Avoidance Reveal Distinct Control Strategies for Limb Elevation versus Limb Progression Assane E.S. Niang * Bradford J. McFadyen * 4 2004 8 2 160 173 10.1123/mcj.8.2.160 Task-specific Stabilization of Postural Coordination during Stance on a Beam Olivier Oullier
Progression When Defined Using a Clinical Versus a Structural Outcome Kerry E. Costello * Janie L. Astephen Wilson * William D. Stanish * Nathan Urquhart * Cheryl L. Hubley-Kozey * 1 02 2020 36 1 39 51 10.1123/jab.2019-0127 jab.2019-0127 TECHNICAL NOTE Ankle and Midfoot Power During Single-Limb Heel