Plantar pressure profile during walking is associated with talar cartilage characteristics in individuals with chronic ankle instability.

BACKGROUND: Individuals with chronic ankle instability typically present with abnormal gait patterns favoring the lateral foot. This gait pattern may alter cartilage stress potentially increasing the risk of osteoarthritis development, thus exploring this relationship may provide insights for early interventions. The purpose of this study was to examine the relationship gait biomechanics and talar articular cartilage characteristics. METHODS: Talar articular cartilage was assessed with ultrasound at rest and after walking for 30-min in twenty-five adults (14 females, 22.6 ± 3.12 years, 168.12 ± 9.83 cm, 76.00 ± 15.47 kg) with chronic ankle instability. Cartilage was segmented into Total, Medial, and Lateral regions. During the 30-min walking period, plantar pressure of the entire foot was recorded every 5-min and condensed to create a biomechanical loading pattern and center of pressure gait line. Relationships between resting cartilage thickness and echo intensity, changes in thickness and echo intensity, and plantar pressure profiles were assessed with correlation coefficients. FINDINGS: There was a significant relationship between plantar pressure in the lateral forefoot and medial talar cartilage deformation (r = 0.408, p < .05). Early stance center of pressure was correlated with deformation in the total (r = 0.439-0.524) and lateral (r = 0.443-0.550) regions (p < .05). There were no significant correlations between echo intensity and biomechanics. INTERPRETATION: This study contributes to the growing evidence that talar cartilage strain patterns are associated with biomechanics during walking. Further validation is needed to determine a causal relationship between biomechanics and ultrasound cartilage characteristics after ankle sprains. In addition, research should continue determining the utility of ultrasound to monitor joint health after musculoskeletal injuries.

Effects of gait training with auditory biofeedback on biomechanics and talar cartilage characteristics in individuals with chronic ankle instability: A randomized controlled trial.

BACKGROUND: Altered walking gait is a typical impairment following ankle sprains which may increase susceptibility to recurring injuries and development of posttraumatic osteoarthritis at the ankle. There is a lack of targeted gait training interventions focusing on specific modifications in individuals with chronic ankle instability (CAI). Additionally, there is a need to focus on cartilage health changes following gait training to mitigate osteoarthritis progression. RESEARCH QUESTION: To determine the immediate and retention effects of gait training using auditory biofeedback (AudFB) in patients with chronic ankle instability (CAI) on biomechanics and talar cartilage characteristics. METHODS: Eighteen participants with CAI were randomly assigned into Control (n = 7) or AudFB (n = 11) groups. Each group completed 8-sessions of 30-minute treadmill walking. The AudFB group received biofeedback through a pressure sensor fashioned to the lateral foot and instructions to walk while avoiding noise from the sensor. The Control group did not receive instructions during sessions. An in-shoe insole system measured peak pressure, maximum force, and center of the pressure gait line (COP) during walking. Ultrasonography captured talar cartilage thickness and echo intensity before and after walking. Biomechanics and ultrasound were measured at baseline, immediately, and 1-week after the intervention. Repeated measures mixed-methods analysis of variance assessed changes within groups across time. RESULTS: The AudFB group significantly reduced pressure and force in the lateral foot and medially shifted their COP at Immediate and 1-week Post. There were no observed changes in the Control group. In addition, neither group demonstrated changes in ultrasound measures at follow-up. SIGNIFICANCE: Implementation of auditory biofeedback during gait training can be a valuable tool for clinicians treating patients with CAI.

Multi-axis destabilisation device influences plantar pressure distribution in adults with chronic ankle instability.

Patients with chronic ankle instability (CAI) walk with increased lateral plantar pressure, precipitating future injuries. Gait retraining to medially shift plantar pressure may prevent recurrent injury. We assessed if a multi-axis destabilisation device changed plantar pressure and muscle activity in patients with CAI during walking. Twelve adults with CAI (age: 23.6 ± 5.0 years; body mass index: 26.7 ± 4.5 kg/m2) participated. Insole plantar pressure and electro-myography were collected synchronously during treadmill walking. The destabilisation device had a half-sphere under both the rearfoot and forefoot. Two 30s walking trials were recorded at baseline, first without and second with the destabilisation device. After 20 min of walking with the destabilisation device, two 30s post-walking trials were collected, first with and second without the destabilisation device. The middle 10 steps of each trial were extracted, plantar pressure quantified, and data averaged across steps for repeated measures ANOVA analysis. Electromyographic data wereextracted from 50 ms pre- through 200 ms post-initial contact. The centre of pressure shifted medially during destabilisation device use (P < 0.002) versus baseline. This shift was notretained upon device removal. Thus, the device capably shifts plantar pressure while worn. Its effects beyond a single sessionare unknown.

Biomechanical Response to External Biofeedback During Functional Tasks in Individuals With Chronic Ankle Instability.

CONTEXT: Altered biomechanics displayed by individuals with chronic ankle instability (CAI) is a possible cause of recurring injuries and posttraumatic osteoarthritis. Current interventions are unable to modify aberrant biomechanics, leading to research efforts to determine if real-time external biofeedback can result in changes. OBJECTIVE: To determine the real-time effects of visual and auditory biofeedback on functional-task biomechanics in individuals with CAI. DESIGN: Crossover study. SETTING: Laboratory. PATIENTS OR OTHER PARTICIPANTS: Nineteen physically active adults with CAI (7 men, 12 women; age = 23.95 ± 5.52 years, height = 168.87 ± 6.94 cm, mass = 74.74 ± 15.41 kg). INTERVENTION(S): Participants randomly performed single-limb static balance, step downs, lateral hops, and forward lunges during a baseline and 2 biofeedback conditions. Visual biofeedback was given through a crossline laser secured to the dorsum of the foot. Auditory biofeedback was given through a pressure sensor placed under the lateral foot and connected to a buzzer that elicited a noise when pressure exceeded the set threshold. Cues provided during the biofeedback conditions were used to promote proper biomechanics during each task. MAIN OUTCOME MEASURE(S): We measured the location of center-of-pressure (COP) data points during balance with eyes open and eyes closed for each condition. Plantar pressure in the lateral column of the foot during functional tasks was extracted. Secondary outcomes of interest were COP area and velocity, time to boundary during static balance, and additional plantar-pressure measures. RESULTS: Both biofeedback conditions reduced COP in the anterolateral quadrant while increasing COP in the posteromedial quadrant of the foot during eyes-open balance. Visual biofeedback increased lateral heel pressure and the lateral heel and midfoot pressure-time integral during hops. The auditory condition produced similar changes during the eyes-closed trials. Auditory biofeedback increased heel pressure during step downs and decreased the lateral forefoot pressure-time integral during lunges. CONCLUSIONS: Real-time improvements in balance strategies were observed during both external biofeedback conditions. Visual and auditory biofeedback appeared to effectively moderate different functional-task biomechanics.

Biomechanical Response to External Biofeedback During Functional Tasks in Individuals With Chronic Ankle Instability.

CONTEXT: Altered biomechanics displayed by individuals with chronic ankle instability (CAI) is a possible cause of recurring injuries and posttraumatic osteoarthritis. Current interventions are unable to modify aberrant biomechanics, leading to research efforts to determine if real-time external biofeedback can result in changes. OBJECTIVE: To determine the real-time effects of visual and auditory biofeedback on functional-task biomechanics in individuals with CAI. DESIGN: Crossover study. SETTING: Laboratory. PATIENTS OR OTHER PARTICIPANTS: Nineteen physically active adults with CAI (7 men, 12 women; age = 23.95 ± 5.52 years, height = 168.87 ± 6.94 cm, mass = 74.74 ± 15.41 kg). INTERVENTION(S): Participants randomly performed single-limb static balance, step downs, lateral hops, and forward lunges during a baseline and 2 biofeedback conditions. Visual biofeedback was given through a crossline laser secured to the dorsum of the foot. Auditory biofeedback was given through a pressure sensor placed under the lateral foot and connected to a buzzer that elicited a noise when pressure exceeded the set threshold. Cues provided during the biofeedback conditions were used to promote proper biomechanics during each task. MAIN OUTCOME MEASURE(S): We measured the location of center-of-pressure (COP) data points during balance with eyes open and eyes closed for each condition. Plantar pressure in the lateral column of the foot during functional tasks was extracted. Secondary outcomes of interest were COP area and velocity, time to boundary during static balance, and additional plantar-pressure measures. RESULTS: Both biofeedback conditions reduced COP in the anterolateral quadrant while increasing COP in the posteromedial quadrant of the foot during eyes-open balance. Visual biofeedback increased lateral heel pressure and the lateral heel and midfoot pressure-time integral during hops. The auditory condition produced similar changes during the eyes-closed trials. Auditory biofeedback increased heel pressure during step downs and decreased the lateral forefoot pressure-time integral during lunges. CONCLUSIONS: Real-time improvements in balance strategies were observed during both external biofeedback conditions. Visual and auditory biofeedback appeared to effectively moderate different functional-task biomechanics.

Novel insight into the coordination between pelvic floor muscles and the glottis through ultrasound imaging: a pilot study.

INTRODUCTION: Pelvic floor physical therapists have long utilized breathing cues with exercises and are beginning to incorporate vocalization tasks. To date, there have been no publications describing pelvic floor displacement during vocalization tasks. This study is a preliminary investigation into the changes in bladder shape distortion as a proxy for pelvic floor muscle displacement during respiratory and phonatory tasks. METHODS: Bladders were imaged using two-dimensional ultrasound in standing position. Measurement consisted of a diagonal line from the most anterior-superior aspect of the bladder to the most inferior-posterior aspect of the bladder. Length was measured at baseline and maximum distortion for each task. The first two tasks cued pelvic floor muscles to contract and then strain. Subsequent tasks only cued glottis function. A linear regression tested correlation between bladder distortion response to glottis tasks and cued pelvic floor tasks. The hypothesis was that diagonal would shorten with contraction, lengthen with strain, and follow a similar pattern seen in respiration for phonation tasks. RESULTS: Ten asymptomatic participants (5 men, 5 women) showed bladder diagonal shortening when cuing pelvic floor contraction for all participants and lengthening for 7 of the 10 participants when cued to strain the pelvic floor. The response of bladder length change was variable for glottis tasks, trending toward lengthening and significantly different in response to contraction. CONCLUSIONS: When cuing pelvic floor to contract, healthy individuals showed shortening of bladder length and most lengthened during strain. When cuing phonation and respiration tasks, there was a tendency toward bladder lengthening.

Gait and plantar sensation changes following massage and textured insole application in patients after anterior cruciate ligament reconstruction.

BACKGROUND: Gait impairments following anterior cruciate ligament reconstruction (ACLR) may contribute to reinjury or future osteoarthritis development. Recently, plantar cutaneous sensation deficits have been reported post-ACLR. These sensory deficits may influence gait and represent a mechanism through which to improve gait. RESEARCH QUESTION: Can established sensory interventions change sensation and gait in patients after ACLR and compared to healthy adults? METHODS: Twenty-two adults (n = 11 post-ACLR, age:20.5 ±â€¯1.9years, body mass index[BMI]:24.5 ±â€¯3.6 kg/m2; n = 11 healthy, age:20.7 ±â€¯1.4years, BMI:23.3 ±â€¯2.7 kg/m2) completed two sessions separated by 48 h. Gait and plantar cutaneous sensation were assessed pre- and post-intervention (massage or textured insoles). Gait analysis was completed using 3D motion capture at 1.4 m/s ±â€¯5% and standard inverse dynamics analysis. Plantar cutaneous sensation was assessed using Semmes Weinstein Monofilaments with a 4-2-1 stepping algorithm at the plantar aspect of the first metatarsal head, base of the fifth metatarsal, and lateral and medial malleoli. Plantar massage was a 5-minute massage to both feet. Textured insoles (coarse grit sandpaper) were worn while walking. Biomechanical data were assessed via mixed-models, repeated measures ANOVAs and 90 % confidence intervals. Wilcoxon Signed Rank tests and Mann-Whitney U tests evaluated plantar cutaneous sensation within and between groups, respectively. RESULTS: Knee adduction moment was lower in the ACLR versus the contralateral limb pre-massage. The vGRF was lower during the first half of stance but greater during the second half of stance in the ACLR versus the control group post-massage. Massage improved ACLR limb sensation over the first metatarsal head (P = 0.042) and medial malleolus (P = 0.027). Textured insole application improved ACLR limb sensation over the first (P = 0.043) and fifth (P = 0.027) metatarsals and medial malleolus (P = 0.028). SIGNIFICANCE: Plantar massage and textured insoles improved plantar cutaneous sensation in the ACLR limb. Neither intervention influenced gait. Improving plantar sensation may be beneficial for patients after ACLR; however, sensory interventions to improve gait are necessary.

Prolonged Rest, Long-Term Dynamic Balance, and Gait in a Mouse Ankle-Sprain Model.

CONTEXT: Lateral ankle sprains (LASs) result in short- and long-term adaptations in the sensorimotor system that are thought to contribute to the development of chronic ankle instability and posttraumatic ankle osteoarthritis. Debate continues as to the appropriateness of rapid return to sport after LASs given the prevalence of long-term consequences. OBJECTIVE: To examine the short- and long-term effects of prolonged rest, as a model of immobilization, on dynamic balance and gait outcomes after a severe LAS in a mouse model. DESIGN: Controlled laboratory study. SETTING: Research laboratory. INTERVENTION(S): At 7 weeks of age, 18 male mice (CBA/J) had their right anterior talofibular and calcaneofibular ligaments transected. Mice were then randomized to 1 of 3 groups representing when access to a running wheel postsurgery was gained: at 3 days, 1 week, and 2 weeks. MAIN OUTCOME MEASURE(S): Dynamic balance and spatial gait characteristics were quantified before surgery (baseline) and at 3 days and 1, 2, 4, 6, 12, 18, 24, 30, 36, 42, 48, and 54 weeks postinjury. RESULTS: Relative to prolonged rest, resting for only 3 days resulted in worse dynamic balance during the later assessment points (42-54 weeks postinjury, P < .01). Mice that underwent a prolonged rest period of 2 weeks crossed the balance beam faster than the group that rested for only 3 days when averaged across all time points (P < .012). Spatial gait characteristics did not differ among the groups (P > .05). CONCLUSIONS: Relative to 3 days of rest, prolonged rest (1 and 2 weeks) after a severe LAS in mice positively affected balance. The apparent benefit of prolonged rest was noted on both dynamic-balance outcomes and performance. Stride length was not altered by the duration of rest after a surgically induced severe LAS in mice. Future research is needed to determine if these results translate to a human model.

A 14-Day Recovery and Physical Activity Levels After an Ankle Sprain in Mice.

CONTEXT: Research is needed to find ways of improving physical activity after a lateral ankle sprain. OBJECTIVE: To investigate the effects of a prolonged rest period on lifelong activity after a surgically induced ankle sprain. DESIGN: Controlled laboratory study. SETTING: Research laboratory. PATIENTS OR OTHER PARTICIPANTS: A total of 18 male CBA/J mice (age at surgery = 7 weeks). MAIN OUTCOME MEASURE(S): We transected the anterior talofibular ligament and calcaneofibular ligament of the right hindlimb. Each mouse was placed in a separate cage and randomized into 1 of 3 groups of 6 mice each. A running wheel was placed in each cage at 3 days, 7 days, or 14 days after surgery. Physical activity was measured daily. Daily duration (ie, time spent on the wheel), distance, and running speed were examined using analysis of variance (group × age) with repeated measures at 15-week periods to approximate the first 3 quartiles of the lifespan. RESULTS: From weeks 3 to 15 after surgery, we observed no differences in duration, distance, or running speed among groups (P > .05). From weeks 16 to 30, distance (F2,14 = 0.57, P = .041) and running speed (F2,14 = 0.93, P = .01) were greater in the 14-day group than in the 3- and 7-day groups. From weeks 31 to 45, duration (F2,14 = 0.74, P = .02), distance (F2,14 = 0.95, P = .009), and running speed (F2,14 = 1.05, P = .007) were greater in the 14-day group than in the 3- and 7-day groups. CONCLUSIONS: Our findings suggest that the longer recovery period of 14 days can increase activity levels throughout the lifespan after a severe ankle sprain. Rest after an ankle injury is critical to restoring physical activity levels across the lifespan. Rest and time away from exercise after an ankle sprain may be necessary to restore physical activity to normal, uninjured levels.

Cortical Measures of Motor Planning and Balance Training in Patients With Chronic Ankle Instability.

CONTEXT: Motor planning, a prerequisite for goal-driven movement, is a complex process that occurs in the cortex. Evidence has suggested that motor planning is altered in patients with chronic ankle instability (CAI). We know balance training can improve balance, but we do not know if it also improves motor planning. Such changes in cortical activity can be assessed using electroencephalography. OBJECTIVE: To evaluate changes in cortical measures of motor planning after balance training in patients with CAI. DESIGN: Controlled laboratory study. SETTING: Research laboratory. PATIENTS OR OTHER PARTICIPANTS: Fifteen patients with CAI (age = 20.80 ± 2.37 years, height = 169.47 ± 7.95 cm, mass = 70.45 ± 19.25 kg). INTERVENTION(S): A 4-week progression-based balance-training program. MAIN OUTCOME MEASURE(S): Motor planning was assessed via electroencephalography before a lateral-stepping task. We calculated event-related spectral perturbations in the θ (4-8 Hz), α (8-12 Hz), ß (14-25 Hz), and γ (30-50 Hz) bands. The change in power (in decibels) was calculated in each band for the 500 milliseconds before the onset of the lateral-stepping movement. Additional outcomes were the Foot and Ankle Ability Measure (FAAM)-Activities of Daily Living and Sport subscales; the anterior-, posteromedial-, and posterolateral-reach directions of the Star Excursion Balance Test; and static balance. Patients completed 3 test sessions: baseline, 24- to 48-hour posttest, and 1-week posttest. Repeated-measures analyses of variance were used to assess changes over time. The α level was set at .05. RESULTS: The FAAM-Activities of Daily Living subscale score was improved at both posttests (P < .05), and the FAAM-Sport subscale score was improved at the 1-week posttest (P = .008). Balance was better in all 3 directions of the Star Excursion Balance Test at both posttest sessions (P < .001). After balance training, no differences were identified in cortical activity at either posttest session (P > .05). CONCLUSIONS: No improvements were identified in electroencephalography measures of motor planning during lateral stepping in patients with CAI. Improved balance suggested that sensorimotor adaptations occurred, but they may not have transferred to the lateral-stepping task or they may have been mediated via other processes in patients with CAI.

Lack of Medical Treatment From a Medical Professional After an Ankle Sprain.

CONTEXT: Despite the prevalence of ankle sprains and the potential for developing chronic ankle instability and ankle osteoarthritis, ankle sprains are often perceived as an innocuous injury. OBJECTIVE: To understand the initial management and treatment sought by patients after a lateral ankle sprain (LAS) and to identify any differences in subjective function and self-reported injury. DESIGN: Cross-sectional study. SETTING: Research laboratory. PATIENTS OR OTHER PARTICIPANTS: A total of 175 participants with chronic ankle instability (73 men, 102 women; age = 20.9 ± 3.4 years, height = 173.5 ± 13.2 cm, mass = 81.4 ± 24.6 kg) were involved in the study. MAIN OUTCOME MEASURE(S): Participants were administered a questionnaire regarding their initial LAS. All participants also completed the Foot and Ankle Ability Measure (FAAM). The primary questions of interest were (1) Did the participants seek treatment from a medical professional for their initial LAS? (2) Did the participants perform rehabilitation? (3) Was the initial LAS immobilized? and (4) Did the participants use crutches? The other variables measured were scores on the FAAM and the FAAM Sports subscale, total number of ankle sprains, and incidents of giving way. RESULTS: Sixty-four percent of participants did not seek medical treatment after their LAS. Those who did not seek medical treatment scored worse on the FAAM (81.21% ± 3.1% versus 89.23% ± 2.8%, P = .03) and the FAAM Sports subscale (72.34% ± 5.3% versus 81.26% ± 3.1%, P = .001). Those not seeking treatment also reported more ankle sprains since the initial injury (4.7 ± 2.4 versus 1.9 ± 0.90, P = .02) and more incidents of giving way each month (3.8 ± 1.9 versus 1.1 ± 0.87, P = .04). CONCLUSIONS: It is not surprising that those who did not seek medical treatment for their LASs had worse subjective function, more ankle sprains, and more incidents of the ankle giving way. The public needs to be educated on the significance of ankle sprains and the need for medical attention to provide appropriate management. However, we also need to continue to evaluate initial management and rehabilitation to ensure that those who seek treatment receive the best care in order to reduce reinjury rates.

Uncontrolled Eating during Pregnancy Predicts Fetal Growth: The Healthy Mom Zone Trial.

Excess maternal weight gain during pregnancy elevates infants' risk for macrosomia and early-onset obesity. Eating behavior is also related to weight gain, but the relationship to fetal growth is unclear. We examined whether Healthy Mom Zone, an individually tailored, adaptive gestational weight gain intervention, and maternal eating behaviors affected fetal growth in pregnant women (n = 27) with a BMI > 24. At study enrollment (6-13 weeks gestation) and monthly thereafter, the Three-Factor Eating Questionnaire was completed. Ultrasounds were obtained monthly from 14-34 weeks gestation. Data were analyzed using multilevel modeling. Higher baseline levels of uncontrolled eating predicted faster rates of fetal growth in late gestation. Cognitive restraint was not associated with fetal growth, but moderated the effect of uncontrolled eating on fetal growth. Emotional eating was not associated with fetal growth. Among women with higher baseline levels of uncontrolled eating, fetuses of women in the control group grew faster and were larger in later gestation than those in the intervention group (study group × baseline uncontrolled eating × gestational week interaction, p = 0.03). This is one of the first intervention studies to use an individually tailored, adaptive design to manage weight gain in pregnancy to demonstrate potential effects on fetal growth. Results also suggest that it may be important to develop intervention content and strategies specific to pregnant women with high vs. low levels of disinhibited eating.

Predicting dynamic balance improvements following 4-weeks of balance training in chronic ankle instability patients.

OBJECTIVES: Balance training typically features as a central component of exercise-based rehabilitation programs for patients with lateral ankle sprain and chronic ankle instability (CAI). The purpose of this study was to conduct a responder/non-responder analysis using existing data to identify factors associated with improvements in dynamic balance performance in CAI patients. DESIGN: Secondary data analysis. METHODS: Data was used from 73 CAI patients who participated in 6 previous investigations that used the same balance training program. We defined treatment success as a patient exceeding the minimal detectable change score (8.15%) for the posteriomedial direction of the Star Excursion Balance Test (SEBT-PM). Baseline measures of participant and injury demographics, patient-reported function, and dynamic balance were entered into a step-wise logistic regression model to determine the best set of predictors of treatment success. RESULTS: Only 28 out of 73 patients (38.4%) demonstrated a successful improvement in SEBT-PM reach after balance training. Of the variables assessed, SEBT-PM reach distance ≤85.18% and self-reported function activities of daily living score ≤92.55% were significant predictors of treatment success (p<0.001). If a patient met both these criteria there was a 70% probability of a successful treatment, indicating a 31.6% increase in the probability of a meaningful balance improvement after completing balance training. CONCLUSIONS: Without screening, less than 40% of CAI patients experience a meaningful improvement in SEBT-PM following balance training. Completing a brief pre-treatment assessment of a patient- and clinician-oriented outcome can significantly improve the probability of determining patients with CAI who may improve dynamic balance after balance training.

Lateral Ankle Sprain in a Mouse Model: Lifelong Sensorimotor Dysfunction.

CONTEXT: Ankle sprains are the most common orthopaedic injury that occurs during sport and physical activity. Many individuals who sprain their ankles develop chronic ankle instability (CAI), a condition characterized by recurrent injury, decreased physical activity, and decreased quality of life. These residual impairments are believed to persist for the remainder of the patient's life, in part due to the link between CAI and posttraumatic ankle osteoarthritis. However, this belief remains speculative due to the lack of long-term prospective investigations. OBJECTIVE: To use a mouse model of mild (MILD) and severe (SEVERE) ankle sprains to quantify balance and locomotor adaptations across the lifespan. DESIGN: Cohort study. SETTING: University research laboratory. PATIENTS OR OTHER PARTICIPANTS: Fifty male mice (CBA/J) were randomly placed into a control (SHAM), MILD, or SEVERE group and housed individually. INTERVENTION(S): The MILD group underwent surgical transection of a single right hind-limb lateral ankle ligament, and the SEVERE group had 2 of the lateral ligaments transected. The SHAM group underwent a sham surgery during which no lateral ligaments were transected. MAIN OUTCOME MEASURE(S): After surgically inducing the ankle sprain, we measured balance and gait using a balance beam and footprint test before and every 6 weeks for 78 weeks. RESULTS: Age-related declines in balance but not stride length were exacerbated by an ankle sprain ( P < .001). Balance and stride lengths changed with age ( P < .001). Foot slips were worse in the SEVERE (4.32 ± 0.98) and MILD (3.53 ± 0.98) groups than in the SHAM group (2.16 ± 0.99; P < .001). Right-limb stride length was shorter in the SEVERE group (6.45 cm ± 0.41 cm) than in the SHAM group (6.87 cm ± 0.40 cm; P = .04). CONCLUSIONS: Transecting the lateral ligaments of a mouse hind foot resulted in lifelong sensorimotor dysfunction. Declines starting at 42 weeks postinjury may have represented the onset of posttraumatic osteoarthritis.

Acute Ankle Sprain in a Mouse Model: Changes in Knee-Joint Space.

CONTEXT: Ankle sprains remain the most common orthopaedic injury. Conducting long-term studies in humans is difficult and costly, so the long-term consequences of an ankle sprain are not entirely known. OBJECTIVE: To measure knee-joint space after a single surgically induced ankle sprain in mice. DESIGN: Randomized controlled trial. SETTING: University research laboratory. PATIENTS OR OTHER PARTICIPANTS: Thirty male mice (CBA/2J) were randomly placed into 1 of 3 surgical groups: the transected calcaneofibular ligament (CFL) group, the transected anterior talofibular ligament/CFL group, or a sham treatment group. The right ankle was operated on in all mice. MAIN OUTCOME MEASURE(S): Three days after surgery, all of the mice were individually housed in cages containing a solid-surface running wheel, and daily running-wheel measurements were recorded. Before surgery and every 6 weeks after surgery, a diagnostic ultrasound was used to measure medial and lateral knee-joint space in both hind limbs. RESULTS: Right medial (P = .003), right lateral (P = .002), left medial (P = .03), and left lateral (P = .002) knee-joint spaces decreased across the life span. The mice in the anterior talofibular ligament/CFL group had decreased right medial (P = .004) joint space compared with the sham and CFL groups starting at 24 weeks of age and continuing throughout the life span. No differences occurred in contralateral knee-joint degeneration among any of the groups. CONCLUSIONS: Based on current data, mice that sustained a surgically induced severe ankle sprain developed greater joint degeneration in the ipsilateral knee. Knee degeneration could result from accommodation to the laxity of the ankle or biomechanical alterations secondary to ankle instability. A single surgically induced ankle sprain could significantly affect knee-joint function.

Number of knee and ankle injuries is associated with poor physical but not mental health.

The knee and ankle are among the most commonly injured joints in the body. Long-term strength and neuromuscular control deficits are common following these injuries, yielding lifelong disability and poor quality of life. However, it is unknown how the number of injuries sustained influences quality of life. OBJECTIVES: Determine the association between the number of ankle or knee injuries sustained and physical and mental quality of life. METHODS: A total of 806 ankle-injured (age:45.2 ± 15.3 yrs; body mass index [BMI]:28.6 ± 7.4 kg/m2), 658 knee-injured (age:49.3 ± 16.1 yrs; BMI:28.4 ± 7.4 kg/m2), and 996 uninjured (age:43.4 ± 16.1 yrs; BMI:26.9 ± 6.5 kg/m2) adults completed the SF-8 survey to determine the physical (PCS) and mental (MCS) contributions to quality of life. Respondents were categorized by injury history (ankle, knee, none) and number of injuries (0, 1, 2, or 3 or more [3+]) to the same joint. Backward linear regression models were used to determine the association between quality of life, age, and injury history separately for SF-8 PCS and MCS, as well as ankle versus knee injury. RESULTS: Reporting 1, 2, or 3+ ankle injuries along with age predicted SF-8 PCS (P < 0.001). Further, 1 or 2 ankle injuries and age (P < 0.001) predicted SF-8 MCS. Reporting 1, 2, or 3+ knee injuries along with age significantly predicted SF-8 PCS (P < 0.001). Age, but not knee injury history, significantly predicted SF-8 MCS (P < 0.001). CONCLUSION: Current age and history of sustaining at least one injury negatively impact physical quality of life following either a knee or ankle injury. However, mental quality of life was predicted most consistently by age. Efforts to reduce injuries should be employed to improve quality of life, but more research is needed to determine what other factors contribute to quality of life across the lifespan.

Epidemiology of Posttraumatic Osteoarthritis.

Osteoarthritis is a leading cause of disability whose prevalence and incidence continue to increase. History of joint injury represents an important risk factor for posttraumatic osteoarthritis and is a significant contributor to the rapidly growing percentage of the population with osteoarthritis. This review will present the epidemiology associated with posttraumatic osteoarthritis, with particular emphasis on the knee and ankle joints. It is important to understand the effect of posttraumatic osteoarthritis on the population so that sufficient resources can be devoted to countering the disease and promoting optimal long-term health for patients after joint injury.

The Relationship Between Early-Stage Knee Osteoarthritis and Lower-Extremity Alignment, Joint Laxity, and Subjective Scores of Pain, Stiffness, and Function.

CONTEXT: Knee osteoarthritis (OA) is a debilitating disease that affects an estimated 27 million Americans. Changes in lower-extremity alignment and joint laxity have been found to redistribute the medial and/or lateral loads at the joint. However, the effect that changes in anteroposterior knee-joint laxity have on lower-extremity alignment and function in individuals with knee OA remains unclear. OBJECTIVE: To examine anteroposterior knee-joint laxity, lower-extremity alignment, and subjective pain, stiffness, and function scores in individuals with early-stage knee OA and matched controls and to determine if a relationship exists among these measures. DESIGN: Case control. SETTING: Sports-medicine research laboratory. PARTICIPANTS: 18 participants with knee OA and 18 healthy matched controls. INTERVENTION: Participants completed the Western Ontario McMaster (WOMAC) osteoarthritis questionnaire and were tested for total anteroposterior knee-joint laxity (A-P) and knee-joint alignment (ALIGN). MAIN OUTCOME MEASURES: WOMAC scores, A-P (mm), and ALIGN (°). RESULTS: A significant multivariate main effect for group (Wilks' Λ = 0.30, F7,26 = 8.58, P < .0001) was found. Knee-OA participants differed in WOMAC scores (P < .0001) but did not differ from healthy controls on ALIGN (P = .49) or total A-P (P = .66). No significant relationships were identified among main outcome measures. CONCLUSION: These data demonstrate that participants with early-stage knee OA had worse pain, stiffness, and functional outcome scores than the matched controls; however, ALIGN and A-P were no different. There was no association identified among participants' subjective scores, ALIGN, or A-P measures in this study.

Weekly Physical Activity Levels of Older Adults Regularly Using a Fitness Facility.

The aim of this paper was to determine if weekly physical activity levels were greater in an independent-living older adult population that was regularly participating in structured fitness activities. Also, lifetime exercise history and sex differences were investigated in an effort to understand how they relate to current weekly step activity. Total weekly step counts, measured with a pedometer, were assessed in two older adult groups; the first consisted of members of a local senior center who regularly used the fitness facility (74.5 ± 6.0 yrs; mean ± SD) while the second group consisted of members who did not use the fitness facility (74.8 ± 6.0 yrs). Participants also completed the Lifetime Physical Activity Questionnaire (LPAQ). No significant difference was found in the total number of weekly steps between groups (p = 0.88) or sexes (p = 0.27). The LPAQ suggested a significant decline in activity with aging (p = 0.01) but no difference between groups (p = 0.54) or sexes (p = 0.80). A relationship was observed between current step activity and MET expenditure over the past year (p = 0.008, r (2) = 0.153) and from ages 35 to 50 years (p = 0.037, r (2) = 0.097). The lack of difference in weekly physical activity level between our groups suggests that independent-living older adults will seek out and perform their desired activity, in either a scheduled exercise program or other leisure-time activities. Also, the best predictor of current physical activity level in independent-living older adults was the activity performed over the past year.

Altered left ventricular performance in aging physically active mice with an ankle sprain injury.

We assessed the impact of differing physical activity levels throughout the lifespan, using a musculoskeletal injury model, on the age-related changes in left ventricular (LV) parameters in active mice. Forty male mice (CBA/J) were randomly placed into one of three running wheel groups (transected CFL group, transected ATFL/CFL group, SHAM group) or a SHAM Sedentary group (SHAMSED). Before surgery and every 6 weeks after surgery, LV parameters were measured under 2.5 % isoflurane inhalation. Group effects for daily distance run was significantly greater for the SHAM and lesser for the ATLF/CFL mice (p = 0.013) with distance run decreasing with age for all mice (p < 0.0001). Beginning at 6 months of age, interaction (group × age) was noted with LV posterior wall thickness-to-radius ratios (h/r) where h/r increased with age in the ATFL/CFL and SHAMSED mice while the SHAM and CFL mice exhibited decreased h/r with age (p = 0.0002). Passive filling velocity (E wave) was significantly greater in the SHAM mice and lowest for the ATFL/CFL and SHAMSED mice (p < 0.0001) beginning at 9 months of age. Active filling velocity (A wave) was not different between groups (p = 0.10). Passive-to-active filling velocity ratio (E/A ratio) was different between groups (p < 0.0001), with higher ratios for the SHAM mice and lower ratios for the ATFL/CFL and SHAMSED mice in response to physical activity beginning at 9 months of age. Passive-to-active filling velocity ratio decreased with age (p < 0.0001). Regular physical activity throughout the lifespan improved LV structure, passive filling velocity, and E/A ratio by 6 to 9 months of age and attenuated any negative alterations throughout the second half of life. The diastolic filling differences were found to be significantly related to the amount of activity performed by 9 months and at the end of the lifespan.