Physical therapy vs. internet-based exercise training (PATH-IN) for patients with knee osteoarthritis: study protocol of a randomized controlled trial.

BACKGROUND: Physical activity improves pain and function among individuals with knee osteoarthritis (OA), but most people with this condition are inactive. Physical therapists play a key role in helping people with knee OA to increase appropriate physical activity. However, health care access issues, financial constraints, and other factors impede some patients from receiving physical therapy (PT) for knee OA. A need exists to develop and evaluate other methods to provide physical activity instruction and support to people with knee OA. This study is examining the effectiveness of an internet-based exercise training (IBET) program designed for knee OA, designed by physical therapists and other clinicians. METHODS/DESIGN: This is a randomized controlled trial of 350 participants with symptomatic knee OA, allocated to three groups: IBET, standard PT, and a wait list (WL) control group (in a 2:2:1 ratio, respectively). The study was funded by the Patient Centered Outcomes Research Institute, which conducted a peer review of the proposal. The IBET program provides patients with a tailored exercise program (based on functional level, symptoms, and current activity), video demonstrations of exercises, and guidance for appropriate exercise progression. The PT group receives up to 8 individual visits with a physical therapist, mirroring standard practice for knee OA and with an emphasis on a home exercise program. Outcomes are assessed at baseline, 4 months (primary time point) and 12 months (to assess maintenance of treatment effects). The primary outcome is the Western Ontario and McMaster Universities Osteoarthritis Index, and secondary outcomes include objective physical function, satisfaction with physical function, physical activity, depressive symptoms and global assessment of change. Linear mixed models will be used to compare both the IBET and standard PT groups to the WL control group, examine whether IBET is non-inferior to PT (a treatment that has an established evidence base for knee OA), and explore whether participant characteristics are associated with differential effects of IBET and/or standard PT. This research is in compliance with the Helsinki Declaration and was approved by the Institutional Review Board of the University of North Carolina at Chapel Hill. DISCUSSION: The IBET program could be disseminated widely at relatively low cost and could be an important resource for helping patients with knee OA to adopt and maintain appropriate physical activity. This trial will provide an important evaluation of the effectiveness of this IBET program for knee OA. TRIAL REGISTRATION: NCT02312713.

The effect of Tai Chi lower extremity exercise on the balance control of older adults in assistant living communities.

BACKGROUND: Although Tai Chi (TC) is an evidence-based fall prevention training for older adults, its effective movements remain unclear, which may limit the practice of TC. The purpose of this study was to compare the effectiveness of TC lower extremity exercise (TC LEE), the 8-form Tai Chi (8-form TC), and a stretching control intervention for improving balance and functional mobility among older adults. METHODS: This was a randomized controlled trial. A total of 102 participants (79 ± 6 years old) were recruited from assisted living facilities. All participants were randomly assigned to the TC LEE (n = 40), 8-form TC (n = 31), and stretching (n = 31) groups in which they received the respective interventions for 16 weeks. The Berg Balance Scale (BBS), Timed Up and Go (TUG) test, and center of pressure (COP) measurements during quiet stance were collected prior to and following the 16-week interventions. Comparisons on all measurements were conducted among all groups. RESULTS: Significant improvements were found in BBS (P = 0.002), TUG test (P = 0.001), root mean square amplitude of COP displacement in the anterior-posterior (P = 0.001) and medial-lateral (P = 0.001) directions, and average COP speed in the anterior-posterior (P = 0.001) and medial-lateral (P = 0.001) directions after training in the TC intervention groups compared with the stretching group. The upper limit of the 95% confidence interval (CI) of differences in change scores on the BBS (-0.8 - 1.3 points) between the TC LEE group and the 8-form TC group was within equivalence margins (1.8 points), while the upper limit of the 95% CI of differences in change scores on the TUG test (0.1 - 2.1 s) exceeded the equivalence margin (0.7 s) with the TC LEE group having the larger change scores. CONCLUSION: TC LEE can improve balance and functional mobility in older adults, and may have greater effect than the 8-form TC on improving functional mobility as measured by the TUG test. TRIAL REGISTRATION: ChiCTR2300070600 retrospectively registered.

Effect of sensor location for modifying center of pressure during gait using haptic feedback in people with chronic ankle instability.

BACKGROUND: Gait retraining using haptic biofeedback medially shifts the center of pressure (COP) while walking in orthopedic populations. However, the ideal sensor location needed to effectively shift COP medially has not been identified in people with chronic ankle instability (CAI). RESEARCH QUESTIONS: Can a heel sensor location feasibly be employed in people with CAI without negatively altering kinematics? Does a heel sensor placement relative to the 5th metatarsal head (5MH) impact COP location while walking in people with CAI? METHODS: In this exploratory crossover study, 10 participants with CAI walked on a treadmill with vibration feedback for 10 minutes with a plantar pressure sensor under the heel and 5MH. Separate 2×2 repeated measures analyses of covariances (rmANCOVAs) were used to compare the averaged COP location and 3-D lower extremity kinematics from the first 10% of stance before and after training and between sensor locations. Baseline measures served as covariates to adjust for baseline differences. RESULTS: Feedback triggered by a heel sensor resulted in 40% of participants avoiding a heel strike. There were no significant main effects or interactions between time and sensor location on COP location when controlling for baseline COP (p>0.05). However, with the 5MH placement, participants displayed less ankle internal rotation(IR) (5MH/Heel: -4.12±0.00º/ -6.43±0.62º), less forefoot abduction (-4.29±0.00º/ -5.14±1.01º), more knee flexion (3.40±0.32º/ 0.14±0.57º), less knee external rotation (-10.95±0.00º/-11.24±1.48º), less hip extension (-0.20±0.00º/-1.42±1.05º), and less hip external rotation (3.12±0.00º/3.75±1.98º). SIGNIFICANCE: A 5MH location may be more feasible based on difficulties maintaining heel strike when the sensor was under the heel. While no sensor location was statistically better at changing the COP, the 5MH location decreased proximal transverse plane motions making participants' gait more like controls. Individual response variations support comprehensive lower extremity assessments and the need to identify responder profiles using sensory feedback in people with CAI.

Effects of a knee extension constraint brace on lower extremity movements after ACL reconstruction.

BACKGROUND: Patients have high reinjury rates after ACL reconstruction. Small knee flexion angles and large peak posterior ground reaction forces in landing tasks increase ACL loading. QUESTIONS/PURPOSES: We determined the effects of a knee extension constraint brace on knee flexion angle, peak posterior ground reaction force, and movement speed in functional activities of patients after ACL reconstruction. PATIENTS AND METHODS: Six male and six female patients 3.5 to 6.5 months after ACL reconstruction participated in the study. Three-dimensional videographic and force plate data were collected while patients performed level walking, jogging, and stair descent wearing a knee extension constraint brace, wearing a nonconstraint brace, and not wearing a knee brace. Knee flexion angle at initial foot contact with the ground, peak posterior ground reaction force, and movement speed were compared across brace conditions and between genders. RESULTS: Wearing the knee extension constraint brace increased the knee flexion angle at initial foot contact for each activity when compared with the other two brace conditions. Wearing the knee extension constraint brace also decreased peak posterior ground reaction force during walking but not during jogging and stair descent. CONCLUSIONS: Although the knee extension constraint brace did not consistently reduce the peak posterior ground reaction force in all functional activities, it consistently increased knee flexion angle and should reduce ACL loading as suggested by previous studies. These results suggest the knee extension constraint brace has potential as a rehabilitation tool to alter lower extremity movement patterns of patients after ACL reconstruction to address high reinjury rates.

Effects of corrective insole on leg muscle activation and lower extremity alignment in rice farmers with pronated foot: a preliminary report.

BACKGROUND: Execution of strenuous activities in conjunction with slippery and viscous muddy working terrain in rice cultivation leads to a high prevalence of farmer musculoskeletal disorders and malalignments. Recommended intervention strategies originally designed for congenitally disabled individuals may also be applicable to farmers, including simple corrective wedges to reduce foot eversion. The objective of the present study was to conduct a preliminary investigation of the effects of corrective wedges on lower extremity muscle activity and alignment when subjects stood on flat rigid ground or muddy terrain, simulating typical work conditions encountered by the unique but populous Thai rice farming workforce. METHODS: Nine healthy farmers with pronated feet were recruited to participate and wedges were custom fabricated for each farmer based on physical therapy assessment and use of rapid prototyping techniques. Participants were asked to stand barefoot or with wedges on the two surface types. RESULTS: Results revealed foot pronation and knee valgus to improve (ranging, on average between 5.5 and 16.1 degrees) when participants were equipped with corrective wedges. The muscle activity of the peroneus longus and the tibialis anterior increased for muddy terrain, as compared with the rigid surface. In general, the wedges induced less tibialis anterior activity and greater peroneus longus activity, compared to when participants were standing barefoot. An elevation in evertor muscle activity may reflect stretching of the shortened muscle as a result of the reduced degree of foot pronation. CONCLUSIONS: Findings demonstrate potential benefits of corrective insole usage for farmers with pronated feet, including improved lower extremity alignment and invertor muscle activity reduction for both rigid and muddy terrains.

Tibiofemoral joint mobilizations following total knee arthroplasty and manipulation under anesthesia.

STUDY DESIGN: Case report. BACKGROUND: The purpose of this case report is to describe the use of tibiofemoral joint mobilizations to improve knee flexion in a patient with arthrofibrosis following total knee arthroplasty (TKA) and failed manipulation under anesthesia (MUA). CASE DESCRIPTION: A 62-year-old female presented to physical therapy 15 days after TKA with full knee extension, 45 deg of active knee flexion, 48 deg of passive knee flexion, pain, and a Lower Extremity Functional Scale (LEFS) score of 28. INTERVENTIONS/OUTCOMES: A multimodal intervention strategy was used initially with minimal improvement in knee flexion. The patient was diagnosed with fibrosis and MUA was performed. Passive knee flexion was 80 deg before MUA and 75 deg after MUA. Focused grade III and IV tibiofemoral joint mobilizations were used after MUA. At discharge, the patient had 90 deg of active and 116 deg of passive knee flexion, no pain, and an LEFS score of 80. DISCUSSION: A conventional multimodal intervention approach was ineffective for a patient who developed arthrofibrosis following TKA. A focused intervention approach of grade III and IV tibiofemoral joint mobilizations improved knee flexion, pain, and function following TKA and failed MUA.

The effect of performance demands on lower extremity biomechanics during landing and cutting tasks.

BACKGROUND: Anterior cruciate ligament (ACL) injuries commonly occur during the early phase of landing and cutting tasks that involve sudden decelerations. The purpose of this study was to investigate the effects of jump height and jump speed on lower extremity biomechanics during a stop-jump task and the effect of cutting speed on lower extremity biomechanics during a side-cutting task. METHODS: Thirty-six recreational athletes performed a stop-jump task under 3 conditions: jumping fast, jumping for maximum height, and jumping for 60% of maximum height. Participants also performed a side-cutting task under 2 conditions: cutting at maximum speed and cutting at 60% of maximum speed. Three-dimensional kinematic and kinetic data were collected. RESULTS: The jumping fast condition resulted in increased peak posterior ground reaction force (PPGRF), knee extension moment at PPGRF, and knee joint stiffness and decreased knee flexion angle compared with the jumping for maximum height condition. The jumping for 60% of maximum height condition resulted in decreased knee flexion angle compared with the jumping for maximum height condition. Participants demonstrated greater PPGRF, knee extension moment at PPGRF, knee valgus angle and varus moment at PPGRF, knee joint stiffness, and knee flexion angle during the cutting at maximum speed condition compared with the cutting at 60% maximum speed condition. CONCLUSION: Performing jump landing at an increased jump speed resulted in lower extremity movement patterns that have been previously associated with an increase in ACL loading. Cutting speed also affected lower extremity biomechanics. Jump speed and cutting speed need to be considered when designing ACL injury risk screening and injury prevention programs.

The relationship between discus throwing performance and combinations of selected technical parameters.

The aim of this study was to determine the relationship between discus throwing performance and the following technical parameters: hip-shoulder and shoulder-arm separation, trunk forward-backward tilt, throwing-arm elevation angles, and the absolute and relative throwing procedure phase times. Videographic data of 51 male and 53 female discus throwers' competitive performances were captured during major meets. The three-dimensional coordinates of 21 body landmarks and the discus were obtained for each thrower's best trial using direct linear transformation. The technical parameters were reduced from the three-dimensional data at six critical instants during the throwing procedure. Hierarchical stepwise multiple regression analyses were performed to determine the relative influence of linear combinations of the technical parameters on discus throwing performance. Specific techniques associated with linear combinations of certain technical parameters were identified using canonical correlations. Males and females were analysed separately. Suggestions for controlling the height of release and the vertical component of the speed of release using an effective technique are made.

Concerns About Ankle Injury Prophylaxis and Acceptance of the Parachute Ankle Brace Among Jumpmaster Students.

Introduction: Several studies have shown that the parachute ankle brace (PAB) is safe, cost-effective, and reduces the rates of ankle injuries during military parachuting. However, the acceptability and usability of the PAB has not been well established in units that regularly do airborne exercises. Many anecdotal concerns in the past may be limiting common use. The purpose of the study is to ascertain the attitudes toward the PAB among experienced paratroopers. Methods: One hundred experienced paratroopers training to be jumpmasters at the Advanced Airborne School (Fort Bragg, NC) voluntarily responded to a 13-item, paper questionnaire to assess attitudes toward the PAB, its use, and concerns about future ankle injuries. The survey was offered to all 100 students enrolled in an Advanced Airborne School course. Results were input into an online database using Qualtrics and qualitative responses were evaluated for thematic content and categorized appropriately. Analysis was performed using Qualtrics and SPSS for descriptive statistics, two-sample t-tests, and chi-square tests. The Wilcoxon signed-rank test was used to evaluate Likert-type responses. Results: Of the 100 paratroopers who responded to the survey 32% had over 10 yr of military service, 58% had over 5 yr of service, and 32% had over 5 yr on active jump status. Results show that none of the respondents had ever used the PAB; 62% had never heard of the PAB, and 72% had never observed use of the PAB. A majority of respondents (87%) had never injured an ankle during a parachute landing fall (PLF), but 79% believed that an ankle injury could affect their career potential as a paratrooper. Almost one-half of the respondents (47%) had seen that ankle injuries affect another paratrooper's career. A third of the respondents (35%) said that they had concerns that would keep them from using the PAB, whereas 21% were uncertain, as they had never heard of it. Only 19% of the respondents were willing to use measures such as taping, lace-up bracing, semi-rigid brace inside a normal boot, specialized jump boot with stabilizing braces built in, or outside-the-boot braces to prevent ankle injury. However, 40% said that they were likely to use these measures on jumps after experiencing an ankle injury. Discussion: Previous research clearly establishes the advantages of the PAB. None of the participants had ever used the PAB but expressed a fear about how an ankle injury might impact their future career potential. Yet half of the jumpmasters indicated a willingness to use prophylactic measures after an ankle injury. Conclusion: This survey assessed the attitude and knowledge related to the PAB among jumpmaster students. Results show that despite the benefits of the PAB, a negative attitude exists toward the PAB, and it is not currently being used. This survey clearly demonstrates the need either to educate paratroopers on the existence of the PAB or to explore other designs that may be more readily accepted in the airborne community.

Changes in pain and disability secondary to shoe lift intervention in subjects with limb length inequality and chronic low back pain: a preliminary report.

STUDY DESIGN: Preassessment and postassessment of treatment intervention. OBJECTIVE: To determine the changes in pain and disability secondary to shoe lift intervention for subjects with chronic low back pain (LBP) who have a limb length inequality (LLI). BACKGROUND: Previous reports have suggested that LLI may be a cause of LBP Most prior studies of lift therapy for management of LLI in patients with LBP have lacked clear guidelines for clinicians regarding the implementation of shoe lift intervention. METHODS AND MEASURES: Twelve subjects (6 male, 6 female) between the ages of 19 and 62 years with LLI (6.4-22.2 mm) and chronic LBP (1-30 years) participated. Visual analog scale pain ratings and disability questionnaire scores were acquired before and after lift intervention. Subjects determined their lift height based on resolution of LBP symptoms. RESULTS: Subjects experienced relief of general pain symptoms (P = .0006) and pain associated with standing (P= .002) following lift intervention, with minimally clinically important (MCID) reductions in general pain for 9 of 12 subjects and MCID reductions in standing pain for 8 of 10 subjects. Subjects also had less disability on the disability questionnaire (P = .001) following the intervention, with 9 of 12 subjects experiencing MCID reductions in disability. CONCLUSION: Shoe lifts may reduce LBP and improve function for patients who have chronic LBP and an LLI. Randomized controlled trials are needed to assess the efficacy of this intervention.

Effects of wearing foot orthosis with medial arch support on the fifth metatarsal loading and ankle inversion angle in selected basketball tasks.

STUDY DESIGN: Preintervention and post-intervention, repeated-measures experimental design. OBJECTIVES: The objective was to investigate the effects of foot orthoses with medial arch support on ankle inversion angle and plantar forces and pressures on the fifth metatarsal during landing for a basketball lay-up and during the stance phase of a shuttle run. BACKGROUND: Proximal fractures of the fifth metatarsal, specifically the Jones fracture, are common in sports. Wearing foot orthoses with medial arch support could increase the ankle inversion angle and the plantar forces and pressure on the fifth metatarsal that may increase the risk for fifth metatarsal fracture, METHODS AND MEASURES: Three-dimensional (3-D) videographic, force plate, and in-shoe plantar force and pressure data were collected during landing after a basketball lay-up and during the stance phase of a shuttle run with and without foot orthoses with medial arch support for 14 male subjects. Two-way ANOVAs with repeated measures were performed to compare ankle inversion angle, maximum forces, and pressure on the fifth metatarsal head and base between conditions and between tasks. RESULTS: The maximum ankle inversion angle and maximum plantar force and pressure on the base of the fifth metatarsal during both tasks as well as the maximum plantar force and pressure on the head of the fifth metatarsal during the stance of the shuttle run were significantly increased (P< or =026) when wearing foot orthoses. No significant differences were found in the maximum vertical ground reaction forces between foot orthotic conditions. CONCLUSION: Generic use of off-the-shelf foot orthoses with medial arch support causes increased plantar forces and pressures on the fifth metatarsal and may increase the risk for proximal fracture of the fifth metatarsal. Future studies are needed to investigate this risk, acknowledging that the differences noted in our study were small in magnitude and the foot type was not measured.

Repeatability of lower extremity kinetics and kinematics for standardized and self-selected running speeds.

INTRODUCTION: The purpose of this study was to determine the effects of self-selected versus standardized running speeds on within-day and between-day repeatability of lower extremity kinematics and kinetics for running gait. METHODS: Subjects (six female, six male, age 18-35) were recreational athletes with no lower extremity injuries. The following study variables were analyzed using the coefficient of variation (CV): the peak angles for knee internal rotation, external rotation, varus, valgus, flexion, and extension; peak angles for ankle dorsiflexion and plantar flexion; peak impact force and propulsive force; and peak anterior, posterior, medial, and lateral ground reaction forces (GRFs). Data for the entire stance phase were analyzed using the coefficient of multiple correlation (CMC) for the following variables: anterior-posterior, medial-lateral, and vertical GRF; the angles and angular velocities for knee internal-external rotation, valgus-varus, flexion-extension, and ankle dorsiflexion-plantar flexion. Each variable was analyzed using a 2 x 2 (speed x day) repeated measures ANOVA (alpha = 0.05). RESULTS: The within-day repeatability for all of the significantly different variables was greater than the between-day repeatability. For variables with a significant difference based on speed, the standardized running speed had greater repeatability. CONCLUSIONS: Within-day repeatability is generally greater than between-day repeatability. Running speed had little effect on the repeatability of any study variable. Having subjects run at a standardized speed may not be as important as previously thought.

Comparison of different structural foot types for measures of standing postural control.

STUDY DESIGN: Matched group comparison of 3 subject groups with 3 different foot structures for force plate and clinical measures of postural control. OBJECTIVES: To determine if subjects with different weight-bearing foot structure would demonstrate differences in static standing postural control, and to determine the reliability of study procedures. BACKGROUND: Weight-bearing foot structure may influence postural control either because of a decreased base of support (supinated foot structure) or because of passive instability of the joints of the foot (pronated foot structure). METHODS AND MEASURES: Young adults were categorized based on weight-bearing foot structure into neutral, pronated, or supinated groups (15 subjects per group). Postural control in single-limb stance with eyes closed was assessed using force plate measures and by measuring duration of single-limb stance on a firm floor and on a balance pad. Force plate measures were normalized center-of-pressure average speed; and standard deviation and maximum displacement in the anterior-posterior and medial-lateral directions. RESULTS: Individuals in the supinated group had significantly greater center-of-pressure average speed, greater maximum displacement in the anterior-posterior direction, and greater SD and maximum displacement in the medial-lateral direction than individuals in the neutral group. The individuals in the pronated group had significantly greater SD and maximum displacement in the anterior-posterior direction, used more trials to complete force plate testing, and had shorter single-limb stance duration than those in the neutral group. CONCLUSION: Individuals with pronated feet or supinated feet have poorer postural control than individuals with neutral feet, but perhaps through different mechanisms.

Differential Diagnosis and Intervention of Proximal Median Nerve Entrapment: A Resident's Case Problem.

Study Design Resident's case problem. Background Entrapment neuropathies represent a diagnostic challenge and require a comprehensive understanding of the nerve's path and the anatomical structures that may cause compression of the nerve. This resident's case problem details the evaluation and differential diagnosis process for median nerve entrapment resulting from forceful and repetitive pronation/supination motions. Diagnosis Median nerve compression syndromes include pronator syndrome, anterior interosseous nerve syndrome, and carpal tunnel syndrome. A cluster of clinical special tests were performed to determine the anatomical site of median nerve entrapment. Based on the patient's history and clinical test results, a diagnosis of pronator syndrome was determined. Provocation testing specific to pronator syndrome assisted with further localizing the site of entrapment to the pronator teres muscle, which guided effective management strategies. Discussion This resident's case problem illustrates the importance of detailed anatomical knowledge and a differential diagnostic process when evaluating a patient with signs and symptoms of an entrapment neuropathy of the median nerve. Electrodiagnostic studies are useful in ruling out carpal tunnel and anterior interosseous nerve syndromes, but are often inconclusive in cases of pronator syndrome. Therefore, a diagnosis of pronator syndrome in this case problem was based on a detailed understanding of median nerve anatomy, potential sites of compression, and unique clinical features associated with this condition. Level of Evidence Differential diagnosis, level 4. J Orthop Sports Phys Ther 2016;46(9):800-808. Epub 5 Aug 2016. doi:10.2519/jospt.2016.6723.

Adding Stiffness to the Foot Modulates Soleus Force-Velocity Behaviour during Human Walking.

Previous studies of human locomotion indicate that foot and ankle structures can interact in complex ways. The structure of the foot defines the input and output lever arms that influences the force-generating capacity of the ankle plantar flexors during push-off. At the same time, deformation of the foot may dissipate some of the mechanical energy generated by the plantar flexors during push-off. We investigated this foot-ankle interplay during walking by adding stiffness to the foot through shoes and insoles, and characterized the resulting changes in in vivo soleus muscle-tendon mechanics using ultrasonography. Added stiffness decreased energy dissipation at the foot (p < 0.001) and increased the gear ratio (i.e., ratio of ground reaction force and plantar flexor muscle lever arms) (p < 0.001). Added foot stiffness also altered soleus muscle behaviour, leading to greater peak force (p < 0.001) and reduced fascicle shortening speed (p < 0.001). Despite this shift in force-velocity behaviour, the whole-body metabolic cost during walking increased with added foot stiffness (p < 0.001). This increased metabolic cost is likely due to the added force demand on the plantar flexors, as walking on a more rigid foot/shoe surface compromises the plantar flexors' mechanical advantage.

Clinician Recommendations and Perceptions of Factors Associated With Ankle Brace Use.

BACKGROUND: Little information is available regarding the ankle braces orthopaedic sports medicine clinicians recommend or clinicians' concerns that may influence their decisions to recommend use of an ankle brace. HYPOTHESES: (1) Clinicians most frequently recommend lace-up braces with straps. (2) Clinicians who are concerned about potential adverse side effects from ankle brace use are less likely to recommend an ankle brace to prevent ankle sprain injuries. STUDY DESIGN: Descriptive survey study. LEVEL OF EVIDENCE: Level 3. METHODS: Surveys were sent via e-mail to 1000 randomly selected members of the Orthopaedic Section of the American Physical Therapy Association (APTA) and 1000 randomly selected members of the National Athletic Trainers' Association (NATA). A total of 377 individuals responded to the survey. RESULTS: Lace-up braces, specifically lace-up braces with straps, were the most frequently recommended type of ankle brace. Regression analyses indicated that the only perceived adverse side effect significantly related to frequency of ankle brace recommendation was a potential negative influence on ankle strength. CONCLUSION: Based on our sample, clinicians recommend lace-up ankle braces with straps most frequently to prevent ankle sprain injuries. Clinicians who are concerned about weakness of ankle musculature may be less likely to recommend use of an ankle brace. CLINICAL RELEVANCE: Clinicians may effectively reduce the number of ankle sprain injuries by recommending an ankle brace use after an initial ankle sprain injury.

Lower Extremity Biomechanics and Self-Reported Foot-Strike Patterns Among Runners in Traditional and Minimalist Shoes.

CONTEXT: The injury incidence rate among runners is approximately 50%. Some individuals have advocated using an anterior-foot-strike pattern to reduce ground reaction forces and injury rates that they attribute to a rear-foot-strike pattern. The proportion of minimalist shoe wearers who adopt an anterior-foot-strike pattern remains unclear. OBJECTIVE: To evaluate the accuracy of self-reported foot-strike patterns, compare negative ankle- and knee-joint angular work among runners using different foot-strike patterns and wearing traditional or minimalist shoes, and describe average vertical-loading rates. DESIGN: Descriptive laboratory study. SETTING: Research laboratory. PATIENTS OR OTHER PARTICIPANTS: A total of 60 healthy volunteers (37 men, 23 women; age = 34.9 ± 8.9 years, height = 1.74 ± 0.08 m, mass = 70.9 ± 13.4 kg) with more than 6 months of experience wearing traditional or minimalist shoes were instructed to classify their foot-strike patterns. INTERVENTION(S): Participants ran in their preferred shoes on an instrumented treadmill with 3-dimensional motion capture. MAIN OUTCOME MEASURE(S): Self-reported foot-strike patterns were compared with 2-dimensional video assessments. Runners were classified into 3 groups based on video assessment: traditional-shoe rear-foot strikers (TSR; n = 22), minimalist-shoe anterior-foot strikers (MSA; n = 21), and minimalist-shoe rear-foot strikers (MSR; n = 17). Ankle and knee negative angular work and average vertical-loading rates during stance phase were compared among groups. RESULTS: Only 41 (68.3%) runners reported foot-strike patterns that agreed with the video assessment (κ = 0.42, P < .001). The TSR runners demonstrated greater ankle-dorsiflexion and knee-extension negative work than MSA and MSR runners (P < .05). The MSA (P < .001) and MSR (P = .01) runners demonstrated greater ankle plantar-flexion negative work than TSR runners. The MSR runners demonstrated a greater average vertical-loading rate than MSA and TSR runners (P < .001). CONCLUSIONS: Runners often cannot report their foot-strike patterns accurately and may not automatically adopt an anterior-foot-strike pattern after transitioning to minimalist running shoes.

The effects of 2 landing techniques on knee kinematics, kinetics, and performance during stop-jump and side-cutting tasks.

BACKGROUND: Anterior cruciate ligament injuries (ACL) commonly occur during jump landing and cutting tasks. Attempts to land softly and land with greater knee flexion are associated with decreased ACL loading. However, their effects on performance are unclear. HYPOTHESIS: Attempts to land softly will decrease peak posterior ground-reaction force (PPGRF) and knee extension moment at PPGRF compared with a natural landing during stop-jump and side-cutting tasks. Attempts to land with greater knee flexion at initial ground contact will increase knee flexion at PPGRF compared with a natural landing during both tasks. In addition, both landing techniques will increase stance time and lower extremity mechanical work as well as decrease jump height and movement speed compared with a natural landing during both tasks. STUDY DESIGN: Controlled laboratory study. METHODS: A total of 18 male and 18 female recreational athletes participated in the study. Three-dimensional kinematic and kinetic data were collected during stop-jump and side-cutting tasks under 3 conditions: natural landing, soft landing, and landing with greater knee flexion at initial ground contact. RESULTS: Attempts to land softly decreased PPGRF and knee extension moment at PPGRF compared with a natural landing during stop-jump tasks. Attempts to land softly decreased PPGRF compared with a natural landing during side-cutting tasks. Attempts to land with greater knee flexion at initial ground contact increased knee flexion angle at PPGRF compared with a natural landing during both stop-jump and side-cutting tasks. Attempts to land softly and land with greater knee flexion at initial ground contact increased stance time and lower extremity mechanical work, as well as decreased jump height and movement speed during both stop-jump and side-cutting tasks. CONCLUSION: Although landing softly and landing with greater knee flexion at initial ground contact may reduce ACL loading during stop-jump and side-cutting tasks, the performance of these tasks decreased, as indicated by increased stance time and mechanical work as well as decreased jump height and movement speed. CLINICAL RELEVANCE: Training effects tested in laboratory environments with the focus on reducing ACL loading may be reduced in actual competition environments when the focus is on athlete performance. The effects of training programs for ACL injury prevention on lower extremity biomechanics in athletic tasks may need to be evaluated in laboratories as well as in actual competitions.

The role of foot orthoses as an intervention for patellofemoral pain.

Foot orthoses often are prescribed for patients with patellofemoral pain. The purpose of this clinical commentary is to review the theoretical and research basis that might support this intervention and to provide our own clinical experience in providing foot orthoses for these patients. Literature is reviewed regarding (1) the effects of foot orthoses on pain and function, (2) the relationship between foot and lower-extremity/patellofemoral joint mechanics, (3) the effects of foot orthoses on lower-extremity mechanics, and (4) the effects of foot orthoses on patellofemoral joint position. The literature and our own clinical experience suggest that patients with patellofemoral pain may benefit from foot orthoses if they also demonstrate signs of excessive foot pronation and/or a lower-extremity alignment profile that includes excessive lower-extremity internal rotation during weight bearing and increased Q angle. The mechanism for foot orthoses having a positive effect on pain and function for these patients may include (1) a reduction in internal rotation of the lower extremity; (2) a reduction in Q angle; (3) reduced laterally-directed soft tissue forces from the patellar tendon, the quadriceps tendon, and the iliotibial band; and (4) reduced patellofemoral contact pressures and altered patellofemoral contact pressure mapping. Foot orthoses may be a valuable adjunct to other intervention strategies for patients who present with the previously stated structural alignment profile.

Toe flexors strength and passive extension range of motion of the first metatarsophalangeal joint in individuals with plantar fasciitis.

STUDY DESIGN: Cross-sectional study. OBJECTIVE: To determine if a difference exists in toe flexors strength and passive extension range of motion of the first metatarsophalangeal joint between individuals with unilateral plantar fasciitis and control subjects. BACKGROUND: Weakness of the dynamic longitudinal arch supporters and shortening of the plantar fascia have been suggested as etiologic factors for plantar fasciitis. METHOD AND MEASURES: Twenty subjects with unilateral plantar fasciitis participated in the study. Subjects had had symptoms for an average (+/-SD) of 19.9 +/- 33.2 months prior to participating in the study. Twenty control subjects matched for sex and age were also tested. Each subject was measured bilaterally for passive extension range of motion of the first metatarsophalangeal joint and peak resistance force observed during an isometric test of toe flexors strength. RESULTS: Subjects with unilateral plantar fasciitis demonstrated weaker toe flexors (P<.05) than the control subjects. A significant main effect for feet also indicated that the toe flexors for the involved feet were significantly weaker than the uninvolved feet (P<.05) of subjects with unilateral plantar fasciitis. Passive extension range of motion of the first metatarsophalangeal joint was not significantly different between the involved and the uninvolved feet for subjects with plantar fasciitis. CONCLUSION: Results for our subjects indicate that the extensibility of soft tissues influencing extension of the first metatarsophalangeal joint was not related to the presence of plantar fasciitis. Additional research is needed to determine if toe flexors weakness is a cause or a result of plantar fasciitis and if strengthening regimes for the toe flexors are effective interventions for plantar fasciitis.