A New Clustering Method for Knee Movement Impairments using Partitioning Around Medoids Model.

BACKGROUND: The movement system impairment (MSI) model is a clinical model that can be used for the classification, diagnosis, and treatment of knee impairments. By using the partitioning around medoids (PAM) clustering method, patients can be easily clustered in homogeneous groups through the determination of the most discriminative variables. The present study aimed to reduce the number of clinical examination variables, determine the important variables, and simplify the MSI model using the PAM clustering method. METHODS: The present cross-sectional study was performed in Shiraz, Iran, during February-December 2018. A total of 209 patients with knee pain were recruited. Patients' knee, femoral and tibial movement impairments, and the perceived pain level were examined in quiet standing, sitting, walking, partial squatting, single-leg stance (both sides), sit-to-stand transfer, and stair ambulation. The tests were repeated after correction for impairments. Both the pain pattern and the types of impairment were subsequently used in the PAM clustering analysis. RESULTS: PAM clustering analysis categorized the patients in two main clusters (valgus and non-valgus) based on the presence or absence of valgus impairment. Secondary analysis of the valgus cluster identified two sub-clusters based on the presence of hypomobility. Analysis of the non-valgus cluster showed four sub-clusters with different characteristics. PAM clustering organized important variables in each analysis and showed that only 23 out of the 41 variables were essential in the sub-clustering of patients with knee pain. CONCLUSION: A new direct knee examination method is introduced for the organization of important discriminative tests, which requires fewer clinical examination variables.

Added Value of Isolated Core Postural Control Training on Knee Pain and Function in Women With Patellofemoral Pain Syndrome: A Randomized Controlled Trial.

OBJECTIVES: To evaluate the added value of isolated core postural control training on knee pain and function in women with patellofemoral pain syndrome (PFPS). DESIGN: Randomized controlled trial. SETTING: Rehabilitation sciences research center. PARTICIPANTS: Women (N=33) between 18 and 30 years of age with PFPS were randomly assigned to a control group (n=16) or the experimental group (n=17). INTERVENTIONS: Participants in both groups received the same stretching and strengthening exercises during 4 weeks (12 sessions 3 days per week). The experimental group also received isolated core postural training with an unstable seat apparatus. MAIN OUTCOME MEASURES: Center of pressure (CoP) trajectories in sitting postural control, pain intensity, and function were recorded before and after the 4-week intervention period. Functional capacity and pain intensity were reassessed 3 months after the intervention. RESULTS: After treatment, both groups had significant improvements in pain, function (P<.001), and CoP trajectories in sitting postural control (control group P<.05, experimental group P<.001). Between-group comparisons demonstrated greater improvements in pain, function, and CoP trajectories in the experimental group (P<.001). This group also had significantly greater improvements in pain and Kujala Anterior Knee Pain Scale score at 3-month follow-up compared to the control group (P<.001). CONCLUSIONS: Adding isolated core postural control training to physiotherapy exercises was associated with significantly greater improvements in pain, function, and CoP trajectories than physiotherapy exercises alone. Therefore, unstable sitting postural control training is potentially useful to enhance rehabilitation management in patients with PFPS.

Improving Balance in Older People: A Double-Blind Randomized Clinical Trial of Three Modes of Balance Training.

The aim of this study was to examine and compare the effects of conventional, multisensory, and dual-task exercises on balance ability in a group of older community dwellers over a four-week period. Forty-four older people were randomly assigned to one of the three training groups. The score on the Fullerton Advanced Balance (FAB) scale, gait stability ratio, and walking speed were evaluated at baseline and after four weeks of training. All three groups showed significant (p < .001) improvement in the FAB scores following the three training programs (on average, 3 points for the conventional and multisensory groups and 3.8 points for the dual-task group). The improvements were comparable across the three intervention groups (p = .23). There were no statistically significant differences, neither within nor between groups, in the gait stability ratio and walking speed across the three training groups. In a four-week period, all the training modes were effective in improving balance of older adults, with no significant superiority of one mode of training over another.

Comparing the effects of 30 minutes exergaming versus brisk walking on physiological and psychological measurements of older adults.

BACKGROUND: Active video games can make physical activity more appealing and enjoyable for older people. This study compared the effects of 30 min of Exergaming versus walking on the physiological and psychological measures of asymptomatic older adults. METHODS: Forty eligible participants (mean age = 69.60 ± 4.16 y/o) were randomly divided into two groups of 20 in a crossover design, who either performed Brisk Walking or Exergaming, one week apart. Before each session, each participant's blood pressure was measured, and the subjects were encouraged to play/walk continuously for 30 min using a self-selected intensity. During both sessions, average and peak heart rate, time spent in each of the heart rate zones, blood pressure, and double product were assessed through a Polar H10 heart rate monitor. Participants also filled out the modified Physical Activity Enjoyment Scale (PACES) questionnaire and Rate of Perceived Exertion (RPE) scale. RESULTS: Findings indicated a significantly higher average (P = 0.003) and peak heart rate (P < 0.001) and double product (P = 0.002) during Exergaming compared to Brisk Walking. Also, the RPE score was significantly lower and PACES score was significantly higher (P < 0.001) during the Exergaming session. The analyses of blood pressure showed significant changes in systolic and diastolic blood pressures following each session, while no statistically significant difference was reported between the two exercise modalities (P = 0.012 and P < 0.001, respectively). CONCLUSION: This study showed that Exergaming can be a good alternative to traditional exercises like walking for older adults, providing physiological benefits while being less exhausting and more enjoyable.

Knee impairments: Comparison between new clinical classification by cluster analysis and movement system impairment model.

BACKGROUND: Although Movement System Impairment (MSI) model classifies patients with knee impairments, it has some limitations. This study compares MSI model with a new Partitioning Around Medoids (PAM) model in knee pain patients. METHODS: In this cross-sectional study, knee movement impairments (signs) and symptoms. (pain) of 200 patients were studied in eight different functional positions. After modification of impairments, the examinations were repeated to record the changes in symptoms. The patients were then classified based on the signs and symptoms firstly by MSI model and secondly using PAM clustering by R software. RESULTS: PAM model has a similar acceptable grouping compared to MSI because most patients are in 4 similar categories in both methods: valgus, varus, hyperextension and hypomobility. However, due to low discriminative power of the tests used for finding hypermobility and patellar dysfunctions, these sub-clusters are absent in PAM model. Instead, two new sub-clusters of self-management and valgus with hypomobility were found. Most importantly, the PAM model sorted the signs and symptoms based on their discriminative power and eliminated trivial tests so that the therapist can classify patients more quickly by performing clinically relevant tests. CONCLUSION: The new PAM method can be advantageous for therapists since it defines the importance of signs over symptoms in examination, prioritizes examination tests, and outlines tests with lower discriminative power. In PAM model, patients in the hypermobility and patellar subgroups of MSI model merged into other sub-clusters due to low discriminating power of their characteristics.

Cross-cultural adaptation, reliability and validity of the Persian version of the Victorian Institute of Sport Assessment-Achilles questionnaire (VISA-A).

PURPOSE: Achilles tendinopathy is a prevalent overuse injury among athletes and in those with a sedentary lifestyle. Current evidence indicates that the Victorian Institute of Sport Assessment-Achilles (VISA-A) questionnaire is a valid, reliable and disease-specific outcome measure for assessing the clinical symptoms in patients with Achilles tendinopathy. The objective of this study was to translate and cross-culturally adapt the VISA-A questionnaire into Persian (VISA-A-P) and evaluating its psychometric properties. MATERIALS AND METHODS: Cultural adaptation of VISA-A-P was conducted according to Beaton's guideline. The final version of VISA-A-P was handed to 61 patients for analysis of psychometric properties. Test-retest reliability, internal consistency, concurrent validity, item-total correlation, and floor/ceiling effect were evaluated in patients with Achilles tendinopathy. To assess test-retest reliability, 35 patients refilled the VISA-A-P twice within 5-7 days. Known-group validity was evaluated using 50 healthy individuals. RESULTS: VISA-A-P showed excellent test-retest reliability (ICC = 0.90), excellent internal consistency (Cronbach's alpha = 0.95), strong correlation with FAAM, and moderate to strong correlation with FAOS questionnaires. There was a significant difference between the average score of patients (34.55 ± 18.24) and the healthy group (73.1 ± 20.10). VISA-A-P showed neither ceiling nor floor effect. CONCLUSIONS: The VISA-A-P is a reliable and valid instrument for measuring the symptoms in Persian speaking populations with Achilles tendinopathy.Implications for rehabilitationAchilles tendinopathy is a debilitating overuse injury that insidiously affects tendoAchilles.VISA-A-P revealed acceptable validity and reliability and it could be used by Persian speaking clinicians and researchers to assess pain and function in people with Achilles tendinopathy.

Electromyographic comparison of vastus medialis obliquus facilitatory versus vastus lateralis inhibitory kinesio taping in athletes with patellofemoral pain: A randomized clinical trial.

BACKGROUND: Patellofemoral pain (PFP) is among the most common orthopedic complications afflicting active young people. Diminished coordination of the vastii, delayed activation of the vastus medialis obliquus (VMO), and decreased VMO-to-vastus lateralis (VL) activity ratio are well documented as underlying causes of PFP. This study compares the effects of VMO facilitatory kinesio tape (KT) versus VL inhibitory KT on electromyographic (EMG) activity of the vastii, balance, and pain in athletes with PFP. METHODS: In this single-blind randomized clinical trial, thirty-two female athletes with PFP (mean age 26.33 ± 5.93 years) were randomly assigned to VMO facilitatory KT (n = 16) or VL inhibitory KT (n = 16) groups. In the facilitatory group, a Y-shaped strip of KT at 25% of its available tension was attached from the origin of the VMO to its insertion and in the inhibitory group, an insertion-to-origin Y-shaped strip of KT at 15% of its available tension was applied on the VL. Pain intensity, dynamic balance, and EMG data were assessed respectively with a visual analogue scale, the modified Star Excursion Balance Test, and an EMG telemetry system, before and immediately after KT application. RESULTS: Pain intensity decreased and dynamic balance improved significantly after taping in both groups, and VMO: VL activity ratio increased significantly in the VL group. However, none of the parameters differed significantly between groups. CONCLUSIONS: Both VMO facilitatory and VL inhibitory KT can improve pain and balance, while the inhibitory technique might be more effective in regulating the VMO to VL activity ratio in athletes with PFP.

The effect of the combination of whole body vibration and shoe with an unstable surface in chronic ankle instability treatment: a randomized clinical trial.

BACKGROUND: Chronic ankle instability (CAI) is a common condition following an ankle sprain. This study investigated the effects of whole body vibration (WBV) and shoe with an unstable surface training on balance, functional performance, strength, joint position sense in people with CAI. METHOD: Thirty- four peoples with unilateral CAI were randomly assigned to three groups: WBV group, WBV with shoe with an unstable surface (WBV-S), and no treatment control group (CON). The WBV group received 4 weeks progressive WBV training and the WBV-S group received progressive WBV training with shoe with an unstable surface. Modified star excursion balance test (mSEBT)reach distance, Hop-Test, muscle strength, and joint position sense were measured at baseline and after the 4 weeks; Moreover, the mSEBT and Hop-Test were reassessed again 2 weeks post intervention. RESULTS: The result showed a significant group-by-time interaction for anterior and posterolateral directions of mSEBT. The reach distance of these directions at post-intervention and follow-up increased significantly compare to pre-intervention in the WBV and WBV-S groups but not significantly change in the CON group. The Hop test in the WBV-S group was significantly more at post-intervention and follow-up compared to pre-intervention. However, no significant changes were observed in WBV and CON groups. No significant changes were observed for mSEBT posteromedial direction, muscles strength, and joint position sense errors. CONCLUSION: The 4 weeks WBV and WBV-S interventions could improve balance in peoples with CAI. Improvement in Hop test was only observed in the WBV-S group suggesting the added value of combining WBV and shoe with an unstable surface as an effective therapy compared to WBV training alone. The use of WBV and WBV-S were not associated with significant changes in strength and joint position sense variables over a four-week period. TRIAL REGISTRATION: This work registered in the Iranian Registry of Clinical Trials ( IRCT20151118025105N4 ).

Effects of Kinesiotape vs Soft and Semirigid Ankle Orthoses on Balance in Patients With Chronic Ankle Instability: A Randomized Controlled Trial.

BACKGROUND: Chronic ankle instability (CAI) is a frequent complication of ankle sprain that may be associated with long-term consequences. Although taping and bracing are common interventions that are widely used by clinicians and athletic trainers for patients with CAI, no studies have compared the effects of kinesiotaping and bracing on balance performance in these patients. The present study aimed to compare the effects of ankle kinesiotaping, a soft ankle orthosis, and a semirigid ankle orthosis on balance performance in patients with CAI. METHODS: Sixty patients with CAI were randomly assigned to 4 groups that received kinesiotaping, a soft orthosis, a semirigid orthosis, or no treatment (control group). Dynamic and static balance were measured with the modified Star Excursion Balance Test, single leg hop test, and single leg stance test before and after a 4-week intervention period. RESULTS: Significant between-group differences were seen in all evaluated outcomes (P ≤ .003). The lowest reach distances in all directions in the modified Star Excursion Balance Test were found in the control group, and these patients also had a significantly shorter measured distance in the single leg hop test, and more errors in the single leg stance test compared with the 3 intervention groups. No significant differences were found among the 3 intervention groups. CONCLUSION: Use of kinesiotaping and a soft or a semirigid ankle brace for 4 weeks were all beneficial in improving static and dynamic balance in individuals with CAI. None of the interventions was superior to the other 2. LEVEL OF EVIDENCE: Level I, randomized controlled trial.

Can fibular reposition taping improve balance performance in individuals with chronic ankle instability? A randomized controlled trial.

BACKGROUND: Lateral ankle sprain results in positional faults in the fibula which are thought to limit accessory motion in the ankle, leading to hypomobility and negatively influencing sensorimotor function and postural control. Although it has been shown that fibular reposition taping (FRT) is effective in the prevention of recurrent lateral ankle sprain, its ability to produce significant changes in balance measures in patients with chronic ankle instability is inconclusive. OBJECTIVE: This study aimed to determine whether a FRT intervention affects balance performance in patients with chronic ankle instability. DESIGN: Randomized controlled trial. METHODS: Sixty individuals with chronic ankle instability were randomly allocated to three groups: FRT, sham taping, or no intervention (control group). Kinesiotape was applied and then re-applied on 3 occasions per week for 2 weeks. Static and dynamic balance were measured with three functional tests before and 1 day after the last session of intervention with the tape removed: single-leg stance test, single-leg hop test for distance, and modified Star Excursion Balance Test (mSEBT). RESULTS: The results of ANCOVA showed that there were no significant differences between the three groups except for mSEBT reach distance in the posterolateral direction, which was significantly greater in the FRT group than the control group (p = 0.03). CONCLUSION: Applying FRT for 2 weeks did not significantly affect static or dynamic balance measures in individuals with chronic ankle instability, hence its clinical efficacy to influence balance remains uncertain in this population. CLINICAL TRIAL REGISTRATION NUMBER: IRCT20171122037576N2.

The effect of cold-water immersion on physical performance.

Cold modalities are widely used after athletic injuries, with known physiological effects. The aim of this study was to determine the effects of cold-water immersion on physical performance. Thirty healthy volunteers (average age of 19-23 years) took part in this pre-post interventional study. First, participants performed two tasks: a 40-yard dash run (to measure speed) and a vertical jump (to measure lower limb power). Then, both legs were immersed in a water bath at 5 °C for 15 min. Following cold-water immersion, the measurements were repeated after 2, 5, 10, 15, 20, 25 and 30 min. Immediately (2 min) after cold-water immersion, there was a decline in both the vertical jump and 40-yard dash tests compared to pre-intervention scores. While this effect lasted up to 20 min after cryotherapy for the 40-yard dash test, for the jump test, the effect only remained up to 10 min. The results showed a decrease in physical performance immediately and 20 min after immersion in cold water (p < 0.05). In addition, there was a gradual increase in the level of physical function over time. Therefore, before returning athletes to activity after the use of cold modalities, care should be taken.

A randomized controlled trial comparing the long-term use of soft lumbosacral orthoses at two different pressures in patients with chronic nonspecific low back pain.

BACKGROUND: There is concern that wearing soft lumbosacral orthoses for prolonged periods may impair motor function. Moreover, the pressure applied by lumbosacral orthoses on the abdominal wall is usually ignored when these orthoses are prescribed. METHOD: In this randomized controlled trial study, 48 patients with chronic nonspecific low back pain were randomly divided into high pressure, normal pressure and control groups. All groups received medication for 4 weeks. The normal pressure and high pressure groups, in addition to medication, used soft lumbosacral orthoses at normal pressure and 50% increased pressure, respectively. Motor function outcome measures were strength, endurance, proprioception and electromyographic activity of the trunk muscles. Clinical outcome measures were pain and disability, which were evaluated in two sessions before and after a 4-week interval. FINDINGS: Isometric strength, endurance and most of the electromyographic parameters were generally unaffected by wearing the lumbosacral orthosis. Pain improved in all groups, and disability and proprioception improved in the high pressure and normal pressure groups. Between-group differences in these three measures indicated better results in the lumbosacral orthoses groups than in the control group. The improvements in pain and proprioception were significantly greater in the high pressure group than the normal pressure group. INTERPRETATION: Long-term use of lumbosacral orthoses had no significant adverse effects on motor function or clinical factors in patients with chronic low back pain. Increasing lumbosacral orthosis tightness may improve motor functioning and the clinical efficacy of the orthosis. CLINICAL TRIAL REGISTRATION NUMBER: Code: IRCT201708192391N38.

Whole body vibration improves core muscle strength and endurance in ambulant individuals with multiple sclerosis: A randomized clinical trial.

BACKGROUND: People with Multiple sclerosis (MS) have been found to impair strength and endurance of core muscles compared with healthy people. Whole body vibration (WBV) is a relatively new method of neuromuscular training which can induce positive effects on mobility and postural control of MS patients. OBJECTIVE: To evaluate the effects of a 6-week WBV training program on the strength and endurance of core muscles in patients with MS. METHODS: Fifty patients were allocated to two groups, one receiving WBV training (intervention) and one no treatment (control). The endurance of core muscles were evaluated using Sorensen, flexion, and side bridge endurance tests. The strength of core muscles was evaluated using a dynamometer. We used the quality of life-54 questionnaire (MSQOL-54) to evaluate patients` quality of life aspects at baseline and two months after the end of study. RESULTS: Forty six patients completed the study (mean age: 37.9 ±â€¯7.7; BMI: 23.8 ±â€¯4.3). All outcome measures including strength and endurance of core muscles as well as MSQOL-54 scores significantly improved in WBV group in comparison to control group. While the within-group comparison showed significant improvement in the WBV group (P < 0.001), in the control group, some outcomes measures including physical and mental components of MSQOL-54 deteriorated (P < 0.001) over the course of study. CONCLUSIONS: Our study shows that strength and endurance of core muscles as well as quality of life of MS patients can be positively influenced by a 6-week WBV training. The program was well-tolerated by patients and no adverse event was observed.

Combined effects of whole body vibration and unstable shoes on balance measures in older adults: A randomized clinical trial.

OBJECTIVE: The purpose of this study was to compare the efficacy of 4 weeks of whole body vibration training on balance in older adults who word two different types of shoes: unstable (unstable group) versus standard shoes (stable group). DESIGN: Randomized, single-blind clinical trial. PARTICIPANTS: Seventy eight eligible older adults were initially enrolled; 59 participants (mean age 69.7±5.3 years) completed the program. INTERVENTION: Participants were randomized 1:1 to an intervention group that received whole body vibration with unstable shoes, and a control group that received whole body vibration with standard shoes. OUTCOME MEASURES: The Fullerton Advanced Balance scale, preferred gait speed, maximum gait speed, and Fall Efficacy Scale were recorded at baseline, after the 4-week intervention, and 1 month after the end of the training program. RESULTS: Both groups showed improvement in all outcome measures at 4 weeks (p < 0.01) with no significant between-group differences. In the unstable group, the gains were maintained at follow-up (p < 0.01) whereas the scores returned to baseline values in the stable group. At follow-up, significant between-group differences were found for Fullerton Advanced Balance scale (p < 0.001), preferred gait speed (p = 0.007) and maximum gait speed (p = 0.007), and all were in favor of the unstable group. CONCLUSION: Combining whole body vibration with unstable shoes can be proposed as a beneficial method with relatively long-term effects to improve balance measures in older people.

Can inhibitory and facilitatory kinesiotaping techniques affect motor neuron excitability? A randomized cross-over trial.

OBJECTIVES: The aim of this study was to investigate the immediate effects of facilitatory and inhibitory kinesiotaping on motor neuron excitability. DESIGN: Randomized cross-over trial. METHOD: Twenty healthy people received inhibitory and facilitatory kinesiotaping on two testing days. The H- and M-waves of the lateral gasterocnemius were recorded before and immediately after applying the two modes of taping. The Hmax/Mmax ratio (a measure of motor neuron excitability) was determined and analyzed. RESULTS: The mean Hmax/Mmax ratios were -0.013 (95% CI: -0.033 to 0.007) for inhibitory taping and 0.007 (95% CI: -0.013 to 0.027) for facilitatory taping. The mean difference between groups was -0.020 (95% CI: -0.048 to 0.008). The statistical model revealed no significant differences between the two interventions (P = 0.160). Furthermore, there were no within-group differences in Hmax/Mmax ratio for either group. CONCLUSIONS: Our findings did not disclose signs of immediate change in motor neuron excitability in the lateral gasterocnemius.

Biomechanics of running with rocker shoes.

OBJECTIVES: Load reduction is an important consideration in conservative management of tendon overuse injuries such as Achilles tendinopathy. Previous research has shown that the use of rocker shoes can reduce the positive ankle power and plantar flexion moment which might help in unloading the Achilles tendon. Despite this promising implication of rocker shoes, the effects on hip and knee biomechanics remain unclear. Moreover, the effect of wearing rocker shoes on different running strike types is unexplored. The aim of this study was to investigate biomechanics of the ankle, knee and hip joints and the role of strike type on these outcomes. DESIGN: Randomized cross-over study. METHODS: In this study, 16 female endurance runners underwent three-dimensional gait analysis wearing rocker shoes and standard shoes. We examined work, moments, and angles of the ankle, knee and hip during the stance phase of running. RESULTS: In comparison with standard shoes, running with rocker shoes significantly (p<0.001) reduced the positive (16%), and negative (32%) work at the ankle joint. Plantar flexion moment peak and impulse were also reduced by 11% and 12%, respectively. Reduction in these variables was almost two times larger for midfoot strikers than for rearfoot strikers. At the knee joint running with rocker shoes significantly increased the positive work (14%), extension moment peak (6%), and extension moment impulse (12%). CONCLUSIONS: These findings indicate that although running with rocker shoes might lower mechanical load on the Achilles tendon, it could increase the risk of overuse injuries of the knee joint.

The immediate effect of lumbopelvic manipulation on EMG of vasti and gluteus medius in athletes with patellofemoral pain syndrome: A randomized controlled trial.

OBJECTIVE: To evaluate the immediate effect of lubmopelvic manipulation on EMG activity of vastus medialis, vastus lateralis and gluteus medius as well as pain and functional performance of athletes with patellofemoral pain syndrome. DESIGN: Randomized placebo-controlled trial. METHODS: Twenty eight athletes with patellofemoral pain syndrome were randomly assigned to two groups. One group received a lubmopelvic manipulation at the side of the involved knee while the other group received a sham manipulation. EMG activity of the vasti and gluteus medius were recorded before and after manipulation while performing a rocking on heel task. The functional abilities were evaluated using two tests: step-down and single-leg hop. Additionally, the pain intensity during the functional tests was assessed using a visual analog scale. RESULTS: The onset and amplitude of EMG activity from vastus medialis and gluteus medius were, respectively, earlier and higher in the manipulation group compared to the sham group. There were no significant differences, however, between two groups in EMG onset of vastus lateralis. While the scores of one-leg hop test were similar for both groups, significant improvement was observed in step-down test and pain intensity in the manipulation group compared to the sham group. CONCLUSIONS: Lubmopelvic manipulation might improve patellofemoral pain and functional level in athletes with patellofemoral pain syndrome. These effects could be due to the changes observed in EMG activity of gluteus medius and vasti muscles. Therefore, the lubmopelvic manipulation might be considered in the rehabilitation protocol of the athletes with patellofemoral pain syndrome.

Rocker shoes reduce Achilles tendon load in running and walking in patients with chronic Achilles tendinopathy.

OBJECTIVES: Relative rest and pain relief play an important role in the management of Achilles tendinopathy, and might be achieved by reducing the load on the Achilles tendon. Previous studies have provided evidence that rocker shoes are able to decrease the ankle internal plantar flexion moment in healthy runners during walking and running. Since plantar flexion moment is related to the Achilles tendon loading, rocker shoes might be considered in the conservative management of Achilles tendinopathy. Therefore, the aim of this study was to investigate the biomechanics of running and walking in a group of patients with Achilles tendinopathy wearing standard shoes versus rocker shoes. DESIGN: Cross-over. METHODS: Thirteen Achilles tendinopathy patients (mean age 48 ± 14.5 years) underwent three-dimensional gait analysis wearing standard running shoes and rocker shoes during running and walking. Surface electromyography of triceps surae and tibialis anterior was recorded simultaneously. RESULTS: Patients had symptoms for an average of 22.5 months (median 11.5 months) and VISA-A scores were 54 ± 16. With the rocker shoes, the peak plantar flexion moment was reduced by 13% in both running (0.28 N m/kg, p<0.001) and walking (0.20 N m/kg, p<0.001). The peak activity of tibialis anterior was increased by 35% (p=0.015) for the rocker shoes in walking. There was no difference between electromyography peak amplitudes of triceps surae between two shoe sessions in both activities. CONCLUSIONS: When used by patients with chronic Achilles tendinopathy, rocker shoes cause a significant reduction in plantar flexion moment in the late stance phase of running and walking without substantial adaptations in triceps surae muscular activity.

Rocker shoe, minimalist shoe, and standard running shoe: a comparison of running economy.

OBJECTIVES: Running with rocker shoes is believed to prevent lower limb injuries. However, it is not clear how running in these shoes affects the energy expenditure. The purpose of this study was, therefore, to assess the effects of rocker shoes on running economy in comparison with standard and minimalist running shoes. DESIGN: Cross-over design. METHODS: Eighteen endurance female runners (age=23.6 ± 3 years), who were inexperienced in running with rocker shoes and with minimalist/barefoot running, participated in this study. Oxygen consumption, carbon dioxide production, heart rate and rate of perceived exertion were measured while participants completed a 6-min sub-maximal treadmill running test for each footwear condition. The data of the last 2 min of each shoe condition were averaged for analysis. A linear mixed model was used to compare differences among three footwear conditions. RESULTS: Oxygen consumption during running with rocker shoes was on average 4.5% higher than with the standard shoes (p<0.001) and 5.6% higher than with the minimalist shoe (p<0.001). No significant differences were found in heart rate and rate of perceived exertion across three shoe conditions. CONCLUSIONS: Female runners, who are not experienced in running with the rocker shoes and minimalist shoes, show more energy expenditure during running with the rocker shoes compared with the standard and minimalist shoes. As the studied shoes were of different masses, part of the effect of increased energy expenditure with the rocker shoe is likely to be due to its larger mass as compared with standard running shoes and minimalist shoes.

Effect of rocker shoes on plantar pressure pattern in healthy female runners.

Rocker profile shoes (rocker shoes) are one of the treatment options of metatarsalgia and forefoot stress fractures. The efficacy of rocker shoes in unloading the forefoot pressure has been shown in walking. In running, however, the effect of rocker shoes on forefoot pressure is unknown. Eighteen healthy female runners participated in this study. In-shoe plantar pressures were recorded during running with the standard running shoes and rocker shoes. Shoe comfort was assessed after each shoe measurement. Peak pressure (PP), maximum mean pressure (MMP) and force-time integral (FTI) were determined for seven foot areas. The effects of shoes on the different outcome variables were statistically analyzed using a linear mixed model. Running with the rocker shoes caused a significant reduction (p<0.001) in all pressure parameters in the central and lateral forefoot. FTI and MMP were also reduced by 11% and 12% in the medial forefoot while running with rocker shoes. Running with rocker shoes resulted in a significant increase in all pressure parameters at the heel region (p<0.001). Running with rocker shoes received a significant (p<0.01) lower comfort rate than running with standard running shoes. Rocker shoes might be beneficial for runners who are recovering from metatarsalgia or stress fractures of the forefoot region, as it reduces plantar pressure in the forefoot region.