Effects of Weight-Bearing Versus Nonweight-Bearing Exercise on Function, Walking Speed, and Position Sense in Participants With Knee Osteoarthritis: A Randomized Controlled Trial

Jan M-H, Lin C-H, Lin Y-F, Lin J-J, Lin D-H. Effects of weight-bearing versus nonweight-bearing exercise on function, walking speed, and position sense in participants with knee osteoarthritis: a randomized controlled trial.

Objective

To investigate whether weight-bearing (WB) exercise enhances functional capacity to a greater extent than nonweight-bearing (NWB) exercise in participants with knee osteoarthritis.

Design

Randomized controlled trial.

Setting

Kinesiology laboratory.

Participants

Participants (N=106) were randomly assigned to WB exercise, NWB exercise, or a control group (no exercise).

Intervention

WB exercise and NWB exercise groups underwent an 8-week knee extension-flexion exercise program.

Main Outcome Measures

Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) function scale, walking speed, muscle torque, and knee reposition error were assessed before and after intervention.

Results

Equally significant improvements were apparent for all outcomes after WB exercise and NWB exercise, except for reposition error, for which improvement was greater in the WB exercise group. In contrast, there were no improvements in the control group.

Conclusions

Simple knee flexion and extension exercises (WB and NWB) performed over 8 weeks resulted in significant improvement in the WOMAC function scale and knee strength compared with the control group. NWB exercise alone may be sufficient enough to improve function and muscle strength. The additional benefit of WB exercise was improved position sense, which may enhance complex walking tasks (walking on figure of 8 route and spongy surface).     

A Specific Inpatient Aquatic Physiotherapy Program Improves Strength After Total Hip or Knee Replacement Surgery: A Randomized Controlled Trial

Rahmann AE, Brauer SG, Nitz JC. A specific inpatient aquatic physiotherapy program improves strength after total hip or knee replacement surgery: a randomized controlled trial.

Objective

To evaluate the effect of inpatient aquatic physiotherapy in addition to usual ward physiotherapy on the recovery of strength, function, and gait speed after total hip or knee replacement surgery.

Design

Pragmatic randomized controlled trial with blinded 6-month follow-up.

Setting

Acute-care private hospital.

Participants

People (n=65) undergoing primary hip or knee arthroplasty (average age, 69.6±8.2y; 30 men).

Interventions

Participants were randomly assigned to receive supplementary inpatient physiotherapy, beginning on day 4: aquatic physiotherapy, nonspecific water exercise, or additional ward physiotherapy.

Main Outcome Measures

Strength, gait speed, and functional ability at day 14.

Results

At day 14, hip abductor strength was significantly greater after aquatic physiotherapy intervention than additional ward treatment (P=.001) or water exercise (P=.011). No other outcome measures were significantly different at any time point in the trial, but relative differences favored the aquatic physiotherapy intervention at day 14. No adverse events occurred with early aquatic intervention.

Conclusions

A specific inpatient aquatic physiotherapy program has a positive effect on early recovery of hip strength after joint replacement surgery. Further studies are required to confirm these findings. Our research indicates that aquatic physiotherapy can be safely considered in this early postoperative phase.     

Physical Function in Hip Osteoarthritis: Relationship to Isometric Knee Extensor Steadiness

Pua Y-H, Clark RA, Bryant AL. Physical function in hip osteoarthritis: relationship to isometric knee extensor steadiness.

Objective

To evaluate, in a community hip osteoarthritis sample, the cross-sectional associations of isometric strength and steadiness of the knee extensors and their interaction with physical performance measures of physical function.

Design

Cross-sectional.

Setting

Human movement laboratory of a university.

Participants

Sixty-seven adults (27 men and 40 women; age, 61±10y) with radiographically confirmed symptomatic hip osteoarthritis.

Interventions

Not applicable.

Main Outcome Measures

Participants performed isometric knee extensor steadiness and strength testing on a dynamometer. Physical function was assessed by using the habitual timed walk test and the self- and fast-paced stair-climbing tests.

Results

In the hierarchical regression models, although there were clear main effects of knee extensor steadiness on fast-paced stair performance, greater knee steadiness predictively associated with faster stair-climbing performance particularly in individuals with high knee extensor strength. In contrast, knee extensor steadiness was not related to gait speed regardless of knee extensor strength levels.

Conclusions

In patients with hip OA, knee extensor steadiness was positively associated with stair-climbing performance, particularly in those with high levels of knee extensor strength. These findings are of importance in developing intervention strategies, but they call for further study.     

Metabolic and Mechanical Energy Costs of Reducing Vertical Center of Mass Movement During Gait

Gordon KE, Ferris DP, Kuo AD. Metabolic and mechanical energy costs of reducing vertical center of mass movement during gait.

Objectives

To test the hypothesis that reducing vertical center of mass (COM) displacement will lower the metabolic cost of human walking. To examine changes in joint work associated with increasing and decreasing vertical COM movement during gait.

Design

Randomized repeated measures.

Setting

Human Neuromechanics Laboratory, University of Michigan.

Participants

Able-bodied subjects (N=10).

Interventions

Subjects walked at 1.2m/s on a treadmill and overground. Subjects manipulated vertical COM displacement either by adjusting stride length or by using visual feedback to reduce COM movement.

Main Outcome Measures

We measured kinematic and kinetic data to calculate vertical and lateral COM displacements, joint torques, and work. In addition, we collected oxygen consumption to calculated metabolic power.

Results

Increasing and decreasing vertical COM displacement beyond subjects' preferred range resulted in increases in the metabolic cost of walking. When vertical COM displacement was reduced, corresponding increases in positive ankle and hip work and negative knee work were observed.

Conclusions

Humans are capable of walking in a manner that will reduce COM displacement from normal. Decreasing vertical COM movement results in increases in metabolic energy costs because of greater mechanical work performed at the hip, knee, and ankle joints. Thus, reducing vertical COM movement is not a successful strategy for improving either metabolic or mechanical energy economy during normal walking by able-bodied subjects.     

The Prevalence of Osteoarthritis of the Intact Hip and Knee Among Traumatic Leg Amputees

Struyf PA, van Heugten CM, Hitters MW, Smeets RJ. The prevalence of osteoarthritis of the intact hip and knee among traumatic leg amputees.

Objective

To determine the prevalence of osteoarthritis (OA) in the knee and/or hip of the intact leg among traumatic leg amputees compared with the general population and its relationship with amputation level, time since amputation, age, and mobility.

Design

Cross-sectional observational study.

Setting

Outpatient population of 2 Dutch rehabilitation centers.

Participants

Patients (N=78) with a unilateral traumatic transtibial amputation, knee disarticulation, or transfemoral amputation of at least 5 years ago; ability to walk with a prosthesis; older than 18 years of age; and able to understand Dutch. Patients were excluded if they had bilateral amputations, other pathologies of the knee or hip, or central neurologic pathologies.

Interventions

Not applicable.

Main Outcome Measure

The prevalence of OA.

Results

The prevalence of knee OA was 27% (men 28.3%, women 22.2%) and hip OA was 14% (men 15.3%, women 11.1%). This was higher compared with the general population (knee OA men 1.58%, women 1.33%, hip OA men 1.13%, women 0.98%, age adjusted). No significant relationships between the prevalence of OA and level of amputation, time since amputation, mobility, and age were found.

Conclusions

The prevalence of OA is significantly greater for both the knee and hip in the traumatic leg amputee population. No specific risk factors were identified. Although no specific risk factors in this specific population could be identified, it might be relevant to apply commonly known strategies to prevent OA as soon as possible after the amputation.     

The effect of exercise training in improving motor performance and corticomotor excitability in people with early Parkinson's disease

Fisher BE, Wu AD, Salem GJ, Song J, Lin C-H, Yip J, Cen S, Gordon J, Jakowec M, Petzinger G. The effect of exercise training in improving motor performance and corticomotor excitability in people with early Parkinson's disease.

Objectives

To obtain preliminary data on the effects of high-intensity exercise on functional performance in people with Parkinson's disease (PD) relative to exercise at low and no intensity and to determine whether improved performance is accompanied by alterations in corticomotor excitability as measured through transcranial magnetic stimulation (TMS).

Design

Cohort (prospective), randomized controlled trial.

Setting

University-based clinical and research facilities.

Participants

Thirty people with PD, within 3 years of diagnosis with Hoehn and Yahr stage 1 or 2.

Interventions

Subjects were randomized to high-intensity exercise using body weight-supported treadmill training, low-intensity exercise, or a zero-intensity education group. Subjects in the 2 exercise groups completed 24 exercise sessions over 8 weeks. Subjects in the zero-intensity group completed 6 education classes over 8 weeks.

Main Outcome Measures

Unified Parkinson's Disease Rating Scales (UPDRS), biomechanic analysis of self-selected and fast walking and sit-to-stand tasks; corticomotor excitability was assessed with cortical silent period (CSP) durations in response to single-pulse TMS.

Results

A small improvement in total and motor UPDRS was observed in all groups. High-intensity group subjects showed postexercise increases in gait speed, step and stride length, and hip and ankle joint excursion during self-selected and fast gait and improved weight distribution during sit-to-stand tasks. Improvements in gait and sit-to-stand measures were not consistently observed in low- and zero-intensity groups. The high-intensity group showed lengthening in CSP.

Conclusions

The findings suggest the dose-dependent benefits of exercise and that high-intensity exercise can normalize corticomotor excitability in early PD.     

Effects of an acute hamstring stretch in people with and without osteoarthritis of the knee

Objective

To compare the effects of an acute stretching intervention on knee extension range of motion, passive resistive torque and stiffness in subjects with osteoarthritis of the knee, and to compare these variables with subjects without osteoarthritis.

Design

Cross-sectional experimental study.

Setting

Human performance laboratory.

Participants

A total of 55 participants were recruited: 28 subjects (males and females) with osteoarthritis of the knee joint and 27 subjects of a similar age without osteoarthritis of the knee joint.

Intervention

Using the Kincom dynamometer, three 60-second stretches with 60 seconds of rest between stretches were applied to the hamstring muscle group.

Main outcome measures

Peak knee extension range of motion, peak passive torque and stiffness in the final 10% of knee extension range of motion.

Results

A significant (P < 0.05) increase in knee extension range of motion, peak passive torque and stiffness was observed in both groups. For knee extension range of motion, the mean difference for the osteoarthritis group and non-osteoarthritis group was 4.9 degrees [95% confidence interval (CI) 0.9 to 8.5] and 4.4 degrees (95% CI 1.8 to 6.8), respectively. For peak passive torque, the mean difference in the osteoarthritis group and the non-osteoarthritis group was 4.4 N m (95% CI 0.8 to 6.9) and 1.0 N m (95% CI −1.4 to 3.5), respectively. For stiffness in the final 10% of knee extension range of motion, the mean difference for the osteoarthritis group and the non-osteoarthritis group was 0.19 N m/degree (95% CI 0.08 to 0.3) and 0.04 N m/degree (95% CI −0.05 to 0.1), respectively. Stiffness in the final 10% of knee extension range of motion was significantly higher in the osteoarthritis group compared with the non-osteoarthritis group after stretching.

Conclusions

Elderly individuals with and without osteoarthritis of the knee are able to demonstrate immediate beneficial adaptations to a stretching intervention. This is important as stretching is often used in preparation for exercise programmes.     

The effects of hip and ankle stretching on gait function of older people

Christiansen CL. The effects of hip and ankle stretching on gait function of older people.

Objective

To examine effects of hip and ankle stretching on gait function of older people.

Design

Randomized controlled trial.

Setting

Flexibility training was performed in participants' homes. Assessments were performed in a biomechanics laboratory.

Participants

Forty healthy volunteers (mean age ± SD, 72.1±4.7y) randomized to 2 groups: intervention (n=20) and control (n=20).

Intervention

Intervention participants performed an 8-week stretching program, and control group participants maintained activity level for 8 weeks. One investigator made weekly visits to instruct and monitor participants.

Main Outcome Measures

Primary outcome measures were passive joint motion for hip extension and ankle dorsiflexion and freely chosen gait speed. Secondary outcome measures were gait parameters during freely chosen gait speed and set gait speed walking (stride length, joint displacement).

Results

Compared with the control group, the intervention group had increased combined hip and knee motion (P=.023), ankle motion (P=.020), and freely chosen gait speed (P=.016). The intervention group showed statistically nonsignificant trends of increased stride length at freely chosen gait speed and set gait speed.

Conclusions

Findings suggest joint motion is a modifiable impairment that is effectively targeted with flexibility training for older people. Participants in the intervention group had improvements in joint motion as well as increased freely chosen gait speed. Mechanisms responsible for changes in freely chosen gait speed warrant further investigation.     

The role of foot and ankle assessment of patients with lower limb osteoarthritis

Objectives

Physiotherapists do not routinely examine the feet of patients with lower limb osteoarthritis, and there is no widely used tool for measuring foot posture. However, differences in foot posture have been demonstrated between patients with medial compartment osteoarthritis of the knee and osteoarthritis of the hip, and guidelines for managing these patients include interventions such as orthotics which presume foot assessment. This study considers a new clinical tool, the Foot Posture Index (FPI). It examines its utility in a physiotherapy outpatient setting with a cohort of patients with medial compartment osteoarthritis of the knee and osteoarthritis of the hip, and investigates the relationship of FPI scores with the range of dorsiflexion of the ankle.

Design

Cross-sectional observational study.

Setting

A specialist orthopaedic hospital.

Participants

In total, there were 60 participants: 20 patients with medial compartment osteoarthritis of the knee, 20 patients with osteoarthritis of the hip, and a control group of 20 age-matched healthy volunteers.

Outcome measures

A single measurement of the FPI and range of dorsiflexion.

Results

Significant differences in FPI scores and range of dorsiflexion were seen between groups. On average, patients with osteoarthritis of the hip had more supinated, plantarflexed feet, and patients with medial compartment osteoarthritis of the knee had pronated feet. Healthy controls fell within the normal range. Patients with osteoarthritis of the hip had a median FPI score of −4.5, patients with medial compartment osteoarthritis of the knee had a median FPI score of 7.0, and the healthy controls had a median FPI score of 1.0. The median difference in FPI scores between patients with osteoarthritis of the hip and medial compartment osteoarthritis of the knee was 12 [95% confidence interval (CI) 10 to 13]; between patients with osteoarthritis of the hip and the healthy group was 6 (95% CI 3 to 9); and between patients with medial compartment osteoarthritis of the knee and the healthy group was 5 (95% CI 3 to 8). The median difference in dorsiflexion scores between patients with osteoarthritis of the hip and medial compartment osteoarthritis of the knee was 10 degrees (95% CI 8 to 15); between patients with osteoarthritis of the hip and the healthy group was 10 degrees (95% CI 7 to 15); and between patients with medial compartment osteoarthritis of the knee and the healthy group was 0 degrees (95% CI −3 to 5). Foot posture and range of dorsiflexion were moderately positively correlated (rho 0.57), with pronated feet having a greater range of dorsiflexion.

Conclusion

The FPI is sufficiently sensitive to measure differences in foot posture of patients with medial compartment osteoarthritis of the knee and osteoarthritis of the hip, and is easy to use. Accurate foot assessment is useful as foot postures may be influenced by specific physiotherapy treatment modalities and orthotic interventions.     

The effects of mode of exercise instruction on compliance with a home exercise program in older adults with osteoarthritis

Objectives

To explore whether compliance with a prescribed home exercise program in elderly people with knee and/or hip osteoarthritis was influenced by mode of exercise instruction.

Design

Participants were randomised to one of three groups who received different modes of exercise instruction. Exercise performance was assessed at baseline and after 4 weeks and 8 weeks of home exercises.

Setting

Eighteen physiotherapy clinics in rural Victoria, Australia.

Participants

One hundred and fifteen males and females (mean age 70.5 years) with osteoarthritis of the knees and/or hips.

Interventions

Participants were randomised to receive verbal instructions on a home exercise program in addition to: (i) a home exercise brochure; (ii) a brochure together with an audiotape; or (iii) a brochure together with a videotape.

Main outcome measures

The Correctness of Exercise Performance scale and exercise log-sheets.

Results

Compliance with the home exercise program was good for all modes of exercise instruction where between 79% and 91% of exercises were performed correctly. Once provided with verbal instructions together with illustrated brochures, the provision of additional videotapes or audiotapes did not further enhance outcome.

Conclusions

Older people with osteoarthritis who received face-to-face instructions and a brochure on how to perform and comply with an 8-week home exercise program did not show additional benefits from other modes of instruction.

Key messages

•

Brochures can be as effective as additional audiotapes or videotapes to enhance correctness of exercise performance in older people with osteoarthritis of the knees and/or hips when given together with verbal instructions.

•

Audiotapes and videotapes may provide additional cues to maintain correctness of performance of exercises that are difficult to perform.

     

Rehabilitation Consumers' Use and Understanding of Quality Information: A Health Literacy Perspective

Magasi S, Durkin E, Wolf MS, Deutsch A. Rehabilitation consumers' use and understanding of quality information: a health literacy perspective.

Objectives

To explore consumers' use and understanding of quality information about postacute rehabilitation facilities.

Design

Thematic, semistructured interviews.

Setting

Two skilled nursing facilities and 2 inpatient rehabilitation facilities in a large Midwestern city.

Participants

Rehabilitation inpatients (n=17) with stroke, hip fractures, and joint replacements and care partners (n=12) of rehabilitation inpatients.

Intervention

None.

Main Outcome Measure

None.

Results

Health literacy imposed barriers to participants' understanding of quality information. Using the Institute of Medicine's Health Literacy Framework, we identified specific barriers that limited participants' abilities to (1) obtain quality information, (2) process and understand quality information, and (3) make appropriate decisions about the quality of a rehabilitation facility. Participants tended to rely on informal and nonquality information when choosing a rehabilitation facility.

Conclusions

Given the barriers imposed by low health literacy, rehabilitation providers have a responsibility to present quality information in a way that consumers, especially those with low health literacy, can use and understand.     

Modulation between high- and low-frequency transcutaneous electric nerve stimulation delays the development of analgesic tolerance in arthritic rats

DeSantana JM, Santana-Filho VJ, Sluka KA. Modulation between high- and low-frequency transcutaneous electric nerve stimulation delays the development of analgesic tolerance in arthritic rats.

Objective

To investigate whether repeated administration of modulating frequency transcutaneous electric nerve stimulation (TENS) prevents development of analgesic tolerance.

Design

Knee joint inflammation (3% carrageenan and kaolin) was induced in rats. Either mixed or alternating frequency was administered daily (20min) for 2 weeks to the inflamed knee under light halothane anesthesia (1%-2%).

Setting

Laboratory.

Animals

Adult male Sprague-Dawley rats (N=36).

Intervention

Mixed- (4Hz and 100Hz) or alternating- (4Hz on 1 day; 100Hz on the next day) frequency TENS at sensory intensity and 100μs pulse duration.

Main Outcome Measures

Paw and joint withdrawal thresholds to mechanical stimuli were assessed before induction of inflammation, and before and after daily application of TENS.

Results

The reduced paw and joint withdrawal thresholds that occur 24 hours after the induction of inflammation were significantly reversed by the first administration of TENS when compared with sham treatment or to the condition before TENS treatment, which was observed through day 9. By the tenth day, repeated daily administration of either mixed- or alternating-frequency TENS did not reverse the decreased paw and joint withdrawal thresholds.

Conclusions

These data suggest that repeated administration of modulating frequency TENS leads to a development of opioid tolerance. However, this tolerance effect is delayed by approximately 5 days compared with administration of low- or high-frequency TENS independently. Clinically, we can infer that a treatment schedule of repeated daily TENS administration will result in a tolerance effect. Moreover, modulating low and high frequency TENS seems to produce a better analgesic effect and tolerance is slower to develop.     

Physiotherapy management of minimally invasive Oxford medial compartment knee arthroplasty: an observational study of 100 patients following an accelerated treatment protocol

Objectives

To describe an accelerated protocol for early discharge of patients undergoing Oxford medial unicompartmental knee arthroplasty using a minimally invasive approach.

Design

Prospective observational study.

Setting

Specialist orthopaedic National Health Service hospital.

Participants

One hundred consecutive patients (40 female, 60 male) undergoing Oxford medial unicompartmental knee arthroplasty with an average age of 64 (range 44-80) years.

Outcome measures

Oxford knee score, American Knee Society score (objective and functional) and the ability to perform functional tasks were recorded pre-operatively and 6 weeks and 1 year postoperatively. Success was taken as an improvement in these scores or as an increased ability to perform functional tasks.

Results

Satisfactory results were attained after accelerated discharge, with the mean objective American Knee Society score increasing from 41/100 (95% confidence interval 38.0-44.5) pre-operatively to 87/100 (95% confidence interval 83.1-90.3) at 1 year, and the Oxford knee score increasing from 24/48 (95% confidence interval 21.9-25.2) to 41/48 (95% confidence interval 39.6-42.8) over the same period. All monitored functional activities improved. The mean values before surgery and 6 weeks and 1 year after surgery are presented.

Conclusion

Outcome following minimally invasive Oxford medial unicompartmental knee replacement is not compromised with the use of an accelerated treatment protocol.     

Effects of resistance training on lower-extremity impairments in older people with hip fracture

Portegijs E, Kallinen M, Rantanen T, Heinonen A, Sihvonen S, Alen M, Kiviranta I, Sipilä S. Effects of resistance training on lower-extremity impairments in older people with hip fracture.

Objective

To study the effects of resistance training on muscle strength parameters, mobility, and balance.

Design

Randomized controlled trial.

Setting

Research laboratory and senior gym.

Participants

Population-based sample of eligible 60- to 85-year-old community-dwelling men and women 0.5 to 7.0 years after hip fracture. Forty-six people had no contraindications and were willing to participate in the exercise trial.

Intervention

Twelve-week intensive progressive strength-power training (n=24), aiming to reduce asymmetric deficit in leg muscle strength and power, or no intervention (n=22).

Main Outcome Measures

Isometric knee extension torque (KET) and leg extension power (LEP) measured in the weaker and stronger leg and the asymmetric deficit ([weak/sum both legs] × 100%), 10-m walking speed, dynamic balance test, and self-reported outdoor mobility.

Results

KET increased in both legs (P<.021), LEP tended to increase in the weaker leg (P=.071), and asymmetric LEP deficit decreased (P=.010) after training compared with the control group. LEP of the stronger leg, asymmetric KET deficit, walking speed, and balance performance were not significantly affected by training. Self-reported ability to walk outdoors improved after training. The compliance to the training was over 90%, and few adverse events (n=4; mainly musculoskeletal) were likely to be caused by the training.

Conclusions

Intensive resistance training is feasible for people with a hip fracture and improved muscle strength and power. More intensive training especially for the weaker leg may be needed to obtain more marked effects on asymmetric deficit, mobility, and balance. Also, the timing and duration of training program should be considered. (ISRCTN identifier ISRCTN34271567.)     

Gait Patterns After Total Hip Arthroplasty and Surface Replacement Arthroplasty

Nantel J, Termoz N, Vendittoli P-A, Lavigne M, Prince F. Gait patterns after total hip arthroplasty and surface replacement arthroplasty.

Objective

To compare gait patterns in patients with total hip arthroplasty (THA) and surface hip arthroplasty.

Design

Observational study.

Setting

Outpatient biomechanical laboratory.

Participants

Two groups of 10 surface hip arthroplasty and THA patients and 10 control subjects participated in the study (N=30). The patients were volunteers recruited from a larger randomized study.

Interventions

Not applicable.

Main Outcomes Measures

Gait patterns, hip abductor muscle strength, clinical outcomes, and radiographic analyses were compared between groups.

Results

In the sagittal plane, the THA group showed a larger flexor moment and larger mechanical work in H2S and K3S power bursts compared with surface hip arthroplasty and control subjects. In the frontal plane, both THA and surface hip arthroplasty patients had smaller hip abductor muscles energy generation (H3F) than the control group. No difference was found for the hip abductor muscles strength.

Conclusions

In the THA group, the larger energy absorption in H2S and K3S would be a cost-effective mechanical adaptation to increase stability. The surface hip arthroplasty characteristics could allow the return to a more normative gait pattern compared with THA. The modification in the frontal plane in surface hip arthroplasty and THA would be related to the hip abductor muscles strength.     

A method to measure the accuracy of loads in knee-ankle-foot orthoses using conventional gait analysis, applied to persons with poliomyelitis

Andrysek J, Redekop S, Matsui NC, Kooy J, Hubbard S. A method to measure the accuracy of loads in knee-ankle-foot orthoses using conventional gait analysis, applied to persons with poliomyelitis.

Objectives

To determine (1) the forces and moments passing through knee-ankle-foot orthoses (KAFOs) during walking and (2) the accuracy with which these loads can be measured using conventional gait analysis techniques.

Design

Comparative case series.

Setting

Rehabilitation facility with human movement laboratory (gait lab).

Participants

Four patients with poliomyelitis wearing KAFOs.

Interventions

KAFOs were instrumented with a load cell, and walking data were concurrently collected using conventional gait analysis.

Main Outcome Measures

Load measurements and gait parameters.

Results

Predominant orthotic loads (knee joint forces and moments) were composed of knee flexion moments and axial compression forces. With conventional gait analysis, peak knee joint moments were substantially underestimated compared with those directly measured using the load cell. Defining the knee axis anatomically versus at the orthotic axis, tracking it dynamically, and compensating for each patient's corrected knee flexion contracture resulted in considerable improvements in the gait lab estimates of knee joint moments.

Conclusions

A practical method that directly measures moments and forces in conventional KAFOs has been applied to show that conventional gait analysis techniques substantially underestimate knee joint moments in the KAFOs of persons with poliomyelitis. Underestimation of orthotic loads could result in underdesigned orthotic components and ultimately higher incidence of component failure in clinical applications.     

Obesity influences transitional states of disability in older adults with knee pain

Rejeski WJ, Ip EH, Marsh AP, Zhang Q, Miller ME. Obesity influences transitional states of disability in older adults with knee pain.

Objectives

This study employed relatively new statistical methods to understand how many states are needed to describe disability in older adults with knee pain, describe the relative probability of transitioning between states over time, and examine whether obesity influences the probability of transitioning between states.

Design

Prospective epidemiologic study of older adults with knee pain.

Setting

Community.

Participants

The participants, 245 women and 235 men, were 65 years or older, had chronic knee pain on most days, and had difficulty with at least 1 mobility-related activity caused by knee pain.

Interventions

Not applicable.

Main Outcome Measure

The primary instrument, the Pepper Assessment Tool for Disability, evaluated self-reported difficulty with mobility, basic activities of daily living (ADLs), and instrumental activities of daily living (IADLs).

Results

The Hidden Markov Model yielded 6 states reflecting changes in mobility, ADLs, and IADLs. There is evidence that loss in more demanding mobility-related activities such as stair climbing is an early sign for the onset of disability and that functional deficits in the lower extremities are critical to the early loss of ADLs. Overall the trend is for older adults to experience greater progression than regression and for obesity to be important in understanding severe states of disability.

Conclusions

These data provide a strong rationale for characterizing disability on a continuum and underscore the fluid nature of disability in older adults. As expected, lower-extremity function plays a key role in the disablement process; obesity is also particularly relevant to understanding severe states of disability.     

Diagnostic Value of History Taking and Physical Examination to Assess Effusion of the Knee in Traumatic Knee Patients in General Practice

Kastelein M, Luijsterburg PA, Wagemakers HP, Bansraj SC, Berger MY, Koes BW, Bierma-Zeinstra SM. Diagnostic value of history taking and physical examination to assess effusion of the knee in traumatic knee patients in general practice.

Objective

To assess the diagnostic value of history taking and physical examination for knee joint effusion in patients with a knee injury who consult their general practitioner (GP). In addition, to determine the association between effusion seen on magnetic resonance imaging (MRI) and internal derangement of the knee.

Design

Prospective, observational cohort study.

Setting

Primary care.

Participants

Patients (N=134) aged 18 to 65 years with a traumatic knee injury who consulted their GP.

Interventions

Not applicable.

Main Outcome Measures

Patients filled out a questionnaire, underwent a standardized physical examination and underwent an MRI scan to assess the presence of effusion. Multivariate logistic regression analysis was used to determine the diagnostic value of history taking and physical examination (P<0.10) as assessed by sensitivity, specificity, predictive values, and likelihood ratios. The relationship between effusion and internal derangement of the knee was assessed with a chi-square test.

Results

Of the 134 participating patients, 42 had knee joint effusion seen on MRI. Multivariate analysis showed an association with knee joint effusion for the symptom “self-noticed swelling” (history taking) and for the “ballottement test” (physical examination). The likelihood ratio positive (LR+) was 1.5 for self-noticed swelling and 1.6 for the ballottement test. These 2 combined improved the diagnostic value to an LR+ of 3.6. Effusion showed a positive association with internal derangement of the knee (chi-square 9.5); 31 of the 42 patients with knee joint effusion had internal derangement of the knee.

Conclusions

In patients with traumatic knee injury, knee joint effusion is frequently seen on MRI. The combination of self-noticed swelling and the ballottement test was of diagnostic value. Knee joint effusion was associated with internal derangement of the knee.     

Muscle strength and flexibility characteristics of people displaying excessive medial knee displacement

Bell DR, Padua DA, Clark MA. Muscle strength and flexibility characteristics of people displaying excessive medial knee displacement.

Objective

To determine differences in strength and range of motion (ROM) between participants who exhibit medial knee displacement (MKD) during a squat that is corrected by a heel lift and those who do not.

Design

Case control.

Setting

Sports medicine research laboratory.

Participants

Thirty-seven healthy subjects (control, 19; MKD, 18) with no lower-extremity injury in the past 6 months volunteered to participate.

Interventions

Not applicable.

Main Outcome Measures

Peak force was measured in newtons using a hand-held dynamometer and passive ROM was measured in degrees with a goniometer. Separate multivariate analyses of variance were used to determine differences in strength and ROM between groups. Post hoc testing was used to elucidate differences between groups.

Results

The MKD group had the following: greater hip external rotation strength (P=.03), increased hip extension strength (P=.01), less plantarflexion strength (P=.007), and increased hip external rotation ROM (P=.008).

Conclusions

The MKD group exhibited tight and weak ankle musculature. Interventions focusing on improving strength and ROM of the ankle may improve kinematics during a squat.