A microprocessor stance and swing control orthosis improves balance, risk of falling, mobility, function, and quality of life of individuals dependent on a knee-ankle-foot orthosis for ambulation.

INTRODUCTION: The C-Brace microprocessor stance and swing control orthosis was designed to overcome safety and functional limitations of traditional knee-ankle-foot orthoses (KAFOs) for individuals with lower limb paresis. However, a systematic comparison to established KAFO types has not been performed in a bigger sample. METHODS: International multicenter, randomized, controlled, cross-over clinical trial. Legacy KAFO users at risk of falling were randomized to KAFO/C-Brace or C-Brace/KAFO use for three months with each orthosis. Primary outcome was balance assessed with the Berg Balance Scale (BBS). Secondary outcomes were falls, mobility, function, and quality of life. RESULTS: Intention-to-treat analysis with 102 participants. With the C-Brace, the BBS improved by 3.3 ± 6.3 points (p < 0.0001). Significantly fewer participants presented BBS scores <40 indicative of increased fall risk (16 vs. 36, p = 0.018). Mean falls reduced from 4.0 ± 16.8 to 1.1 ± 3.3 (p = 0.002). Outcomes for function, mobility, and quality of life showed significant improvements with the C-Brace. DISCUSSION: The improvements in fall risk and mobility can be attributed to the stumble recovery and controlled knee flexion during weight bearing of the C-Brace and have a positive impact on the quality of life of users. CONCLUSION: The C-Brace represents an option for KAFO users with increased fall risk and reduced mobility.

When prescribing traditional knee-ankle-foot orthoses (KAFOs), their known limitations, such as limited function and mobility, and the requirement to walk with compensatory mechanisms, especially on non-level terrains, should be considered.For patients with compromised balance and increased risk of falling when using a traditional KAFO, a microprocessor stance and swing control orthosis (MP-SSCO) may be considered as an orthotic option to reduce their fall risk.For patients with mobility restrictions using a traditional KAFO, a MP-SSCO may be considered to improve function, mobility, reintegration into normal living, and quality of life.

Mechanisms of limb collapse following a slip among young and older adults.

Recovery from a large perturbation, such as a slip, can be successful when stability of movement can be reestablished with protective stepping. Nevertheless, one dilemma for executing a protective step is that its liftoff can weaken support against limb collapse. This study investigated whether failures in limb support leading to falls after a protective step result from insufficient joint moment generation, and whether such insufficiency is greater among older fallers. A novel, unexpected slip was induced immediately following seat-off during a sit-to-stand. Joint work and mechanical energy were calculated for 43 young (9 falls, 34 recoveries) and 22 older (13 falls, 9 recoveries) adults who responded with a protective step. Comparisons of the work produced at three joints of the bilateral lower limbs revealed that insufficient concentric knee and hip extensor work prior to step liftoff was a primary differentiating factor between falling and recovery, regardless of age. Also, during stepping, fallers regardless of age failed to limit the eccentric knee extensor work at their stance limb sufficiently to retard rapid knee flexion and the consequent potential energy loss. We concluded that young and older fallers had comparable weak limb support. The greater fall incidence among the older adults likely resulted from a greater proportion of subjects who responded to the slip with insufficient knee extensor support, possibly attributable to age-differences in chair-rising. One strategy to address this dilemma may rely on task-specific training to enhance feedforward control that improves movement stability, and thus lessens the reliance on protective stepping.

Changes in the long head of the biceps tendon in rotator cuff tear shoulders.

BACKGROUND: Morphologic changes in the long head of the biceps tendon have been described in association with rotator cuff disease, yet mechanical significance of these changes remains unclear. METHODS: An experiment was designed to test the hypotheses that the cross-sectional area and material properties of the long head of the biceps tendon are different in shoulders with full thickness rotator cuff tears and shoulders with intact rotator cuff tendons. Seven pairs of cadaver shoulders were tested. In each pair one shoulder had a full thickness rotator cuff tear and the other did not. Thus, a matched design was used. Cross sectional areas were measured. Tendon material properties were measured using an optical strain system. FINDINGS: We were unable to detect a statistically significant difference in the long head of the biceps area or material properties between tendons in shoulders with and without rotator cuff tears. An a priori power analysis was conducted indicating the sample size was sufficient to detect a difference of 70 MPa in the elastic modulus measurement. INTERPRETATION: Our data indicate there is no difference in the long head of the biceps cross sectional area or material properties. Therefore, the long head of the biceps tendon appears to retain its material properties in the presence of a rotator cuff tear. The clinical significance of this finding is that the long head of the biceps can be retained in the presence of a rotator cuff tear without concern that mechanical properties have substantially deteriorated.

Does knee osteoarthritis alter the neuromuscular responses to a perturbation during single lower limb stance?

PURPOSE: Evidence substantiating an association between knee osteoarthritis (OA) and altered joint protection responses is relevant to the management of knee OA. The purpose of this study was to detect neuromuscular response times of the vastus lateralis and biceps femoris muscles following a perturbation during single lower limb stance. We hypothesized that muscle response times are: (1) delayed in older adults with knee OA when compared to young and older adults (without diagnosed knee OA) and (2) dependent on the magnitude of load released. SUBJECTS: Ten young adults, 10 older adults, and 7 older adults with symptomatic knee OA participated. METHODS: While in single lower limb stance, the subjects flexed the knee into a range of 33 to 37 degrees while a posterior load of either 6 or 9 kg was applied at the proximal tibia. The load was released after the subjects held the required position for 1 full second. Muscle response times were measured by electromyography. Separate 3 (group) by 2 (load) mixed factorial analysis of variance procedures were performed for electromyography data from the vastus lateralis and biceps femoris. RESULTS: There was no difference in vastus lateralis response times between older adults with knee OA and older adults or between older adults with knee OA and young adults. Older adults did have longer vastus lateralis response times than young adults. There was no difference in biceps femoris response times between older adults with knee OA and older adults; however, both groups had longer biceps femoris response times than young adults. Furthermore, there were no differences in either vastus lateralis or biceps femoris response times between 6 kg and 9 kg loads. CONCLUSION: Although knee OA did not alter muscle responses in our study, the type of functional weightbearing perturbation described could be safely used in the physical therapy clinic to help improve balance and stability while decreasing discomfort in older adults with symptomatic knee OA.

The effects of two different ankle-foot orthoses on gait of patients with acute hemiparetic cerebrovascular accident.

Objective. To compare the effects of two types of ankle-foot orthoses on gait of patients with cerebrovascular accident (CVA) and to evaluate their preference in using each AFO type. Design. Thirty individuals with acute hemiparetic CVA were tested without an AFO, with an off-the-shelf carbon AFO (C-AFO), and with a custom plastic AFO (P-AFO) in random order at the time of initial orthotic fitting. Gait velocity, cadence, stride length, and step length were collected using an electronic walkway and the subjects were surveyed about their perceptions of each device. Results. Subjects walked significantly faster, with a higher cadence, longer stride, and step lengths, when using either the P-AFO or the C-AFO as compared to no AFO (P < 0.05). No significant difference was observed between gait parameters of the two AFOs. However, the subjects demonstrated a statistically significant preference of using P-AFO in relation to their balance, confidence, and sense of safety during ambulation (P < 0.05). Moreover, if they had a choice, 50.87 ± 14.7% of the participants preferred the P-AFO and 23.56 ± 9.70% preferred the C-AFO. Conclusions. AFO use significantly improved gait in patients with acute CVA. The majority of users preferred the P-AFO over the Cf-AFO especially when asked about balance and sense of safety.

Gait assessment during the initial fitting of an ankle foot orthosis in individuals with stroke.

PURPOSE: To evaluate if the measurement of gait parameters, examined during the fitting of an Ankle Foot Orthosis (AFO), has a beneficial effect on the gait pattern of individuals who were affected by a stroke. Also, this study seeks to provide evidence regarding the use of the portable GaitRite system in a clinical setting. METHOD: Before-after trial conducted at a stroke outpatient orthotic clinic of a freestanding rehabilitation hospital. Thirteen individuals with acute and 27 individuals with chronic stroke participated in the assessment of gait velocity, cadence, step length and stance phase. RESULTS: AFO use significantly improves gait velocity, cadence, step, and stride length in individuals with hemiparesis due to stroke. CONCLUSION: The results of the current study indicate that the assessment of temporo-spatial characteristics of gait can be incorporated into a clinical routine. This will be useful for patient education, justification of medical necessity of paying, monitoring progress, and in the decision-making process of weaning patients off orthoses.

Quantitative morphology of full thickness rotator cuff tears.

The occurrence of full thickness rotator cuff tears (RCTs) at time of death, the size and distribution of those tears among the tendons of the rotator cuff, and the anterior to posterior and medial to lateral dimensions of the RCTs were determined. A subset of 57 shoulders from a group of 414 were found to have full thickness rotator cuff tears. The three-dimensional coordinates of specific bony landmarks and points defining the circumference of the RCT were digitized using a Flock of Birds DC electromagnetic tracking device. Bony landmarks were used to determine the separation between adjacent tendons of the rotator cuff. Points describing the circumference of the RCT were used to calculate the area of the tear. The majority of tears occurred in the supraspinatus tendon alone (25), or in both the supraspinatus and infraspinatus tendons (22). The areas of the RCTs ranged from 0.07 cm(2) to 19.17 cm(2) with an average of 4.43 cm(2). The mean anterior to posterior length was 1.95 cm. The mean medial to lateral length was 1.98 cm.

Glenoid inclination is associated with full-thickness rotator cuff tears.

Anatomic factors, such as a hooked acromion, have been associated with rotator cuff disorders. Orientation of the glenoid relative to the scapula has been implicated in shoulder instability, but it has not been linked to rotator cuff disorders. The purpose of the current study was to test the hypothesis that superior inclination of the glenoid is associated with full-thickness rotator cuff tears. Glenoid inclination angles were measured from 16 shoulder radiographs of a convenience sample of eight cadavers in which one shoulder had an intact rotator cuff and the other shoulder had a full-thickness rotator cuff tear. Glenoid inclination angles for shoulders with rotator cuff tears were compared with contralateral normal shoulders using nonparametric statistical analysis. The glenoid inclination angle was greater in cadaver shoulders having full-thickness rotator cuff tears (98.6 degrees ) than in shoulders without tears (91.0 degrees ). A second experiment was done to assess the reliability of using 34 Grashey view radiographs from a clinical population to measure glenoid inclination angle. A method to measure the glenoid inclination on Grashey views was tested and was found to correlate with the inclination angles measured on cadaveric scapulae. Intrarater reliability of measurements from clinical Grashey views was 0.93, and interrater reliability was at least 0.88.