skip to main content

This content will become publicly available on January 1, 2024

Title: Motion Analysis of Balance Pre and Post Sensorimotor Exercises to Enhance Elderly Mobility: A Case Study
Quantitative assessment of movement using motion capture provides insights on mobility which are not evident from clinical evaluation. Here, in older individuals that were healthy or had suffered a stroke, we aimed to investigate their balance in terms of changes in body kinematics and muscle activity. Our research question involved determining the effects on post- compared to pre-sensorimotor training exercises on maintaining or improving balance. Our research hypothesis was that training would improve the gait and balance by increasing joint angles and extensor muscle activities in lower extremities and spatiotemporal measures of stroke and elderly people. This manuscript describes a motion capture-based evaluation protocol to assess joint angles and spatiotemporal parameters (cadence, step length and walking speed), as well as major extensor and flexor muscle activities. We also conducted a case study on a healthy older participant (male, age, 65) and an older participant with chronic stroke (female, age, 55). Both participants performed a walking task along a path with a rectangular shape which included tandem walking forward, right side stepping, tandem walking backward, left side stepping to the starting location. For the stroke participant, the training improved the task completion time by 19 s. Her impaired left leg had more » improved step length (by 0.197 m) and cadence (by 10 steps/min) when walking forward, and cadence (by 12 steps/min) when walking backward. The non-impaired right leg improved cadence when walking forward (by 15 steps/min) and backward (by 27 steps/min). The joint range of motion (ROM) did not change in most cases. However, the ROM of the hip joint increased significantly by 5.8 degrees (p = 0.019) on the left leg side whereas the ROMs of hip joint and knee joint increased significantly by 4.1 degrees (p = 0.046) and 8.1 degrees (p = 0.007) on the right leg side during backward walking. For the healthy participant, the significant changes were only found in his right knee joint ROM having increased by 4.2 degrees (p = 0.031) and in his left ankle joint ROM having increased by 5.5 degrees (p = 0.006) during the left side stepping. « less
Authors:
; ;
Award ID(s):
1700219 1654474 1533479
Publication Date:
NSF-PAR ID:
10403997
Journal Name:
Applied Sciences
Volume:
13
Issue:
2
Page Range or eLocation-ID:
889
ISSN:
2076-3417
Sponsoring Org:
National Science Foundation
More Like this
  1. Abstract Background To compare the performance (as determined by lower extremity kinematics) of knee exercises in healthy middle-aged and older individuals immediately after instruction and one week later. Methods This is a cross-sectional study in a laboratory setting. Nineteen healthy volunteers (age [y] 63.1 ± 8.6, mass [kg] 76.3 ± 14.7, height [m] 1.7 ± 0.1) participated in this study. High speed video and reflective markers were used to track motion during four exercises. The exercises were knee flexion, straight leg raise, and “V “in supine position, and hip abduction in side lying position. All participants received verbal and tactile cues during the training phase and the therapist observed and, if necessary, corrected the exercises. Upon return a week later the participants performed the same exercises without any further instructions. Knee and hip sagittal and rotational angles were extracted from the motion capture. A repeated measures t-test was used to compare the motions between two visits. Results Participants demonstrated more knee flexion during straight leg raise and “V in” exercises at the 2nd visit compared to the 1st visit (both p  <  0.05). During the “V out” exercise, they performed more external rotation ( p  <  0.05) while they showed more internal rotation during the “V in” exercisemore »at the 2nd visit compared to the 1st visit. Conclusions Exercise performance declined significantly in healthy middle-aged and older individuals one week after instruction. This decline occurred despite an instructional exercise sheet being given to every participant. Other approaches designed to help individuals retain the ability to perform rehabilitative exercises correctly need to be explored.« less
  2. Many control methods have been proposed for powered prosthetic legs, ranging from finite state machines that switch between discrete phases of gait to unified controllers that have a continuous sense of phase. In particular, recent work has shown that a mechanical phase variable can parameterize the entire gait cycle for controlling a prosthetic leg during steady rhythmic locomotion. However, the unified approach does not provide voluntary control over non-rhythmic motions like stepping forward and back. In this paper we present a phasing algorithm that uses the amputee’s hip angle to control both rhythmic and non-rhythmic motion through two modes: 1) a piecewise (PW) function that provides users voluntary control over stance and swing in a piecewise manner, and 2) a unified function that continuously synchronizes the motion of the prosthetic leg with the amputee user at different walking speeds. The two phase variable approaches are compared in experiments with a powered knee-ankle prosthesis used by an above-knee amputee subject.
  3. Background:

    Thigh muscle weakness after anterior cruciate ligament reconstruction (ACLR) can persist after returning to activity. While resistance training can improve muscle function, “nonfunctional” training methods are not optimal for inducing transfer of benefits to activities such as walking. Here, we tested the feasibility of a novel functional resistance training (FRT) approach to restore strength and function in an individual with ACLR.

    Hypothesis:

    FRT would improve knee strength and function after ACLR.

    Study Design:

    Case report.

    Level of Evidence:

    Level 5.

    Methods:

    A 15-year-old male patient volunteered for an 8-week intervention where he performed 30 minutes of treadmill walking, 3 times per week, while wearing a custom-designed knee brace that provided resistance to the thigh muscles of his ACLR leg. Thigh strength, gait mechanics, and corticospinal and spinal excitability were assessed before and immediately after the 8-week intervention. Voluntary muscle activation was evaluated immediately after the intervention.

    Results:

    Knee extensor and flexor strength increased in the ACLR leg from pre- to posttraining (130 to 225 N·m [+74%] and 44 to 88 N·m [+99%], respectively) and increases in between-limb extensor and flexor strength symmetry (45% to 92% [+74%] and 47% to 72% [+65%], respectively) were also noted. After the intervention, voluntary muscle activation in the ACLR legmore »was 72%, compared with the non-ACLR leg at 75%. Knee angle and moment during late stance phase decreased (ie, improved) in the ACLR leg and appeared more similar to the non-ACLR leg after FRT training (18° to 14° [−23.4] and 0.07 to −0.02 N·m·kg−1·m−1[−122.8%], respectively). Corticospinal and spinal excitability in the ACLR leg decreased (3511 to 2511 [−28.5%] and 0.42 to 0.24 [−43.7%], respectively) from pre- to posttraining.

    Conclusion:

    A full 8 weeks of FRT that targeted both quadriceps and hamstring muscles lead to improvements in strength and gait, suggesting that FRT may constitute a promising and practical alternative to traditional methods of resistance training.

    Clinical Relevance:

    FRT may serve as a viable approach to improve knee strength and function after ACL reconstruction.

    « less
  4. Reaching movements performed from a crouched body posture require a shift of body weight from both arms to one arm. This situation has remained unexamined despite the analogous load requirements during step initiation and the many studies of reaching from a seated or standing posture. To determine whether the body weight shift involves anticipatory or exclusively reactive control, we obtained force plate records, hand kinematics, and arm muscle activity from 11 healthy right-handed participants. They performed reaching movements with their left and right arm in two speed contexts, “comfortable” and “as fast as possible,” and two postural contexts, a less stable knees-together posture and a more stable knees-apart posture. Weight-shifts involved anticipatory postural actions (APAs) by the reaching and stance arms that were opposing in the vertical axis and aligned in the side-to-side axis similar to APAs by the legs for step initiation. Weight-shift APAs were correlated in time and magnitude, present in both speed contexts, more vigorous with the knees placed together, and similar when reaching with the dominant and nondominant arm. The initial weight-shift was preceded by bursts of muscle activity in the shoulder and elbow extensors (posterior deltoid and triceps lateral) of the reach arm and shouldermore »flexor (pectoralis major) of the stance arm, which indicates their causal role; leg muscles may have indirectly contributed but were not recorded. The strong functional similarity of weight-shift APAs during crouched reaching to human stepping and cat reaching suggests that they are a core feature of posture-movement coordination. NEW & NOTEWORTHY This work demonstrates that reaching from a crouched posture is preceded by bimanual anticipatory postural adjustments (APAs) that shift the body weight to the stance limb. Weight-shift APAs are more robust in an unstable body posture (knees together) and involve the shoulder and elbow extensors of the reach arm and shoulder flexor of the stance arm. This pattern mirrors the forelimb coordination of cats reaching and humans initiating a step.« less
  5. Although there has been recent progress in control of multi-joint prosthetic legs for rhythmic tasks such as walking, control of these systems for non-rhythmic motions and general real-world maneuvers is still an open problem. In this article, we develop a new controller that is capable of both rhythmic (constant-speed) walking, transitions between speeds and/or tasks, and some common volitional leg motions. We introduce a new piecewise holonomic phase variable, which, through a finite state machine, forms the basis of our controller. The phase variable is constructed by measuring the thigh angle, and the transitions in the finite state machine are formulated through sensing foot contact along with attributes of a nominal reference gait trajectory. The controller was implemented on a powered knee-ankle prosthesis and tested with a transfemoral amputee subject, who successfully performed a wide range of rhythmic and non-rhythmic tasks, including slow and fast walking, quick start and stop, backward walking, walking over obstacles, and kicking a soccer ball. Use of the powered leg resulted in clinically significant reductions in amputee compensations for rhythmic tasks (including vaulting and hip circumduction) when compared to use of the take-home passive leg. In addition, considerable improvements were also observed in the performancemore »for non-rhythmic tasks. The proposed approach is expected to provide a better understanding of rhythmic and non-rhythmic motions in a unified framework, which in turn can lead to more reliable control of multi-joint prostheses for a wider range of real-world tasks.« less