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Kinetic alterations of the lower limb during stair locomotion in anterior cruciate ligament injured subjects
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Journal of Biomechanics 2006, Vol. 39 (Suppl 1)
tendon (BPTB) or with a portion of the semitendinosus and gracilis tendons (QSTG). The chosen technique will impact the extensor or flexor mechanisms respectively, thus affecting their force production capacity. The purpose of this investigation was to determine how surgical repair technique alters knee joint loading during isometric knee joint flexion-extension tasks since abnormal joint loading has been linked to degenerative joint disease. Methods: A custom built apparatus with a force transducer proximal to the ankle joint was used to estimate knee joint varus/valgus and flexor/extensor moments during isometric contraction at 50, 70, 90 degrees knee flexion. A biomechanical model of the knee including muscle and joint models was developed to estimate knee joint forces. The muscle model used surface and fine-wire electromyography signals of twelve knee joint flexors and extensors as inputs. Muscle model parameters were optimized to match the summed muscle moments with externally measured joint moments. The knee joint model adapted from Delp et al (2000) included subject specific anthropometric modifications and a modified patellofemoral joint to determine the forces transmitted via the patellar tendon to the tibia. Joint contact forces were estimated from the sum of the muscle force vectors with respect to the estimated contact points of the surface of the tibia. Results: Subjects undergoing the QSTG surgery produced higher anterior tibial shear force during knee flexion exercises at 90 and 70 degrees knee flexion while the BPTB subjects had lower compressive forces at 90 degrees flexion. Altered neuromuscular control during target matching tasks led to differential loading of the soft tissues around the joint. Conclusions: Choice of surgical technique affects knee joint forces and soft tissue loading due to altered neuromuscular control. The long term effects may have implications for rehabilitation and joint health. 7016 Mo-Tu, no. 13 (P61) Method for the recovery through kinetotherapy of the paralysis of the external scyatic popliteus nerve M. Chirazi. Faculty ef Physical Education and Sports, University AI I. Cuza,
lasi, Romania Actuality: At the first sight the paralysis of this nerve doesn't put problems in the static or in the dynamic of the patient, but, keeping the subject under observation a longer period of time, we shall realize that this infirmity will determine a handicap which is difficult to pass (socially, professionally and psychologically). Hypothesis: We suppose that the utilization of a special apparatus that allows the realization of the "autepassive movements" associated with the other methods of treatment in the recovery of the External Scyatic Popliteus Nerve will bring at the rehabilitation and the integration of patients in the socioprofessional activities in a short period of time. Methods of research: 1. the study of the specialty literature; 2. the experimental clinical study; 3. the method of observation; 4. statistical and mathematical. The practical study consisted in the evaluation (of the joint, of the muscle and anthropometric, initially and finally of the leg affected by paralysis or paresis; at the patients with paralysis that presented the atrophy of the antagonists muscles, it was effectuated an initial and a final test of the joint. After the initial evaluation, it continued with the application of the kinetotherapeutical programs, in function of patient, age, sex, functional deficit, and, after that, the final evaluation (after 4 weeks of kinetotherapeutical treatment). There were used 10 programs for recovery, in this way: - 3 programs during the period of hospitalization - 7 programs for recovery after this period. Conclusions: The paralysis of the External Scyatic Popliteus Nerve was more frequent in the male subjects (71.43%), in comparison with the female subjects (28.57%). Comparing the evolution of the functionally increment, considering the sex of the patient, it was concluded: 1. the males got a media of the functionally increment of 34.33% (from the initial 29.67% to the final 64%); 2. the females got a media of the functionally increment of 29.17% (from the initial 34.17% to the final 63.33%); 3. for the entire sample of patients, it was gotten a media of the functionally increment of 32.86% (from the initial 30.95% to the 63.81%). References Cordun M. (1999) Kinetologia medical&, Ed. Axa, Bucure~ti. Sbenghe T. (1999) Bazele teoretice ,~i practice ale Kinetoterapiei, Ed. Medical&, Bucure,~ti.
Poster Presentations 5495 Mo-Tu, no. 14 (P61) The effect of taping on the shock attenuation capacity of the heel pad in patients with plantar heel pain C.-L. Chen 1, S.-E Wang 2, C.-L. Wang 3, Y.-W. Shau 4, H. Chai 2. 1Department
of Rehabilitation Technology, Tzuhui Institute of Technology, Pingtung, Taiwan, 2School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University, Taipei, Taiwan, 3Department of Orthopedic Surgery, National Taiwan University Hospital, Taipei, Taiwan, 4Institute of Applied Mechanics, National Taiwan University, Taipei, Taiwan Decreased shock attenuation capacity of the heel pad has been documented as one of the predisposing factors of plantar heel pain. Heel pad taping is frequently used by the athletes to reduce or prevent plantar heel pain through confining the heel pad in a limited space and increasing its cushion effect. There is no scientific evidence, however, to explore this confinement effect in detail. The purpose of this study was to examine the differences in thickness, compression index (CI), and energy dissipation rate (EDR) of the heel pad under the taped and un-taped conditions. Ten patients with unilateral plantar heel pain participated in this study. Each participant performed a dynamic loading-unloading process to the heel pad by loading the whole body weight onto one foot and then releasing immediately. Both ultrasonographic images and loading force were collected synchronously to analyze changes in strain and stress of the heel pad over time. The 2 (taped vs. un-taped) 2 (affected vs. intact foot) mixed model ANOVA was used for statistical analysis. The results revealed that, adjusted for strain rate and BMI, heel pad thickness increased (p<0.0001) while CI and EDR decreased (p<0.005 and p<0.05, respectively) when the heel pad taping was applied, indicating the improvement in shock attenuation capacity of the heel pad. These differences were not significant between both feet (p >0.05). It is concluded that the confinement of heel pad taping would change the mechanical properties of the heel pad for patients with plantar heel pain, which provides a strong theoretical evidence for using heel pad taping. 5537 Mo-Tu, no. 15 (P61) Kinetic alterations of the lower limb during stair locomotion in anterior cruciate ligament injured subjects H.-C. Lin 1,2, T.-W. Lu 1, H.-C. Hsu 3. 1Institute of Biomedical Engineering,
National Taiwan University, Taipei, Taiwan, 2School of Physical Therapy, China Medical University, Taichung, Taiwan, 3Department of Orthopedics, China Medical University Hospital, Taichung, Taiwan Introduction: The anterior cruciate ligament (ACL) plays an important role in the normal function of the knee. To restore stability and function of the knee after ACL injury, surgical reconstruction is frequently considered. Stair locomotion, a frequent activity of daily living, places greater mechanical loading on the lower limb joints than during walking. This study aimed to investigate the possible kinetic changes among the lower limb joints during stair locomotion after ACL injury and reconstruction. Methods: Ten ACL-deficient (ACLD), ten ACL-reconstructed (ACLR) subjects and ten normal controls performed stair ascent and descent on a three-step stair in a gait laboratory while the kinematic and kinetic data were collected. Peak angular moments and impulses of the lower limb joints during the stance phase of the stair activities were calculated and compared between groups. Results: Compared to normal, the ACLD group had similar Ioadings at the affected knees while the ACLR group had reduced Ioadings during both stair activities. During stair ascent, both groups had increased extensor impulses at the affected hips. During stair descent, the ACLD subjects decreased abductor moments at the affected hips with increased extensor moments and impulses at the unaffected knees. The ACLR group reduced joint moments of the affected limbs with larger adductor moments at the unaffected knees. Compared to ACLD, the ACLR group showed a trend of decreased Ioadings at the affected knees with extensor moments and impulses reaching statistical significance during stair descent. Discussion and Conclusion: The ACLD group maintained a relatively normal loading at the affected knees through adaptations at the affected hip and unaffected hip and knee while the ACLR group significantly reduced the affected knee moments with kinetic compensations at the affected hips and unaffected knees. The reduced loading at the ACLR knees may be helpful for the protection of the ACL graft. Rehabilitation of the ACLR knees, including muscle strengthening, is required for better loading distribution among the joints and for better functional performance.
Journal of Biomechanics 2006, Vol. 39 (Suppl 1)
tendon (BPTB) or with a portion of the semitendinosus and gracilis tendons (QSTG). The chosen technique will impact the extensor or flexor mechanisms respectively, thus affecting their force production capacity. The purpose of this investigation was to determine how surgical repair technique alters knee joint loading during isometric knee joint flexion-extension tasks since abnormal joint loading has been linked to degenerative joint disease. Methods: A custom built apparatus with a force transducer proximal to the ankle joint was used to estimate knee joint varus/valgus and flexor/extensor moments during isometric contraction at 50, 70, 90 degrees knee flexion. A biomechanical model of the knee including muscle and joint models was developed to estimate knee joint forces. The muscle model used surface and fine-wire electromyography signals of twelve knee joint flexors and extensors as inputs. Muscle model parameters were optimized to match the summed muscle moments with externally measured joint moments. The knee joint model adapted from Delp et al (2000) included subject specific anthropometric modifications and a modified patellofemoral joint to determine the forces transmitted via the patellar tendon to the tibia. Joint contact forces were estimated from the sum of the muscle force vectors with respect to the estimated contact points of the surface of the tibia. Results: Subjects undergoing the QSTG surgery produced higher anterior tibial shear force during knee flexion exercises at 90 and 70 degrees knee flexion while the BPTB subjects had lower compressive forces at 90 degrees flexion. Altered neuromuscular control during target matching tasks led to differential loading of the soft tissues around the joint. Conclusions: Choice of surgical technique affects knee joint forces and soft tissue loading due to altered neuromuscular control. The long term effects may have implications for rehabilitation and joint health. 7016 Mo-Tu, no. 13 (P61) Method for the recovery through kinetotherapy of the paralysis of the external scyatic popliteus nerve M. Chirazi. Faculty ef Physical Education and Sports, University AI I. Cuza,
lasi, Romania Actuality: At the first sight the paralysis of this nerve doesn't put problems in the static or in the dynamic of the patient, but, keeping the subject under observation a longer period of time, we shall realize that this infirmity will determine a handicap which is difficult to pass (socially, professionally and psychologically). Hypothesis: We suppose that the utilization of a special apparatus that allows the realization of the "autepassive movements" associated with the other methods of treatment in the recovery of the External Scyatic Popliteus Nerve will bring at the rehabilitation and the integration of patients in the socioprofessional activities in a short period of time. Methods of research: 1. the study of the specialty literature; 2. the experimental clinical study; 3. the method of observation; 4. statistical and mathematical. The practical study consisted in the evaluation (of the joint, of the muscle and anthropometric, initially and finally of the leg affected by paralysis or paresis; at the patients with paralysis that presented the atrophy of the antagonists muscles, it was effectuated an initial and a final test of the joint. After the initial evaluation, it continued with the application of the kinetotherapeutical programs, in function of patient, age, sex, functional deficit, and, after that, the final evaluation (after 4 weeks of kinetotherapeutical treatment). There were used 10 programs for recovery, in this way: - 3 programs during the period of hospitalization - 7 programs for recovery after this period. Conclusions: The paralysis of the External Scyatic Popliteus Nerve was more frequent in the male subjects (71.43%), in comparison with the female subjects (28.57%). Comparing the evolution of the functionally increment, considering the sex of the patient, it was concluded: 1. the males got a media of the functionally increment of 34.33% (from the initial 29.67% to the final 64%); 2. the females got a media of the functionally increment of 29.17% (from the initial 34.17% to the final 63.33%); 3. for the entire sample of patients, it was gotten a media of the functionally increment of 32.86% (from the initial 30.95% to the 63.81%). References Cordun M. (1999) Kinetologia medical&, Ed. Axa, Bucure~ti. Sbenghe T. (1999) Bazele teoretice ,~i practice ale Kinetoterapiei, Ed. Medical&, Bucure,~ti.
Poster Presentations 5495 Mo-Tu, no. 14 (P61) The effect of taping on the shock attenuation capacity of the heel pad in patients with plantar heel pain C.-L. Chen 1, S.-E Wang 2, C.-L. Wang 3, Y.-W. Shau 4, H. Chai 2. 1Department
of Rehabilitation Technology, Tzuhui Institute of Technology, Pingtung, Taiwan, 2School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University, Taipei, Taiwan, 3Department of Orthopedic Surgery, National Taiwan University Hospital, Taipei, Taiwan, 4Institute of Applied Mechanics, National Taiwan University, Taipei, Taiwan Decreased shock attenuation capacity of the heel pad has been documented as one of the predisposing factors of plantar heel pain. Heel pad taping is frequently used by the athletes to reduce or prevent plantar heel pain through confining the heel pad in a limited space and increasing its cushion effect. There is no scientific evidence, however, to explore this confinement effect in detail. The purpose of this study was to examine the differences in thickness, compression index (CI), and energy dissipation rate (EDR) of the heel pad under the taped and un-taped conditions. Ten patients with unilateral plantar heel pain participated in this study. Each participant performed a dynamic loading-unloading process to the heel pad by loading the whole body weight onto one foot and then releasing immediately. Both ultrasonographic images and loading force were collected synchronously to analyze changes in strain and stress of the heel pad over time. The 2 (taped vs. un-taped) 2 (affected vs. intact foot) mixed model ANOVA was used for statistical analysis. The results revealed that, adjusted for strain rate and BMI, heel pad thickness increased (p<0.0001) while CI and EDR decreased (p<0.005 and p<0.05, respectively) when the heel pad taping was applied, indicating the improvement in shock attenuation capacity of the heel pad. These differences were not significant between both feet (p >0.05). It is concluded that the confinement of heel pad taping would change the mechanical properties of the heel pad for patients with plantar heel pain, which provides a strong theoretical evidence for using heel pad taping. 5537 Mo-Tu, no. 15 (P61) Kinetic alterations of the lower limb during stair locomotion in anterior cruciate ligament injured subjects H.-C. Lin 1,2, T.-W. Lu 1, H.-C. Hsu 3. 1Institute of Biomedical Engineering,
National Taiwan University, Taipei, Taiwan, 2School of Physical Therapy, China Medical University, Taichung, Taiwan, 3Department of Orthopedics, China Medical University Hospital, Taichung, Taiwan Introduction: The anterior cruciate ligament (ACL) plays an important role in the normal function of the knee. To restore stability and function of the knee after ACL injury, surgical reconstruction is frequently considered. Stair locomotion, a frequent activity of daily living, places greater mechanical loading on the lower limb joints than during walking. This study aimed to investigate the possible kinetic changes among the lower limb joints during stair locomotion after ACL injury and reconstruction. Methods: Ten ACL-deficient (ACLD), ten ACL-reconstructed (ACLR) subjects and ten normal controls performed stair ascent and descent on a three-step stair in a gait laboratory while the kinematic and kinetic data were collected. Peak angular moments and impulses of the lower limb joints during the stance phase of the stair activities were calculated and compared between groups. Results: Compared to normal, the ACLD group had similar Ioadings at the affected knees while the ACLR group had reduced Ioadings during both stair activities. During stair ascent, both groups had increased extensor impulses at the affected hips. During stair descent, the ACLD subjects decreased abductor moments at the affected hips with increased extensor moments and impulses at the unaffected knees. The ACLR group reduced joint moments of the affected limbs with larger adductor moments at the unaffected knees. Compared to ACLD, the ACLR group showed a trend of decreased Ioadings at the affected knees with extensor moments and impulses reaching statistical significance during stair descent. Discussion and Conclusion: The ACLD group maintained a relatively normal loading at the affected knees through adaptations at the affected hip and unaffected hip and knee while the ACLR group significantly reduced the affected knee moments with kinetic compensations at the affected hips and unaffected knees. The reduced loading at the ACLR knees may be helpful for the protection of the ACL graft. Rehabilitation of the ACLR knees, including muscle strengthening, is required for better loading distribution among the joints and for better functional performance.