Early postoperative functional differences between total knee arthroplasties supplied with mobile-bearing platform or fixed-bearing system--an analysis of gait pattern

AIM: The goal of this study was to analyze differences of gait patterns among patients with total knee arthroplasty supplied with mobile-bearing platform in contrast to patients supplied with fixed-bearing knee systems. METHOD: For that reason 17 patients with mobile-bearing knee systems and two groups of 15 patients each with fixed-bearing knee systems have been examined clinically, radiologically, and by means of gait analysis up to 6 months postoperatively. Additionally 20 knee-healthy control subjects have been gait-analyzed for comparison. RESULTS: There existed no different developments of gait characteristics between the groups of patients in the preoperative status. After the operation an increase of the ground reaction force of the operated leg was observed in all groups. The functional range of motion in the operated knee joint improved among patients postoperatively. Besides, in the group with the mobile-bearing knee a significantly stronger flection of the operated leg during the stance phase under load could be proven. Between the groups of patients the average values of the respective radiological alignments did not exhibit statistically significant differences. No severe complications have been observed. CONCLUSION: For the group of patients with fixed-bearing knee course samples have been registered, which approximate the reference values of healthy control subjects more strongly. The entire course sample is characterized by an increased range of motion of the opposite side and the adjacent joints. The parameters measurable in the gait analysis point to a better biomechanical situation after implantation of the mobile-bearing system.     

Significance of static prosthesis alignment for standing and walking of patients with lower limb amputation

The influence of three alignment parameters of a transtibial prosthesis (sagittal foot position, plantar flexion, mediolateral foot position) on the load and motion of the lower extremity joints was investigated in 13 unilateral transtibial amputees. The aim was to determine whether a correlation exists between static prosthetic alignment and gait pattern that would allow an optimal biomechanical prosthetic alignment. The gait pattern was measured using kinematic, kinetic, and electromyographic methods. Statics was defined using the alignment apparatus L.A.S.A.R. Posture. The electromyogram of the m. vastus lateralis and m. biceps femoris was recorded on both sides. The motion of joints is described by joint angles. External joint moments define the mechanical loads. Alignment has almost no influence on muscle activity and joint mechanics of the contralateral leg. In contrast, prosthetic alignment affects clearly and systematically the load and motion of the knee joint during the stance phase on the ipsilateral side. The sagittal foot position influences the maximal flexion angle in the stance phase. The plantar flexion of the foot affects the temporal structure of knee motion. The mediolateral foot position causes correspondingly different varus and valgus moments acting on the knee. Swing phase motion does not depend on prosthetic alignment. The iEMG of the m. vastus lateralis is reduced. Innervation characteristics of the m. biceps femoris on the prosthetically fitted leg has completely changed. The ischiocrural muscles take over the neuromuscular action of the m. gastrocnemius to compensate for the external knee extension moment during the second part of the stance phase. Prosthetic statics determines if the knee joint is physiologically stressed in a standing posture and during walking. Statics will be correct if the anatomical knee axis of the standing amputee is located about 15 mm posterior to the load line in the sagittal plane. In the frontal plane, the load line touches the lateral patella border and strikes the middle of the foot about 5 cm anterior to the adapter. During walking, attention should be paid to performance of knee flexion in the stance phase.     

Gait and function in patients with a femoral endoprosthesis after tumor resection: 18 patients evaluated 12 years after surgery

We performed gait analysis in 18 patients with a femoral endoprosthesis: 12 distal, 3 proximal and 3 total. Follow-up after surgery was mean 12 (0.6-19) years. The gait parameters measured were walking velocity, step length, duration of stance phase and swing phase. Goniometry of the hip, knee and ankle in both legs was determined during free-paced walking. The functional outcome score of the Musculoskeletal Tumor Society (MSTS) and the Ambulation score were also assessed in all patients. The mean free-paced walking velocity was 88% of normal. The step length of the uninvolved leg was longer than that of the involved one. The swing phase of the involved leg was longer than that of the uninvolved leg, and the stance phase of the involved leg was shorter than that of the uninvolved leg. Goniometry showed three abnormal patterns in the involved leg: a stiff knee gait in 10 patients, a flexed knee gait in 6, and an abnormal flexion-extension pattern in the hip in 9. Goniometry of the uninvolved leg was normal. The mean MSTS score was 22 points (72%). This showed a significant positive correlation to the Ambulation score, but no correlation to any of the temporal variables. Our findings indicate that the time of load on the involved leg, whether conscious or not, is reduced. Follow-up studies are needed to evaluate the effects of the asymmetrical gait pattern observed and the abnormal goniometric results on the development of endoprosthesis-related complications.     

Gait and function in patients with a femoral endoprosthesis after tumor resection

We performed gait analysis in 18 patients with a femoral endoprosthesis: 12 distal, 3 proximal and 3 total. Follow-up after surgery was mean 12 (0.6-19) years. The gait parameters measured were walking velocity, step length, duration of stance phase and swing phase. Goniometry of the hip, knee and ankle in both legs was determined during free-paced walking. The functional outcome score of the Musculoskeletal Tumor Society (MSTS) and the Ambulation score were also assessed in all patients.

The mean free-paced walking velocity was 88% of normal. The step length of the uninvolved leg was longer than that of the involved one. The swing phase of the involved leg was longer than that of the uninvolved leg, and the stance phase of the involved leg was shorter than that of the uninvolved leg. Goniometry showed three abnormal patterns in the involved leg: a stiff knee gait in 10 patients, a flexed knee gait in 6, and an abnormal flexion-extension pattern in the hip in 9. Goniometry of the uninvolved leg was normal. The mean MSTS score was 22 points (72%). This showed a significant positive correlation to the Ambulation score, but no correlation to any of the temporal variables.

Our findings indicate that the time of load on the involved leg, whether conscious or not, is reduced. Follow-up studies are needed to evaluate the effects of the asymmetrical gait pattern observed and the abnormal goniometric results on the development of endoprosthesis-related complications.     

Gait analysis after successful mobile bearing total ankle replacement

BACKGROUND: The effect of total ankle replacement on gait is not fully known in terms of joint kinematics, ground reaction force, and activity of the muscles of the lower leg. METHODS: A comparative gait study was done in 10 patients after uneventful unilateral mobile-bearing total ankle replacement and 10 healthy controls. A rigid body model was used to describe the motion of the knee and the three-dimensional motion of the ankle-hindfoot complex during barefoot walking. An opto-electronic motion analysis system was used to analyze bilateral movement patterns, synchronized with recordings of the ipsilateral vertical ground reaction forces and the electromyographic activity of four lower leg muscles. RESULTS: Velocity was 6% lower in the patient group. Dorsiflexion in the operated ankles was reduced (p < 0.001). No differences were found in the joint angular pattern of the knee joint and only minimal changes were found at the hindfoot-to-tibia and forefoot-to-hindfoot levels. The ground reaction force at midstance was somewhat increased (p = 0.005), while the magnitude of the vertical peak at terminal stance was decreased (p < 0.001). EMG activity patterns in the patient group were normal except for a higher activity of the gastrocnemius in early stance and the anterior tibial muscle in late stance. CONCLUSIONS: There is a near normal gait pattern in terms of joint kinematics of the knee, ankle, and foot after uneventful mobile-bearing total ankle replacement. The ground reaction forces and the EMG activity, however, do not fully normalize.     

Ipsilateral fracture dislocations of the hip and knee joints with contralateral open fracture of the leg: a rare case and its management principles

This paper discussed the injury mechanism and management of a patient who had concomitant ipsilateral hip and knee dislocations and contralateral open leg fracture.A 32-year-old man presented with ipsilateral fracture-dislocations of the left hip (Pipkin's type IV) and knee (Moore II) joints and contralateral open fracture of the leg bones after a car accident. After emergency resuscitative measures, the hip joint was reduced and Pipkin's fracture was fixed using Ganz approach with lag screws; knee joint was reduced closely and tibial plateau fracture was stabilized with lateral buttress plate and a transarticular spanning fixator. The open fracture on the other leg was de-brided and fixed with an external fixator. There was no instability in both joints after fixation when he was examined under anesthesia. The fractures united after 3 months and the patient had no residual instability of hip and knee. There was no clinical or radiological evidence of osteonecrosis in the hip joint after 6 months. At one-year follow-up, he had satisfactory functional outcome with almost normal range of motion at both joints.Ipsilateral hip and knee dislocations are rare injuries and more caution is needed for early diagnosis. A timely appropriate intervention can provide good functional outcome to the patient in this situation.     

Periprosthetic bone remodelling after total knee arthroplasty: early assessment by dual energy X-ray absorptiometry

The present investigation aims to evaluate periprosthetic bone remodelling after total knee arthroplasty by the use of dual-energy X-ray absorptiometry (DXA). Twelve patients affected by osteoarthrosis of the knee joint underwent primary total knee arthroplasty at an average age of 70.5 years. None of them had received a knee prosthesis before on the contralateral side. Anteroposterior and lateral DXA measurements of the femur, tibia and total knee (both sides) were taken 2 weeks, 3 and 9 months postoperatively. The 2-week measurement was used as an individual reference value to be compared with the 3- and 9-month findings. In addition, the contralateral knee was investigated also in order to estimate how far bone mineral loss was due to implantation or to an individual decline in bone mineral density (BMD). The comparison of BMD values after knee arthroplasty revealed a conspicuous decrease of bone density within 9 months. Bone mineral loss amounted to an average of 9.2% in anteroposterior and 17.8% in lateral DXA measurements. Lateral femur shots showed an average decrease of density of even 21.5%. In contrast, the BMD values of the contralateral knees remained almost unchanged. DXA, especially lateral shots of the femur, promises to be a suitable method for early assessment of periprosthetic bone remodelling after total knee arthroplasty. Received: 27 March 1998     

Allergic cobalt reaction (metallosis) following knee arthroplasty with vitallium endoprosthesis ad modum Walldius (author's transl)]

A case report is given on a woman with rheumatoid arthritis and deformed knee joints. She got a knee arthroplasty with a metal-to-metal Vitallium endoprosthesis ad modum Walldius. About one year after the arthroplasty she showed both a sterile fistulation from the knee joint and an eczema of the skin of the operated knee. An epicutaneous test for cobalt was positive. It is suggested that the metal-to-metal contact in the prosthesis and the proximity of the prosthesis to the skin is a possible explanation to the allergic reaction.     

Endoprosthetic procedures in rheumatoid patients

Rheumatoid diseases are generalized chronic inflammatory diseases of the musculoskeletal system. Although the different structures and different joints are affected, all cause a very uniform type of pathology and joint destruction. The main indication for implantation of the endoprosthesis are severe pain and walking disability with poor quality of life. On the X-ray involvement includes periarticular osteopenia, cystic changes, and destruction's affected joints. Endoprosthetic replacement has been successful in the treatment of severe rheumatoid disease of almost all joints of all ages, but predominantly replacement of the hip, knee, shoulder, elbow and MCP joints. Arthroplasty has proved to be an excellent addition to the therapeutic armamentarium for the rehabilitation of handicapped patients with rheumatoid disease. Advancements in endoprosthetic technology and surgical techniques, allow us to perform alloarthroplasty in most of the patients with severe rheumatoid disease of all different joints.     

The role of the contralateral limb in below-knee amputee gait

Very little quantitative biomechanical research has been carried out evaluating issues relevant to prosthetic management. The literature available suggests that amputees may demonstrate an asymmetrical gait pattern. Furthermore, studies suggest that the forces occurring during amputee gait may be unequally distributed between the contralateral and prosthetic lower limbs. This study investigates the role of the contralateral limb in amputee gait by determining lower limb joint reaction forces and symmetry of motion in an amputee and non-amputee population. Seven adult below-knee amputees and four non-amputees participated in the study. Testing involved collection of kinematic coordinate data employing a WATSMART video system and ground reaction force data using a Kistler force plate. The degree of lower limb symmetry was determined using bilateral angle-angle diagrams and a chain encoding technique. Ankle, knee and hip joint reaction forces were estimated in order to evaluate the forces acting across the joints of the amputee's contralateral limb. The amputees demonstrated a lesser degree of lower limb symmetry than the non-amputees. This asymmetrical movement was attributed to the inherent variability of the actions of the prosthetic lower limb. The forces acting across the joints of the contralateral limb were not significantly higher than that of the non-amputee. This suggests that, providing the adult amputee has a good prosthetic fit, there will not be increased forces across the joints of the contralateral limb and consequently no predisposition for the long-term wearer to develop premature degenerative arthritis.     

Selective thigh muscle atrophy in trans-tibial amputees: an ultrasonographic study

In trans-tibial amputees, PTB (patellar tendon bearing) prostheses provide almost physiological mobility of the knee joint in the sagittal plane. Nevertheless, there are characteristic adaptations of the knee joint muscles. Myosonography is a suitable method for depicting muscle atrophy and hypertrophy due to muscle dysfunction. The present study was intended to assess anatomical alterations of thigh muscles in trans-tibial amputees wearing a PTB prothesis. Thicknesses and cross-sectional areas of the quadriceps femoris, sartorius, gracilis, semitendinosus and biceps femoris muscles were determined ultrasonographically on both limbs in 17 amputees with a PTB prothesis. The gait was analysed using an optoelectronical system, force plates and surface electromyography of the vastus lateralis and biceps femoris muscles. Quadriceps femoris and sartorius muscles of the amputated extremity exhibited significant atrophy compared with the contralateral limb (reduction of muscle thickness ranged between 11.7% and 30.4%), whereas the gracilis and hamstring muscles were not significantly affected. Even the quadriceps femoris muscle of the non-amputated limb showed a slight atrophy compared with a reference group. Increased echointensities were found predominantly in the quadriceps muscle on the amputated leg. During gait, electromyographical activity within the amputated limb was reduced in the vastus lateralis and increased in the biceps femoris muscle. Even long-term adaptation to PTB prostheses results in characteristic deviation from normal gait. Atrophy occurs in the ventral thigh muscles, predominantly on the amputated leg, whereas the dorsal thigh muscles are hardly affected, probably due to compensatory hyperactivity. Received: 14 March 2000     

Gait Asymmetry Variation in Kinematics,Kinetics, and Muscle Force along with the Severity Levels of Knee Osteoarthritis

Objective

Knee osteoarthritis (OA) patients exhibit greater gait asymmetry than healthy controls. However, gait asymmetry in kinematics, kinetics and muscle forces across patients with different severity levels of knee OA is still unknown. The study aimed to investigate the changes of gait asymmetry in lower limb kinematics, kinetics, and muscle force across patients with different severity levels of knee OA.

Methods

This is a cross-sectional study. From January 2020 to January 2021, 118 patients with symptomatic and radiographic medial knee OA were categorized into three groups using the Kellgren and Lawrence scale (mild: grade 1 and 2, n = 37; moderate: grade 3, n = 31; severe: grade 4, n = 50). During self-paced walking, marker trajectories and ground reaction forces data were recorded. Musculoskeletal simulations were used to determine gait kinematics, kinetics, and muscle force. One-way analysis of variance with Tukey's post-hoc test was used to evaluate group difference. Paired-sample t-test was used to compared the between-limb difference.

Results

In the Severe group, significantly greater asymmetry index in knee flexion/extension range of motion (45%) was observed with a greater value on the contralateral side (p < 0.01), compared to the Mild (15%) and Moderate (15%) groups. Significantly higher peak hip contact force (JCF) on the contralateral side was found in the Mild (more affected side: 3.80 ± 0.67 BW, contralateral side: 4.01 ± 0.58 BW), Moderate (more affected side: 3.67 ± 0.56 BW, contralateral side: 4.07 ± 0.81 BW), and Severe groups (more affected side: 3.66 ± 0.79 BW, contralateral side: 3.94 ± 0.64 BW) (p < 0.05). Significantly greater gluteus medius muscle force on the contralateral side was found in Mild (more affected side: 0.48 ± 0.09 BW, contralateral side: 0.52 ± 0.12 BW), Moderate (more affected side: 0.45 ± 0.10 BW, contralateral side: 0.51 ± 0.15 BW), and Severe groups (more affected side: 0.42 ± 0.15 BW, contralateral side: 0.47 ± 0.12 BW) (p < 0.05). The contralateral side showing significantly higher peak knee adduction moment and medial knee JCF was only observed in the Mild group (p < 0.05).

Conclusions

Gait asymmetry in kinematics and muscle forces increased from mild to severe knee OA. Asymmetrical gait pattern tends to transfer loads from the more affected side to the contralateral side. Peak hip JCF and gluteus medius muscle force can be used to detect this asymmetrical gait pattern in patients with knee OA, regardless of severity levels.     

Experimental Osteoarthritis in the Rabbit: A Study of 133Xenon Washout Rates from the Synovial Cavity

Synovial perfusion in 6 rabbit knees, with experimentally induced osteoarthritis (joint instability), was studied by recording the initial ¹³³Xe washout rates from the joint space. The Unstable, osteoarthritic knee was compared with the contralateral sham operated control knee at intervals of 6 to 96 weeks postoperatively. Within the first half year the ratio between the ¹³³Xe washout rates in the osteoarthritic and control joints was significantly increased. These findings were supported by the increased blood flow to the joint region, visualized by scintigraphy of osteoarthritic rabbits given ^99mTc-microspheres intracardially. However, methodological sources of error do not allow any conclusions regarding the much less increased ¹³³Xe washout rates found in advanced osteoarthritis.

The initially increased synovial blood flow coincided with the existence of joint effusion and the early development of osteophytes, all conditions supposed to be a consequence of posttraumatic synovitis. Attention is drawn to these pathogenic phenomena in studies dealing with the initial changes in experimental models of osteoarthritis and to a possible etiological significance.     

Rotational instability of the patella on radiographic images

In the period from 1980 to 1981, knee joint radiographs were made in 82 patients following the clinical diagnosis of patellar chondropathy. A total of 119 knee joints with patellar chondropathy and 45 with no specific complaints on the contralateral side, in addition to a control cohort consisting of 28 persons, i.e., 56 knee joints with no complaints, were evaluated. Tangential radiographic images of the patellae enabled us to measure directly the rotation of the patella around the axis perpendicular to its center. It could be established that all healthy patellae underwent medial rotation between 45 and 60 degrees of knee flexion which was maintained up to 90 degrees, whereas the affected knee joints did not rotate.     

Rotational instability of the patella on radiographic images

Summary In the period from 1980 to 1981, knee joint radiographs were made in 82 patients following the clinical diagnosis of patellar chondropathy. A total of 119 knee joints with patellar chondropathy and 45 with no specific complaints on the contralateral side, in addition to a control cohort consisting of 28 persons, i.e., 56 knee joints with no complaints, were evaluated. Tangential radiographic images of the patellae enabled us to measure directly the rotation of the patella around the axis perpendicular to its center. It could be established that all healthy patellae underwent medial rotation between 45 and 60 degrees of knee flexion which was maintained up to 90 degrees, whereas the affected knee joints did not rotate.     

Joint preserving procedures and endoprostheses in hemophiliacs – indications and long term results

Hemophilic arthropathy is the result of recurrent joint bleedings in patients with severe haemophilia A or B and von Willebrand Syndrome. Conservative orthopaedic treatment is preferred in every stage of the arthropathy. Synovectomy is indicated only after failure of the conservative regimen after 3 to 6 months in order to control synovitis and recurrent bleeding. This paper presents the indications, methods, and results of different joint preserving operations. Especially synovectomy of the elbow joint with or without radial head resection shows very good long term results. Radiosynoviorthesis is an alternative in certain cases. The end stages of hemophilic arthropathy are characterised by pronounced joint contractures. We achieved very good long term results by implanting total hip joints (n = 13) and total knee joints (n = 20) with a median follow up of 102 respectively 53 months. No perioperative complications like bleeding or infection were registrated. Only one aseptic loosening of a cemented cup occurred 14 years postoperatively as well as one septic loosening 14 months postoperatively in an HIV positive haemophilic. Another HIV positive patient developed a hematogenic abscess on both operated on hips without loosening of the endoprosthesis. Bicondylar prosthesis (n = 14) showed 6 very good, 6 good and 2 fair results in the HSS-score. Only one subsidence of an uncemented tibia plateau without definitive loosening occurred 55 months later. The functional results of constrained knee endoprostheses (n = 6) were not as good (2 good, 2 fair, 2 poor). However, these patients suffered preoperatively from severe contractures and malalignments. Aseptic loosening or late infections did not occur even in case of HIV infections.     

Is gait normal after total knee arthroplasty? Systematic review of the literature

Background  Development or retention of abnormal gait patterns after total knee arthroplasty may be related to the predictable pattern of further deterioration of other lower extremity joints. The purpose of this study was to determine whether gait mechanics are abnormal after total knee arthroplasty by conducting a systematic review of the literature. Methods  Articles were identified by searching the following electronic databases: PubMed, Cinahl, Web of Science: 221 references were retrieved. The titles and abstracts were reviewed to identify studies that potentially met the inclusion criteria. These articles were retrieved for further assessment. Ten articles met the inclusion criteria and were included in the review. Results  There was a lack of common variables across the studies. Studies indicated smaller peak knee flexion during weight acceptance and less knee flexion excursion in total knee arthroplasty subjects compared to controls. Knee angle at foot strike was generally similar in arthroplasty groups compared to controls. Maximum external knee flexion moment was generally lower in arthroplasty groups compared to controls. Conflicting results were found for other knee moments. Several other stance phase variables were reported by individual studies only. Conclusions  Peak knee flexion and knee flexion excursion during weight acceptance are smaller in the operated knee following total knee arthroplasty compared to healthy controls. There may also be a smaller peak knee flexion moment after arthroplasty compared to controls. Knee mechanics in the operated knee are not normal after total knee arthroplasty. Abnormal gait mechanics may predispose the individual to further joint degeneration, particularly in the nonoperated knee. Further research should focus on the effects of unilateral total knee arthroplasty on the nonoperated knee.     

Changed gait pattern in patients with total knee arthroplasty but minimal influence of tibial insert design: gait analysis during level walking in 39 TKR patients and 18 healthy controls

INTRODUCTION: Previous radiostereometric studies have revealed abnormal anterior-posterior translation of the femur in patients operated with AMK (DePuy, Johnson and Johnson, Leeds, UK) total knee arthroplasty (TKA). Based on these observations, we hypothesized that patients with TKA have an abnormal gait pattern, and that there are differences in kinematics depending on the design of the tibial joint area. METHOD: We used a gait analysis system to evaluate the influence of joint area design on the kinematics of the hip and knee during level walking. 39 TKA patients (42 knees) and 18 healthy age-matched controls were studied. Patients with 5 degrees varus/valgus alignment or less were randomized to receive either a relatively flat or a concave tibial insert with retention of the posterior cruciate ligament. Patients who had more than 5 degrees varus-valgus alignment and/or extension defect of 10 degrees or more were randomized to receive the concave or a posterior-stabilized tibial component with resection of the posterior cruciate ligament. RESULTS: Patients with TKA tended to have less hip and knee extension and decreased knee and hip extension moment than controls. They also tended to walk more slowly. TKA altered the gait pattern, but choice of implant design had little influence. INTERPRETATION: In patients with a similar degree of degenerative joint disease and within the limits of the constraints offered by the prostheses under study, the choice of joint area constraint has little influence on the gait pattern.     

Variability of gait in the early postoperative period of total knee arthroplasty with different surgical technique

Purpose

The purpose of this study was to work out an objective and sensitive method for the early postoperative period following total knee arthroplasty (TKA) in which analysis of the gait parameters is possible and also to investigate the influence of different surgical approaches for TKA on the gait during stepping in the first three months of the postoperative period.

Methods

Three groups of patients: age-matched healthy elderly patients as a control group, patients operated upon by the conventional technique and finally by the minimally invasive technique combined with computer-assisted navigation. All three groups included ten patients. The motions of knee, shoulder and pelvis were measured by ZEBRIS ultrasound-based system preoperatively plus six and 12 weeks postoperatively. From the joint motion, the variability of cadence, and the variability of knee joint motion and that of pelvis and shoulder girdle was determined.

Results

Osteoarthritis (OA) of the knee joint and TKA using both operation techniques significantly influenced the variability of stepping parameters compared to the controls. In the early postoperative period a significant difference was detected between the two groups of the operated patients in all parameters.

Conclusion

Our data prove that our method seems appropriate to provide objective measurement of the gait in the early postoperative period. The variability of motion of the patient groups approaches that of the healthy control group steadily, but does not reach them.     

Effects of restriction of forefoot rocker functions by immobilisation of metatarsophalangeal joints on kinematics and kinetics during walking

ObjectiveThis study was conducted to investigate the effects of restriction of forefoot rocker (FFR) functions by immobilisation of unilateral metatarsophalangeal joints (MPJs) on kinematic and kinetic factors during walking.MethodsEighteen healthy young adults participated in this study. To immobilise the MPJs of the right leg, an aluminium sole plate (AS) was fixed on the sole of the foot. Kinematic and kinetic data were collected while each subject walked at a comfortable speed with the AS and without.ResultsIn the AS condition, the walking speed and contralateral step length were significantly decreased, and an asymmetrical centre of mass (COM) movement was observed. The range of plantarflexion motion and positive work by the ankle joint were decreased markedly during the late stance of the AS limb. In contrast, maximum hip and knee flexion angles in the swing phase of the AS limb and positive work by the bilateral hip joints over the gait cycle were increased.ConclusionsThe results suggested that MPJ immobilisation may result in marked motion limitation of ankle plantarflexion and inhibition of push-off by the ankle joint despite no restrictions on the ankle joint. These changes may interfere with gait speed and a smooth and symmetrical COM shift during walking.