Objective To conduct the biomechanical analysis on a new power-assisted knee orthosis.Methods A self-force source power-assisted knee orthosis was used,and four motions(level walking,sitting and standing,ascending and descending stairs)were measured before and after wearing the orthosis.A musculoskeletal multibody dynamic model was adopted to calculate the joint angles and pressures at the knee,patellofemoral and hip joints.The effects of power-assisted knee orthosis on biomechanical changes of lower limbs were investigated by comparing the joint angles and pressures before and after wearing this orthosis.Results The orthosis would reduce the knee angles during level walking,as well as the knee pressures during sitting and standing on the wearing side.Wearing the orthosis did not significantly affect the joint angles during sitting and standing;however,it led to a significant decrease in joint pressures at both bilateral knee joints and patellofemoral joints.During ascending and descending stairs,the knee angle change on the wearing side was opposite to that on the non-wearing side.The increase of the peak knee angle was(14.3±3.6)%on the non-wearing side during ascending stairs.Conclusions The power-assisted knee orthosis can offer a conservative treatment for individuals with various knee diseases by reducing joint angles and pressures in daily motions.

Objective To conduct the biomechanical analysis on a new power-assisted knee orthosis.Methods A self-force source power-assisted knee orthosis was used,and four motions(level walking,sitting and standing,ascending and descending stairs)were measured before and after wearing the orthosis.A musculoskeletal multibody dynamic model was adopted to calculate the joint angles and pressures at the knee,patellofemoral and hip joints.The effects of power-assisted knee orthosis on biomechanical changes of lower limbs were investigated by comparing the joint angles and pressures before and after wearing this orthosis.Results The orthosis would reduce the knee angles during level walking,as well as the knee pressures during sitting and standing on the wearing side.Wearing the orthosis did not significantly affect the joint angles during sitting and standing;however,it led to a significant decrease in joint pressures at both bilateral knee joints and patellofemoral joints.During ascending and descending stairs,the knee angle change on the wearing side was opposite to that on the non-wearing side.The increase of the peak knee angle was(14.3±3.6)%on the non-wearing side during ascending stairs.Conclusions The power-assisted knee orthosis can offer a conservative treatment for individuals with various knee diseases by reducing joint angles and pressures in daily motions.

Objective:To investigate the efficacy of enhanced recovery after surgery(ERAS)combined with laparoscopy for the treatment of colorectal cancer in the elderly and its effects on proinflammatory factors and immune responses.Methods:A total of 158 elderly patients with colorectal cancer treated with surgery were retrospectively analyzed.According to different treatment methods, they were divided into the control group(76 cases)and the study group(82 cases). The control group received traditional open surgery and routine perioperative care.The study group received laparoscopic radical resection of colorectal cancer plus perioperative ERAS.Surgery parameters, complications, postoperative immune function and proinflammatory factor levels were compared between the two groups.Results:The operation duration of the study group was significantly longer than that of the control group[(128.5±33.7)min vs.(117.4±28.7)min, t=2.220, P=0.028], whereas the intraoperative blood loss[(100.8±20.5)ml vs.(250.7±62.3)ml, t=20.621, P<0.01]and the incision length[(4.5±1.2)cm vs.(17.5±3.0)cm, t=36.243, P<0.01]were significantly less than those in the control group.The time to first flatus[(2.0±0.9)d vs.(3.8±1.8)d, t=8.037, P<0.01], time to first defecation[(2.8±0.8)d vs.(4.5±1.1)d, t=11.167, P<0.01], time to first ambulation[(1.2±0.2)d vs.(3.8±1.3)d, t=17.888, P<0.01]and hospitalization length[(7.1±0.2)d vs.(11.4±2.2)d, t=17.625, P<0.01]were also significantly shorter than those in the control group.The incidences of surgical site infections(2.4% vs.10.5%, χ2=4.351, P=0.037), abdominal distension(7.3% vs.19.7%, χ2=5.279, P=0.023)and intestinal obstruction(9.8% vs.22.4%, χ2=4.711, P=0.030)in the study group were significantly lower than those in the control group.The levels of C-reactive protein, interleukin-6 and tumor necrosis factor-α in the study group were significantly lower than those in the control group at 1 d, 3 d and 7 d after surgery( t= 9.612, 7.300, 5.446, 8.762, 12.138, 15.370, 10.186, 10.432, 13.512, respectively, all P<0.05). The levels of CD3 + , CD4 + and CD4 + /CD8 + in the study group were significantly higher than those in the control group at 1 d, 3 d and 7 d after surgery( t= 2.128, 2.957, 2.313, 2.914, 2.937, 2.809, 5.089, 5.623, 5.409, respectively, P<0.05 for all), and the levels of CD8 + were significantly lower than those of the control group( t= 2.008, 2.580, 4.902, all P<0.05). Conclusions:Laparoscopy combined with ERAS for the treatment of colorectal cancer in the elderly can reduce surgical injury and complications and mitigate inflammatory responses with little impact on immune responses.