The Achilles tendon (AT) has the capacity to store and release elastic energy during walking, contributing to metabolic energy savings. In diabetes patients, it is hypothesized that a stiffer Achilles tendon may reduce the capacity for energy saving through this mechanism, thereby contributing to an increased metabolic cost of walking (CoW). The aim of this study was to investigate the effects of diabetes and diabetic peripheral neuropathy (DPN) on the Achilles tendon and plantarflexor muscle-tendon unit behavior during walking. Twenty-three nondiabetic controls (Ctrl); 20 diabetic patients without peripheral neuropathy (DM), and 13 patients with moderate/severe DPN underwent gait analysis using a motion analysis system, force plates, and ultrasound measurements of the gastrocnemius muscle, using a muscle model to determine Achilles tendon and muscle-tendon length changes. During walking, the DM and particularly the DPN group displayed significantly less Achilles tendon elongation (Ctrl: 1.81; DM: 1.66; and DPN: 1.54 cm), higher tendon stiffness (Ctrl: 210; DM: 231; and DPN: 240 N/mm), and higher tendon hysteresis (Ctrl: 18; DM: 21; and DPN: 24%) compared with controls. The muscle fascicles of the gastrocnemius underwent very small length changes in all groups during walking (~0.43 cm), with the smallest length changes in the DPN group. Achilles tendon forces were significantly lower in the diabetes groups compared with controls (Ctrl: 2666; DM: 2609; and DPN: 2150 N). The results strongly point toward the reduced energy saving capacity of the Achilles tendon during walking in diabetes patients as an important factor contributing to the increased metabolic CoW in these patients. NEW & NOTEWORTHY From measurements taken during walking we observed that the Achilles tendon in people with diabetes and particularly people with diabetic peripheral neuropathy was stiffer, was less elongated, and was subject to lower forces compared with controls without diabetes. These altered properties of the Achilles tendon in people with diabetes reduce the tendon’s energy saving capacity and contribute toward the higher metabolic energy cost of walking in these patients.

People with diabetes walk slower and display biomechanical gait alterations compared with controls, but it remains unknown whether the metabolic cost of walking (CoW) is elevated. The aim of this study was to investigate the CoW and the lower limb concentric joint work as a major determinant of the CoW, in patients with diabetes and diabetic peripheral neuropathy (DPN). Thirty-one nondiabetic controls (Ctrl), 22 diabetic patients without peripheral neuropathy (DM), and 14 patients with moderate/severe DPN underwent gait analysis using a motion analysis system and force plates and treadmill walking using a gas analyzer to measure oxygen uptake. The CoW was significantly higher particularly in the DPN group compared with controls and also in the DM group (at selected speeds only) compared with controls, across a range of matched walking speeds. Despite the higher CoW in patients with diabetes, concentric lower limb joint work was significantly lower in DM and DPN groups compared with controls. The higher CoW is likely due to energetic inefficiencies associated with diabetes and DPN reflecting physiological and biomechanical characteristics. The lower concentric joint work in patients with diabetes might be a consequence of kinematic gait alterations and may represent a natural strategy aimed at minimizing the CoW.

Diabetes patients display gait alterations compared to controls including a higher metabolic cost of walking. This study aimed to investigate whether differences in external moment arm (ExtMA) and effective mechanical advantage (EMA) at the ankle in diabetes patients could partly explain the increased cost of walking compared to controls. Thirty one non-diabetic controls (Ctrl); 22 diabetes patients without peripheral neuropathy (DM) and 14 patients with moderate/severe diabetic peripheral neuropathy (DPN) underwent gait analysis using a motion analysis system and force plates. The internal Achilles tendon moment arm length was determined using magnetic resonance imaging during weight-bearing and ExtMA was calculated using gait analysis. A greater value (P<0.01) for the EMA at the ankle was found in the DPN (0.488) and DM (0.46) groups compared to Ctrl (0.448). The increased EMA was mainly caused by a smaller ExtMA in the DPN (9.63cm; P<0.01) and DM (10.31cm) groups compared to Ctrl (10.42cm) These findings indicate that the ankle plantarflexor muscles would need to generate lower forces to overcome the external resistance during walking compared to controls. Our findings do not explain the previously observedhigher metabolic cost of walking in the DM and DPN groups, but uncover a new mechanism through which patients with diabetes and particularly those with DPN reduce the joint moment at the ankle during walking: by applying the ground reaction force more proximally on the foot, or at an angle directed more towards the ankle, thereby increasing the EMA and reducing the ankle joint moment.

People with diabetic peripheral neuropathy (DPN) exhibit marked unsteadiness during gait (1), increasing their risk of falling 20-fold compared with their matched counterparts without diabetes (2). Unsteadiness and associated restrictions in activities of daily living predict depressive symptoms in patients with DPN (3), highlighting the negative spiral between DPN, unsteadiness, falls, and psychological distress (4). However, because unsteadiness has been assessed by self-report in most previous studies, it remains unknown whether a person’s perception of unsteadiness actually correlates with objective measures of balance and gait. This study aimed to assess self-perceived unsteadiness in patients with and without DPN as compared with people without diabetes and to investigate how self-perceived unsteadiness influences gait and balance control. Three groups were investigated: patients with DPN (DPN group; neuropathy disability score [NDS] ≥6, vibration perception threshold [VPT] ≥25 V), patients with diabetes but no neuropathy (DM group; NDS ≤3, VPT ≤15 V [5]), and matched control subjects without diabetes (Table 1). Self-perceived unsteadiness was assessed using two items from the neuropathy-specific quality of life questionnaire (Neuro-QoL) asking about problems with balance experienced during walking and standing (6 …

(1) Background: Shooting performance is one of the most important determinants of basketball success and is strongly influenced by vertical jump performance. A lot of research attention has been paid to training programs that may improve the vertical jump. However, the literature regarding the improvement of accuracy during the jump shot is limited. The aim of this study was to determine the effects of the combination of two training programs on explosive power of the lower extremities during the made jump shot. (2) Methods: A total of 61 male basketball players were assigned into training group (T, n = 31, age 15.32 ± 0.65) which was conducting a specific, i.e., experimental training program, and control group (C, n = 30, age 16.3 ± 0.71 years) involved in a regular training program. The experimental training program included specific plyometric training with shooting training which lasted for 10 weeks. The obtained data were processed by nonparametric statistics to determine the differences in the vertical jump outcomes, as well as to determine the level of impact of the experimental training program. Wilcoxon and Kruskal–Wallis tests were used. (3) Results: A significant improvement (p ≤ 0.05) was noticed in the T group, in every vertical jump variable (flight time, height of the jump, power, and speed of the jump during a jump shot for two and three points), while there was no improvement within the C group. (4) Conclusions: The combination of plyometric and shooting training has a positive impact on the explosive power of the lower extremities during the jump shot.

Given the increasing use of innovative force plate systems in applied sports settings and the impact that anterior cruciate ligament (ACL) injuries have on team success, the purpose of the present study was to compare the lower-body neuromuscular performance characteristics of athletes who underwent ACL reconstruction (ACLR) and their non-injured counterparts (i.e., healthy controls). Forty-five male (thirteen injured) and twenty-six female (ten injured) semi-professional soccer players volunteered to participate in the present study. Each athlete performed three countermovement vertical jumps (CMJs) while standing on a uniaxial force plate system sampling at 1000 Hz. The injured athletes completed a nine-month recovery protocol and were screened 11–13 months post-ACLR. The dependent variables included the force–time metrics within both the eccentric and concentric phases of the CMJ. Independent t-tests or Mann–Whitney U-test were used to examine statistically significant (p < 0.05) differences in each variable (i.e., ACL-injured vs. healthy controls). The results revealed no significant between-group differences in any CMJ force–time metrics of interest (e.g., concentric peak force, eccentric mean power, countermovement depth) between ACL-injured and non-injured athletes, including inter-limb asymmetry measures (i.e., peak takeoff and landing force). Besides implying the effectiveness of the implemented rehabilitation protocol, these findings suggest that the CMJ may not present a sufficient neuromuscular performance stimulus needed to expose lower-limb asymmetries and strength and power deficiencies 11–13 months post-ACLR.