limb task), and double support. This qualitative aspect of interlimb coordination is a strong indicator of whether or not a discrete reach-to-grasp movement is superimposed upon the normal arm swing during gait, as suggested by Carnahan et al. ( 1996 ). If the reach is simply executed as an extension
Grace C. Bellinger, Kristen A. Pickett and Andrea H. Mason
John Komar, Ross H. Sanders, Didier Chollet and Ludovic Seifert
This study compared interlimb coordination and indicators of swim efficiency and effectiveness between expert and recreational breaststroke swimmers. Arm-leg coordination of 8 expert and 10 recreational swimmers at two different paces, slow and sprint, were compared using relative phase between elbow and knee. For each participant, knee and elbow angles were assessed using a 3-dimensional video analysis system with four below and two above cameras. During each phase of the cycle, indicators of swim efficiency (intracyclic velocity variations) and effectiveness (horizontal distance, velocity peaks, acceleration peaks) were calculated. Two coordination patterns emerged between expert and recreational swimmers, with significant differences in the relative phase at the beginning of a cycle (−172.4° for experts and −106.6° for recreational swimmers) and the maximum value of relative phase (9.1° for experts and 45.9° for recreational swimmers; all P < .05). Experts’ coordination was associated with higher swim effectiveness (higher acceleration peak: 2.4 m/s2 for experts and 1.6 m/s2 for recreational swimmers) and higher distance covered by the center of mass during each phase of the cycle (all P < .05). This study emphasized how experts coordinate arms and legs to achieve effective behavior, therefore exhibiting flexibility, mainly in the timing of the glide phase, to adapt to different speed.
Ching-yi Wu, Shih-han Chou, Mei-ying Kuo, Chiung-ling Chen, Tung-wu Lu and Yang-chieh Fu
Stroke patients are often left with hemiplegia or hemiparesis of the upper extremities, severely limiting the ability to perform bimanual and functional activities. No studies have investigated how stroke patients adapt their movements to changes in object size in functionally asymmetric bimanual tasks. The influence of object size on intralimb and interlimb coordination during an asymmetrical, functional bimanual task was examined in patients with left cerebral vascular accidents (LCVA) and healthy controls. Fourteen LCVA patients and 13 age-matched controls were instructed to reach to grasp a large and a small jar with the right/affected hand and to open the cap with the other hand. Movement kinematics was analyzed for intralimb coordination (spatial and temporal planning of reaching and grasping) and interlimb coordination (bimanual synchronization and temporal association of the hands). The results demonstrate a spatial adaptation of reaching in the affected hand to the object size and deficits in temporal planning of grasping with the affected hand to object size in the stroke patients. Movement adaptations of the unaffected hand in the stroke patients were similar to those in the healthy adults. Bimanual coordination was independent of object size for both groups.
Eryk P. Przysucha and Brian K.V. Maraj
The nature of intra- and interlimb (bimanual) coordination was examined in ten boys with (M = 10.5 years, SD = 1.0) and without DCD (M = 10.8 years, SD = .9) in a two-handed catching task. Children with developmental coordination disorder (DCD) caught significantly fewer balls (MDCD = 56%, SD = 17.6 vs. MnoDCD = 93%, SD = 7.5), and both groups solved the “degrees of freedom problem” differently at intralimb level of coordination. Typically developing children coupled and decoupled the respective spatial relations, whereas the majority of children with DCD segmented their actions. At interlimb level, both groups exhibited a comparable degree of spatial symmetry. However, individual profiles also showed that children with varying degrees of movement issues exhibited movement patterns that were qualitatively and functionally diverse. Overall, in the context of previous research on interlimb coordination it appears that spatial, in addition to temporal organization, may be jeopardized in at least some children with DCD.
Jill Whitall, Larry Forrester and Nancy Getchell
The present study examined the effect of nonspecific task constraints on the multilimb coordination task of preferred-speed crawling. Adult subjects undertook three trials each of the following randomly ordered conditions: forward prone (FP), backward supine (BS), backward prone (BP) and forward supine (FS). Subjects adopted specific coordinative solutions consistent with task-related function rather than anatomical specification. The patterns were relatively stable, with BP being least stable. Across conditions, subjects changed their velocity in a predictable order that corresponded to the various constraints. These velocity changes were largely attributable to stride length adjustments and not limb frequency. Within a condition, neither velocity nor anthropometrics appeared to influence the coordinative solution. Overall, rather large differences were found in coordinative solutions, possibly owing to the nature of the tasks and/or individual searching strategies. The results were interpretable within a dynamic approach to coordination and support the idea that coordination is functionally rather than anatomically determined.
Veerle Puttemans, Sophie Vangheluwe, Nicole Wenderoth and Stephan P. Swinnen
When performing movements with different spatial trajectories in both upper limbs simultaneously, patterns of interference emerge that can be overcome with practice. Even though studies on the role of augmented feedback in motor learning have been abundant, it still remains to be discovered how overcoming such specific patterns of spatial interference can be optimized by instructional intervention. In the present study, one group acquired a bimanual movement with normal vision, whereas a second group received augmented feedback of the obtained trajectories on a computer screen in real time. Findings revealed that, relative to normal vision, the augmented feedback hampered skill learning and transfer to different environmental conditions. These observations are discussed in view of the benefits and pitfalls of augmented feedback in relation to task context and instructional condition.
Pei-Chun Kao and Daniel P. Ferris
During passive lower limb movement, active use of the upper limbs increases unintentional lower limb muscle activation. We hypothesized that faster movement frequencies would amplify lower limb muscle activation during upper limb exertion but would not affect lower limb muscle activation when the upper limbs were relaxed. We studied 10 healthy participants exercising on a recumbent stepping machine that mechanically coupled the four limbs via handles and pedals. Participants exercised at four frequencies (30, 60, 90, 120 steps/min) under four conditions of active and passive movement. Self-driven lower limb motion resulted in greater muscle activation compared to externally driven lower limb motion. Muscle activation amplitude increased with frequency for all conditions except for externally driven stepping. These results indicate that fast upper limb movement facilitates neuromuscular recruitment of lower limb muscles during stepping tasks. If a similar effect occurs in neurologically impaired individuals during active stepping, self-assisted exercise might enhance neuromuscular recruitment during rehabilitation.
Hai-Jung Steffi Shih, Danielle N. Jarvis, Pamela Mikkelsen and Kornelia Kulig
By investigating the relationship of concurrent vGRF under both legs, we may reveal valuable information regarding an essential aspect of bipedal movements: interlimb coordination. Similar rate of vGRF development under 2 legs may be classified as in-phase coordination, which is expected for
Kelly de Jesus, Ross Sanders, Karla de Jesus, João Ribeiro, Pedro Figueiredo, João P. Vilas-Boas and Ricardo J. Fernandes
Coaches are often challenged to optimize swimmers’ technique at different training and competition intensities, but 3-dimensional (3D) analysis has not been conducted for a wide range of training zones.
To analyze front-crawl 3D kinematics and interlimb coordination from low to severe swimming intensities.
Ten male swimmers performed a 200-m front crawl at 7 incrementally increasing paces until exhaustion (0.05-m/s increments and 30-s intervals), with images from 2 cycles in each step (at the 25- and 175-m laps) being recorded by 2 surface and 4 underwater video cameras. Metabolic anaerobic threshold (AnT) was also assessed using the lactate-concentration–velocity curve-modeling method.
Stroke frequency increased, stroke length decreased, hand and foot speed increased, and the index of interlimb coordination increased (within a catch-up mode) from low to severe intensities (P ≤ .05) and within the 200-m steps performed above the AnT (at or closer to the 4th step; P ≤ .05). Concurrently, intracyclic velocity variations and propelling efficiency remained similar between and within swimming intensities (P > .05).
Swimming intensity has a significant impact on swimmers’ segmental kinematics and interlimb coordination, with modifications being more evident after the point when AnT is reached. As competitive swimming events are conducted at high intensities (in which anaerobic metabolism becomes more prevalent), coaches should implement specific training series that lead swimmers to adapt their technique to the task constraints that exist in nonhomeostatic race conditions.
Tiago M. Barbosa, Kelly de Jesus, J. Arturo Abraldes, João Ribeiro, Pedro Figueiredo, João Paulo Vilas-Boas and Ricardo J. Fernandes
The assessment of energetic and mechanical parameters in swimming often requires the use of an intermittent incremental protocol, whose step lengths are corner stones for the efficiency of the evaluation procedures.
To analyze changes in swimming kinematics and interlimb coordination behavior in 3 variants, with different step lengths, of an intermittent incremental protocol.
Twenty-two male swimmers performed n × d i variants of an intermittent and incremental protocol (n ≤ 7; d 1 = 200 m, d 2 = 300 m, and d 3 = 400 m). Swimmers were videotaped in the sagittal plane for 2-dimensional kinematical analysis using a dualmedia setup. Video images were digitized with a motion-capture system. Parameters that were assessed included the stroke kinematics, the segmental and anatomical landmark kinematics, and interlimb coordination. Movement efficiency was also estimated.
There were no significant variations in any of the selected variables according to the step lengths. A high to very high relationship was observed between step lengths. The bias was much reduced and the 95%CI fairly tight.
Since there were no meaningful differences between the 3 protocol variants, the 1 with shortest step length (ie, 200 m) should be adopted for logistical reasons.