scholarly journals Evidence for a vertebrate catapult: elastic energy storage in the plantaris tendon during frog jumping

2011 ◽  
Vol 8 (3) ◽  
pp. 386-389 ◽  
Author(s):  
Henry C. Astley ◽  
Thomas J. Roberts

Anuran jumping is one of the most powerful accelerations in vertebrate locomotion. Several species are hypothesized to use a catapult-like mechanism to store and rapidly release elastic energy, producing power outputs far beyond the capability of muscle. Most evidence for this mechanism comes from measurements of whole-body power output; the decoupling of joint motion and muscle shortening expected in a catapult-like mechanism has not been demonstrated. We used high-speed marker-based biplanar X-ray cinefluoroscopy to quantify plantaris muscle fascicle strain and ankle joint motion in frogs in order to test for two hallmarks of a catapult mechanism: (i) shortening of fascicles prior to joint movement (during tendon stretch), and (ii) rapid joint movement during the jump without rapid muscle-shortening (during tendon recoil). During all jumps, muscle fascicles shortened by an average of 7.8 per cent (54% of total strain) prior to joint movement, stretching the tendon. The subsequent period of initial joint movement and high joint angular acceleration occurred with minimal muscle fascicle length change, consistent with the recoil of the elastic tendon. These data support the plantaris longus tendon as a site of elastic energy storage during frog jumping, and demonstrate that catapult mechanisms may be employed even in sub-maximal jumps.

2008 ◽  
Vol 20 (05) ◽  
pp. 303-312
Author(s):  
Wensheng Hou ◽  
Xiaoying Wu ◽  
Yingtao Jiang ◽  
Jun Zheng ◽  
Xiaolin Zheng ◽  
...  

Flexion of the index finger is a fairly complex process requiring the coordination of different joints. This study is the first attempt to investigate how the angular velocity profile of the three right index joints (DIP, PIP, and MCP) varies with respect to time during the course of flexion. Ten right-handed subjects (healthy college students between 21 and 23 years old) were recruited to participate in the experiment. Each of these human subjects was instructed to perform a flexion task with his/her right hand. Five miniaturized (5-mm diameter) reflective markers were applied to each human subject: three placed at the DIP, PIP, and MCP joints of the index finger on the side close to thumb, and the rest at the predetermined landmarks on dorsum of thumb. A high-speed camera was used to record the motion of the index finger during a paced flexion, and the instantaneous angular velocity of each joint was determined by relating the marker displacement to the frame frequency (~5 ms between two consecutive frames). Opposite to the general belief that the speed is constant throughout a flexion cycle, to our best knowledge, this study, for the first time, has revealed that the speed of multi-joint movement actually varies with time. It has been identified that during one full flexion cycle, the angular velocity of the three joints of interest undergoes five distinguishable phases, referred as phases P1 (slow), P2 (fast), P3 (slow), P4 (fast), and P5 (slow), respectively. It has also been observed that duration of each of phases P1, P2, P4, or P5 accounts for approximately 10–15% of the whole flexion cycle, while P3 lasts for nearly half a cycle. Furthermore, although the flexions of DIP, PIP, and MCP joints cycle through the same five phases, the starts of their respective phases tend to vary. In P2 and P5, flexion of MCP takes place considerably later than those of PIP and DIP, whereas DIP flexes earlier than PIP in P2. The angular velocity of each joint reaches its peaks in P2 and P4; the peak velocity of DIP occurs earlier than that of PIP or MCP in P2, whereas peak of MCP is reached later than that of PIP. Moreover, the three joints of index finger flex with different angular velocities in each of the five phases: PIP moves significantly faster than MCP in P2, whereas DIP moves faster than MCP in P4. The results from our study indicate that the multi-joint motion of index finger is an uneven course, i.e. different joints flex with different angular velocities during the flexion. The temporal features of the velocity due to a single joint or multi-joint motion provide useful information to further clarify the dexterity of finger movement.


1990 ◽  
Vol 259 (2) ◽  
pp. R223-R230 ◽  
Author(s):  
R. L. Marsh

The kinetic properties of muscle that could influence locomotor frequency include rate of activation, rate of cross-bridge "attachment", intrinsic shortening velocity, and rate of deactivation. The latter two mechanisms are examined using examples from high-speed running in lizards and escape swimming in scallops. During running, inertial loading and elastic energy storage probably mitigate the effects of thermal alterations in intrinsic muscle shortening velocity. The result is a rather low thermal dependence of stride frequency over a 15-20 degree C temperature range. However, at lower temperatures, the longer times required for deactivation cause the thermal dependence of frequency to increase greatly. Scallops use a single muscle to swim by jet propulsion. In vivo shortening velocity in these animals also shows a low thermal dependence. As with high-speed running, the mechanics of jet propulsion may limit the effects of thermally induced changes in intrinsic shortening velocity. The largest thermal effect during swimming is on the initial phase of valve opening. The effects of temperature on the rate of deactivation of the adductor muscle could play an important role in limiting reextension of the muscle, which is dependent on elastic energy storage in the hinge ligament. These examples illustrate that the relative importance of various intrinsic contractile properties in controlling locomotor performance depends on the mechanics of the movements.


Science ◽  
2013 ◽  
Vol 340 (6137) ◽  
pp. 1217-1220 ◽  
Author(s):  
N. T. George ◽  
T. C. Irving ◽  
C. D. Williams ◽  
T. L. Daniel

Muscles not only generate force. They may act as springs, providing energy storage to drive locomotion. Although extensible myofilaments are implicated as sites of energy storage, we show that intramuscular temperature gradients may enable molecular motors (cross-bridges) to store elastic strain energy. By using time-resolved small-angle x-ray diffraction paired with in situ measurements of mechanical energy exchange in flight muscles of Manduca sexta, we produced high-speed movies of x-ray equatorial reflections, indicating cross-bridge association with myofilaments. A temperature gradient within the flight muscle leads to lower cross-bridge cycling in the cooler regions. Those cross-bridges could elastically return energy at the extrema of muscle lengthening and shortening, helping drive cyclic wing motions. These results suggest that cross-bridges can perform functions other than contraction, acting as molecular links for elastic energy storage.


Nature ◽  
2013 ◽  
Vol 498 (7455) ◽  
pp. 483-486 ◽  
Author(s):  
Neil T. Roach ◽  
Madhusudhan Venkadesan ◽  
Michael J. Rainbow ◽  
Daniel E. Lieberman

Animal locomotion depends on the organization, physiology and biomechanical properties of muscles and skeletons. Musculoskeletal systems encompass the mechanical interactions of muscles and skeletal elements that ultimately transmit force for movement and support. Muscles not only perform work by contracting and shortening to generate force, they can also operate as brakes to slow the whole body or a single appendage. Muscles can also function as struts (rod-like) to maintain the position of a joint and facilitate elastic energy storage and recovery. Skeletal muscles share a basic organization and all rely on the same protein machinery for generating force and movement. Variation in muscle function, therefore, depends on the underlying mechanical and energetic components, enzymatic properties, and activation by the nervous system. Muscles require either an internal, external or hydrostatic skeletal system to transmit force for movement and support.


1995 ◽  
Vol 198 (9) ◽  
pp. 1829-1841 ◽  
Author(s):  
A Biewener ◽  
R Baudinette

In order to evaluate the role of elastic energy recovery in the hopping of macropodids, in vivo measurements of muscle­tendon forces using buckle force transducers attached to the tendons of the gastrocnemius (G), plantaris (PL) and flexor digitorum longus (FDL) of tammar wallabies were made as the animals hopped on a treadmill at speeds ranging from 2.1 to 6.3 m s-1. These muscles and tendons constitute the main structures that are most important in energy storage and recovery. Electromyographic recordings from the lateral gastrocnemius and plantaris muscles, together with high-speed films (200 frames s-1) and video (60 fields s-1), were also used to correlate muscle activation and kinematic patterns of limb movement with force development. On the basis of in situ calibrations of the buckle transducers, we found that muscle forces and elastic energy storage increased with increased hopping speed in all three muscle­tendon units. Elastic energy recovery reached a maximum of 25 % of metabolic energy expenditure at 6.3 m s-1 and is probably greater than this at higher speeds. Force sharing among the three muscles was consistently maintained over this range of speeds in terms of recruitment. Although forces and stresses were generally comparable within the gastrocnemius and plantaris muscles, maximal tendon stresses were considerably greater in the gastrocnemius, because of its smaller cross-sectional area (peak muscle stress: 227 versus 262 kPa; peak tendon stress: 36 versus 32 MPa, G versus PL). As a result, energy storage was greatest in the gastrocnemius tendon despite its much shorter length, which limits its volume and, hence, energy storage capacity, compared with PL and FDL tendons. Forces and stresses (17 MPa maximum) developed within the FDL tendon were consistently much lower than those for the other two tendons. Peak stresses in these three tendons indicated safety factors of 3.0 for G, 3.3 for PL and 6.0 for FDL. The lower stresses developed within the tendons of the plantaris and, especially, the flexor digitorum longus may indicate the need to maintain sufficient stiffness for phalangeal control of foot placement, at the expense of reduced strain energy recovery.


2005 ◽  
Vol 21 (1) ◽  
pp. 72-84 ◽  
Author(s):  
Tetsuro Muraoka ◽  
Tadashi Muramatsu ◽  
Daisuke Takeshita ◽  
Hiroaki Kanehisa ◽  
Tetsuo Fukunaga

This study estimated the passive ankle joint moment during standing and walking initiation and its contribution to total ankle joint moment during that time. The decrement of passive joint moment due to muscle fascicle shortening upon contraction was taken into account. Muscle fascicle length in the medial gastrocnemius, which was assumed to represent muscle fascicle length in plantarflexors, was measured using ultrasonography during standing, walking initiation, and cyclical slow passive ankle joint motion. Total ankle joint moment during standing and walking initiation was calculated from ground reaction forces and joint kinematics. Passive ankle joint moment during the cyclical ankle joint motion was measured via a dynamometer. Passive ankle joint moment during standing and at the time (Tp) when the MG muscle-tendon complex length was longest in the stance phase during walking initiation were 2.3 and 5.4 Nm, respectively. The muscle fascicle shortened by 2.9 mm during standing compared with the length at rest, which decreased the contribution of passive joint moment from 19.9% to 17.4%. The muscle fascicle shortened by 4.3 mm at Tp compared with the length at rest, which decreased the contribution of passive joint moment from 8.0% to 5.8%. These findings suggest that (a) passive ankle joint moment plays an important role during standing and walking initiation even in view of the decrement of passive joint moment due to muscle fascicle shortening upon muscle contraction, and (b) muscle fascicle shortening upon muscle contraction must be taken into account when estimating passive joint moment during movements.


Jumping, climbing and suspensory locomotion are specialized locomotor mechanisms used on land and in the air. Jumping is used for rapid launches from substrates. Climbing and suspensory movements enable locomotion up, under and through vertically-structured habitats, such as forests. Elastic energy storage is particularly important for jumping and catapult systems and we address the core concepts of power amplification that are exemplified in nature’s extreme jumpers. We examine the diverse mechanisms of attachment that characterize animals that can grasp and adhere to a diversity of structures. We conclude the chapter by examining the integration of biological capabilities with engineering innovations in these systems.


2014 ◽  
Vol 644-650 ◽  
pp. 879-883
Author(s):  
Jing Jing Yu

In various forms of movement of finger rehabilitation training, Continuous Passive Motion (CPM) of single degree of freedom (1 DOF) has outstanding application value. Taking classic flexion and extension movement for instance, this study collected the joint angle data of finger flexion and extension motion by experiments and confirmed that the joint motion of finger are not independent of each other but there is certain rule. This paper studies the finger joint movement rule from qualitative and quantitative aspects, and the conclusion can guide the design of the mechanism and control method of finger rehabilitation training robot.


2001 ◽  
Vol 20 (2) ◽  
pp. 141-147 ◽  
Author(s):  
Takashi Abe ◽  
Senshi Fukashiro ◽  
Yasuhiro Harada ◽  
Kazuhisa Kawamoto

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